From cd626fec2bcfa6b78d34a1ae023943c8a15a6641 Mon Sep 17 00:00:00 2001
From: Josh Triplett <josh@joshtriplett.org>
Date: Mon, 6 Dec 2021 14:09:24 -0800
Subject: Stabilize -Z print-link-args as --print link-args

We have stable options for adding linker arguments; we should have a
stable option to help debug linker arguments.
---
 src/test/run-make-fulldeps/codegen-options-parsing/Makefile     | 4 ++--
 src/test/run-make-fulldeps/interdependent-c-libraries/Makefile  | 2 +-
 src/test/run-make-fulldeps/link-arg/Makefile                    | 2 +-
 src/test/run-make-fulldeps/metadata-flag-frobs-symbols/Makefile | 2 +-
 src/test/run-make-fulldeps/no-builtins-lto/Makefile             | 2 +-
 src/test/run-make-fulldeps/redundant-libs/Makefile              | 2 +-
 src/test/run-make-fulldeps/static-nobundle/Makefile             | 4 ++--
 7 files changed, 9 insertions(+), 9 deletions(-)

(limited to 'src')

diff --git a/src/test/run-make-fulldeps/codegen-options-parsing/Makefile b/src/test/run-make-fulldeps/codegen-options-parsing/Makefile
index 39e9a9bdd6b..f1410b69b3f 100644
--- a/src/test/run-make-fulldeps/codegen-options-parsing/Makefile
+++ b/src/test/run-make-fulldeps/codegen-options-parsing/Makefile
@@ -24,8 +24,8 @@ all:
 	$(RUSTC) -C lto dummy.rs
 
 	# Should not link dead code...
-	$(RUSTC) -Z print-link-args dummy.rs 2>&1 | \
+	$(RUSTC) --print link-args dummy.rs 2>&1 | \
 		$(CGREP) -e '--gc-sections|-z[^ ]* [^ ]*<ignore>|-dead_strip|/OPT:REF'
 	# ... unless you specifically ask to keep it
-	$(RUSTC) -Z print-link-args -C link-dead-code dummy.rs 2>&1 | \
+	$(RUSTC) --print link-args -C link-dead-code dummy.rs 2>&1 | \
 		$(CGREP) -ve '--gc-sections|-z[^ ]* [^ ]*<ignore>|-dead_strip|/OPT:REF'
diff --git a/src/test/run-make-fulldeps/interdependent-c-libraries/Makefile b/src/test/run-make-fulldeps/interdependent-c-libraries/Makefile
index 1268022e37b..0a50859cdaa 100644
--- a/src/test/run-make-fulldeps/interdependent-c-libraries/Makefile
+++ b/src/test/run-make-fulldeps/interdependent-c-libraries/Makefile
@@ -11,4 +11,4 @@
 all: $(call NATIVE_STATICLIB,foo) $(call NATIVE_STATICLIB,bar)
 	$(RUSTC) foo.rs
 	$(RUSTC) bar.rs
-	$(RUSTC) main.rs -Z print-link-args
+	$(RUSTC) main.rs --print link-args
diff --git a/src/test/run-make-fulldeps/link-arg/Makefile b/src/test/run-make-fulldeps/link-arg/Makefile
index d7c9fd27112..0360ede7625 100644
--- a/src/test/run-make-fulldeps/link-arg/Makefile
+++ b/src/test/run-make-fulldeps/link-arg/Makefile
@@ -1,5 +1,5 @@
 -include ../tools.mk
-RUSTC_FLAGS = -C link-arg="-lfoo" -C link-arg="-lbar" -Z print-link-args
+RUSTC_FLAGS = -C link-arg="-lfoo" -C link-arg="-lbar" --print link-args
 
 all:
 	$(RUSTC) $(RUSTC_FLAGS) empty.rs | $(CGREP) lfoo lbar
diff --git a/src/test/run-make-fulldeps/metadata-flag-frobs-symbols/Makefile b/src/test/run-make-fulldeps/metadata-flag-frobs-symbols/Makefile
index 09e6ae0bbf7..3ffbba9444b 100644
--- a/src/test/run-make-fulldeps/metadata-flag-frobs-symbols/Makefile
+++ b/src/test/run-make-fulldeps/metadata-flag-frobs-symbols/Makefile
@@ -6,5 +6,5 @@ all:
 	$(RUSTC) bar.rs \
 		--extern foo1=$(TMPDIR)/libfoo-a.rlib \
 		--extern foo2=$(TMPDIR)/libfoo-b.rlib \
-		-Z print-link-args
+		--print link-args
 	$(call RUN,bar)
diff --git a/src/test/run-make-fulldeps/no-builtins-lto/Makefile b/src/test/run-make-fulldeps/no-builtins-lto/Makefile
index b9688f16c64..2e41be39d5d 100644
--- a/src/test/run-make-fulldeps/no-builtins-lto/Makefile
+++ b/src/test/run-make-fulldeps/no-builtins-lto/Makefile
@@ -6,4 +6,4 @@ all:
 	# Build an executable that depends on that crate using LTO. The no_builtins crate doesn't
 	# participate in LTO, so its rlib must be explicitly linked into the final binary. Verify this by
 	# grepping the linker arguments.
-	$(RUSTC) main.rs -C lto -Z print-link-args | $(CGREP) 'libno_builtins.rlib'
+	$(RUSTC) main.rs -C lto --print link-args | $(CGREP) 'libno_builtins.rlib'
diff --git a/src/test/run-make-fulldeps/redundant-libs/Makefile b/src/test/run-make-fulldeps/redundant-libs/Makefile
index 8468d102bec..e09841fb42e 100644
--- a/src/test/run-make-fulldeps/redundant-libs/Makefile
+++ b/src/test/run-make-fulldeps/redundant-libs/Makefile
@@ -16,7 +16,7 @@ RUSTC_FLAGS = \
     -l foo \
     -l static=baz \
     -l foo \
-    -Z print-link-args
+    --print link-args
 
 all: $(call DYLIB,foo) $(call STATICLIB,bar) $(call STATICLIB,baz)
 	$(RUSTC) $(RUSTC_FLAGS) main.rs
diff --git a/src/test/run-make-fulldeps/static-nobundle/Makefile b/src/test/run-make-fulldeps/static-nobundle/Makefile
index abc32d4423b..8f78c401a11 100644
--- a/src/test/run-make-fulldeps/static-nobundle/Makefile
+++ b/src/test/run-make-fulldeps/static-nobundle/Makefile
@@ -13,9 +13,9 @@ all: $(call NATIVE_STATICLIB,aaa)
 	nm $(TMPDIR)/libbbb.rlib | $(CGREP) -e "U _*native_func"
 
 	# Check that aaa gets linked (either as `-l aaa` or `aaa.lib`) when building ccc.
-	$(RUSTC) ccc.rs -C prefer-dynamic --crate-type=dylib -Z print-link-args | $(CGREP) -e '-l[" ]*aaa|aaa\.lib'
+	$(RUSTC) ccc.rs -C prefer-dynamic --crate-type=dylib --print link-args | $(CGREP) -e '-l[" ]*aaa|aaa\.lib'
 
 	# Check that aaa does NOT get linked when building ddd.
-	$(RUSTC) ddd.rs -Z print-link-args | $(CGREP) -ve '-l[" ]*aaa|aaa\.lib'
+	$(RUSTC) ddd.rs --print link-args | $(CGREP) -ve '-l[" ]*aaa|aaa\.lib'
 
 	$(call RUN,ddd)
-- 
cgit 1.4.1-3-g733a5


From 371bd4643587da89ce1bbe7e577f49d9b8acb990 Mon Sep 17 00:00:00 2001
From: Josh Triplett <josh@joshtriplett.org>
Date: Mon, 6 Dec 2021 14:10:25 -0800
Subject: Document `--print link-args`

The documentation makes it clear that the *exact* format of the output
is not a stable guarantee.
---
 src/doc/rustc/src/command-line-arguments.md | 6 ++++++
 1 file changed, 6 insertions(+)

(limited to 'src')

diff --git a/src/doc/rustc/src/command-line-arguments.md b/src/doc/rustc/src/command-line-arguments.md
index 7f482f0f2b1..11925ab9785 100644
--- a/src/doc/rustc/src/command-line-arguments.md
+++ b/src/doc/rustc/src/command-line-arguments.md
@@ -170,6 +170,12 @@ The valid types of print values are:
   include a diagnostic note that indicates the linker flags to use when
   linking the resulting static library. The note starts with the text
   `native-static-libs:` to make it easier to fetch the output.
+- `link-args` — This flag does not disable the `--emit` step. When linking,
+  this flag causes `rustc` to print the full linker invocation in a
+  human-readable form. This can be useful when debugging linker options. The
+  exact format of this debugging output is not a stable guarantee, other than
+  that it will include the linker executable and the text of each command-line
+  argument passed to the linker.
 
 [conditional compilation]: ../reference/conditional-compilation.html
 
-- 
cgit 1.4.1-3-g733a5


From 36a11417fafcbfae0500884df2d4b6dd2c5e5a0f Mon Sep 17 00:00:00 2001
From: 5225225 <5225225@mailbox.org>
Date: Sun, 9 Jan 2022 22:15:23 +0000
Subject: Make message for &T -> &mut T transmute more accurate

---
 compiler/rustc_lint/src/builtin.rs                 | 6 +++---
 src/test/ui/transmute/transmute-imut-to-mut.rs     | 2 +-
 src/test/ui/transmute/transmute-imut-to-mut.stderr | 2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

(limited to 'src')

diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs
index c0384875a47..2b373a53b63 100644
--- a/compiler/rustc_lint/src/builtin.rs
+++ b/compiler/rustc_lint/src/builtin.rs
@@ -1248,7 +1248,7 @@ declare_lint! {
     /// [`UnsafeCell`]: https://doc.rust-lang.org/std/cell/struct.UnsafeCell.html
     MUTABLE_TRANSMUTES,
     Deny,
-    "mutating transmuted &mut T from &T may cause undefined behavior"
+    "transmuting &T to &mut T is undefined behavior, even if the reference is unused"
 }
 
 declare_lint_pass!(MutableTransmutes => [MUTABLE_TRANSMUTES]);
@@ -1260,8 +1260,8 @@ impl<'tcx> LateLintPass<'tcx> for MutableTransmutes {
             get_transmute_from_to(cx, expr).map(|(ty1, ty2)| (ty1.kind(), ty2.kind()))
         {
             if to_mt == hir::Mutability::Mut && from_mt == hir::Mutability::Not {
-                let msg = "mutating transmuted &mut T from &T may cause undefined behavior, \
-                               consider instead using an UnsafeCell";
+                let msg = "transmuting &T to &mut T is undefined behavior, \
+                    even if the reference is unused, consider instead using an UnsafeCell";
                 cx.struct_span_lint(MUTABLE_TRANSMUTES, expr.span, |lint| lint.build(msg).emit());
             }
         }
diff --git a/src/test/ui/transmute/transmute-imut-to-mut.rs b/src/test/ui/transmute/transmute-imut-to-mut.rs
index 8e34e0ae8c7..9f3f76c1ef3 100644
--- a/src/test/ui/transmute/transmute-imut-to-mut.rs
+++ b/src/test/ui/transmute/transmute-imut-to-mut.rs
@@ -4,5 +4,5 @@ use std::mem::transmute;
 
 fn main() {
     let _a: &mut u8 = unsafe { transmute(&1u8) };
-    //~^ ERROR mutating transmuted &mut T from &T may cause undefined behavior
+    //~^ ERROR transmuting &T to &mut T is undefined behavior, even if the reference is unused, consider instead using an UnsafeCell
 }
diff --git a/src/test/ui/transmute/transmute-imut-to-mut.stderr b/src/test/ui/transmute/transmute-imut-to-mut.stderr
index d323c1a73b7..1e9dff3ce89 100644
--- a/src/test/ui/transmute/transmute-imut-to-mut.stderr
+++ b/src/test/ui/transmute/transmute-imut-to-mut.stderr
@@ -1,4 +1,4 @@
-error: mutating transmuted &mut T from &T may cause undefined behavior, consider instead using an UnsafeCell
+error: transmuting &T to &mut T is undefined behavior, even if the reference is unused, consider instead using an UnsafeCell
   --> $DIR/transmute-imut-to-mut.rs:6:32
    |
 LL |     let _a: &mut u8 = unsafe { transmute(&1u8) };
-- 
cgit 1.4.1-3-g733a5


From dc1c39b10ed4650de784e860e2778c3e246f585e Mon Sep 17 00:00:00 2001
From: Andy Russell <arussell123@gmail.com>
Date: Thu, 9 Dec 2021 00:21:36 -0500
Subject: rustdoc: decouple stability and const-stability

---
 src/librustdoc/html/render/mod.rs  | 91 +++++++++++++++++++++++---------------
 src/test/rustdoc/const-display.rs  | 17 +++++++
 src/test/rustdoc/deref-const-fn.rs |  2 +-
 3 files changed, 73 insertions(+), 37 deletions(-)

(limited to 'src')

diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index dda74904931..3dfe03b54e9 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -792,6 +792,20 @@ fn assoc_type(
     }
 }
 
+/// Writes a span containing the versions at which an item became stable and/or const-stable. For
+/// example, if the item became stable at 1.0.0, and const-stable at 1.45.0, this function would
+/// write a span containing "1.0.0 (const: 1.45.0)".
+///
+/// Returns `true` if a stability annotation was rendered.
+///
+/// Stability and const-stability are considered separately. If the item is unstable, no version
+/// will be written. If the item is const-unstable, "const: unstable" will be appended to the
+/// span, with a link to the tracking issue if present. If an item's stability or const-stability
+/// version matches the version of its enclosing item, that version will be omitted.
+///
+/// Note that it is possible for an unstable function to be const-stable. In that case, the span
+/// will include the const-stable version, but no stable version will be emitted, as a natural
+/// consequence of the above rules.
 fn render_stability_since_raw(
     w: &mut Buffer,
     ver: Option<Symbol>,
@@ -799,51 +813,56 @@ fn render_stability_since_raw(
     containing_ver: Option<Symbol>,
     containing_const_ver: Option<Symbol>,
 ) -> bool {
-    let ver = ver.filter(|inner| !inner.is_empty());
+    let stable_version = ver.filter(|inner| !inner.is_empty() && Some(*inner) != containing_ver);
 
-    match (ver, const_stability) {
-        // stable and const stable
-        (Some(v), Some(ConstStability { level: StabilityLevel::Stable { since }, .. }))
+    let mut title = String::new();
+    let mut stability = String::new();
+
+    if let Some(ver) = stable_version {
+        stability.push_str(&ver.as_str());
+        title.push_str(&format!("Stable since Rust version {}", ver));
+    }
+
+    let const_title_and_stability = match const_stability {
+        Some(ConstStability { level: StabilityLevel::Stable { since }, .. })
             if Some(since) != containing_const_ver =>
         {
-            write!(
-                w,
-                "<span class=\"since\" title=\"Stable since Rust version {0}, const since {1}\">{0} (const: {1})</span>",
-                v, since
-            );
+            Some((format!("const since {}", since), format!("const: {}", since)))
         }
-        // stable and const unstable
-        (
-            Some(v),
-            Some(ConstStability { level: StabilityLevel::Unstable { issue, .. }, feature, .. }),
-        ) => {
-            write!(
-                w,
-                "<span class=\"since\" title=\"Stable since Rust version {0}, const unstable\">{0} (const: ",
-                v
-            );
-            if let Some(n) = issue {
-                write!(
-                    w,
-                    "<a href=\"https://github.com/rust-lang/rust/issues/{}\" title=\"Tracking issue for {}\">unstable</a>",
+        Some(ConstStability { level: StabilityLevel::Unstable { issue, .. }, feature, .. }) => {
+            let unstable = if let Some(n) = issue {
+                format!(
+                    r#"<a href="https://github.com/rust-lang/rust/issues/{}" title="Tracking issue for {}">unstable</a>"#,
                     n, feature
-                );
+                )
             } else {
-                write!(w, "unstable");
-            }
-            write!(w, ")</span>");
+                String::from("unstable")
+            };
+
+            Some((String::from("const unstable"), format!("const: {}", unstable)))
         }
-        // stable
-        (Some(v), _) if ver != containing_ver => {
-            write!(
-                w,
-                "<span class=\"since\" title=\"Stable since Rust version {0}\">{0}</span>",
-                v
-            );
+        _ => None,
+    };
+
+    if let Some((const_title, const_stability)) = const_title_and_stability {
+        if !title.is_empty() {
+            title.push_str(&format!(", {}", const_title));
+        } else {
+            title.push_str(&const_title);
+        }
+
+        if !stability.is_empty() {
+            stability.push_str(&format!(" ({})", const_stability));
+        } else {
+            stability.push_str(&const_stability);
         }
-        _ => return false,
     }
-    true
+
+    if !stability.is_empty() {
+        write!(w, r#"<span class="since" title="{}">{}</span>"#, title, stability);
+    }
+
+    !stability.is_empty()
 }
 
 fn render_assoc_item(
diff --git a/src/test/rustdoc/const-display.rs b/src/test/rustdoc/const-display.rs
index fb8ea7e33c2..b8e101038f8 100644
--- a/src/test/rustdoc/const-display.rs
+++ b/src/test/rustdoc/const-display.rs
@@ -67,3 +67,20 @@ impl Foo {
     #[rustc_const_stable(feature = "rust1", since = "1.2.0")]
     pub const fn stable_impl() -> u32 { 42 }
 }
+
+#[stable(feature = "rust1", since = "1.0.0")]
+pub struct Bar;
+
+impl Bar {
+    // Do not show non-const stabilities that are the same as the enclosing item.
+    // @matches 'foo/struct.Bar.html' '//span[@class="since"]' '^const: 1.2.0$'
+    #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_stable(feature = "rust1", since = "1.2.0")]
+    pub const fn stable_impl() -> u32 { 42 }
+
+    // Show const-stability even for unstable functions.
+    // @matches 'foo/struct.Bar.html' '//span[@class="since"]' '^const: 1.3.0$'
+    #[unstable(feature = "foo2", issue = "none")]
+    #[rustc_const_stable(feature = "rust1", since = "1.3.0")]
+    pub const fn const_stable_unstable() -> u32 { 42 }
+}
diff --git a/src/test/rustdoc/deref-const-fn.rs b/src/test/rustdoc/deref-const-fn.rs
index ca51f3c7b5a..8ecca6d12d2 100644
--- a/src/test/rustdoc/deref-const-fn.rs
+++ b/src/test/rustdoc/deref-const-fn.rs
@@ -13,7 +13,7 @@ pub struct Bar;
 
 impl Bar {
     // @has - '//*[@id="method.len"]' 'pub const fn len(&self) -> usize'
-    // @has - '//*[@id="method.len"]//span[@class="since"]' '1.0.0 (const: 1.0.0)'
+    // @has - '//*[@id="method.len"]//span[@class="since"]' 'const: 1.0.0'
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_const_stable(feature = "rust1", since = "1.0.0")]
     pub const fn len(&self) -> usize { 0 }
-- 
cgit 1.4.1-3-g733a5


From b2d8f0c77db87cc84551598ceba3f4e8615eb66c Mon Sep 17 00:00:00 2001
From: lcnr <rust@lcnr.de>
Date: Wed, 5 Jan 2022 11:43:21 +0100
Subject: generic_arg_infer: placeholder in signature err

---
 compiler/rustc_typeck/src/astconv/mod.rs           |   4 +-
 compiler/rustc_typeck/src/collect.rs               |  40 ++++---
 compiler/rustc_typeck/src/collect/type_of.rs       |   2 +-
 .../generic_arg_infer/array-in-sig.rs              |  12 ---
 .../generic_arg_infer/array-in-sig.stderr          |   9 --
 .../generic_arg_infer/in-signature.rs              |  61 +++++++++++
 .../generic_arg_infer/in-signature.stderr          | 119 ++++++++++++++++++++
 src/test/ui/did_you_mean/bad-assoc-ty.rs           |  20 ++--
 src/test/ui/did_you_mean/bad-assoc-ty.stderr       |  20 ++--
 src/test/ui/error-codes/E0121.stderr               |   4 +-
 src/test/ui/fn/issue-80179.rs                      |   4 +-
 src/test/ui/fn/issue-80179.stderr                  |   4 +-
 .../issues/issue-69396-const-no-type-in-macro.rs   |   2 +-
 .../issue-69396-const-no-type-in-macro.stderr      |   2 +-
 src/test/ui/self/self-infer.rs                     |   4 +-
 src/test/ui/self/self-infer.stderr                 |   4 +-
 src/test/ui/suggestions/unnamable-types.rs         |   4 +-
 src/test/ui/suggestions/unnamable-types.stderr     |   4 +-
 src/test/ui/type-alias-impl-trait/issue-77179.rs   |   2 +-
 .../ui/type-alias-impl-trait/issue-77179.stderr    |   2 +-
 src/test/ui/typeck/issue-74086.rs                  |   2 +-
 src/test/ui/typeck/issue-74086.stderr              |   2 +-
 src/test/ui/typeck/issue-75883.rs                  |   4 +-
 src/test/ui/typeck/issue-75883.stderr              |   4 +-
 src/test/ui/typeck/issue-75889.stderr              |   4 +-
 src/test/ui/typeck/issue-80779.rs                  |   4 +-
 src/test/ui/typeck/issue-80779.stderr              |   4 +-
 src/test/ui/typeck/issue-81885.rs                  |   4 +-
 src/test/ui/typeck/issue-81885.stderr              |   4 +-
 ...issue-83621-placeholder-static-in-extern.stderr |   2 +-
 src/test/ui/typeck/issue-91450-inner-ty-error.rs   |   2 +-
 .../ui/typeck/issue-91450-inner-ty-error.stderr    |   2 +-
 src/test/ui/typeck/type-placeholder-fn-in-const.rs |   6 +-
 .../ui/typeck/type-placeholder-fn-in-const.stderr  |   6 +-
 src/test/ui/typeck/typeck_type_placeholder_item.rs | 120 ++++++++++-----------
 .../ui/typeck/typeck_type_placeholder_item.stderr  | 120 ++++++++++-----------
 .../ui/typeck/typeck_type_placeholder_item_help.rs |  12 +--
 .../typeck_type_placeholder_item_help.stderr       |  12 +--
 38 files changed, 402 insertions(+), 235 deletions(-)
 delete mode 100644 src/test/ui/const-generics/generic_arg_infer/array-in-sig.rs
 delete mode 100644 src/test/ui/const-generics/generic_arg_infer/array-in-sig.stderr
 create mode 100644 src/test/ui/const-generics/generic_arg_infer/in-signature.rs
 create mode 100644 src/test/ui/const-generics/generic_arg_infer/in-signature.stderr

(limited to 'src')

diff --git a/compiler/rustc_typeck/src/astconv/mod.rs b/compiler/rustc_typeck/src/astconv/mod.rs
index 2ada1c0ddf4..fca72837d12 100644
--- a/compiler/rustc_typeck/src/astconv/mod.rs
+++ b/compiler/rustc_typeck/src/astconv/mod.rs
@@ -6,7 +6,7 @@ mod errors;
 mod generics;
 
 use crate::bounds::Bounds;
-use crate::collect::PlaceholderHirTyCollector;
+use crate::collect::HirPlaceholderCollector;
 use crate::errors::{
     AmbiguousLifetimeBound, MultipleRelaxedDefaultBounds, TraitObjectDeclaredWithNoTraits,
     TypeofReservedKeywordUsed, ValueOfAssociatedStructAlreadySpecified,
@@ -2478,7 +2478,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         debug!(?bound_vars);
 
         // We proactively collect all the inferred type params to emit a single error per fn def.
-        let mut visitor = PlaceholderHirTyCollector::default();
+        let mut visitor = HirPlaceholderCollector::default();
         for ty in decl.inputs {
             visitor.visit_ty(ty);
         }
diff --git a/compiler/rustc_typeck/src/collect.rs b/compiler/rustc_typeck/src/collect.rs
index 8204b5cc361..97a21de5d3a 100644
--- a/compiler/rustc_typeck/src/collect.rs
+++ b/compiler/rustc_typeck/src/collect.rs
@@ -112,9 +112,9 @@ pub struct ItemCtxt<'tcx> {
 ///////////////////////////////////////////////////////////////////////////
 
 #[derive(Default)]
-crate struct PlaceholderHirTyCollector(crate Vec<Span>);
+crate struct HirPlaceholderCollector(crate Vec<Span>);
 
-impl<'v> Visitor<'v> for PlaceholderHirTyCollector {
+impl<'v> Visitor<'v> for HirPlaceholderCollector {
     fn visit_ty(&mut self, t: &'v hir::Ty<'v>) {
         if let hir::TyKind::Infer = t.kind {
             self.0.push(t.span);
@@ -131,6 +131,12 @@ impl<'v> Visitor<'v> for PlaceholderHirTyCollector {
             _ => {}
         }
     }
+    fn visit_array_length(&mut self, length: &'v hir::ArrayLen) {
+        if let &hir::ArrayLen::Infer(_, span) = length {
+            self.0.push(span);
+        }
+        intravisit::walk_array_len(self, length)
+    }
 }
 
 struct CollectItemTypesVisitor<'tcx> {
@@ -175,7 +181,7 @@ crate fn placeholder_type_error<'tcx>(
         sugg.push((span, format!(", {}", type_name)));
     }
 
-    let mut err = bad_placeholder(tcx, "type", placeholder_types, kind);
+    let mut err = bad_placeholder(tcx, placeholder_types, kind);
 
     // Suggest, but only if it is not a function in const or static
     if suggest {
@@ -233,7 +239,7 @@ fn reject_placeholder_type_signatures_in_item<'tcx>(
         _ => return,
     };
 
-    let mut visitor = PlaceholderHirTyCollector::default();
+    let mut visitor = HirPlaceholderCollector::default();
     visitor.visit_item(item);
 
     placeholder_type_error(
@@ -311,7 +317,6 @@ impl<'tcx> Visitor<'tcx> for CollectItemTypesVisitor<'tcx> {
 
 fn bad_placeholder<'tcx>(
     tcx: TyCtxt<'tcx>,
-    placeholder_kind: &'static str,
     mut spans: Vec<Span>,
     kind: &'static str,
 ) -> rustc_errors::DiagnosticBuilder<'tcx> {
@@ -322,8 +327,7 @@ fn bad_placeholder<'tcx>(
         tcx.sess,
         spans.clone(),
         E0121,
-        "the {} placeholder `_` is not allowed within types on item signatures for {}",
-        placeholder_kind,
+        "the placeholder `_` is not allowed within types on item signatures for {}",
         kind
     );
     for span in spans {
@@ -737,7 +741,7 @@ fn convert_item(tcx: TyCtxt<'_>, item_id: hir::ItemId) {
                 match item.kind {
                     hir::ForeignItemKind::Fn(..) => tcx.ensure().fn_sig(item.def_id),
                     hir::ForeignItemKind::Static(..) => {
-                        let mut visitor = PlaceholderHirTyCollector::default();
+                        let mut visitor = HirPlaceholderCollector::default();
                         visitor.visit_foreign_item(item);
                         placeholder_type_error(
                             tcx,
@@ -820,7 +824,7 @@ fn convert_item(tcx: TyCtxt<'_>, item_id: hir::ItemId) {
                 hir::ItemKind::Const(ty, ..) | hir::ItemKind::Static(ty, ..) => {
                     // (#75889): Account for `const C: dyn Fn() -> _ = "";`
                     if let hir::TyKind::TraitObject(..) = ty.kind {
-                        let mut visitor = PlaceholderHirTyCollector::default();
+                        let mut visitor = HirPlaceholderCollector::default();
                         visitor.visit_item(it);
                         placeholder_type_error(
                             tcx,
@@ -856,7 +860,7 @@ fn convert_trait_item(tcx: TyCtxt<'_>, trait_item_id: hir::TraitItemId) {
         hir::TraitItemKind::Const(..) => {
             tcx.ensure().type_of(trait_item_id.def_id);
             // Account for `const C: _;`.
-            let mut visitor = PlaceholderHirTyCollector::default();
+            let mut visitor = HirPlaceholderCollector::default();
             visitor.visit_trait_item(trait_item);
             placeholder_type_error(tcx, None, &[], visitor.0, false, None, "constant");
         }
@@ -865,7 +869,7 @@ fn convert_trait_item(tcx: TyCtxt<'_>, trait_item_id: hir::TraitItemId) {
             tcx.ensure().item_bounds(trait_item_id.def_id);
             tcx.ensure().type_of(trait_item_id.def_id);
             // Account for `type T = _;`.
-            let mut visitor = PlaceholderHirTyCollector::default();
+            let mut visitor = HirPlaceholderCollector::default();
             visitor.visit_trait_item(trait_item);
             placeholder_type_error(tcx, None, &[], visitor.0, false, None, "associated type");
         }
@@ -874,7 +878,7 @@ fn convert_trait_item(tcx: TyCtxt<'_>, trait_item_id: hir::TraitItemId) {
             tcx.ensure().item_bounds(trait_item_id.def_id);
             // #74612: Visit and try to find bad placeholders
             // even if there is no concrete type.
-            let mut visitor = PlaceholderHirTyCollector::default();
+            let mut visitor = HirPlaceholderCollector::default();
             visitor.visit_trait_item(trait_item);
 
             placeholder_type_error(tcx, None, &[], visitor.0, false, None, "associated type");
@@ -896,7 +900,7 @@ fn convert_impl_item(tcx: TyCtxt<'_>, impl_item_id: hir::ImplItemId) {
         }
         hir::ImplItemKind::TyAlias(_) => {
             // Account for `type T = _;`
-            let mut visitor = PlaceholderHirTyCollector::default();
+            let mut visitor = HirPlaceholderCollector::default();
             visitor.visit_impl_item(impl_item);
 
             placeholder_type_error(tcx, None, &[], visitor.0, false, None, "associated type");
@@ -1816,10 +1820,14 @@ fn are_suggestable_generic_args(generic_args: &[hir::GenericArg<'_>]) -> bool {
 /// Whether `ty` is a type with `_` placeholders that can be inferred. Used in diagnostics only to
 /// use inference to provide suggestions for the appropriate type if possible.
 fn is_suggestable_infer_ty(ty: &hir::Ty<'_>) -> bool {
+    debug!(?ty);
     use hir::TyKind::*;
     match &ty.kind {
         Infer => true,
-        Slice(ty) | Array(ty, _) => is_suggestable_infer_ty(ty),
+        Slice(ty) => is_suggestable_infer_ty(ty),
+        Array(ty, length) => {
+            is_suggestable_infer_ty(ty) || matches!(length, hir::ArrayLen::Infer(_, _))
+        }
         Tup(tys) => tys.iter().any(is_suggestable_infer_ty),
         Ptr(mut_ty) | Rptr(_, mut_ty) => is_suggestable_infer_ty(mut_ty.ty),
         OpaqueDef(_, generic_args) => are_suggestable_generic_args(generic_args),
@@ -1871,9 +1879,9 @@ fn fn_sig(tcx: TyCtxt<'_>, def_id: DefId) -> ty::PolyFnSig<'_> {
                     });
                     let fn_sig = ty::Binder::dummy(fn_sig);
 
-                    let mut visitor = PlaceholderHirTyCollector::default();
+                    let mut visitor = HirPlaceholderCollector::default();
                     visitor.visit_ty(ty);
-                    let mut diag = bad_placeholder(tcx, "type", visitor.0, "return type");
+                    let mut diag = bad_placeholder(tcx, visitor.0, "return type");
                     let ret_ty = fn_sig.skip_binder().output();
                     if !ret_ty.references_error() {
                         if !ret_ty.is_closure() {
diff --git a/compiler/rustc_typeck/src/collect/type_of.rs b/compiler/rustc_typeck/src/collect/type_of.rs
index a6e8b36f78b..63020b7f90f 100644
--- a/compiler/rustc_typeck/src/collect/type_of.rs
+++ b/compiler/rustc_typeck/src/collect/type_of.rs
@@ -750,7 +750,7 @@ fn infer_placeholder_type<'a>(
             err.emit();
         }
         None => {
-            let mut diag = bad_placeholder(tcx, "type", vec![span], kind);
+            let mut diag = bad_placeholder(tcx, vec![span], kind);
 
             if !ty.references_error() {
                 let mut mk_nameable = MakeNameable::new(tcx);
diff --git a/src/test/ui/const-generics/generic_arg_infer/array-in-sig.rs b/src/test/ui/const-generics/generic_arg_infer/array-in-sig.rs
deleted file mode 100644
index 56b88a426a1..00000000000
--- a/src/test/ui/const-generics/generic_arg_infer/array-in-sig.rs
+++ /dev/null
@@ -1,12 +0,0 @@
-// To avoid having to `or` gate `_` as an expr.
-#![feature(generic_arg_infer)]
-
-fn foo() -> [u8; _] {
-    //~^ ERROR the const placeholder `_` is not allowed within types on item signatures for generics
-    // FIXME(generic_arg_infer): this error message should say in the return type or sth like that.
-    [0; 3]
-}
-
-fn main() {
-    foo();
-}
diff --git a/src/test/ui/const-generics/generic_arg_infer/array-in-sig.stderr b/src/test/ui/const-generics/generic_arg_infer/array-in-sig.stderr
deleted file mode 100644
index eaa12b4192d..00000000000
--- a/src/test/ui/const-generics/generic_arg_infer/array-in-sig.stderr
+++ /dev/null
@@ -1,9 +0,0 @@
-error[E0121]: the const placeholder `_` is not allowed within types on item signatures for generics
-  --> $DIR/array-in-sig.rs:4:18
-   |
-LL | fn foo() -> [u8; _] {
-   |                  ^ not allowed in type signatures
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0121`.
diff --git a/src/test/ui/const-generics/generic_arg_infer/in-signature.rs b/src/test/ui/const-generics/generic_arg_infer/in-signature.rs
new file mode 100644
index 00000000000..1f60b224241
--- /dev/null
+++ b/src/test/ui/const-generics/generic_arg_infer/in-signature.rs
@@ -0,0 +1,61 @@
+#![crate_type = "rlib"]
+#![feature(generic_arg_infer)]
+
+struct Foo<const N: usize>;
+struct Bar<T, const N: usize>(T);
+
+fn arr_fn() -> [u8; _] {
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
+    [0; 3]
+}
+
+fn ty_fn() -> Bar<i32, _> {
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
+    Bar::<i32, 3>(0)
+}
+
+fn ty_fn_mixed() -> Bar<_, _> {
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
+    Bar::<i32, 3>(0)
+}
+
+const ARR_CT: [u8; _] = [0; 3];
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for constants
+static ARR_STATIC: [u8; _] = [0; 3];
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for static variables
+const TY_CT: Bar<i32, _> = Bar::<i32, 3>(0);
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for constants
+static TY_STATIC: Bar<i32, _> = Bar::<i32, 3>(0);
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for static variables
+const TY_CT_MIXED: Bar<_, _> = Bar::<i32, 3>(0);
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for constants
+static TY_STATIC_MIXED: Bar<_, _> = Bar::<i32, 3>(0);
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for static variables
+trait ArrAssocConst {
+    const ARR: [u8; _];
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for constants
+}
+trait TyAssocConst {
+    const ARR: Bar<i32, _>;
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for constants
+}
+trait TyAssocConstMixed {
+    const ARR: Bar<_, _>;
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for constants
+}
+
+trait AssocTy {
+    type Assoc;
+}
+impl AssocTy for i8 {
+    type Assoc = [u8; _];
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for associated types
+}
+impl AssocTy for i16 {
+    type Assoc = Bar<i32, _>;
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for associated types
+}
+impl AssocTy for i32 {
+    type Assoc = Bar<_, _>;
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for associated types
+}
diff --git a/src/test/ui/const-generics/generic_arg_infer/in-signature.stderr b/src/test/ui/const-generics/generic_arg_infer/in-signature.stderr
new file mode 100644
index 00000000000..7581cf4120e
--- /dev/null
+++ b/src/test/ui/const-generics/generic_arg_infer/in-signature.stderr
@@ -0,0 +1,119 @@
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
+  --> $DIR/in-signature.rs:7:21
+   |
+LL | fn arr_fn() -> [u8; _] {
+   |                -----^-
+   |                |    |
+   |                |    not allowed in type signatures
+   |                help: replace with the correct return type: `[u8; 3]`
+
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
+  --> $DIR/in-signature.rs:12:24
+   |
+LL | fn ty_fn() -> Bar<i32, _> {
+   |               ---------^-
+   |               |        |
+   |               |        not allowed in type signatures
+   |               help: replace with the correct return type: `Bar<i32, 3_usize>`
+
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
+  --> $DIR/in-signature.rs:17:25
+   |
+LL | fn ty_fn_mixed() -> Bar<_, _> {
+   |                     ----^--^-
+   |                     |   |  |
+   |                     |   |  not allowed in type signatures
+   |                     |   not allowed in type signatures
+   |                     help: replace with the correct return type: `Bar<i32, 3_usize>`
+
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
+  --> $DIR/in-signature.rs:22:15
+   |
+LL | const ARR_CT: [u8; _] = [0; 3];
+   |               ^^^^^^^ not allowed in type signatures
+
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for static variables
+  --> $DIR/in-signature.rs:24:20
+   |
+LL | static ARR_STATIC: [u8; _] = [0; 3];
+   |                    ^^^^^^^ not allowed in type signatures
+
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
+  --> $DIR/in-signature.rs:26:14
+   |
+LL | const TY_CT: Bar<i32, _> = Bar::<i32, 3>(0);
+   |              ^^^^^^^^^^^
+   |              |
+   |              not allowed in type signatures
+   |              help: replace with the correct type: `Bar<i32, 3_usize>`
+
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for static variables
+  --> $DIR/in-signature.rs:28:19
+   |
+LL | static TY_STATIC: Bar<i32, _> = Bar::<i32, 3>(0);
+   |                   ^^^^^^^^^^^
+   |                   |
+   |                   not allowed in type signatures
+   |                   help: replace with the correct type: `Bar<i32, 3_usize>`
+
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
+  --> $DIR/in-signature.rs:30:20
+   |
+LL | const TY_CT_MIXED: Bar<_, _> = Bar::<i32, 3>(0);
+   |                    ^^^^^^^^^
+   |                    |
+   |                    not allowed in type signatures
+   |                    help: replace with the correct type: `Bar<i32, 3_usize>`
+
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for static variables
+  --> $DIR/in-signature.rs:32:25
+   |
+LL | static TY_STATIC_MIXED: Bar<_, _> = Bar::<i32, 3>(0);
+   |                         ^^^^^^^^^
+   |                         |
+   |                         not allowed in type signatures
+   |                         help: replace with the correct type: `Bar<i32, 3_usize>`
+
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
+  --> $DIR/in-signature.rs:35:21
+   |
+LL |     const ARR: [u8; _];
+   |                     ^ not allowed in type signatures
+
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
+  --> $DIR/in-signature.rs:39:25
+   |
+LL |     const ARR: Bar<i32, _>;
+   |                         ^ not allowed in type signatures
+
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
+  --> $DIR/in-signature.rs:43:20
+   |
+LL |     const ARR: Bar<_, _>;
+   |                    ^  ^ not allowed in type signatures
+   |                    |
+   |                    not allowed in type signatures
+
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for associated types
+  --> $DIR/in-signature.rs:51:23
+   |
+LL |     type Assoc = [u8; _];
+   |                       ^ not allowed in type signatures
+
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for associated types
+  --> $DIR/in-signature.rs:55:27
+   |
+LL |     type Assoc = Bar<i32, _>;
+   |                           ^ not allowed in type signatures
+
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for associated types
+  --> $DIR/in-signature.rs:59:22
+   |
+LL |     type Assoc = Bar<_, _>;
+   |                      ^  ^ not allowed in type signatures
+   |                      |
+   |                      not allowed in type signatures
+
+error: aborting due to 15 previous errors
+
+For more information about this error, try `rustc --explain E0121`.
diff --git a/src/test/ui/did_you_mean/bad-assoc-ty.rs b/src/test/ui/did_you_mean/bad-assoc-ty.rs
index 609a5b0de6b..f787c416c2d 100644
--- a/src/test/ui/did_you_mean/bad-assoc-ty.rs
+++ b/src/test/ui/did_you_mean/bad-assoc-ty.rs
@@ -16,7 +16,7 @@ type D = (u8, u8)::AssocTy;
 
 type E = _::AssocTy;
 //~^ ERROR missing angle brackets in associated item path
-//~| ERROR the type placeholder `_` is not allowed within types on item signatures for type aliases
+//~| ERROR the placeholder `_` is not allowed within types on item signatures for type aliases
 
 type F = &'static (u8)::AssocTy;
 //~^ ERROR missing angle brackets in associated item path
@@ -49,37 +49,37 @@ type I = ty!()::AssocTy;
 
 trait K<A, B> {}
 fn foo<X: K<_, _>>(x: X) {}
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
 
 fn bar<F>(_: F) where F: Fn() -> _ {}
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
 
 fn baz<F: Fn() -> _>(_: F) {}
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
 
 struct L<F>(F) where F: Fn() -> _;
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for structs
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for structs
 struct M<F> where F: Fn() -> _ {
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for structs
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for structs
     a: F,
 }
 enum N<F> where F: Fn() -> _ {
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for enums
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for enums
     Foo(F),
 }
 
 union O<F> where F: Fn() -> _ {
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for unions
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for unions
     foo: F,
 }
 
 trait P<F> where F: Fn() -> _ {
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for traits
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for traits
 }
 
 trait Q {
     fn foo<F>(_: F) where F: Fn() -> _ {}
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
 }
 
 fn main() {}
diff --git a/src/test/ui/did_you_mean/bad-assoc-ty.stderr b/src/test/ui/did_you_mean/bad-assoc-ty.stderr
index 11514a28b2c..2326af934d0 100644
--- a/src/test/ui/did_you_mean/bad-assoc-ty.stderr
+++ b/src/test/ui/did_you_mean/bad-assoc-ty.stderr
@@ -81,7 +81,7 @@ error[E0223]: ambiguous associated type
 LL | type D = (u8, u8)::AssocTy;
    |          ^^^^^^^^^^^^^^^^^ help: use fully-qualified syntax: `<(u8, u8) as Trait>::AssocTy`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for type aliases
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for type aliases
   --> $DIR/bad-assoc-ty.rs:17:10
    |
 LL | type E = _::AssocTy;
@@ -136,7 +136,7 @@ error[E0223]: ambiguous associated type
 LL | type I = ty!()::AssocTy;
    |          ^^^^^^^^^^^^^^ help: use fully-qualified syntax: `<u8 as Trait>::AssocTy`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/bad-assoc-ty.rs:51:13
    |
 LL | fn foo<X: K<_, _>>(x: X) {}
@@ -149,7 +149,7 @@ help: use type parameters instead
 LL | fn foo<X: K<T, T>, T>(x: X) {}
    |             ~  ~ +++
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/bad-assoc-ty.rs:54:34
    |
 LL | fn bar<F>(_: F) where F: Fn() -> _ {}
@@ -160,7 +160,7 @@ help: use type parameters instead
 LL | fn bar<F, T>(_: F) where F: Fn() -> T {}
    |         +++                         ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/bad-assoc-ty.rs:57:19
    |
 LL | fn baz<F: Fn() -> _>(_: F) {}
@@ -171,7 +171,7 @@ help: use type parameters instead
 LL | fn baz<F: Fn() -> T, T>(_: F) {}
    |                   ~+++
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for structs
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for structs
   --> $DIR/bad-assoc-ty.rs:60:33
    |
 LL | struct L<F>(F) where F: Fn() -> _;
@@ -182,7 +182,7 @@ help: use type parameters instead
 LL | struct L<F, T>(F) where F: Fn() -> T;
    |           +++                      ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for structs
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for structs
   --> $DIR/bad-assoc-ty.rs:62:30
    |
 LL | struct M<F> where F: Fn() -> _ {
@@ -193,7 +193,7 @@ help: use type parameters instead
 LL | struct M<F, T> where F: Fn() -> T {
    |           +++                   ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for enums
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for enums
   --> $DIR/bad-assoc-ty.rs:66:28
    |
 LL | enum N<F> where F: Fn() -> _ {
@@ -204,7 +204,7 @@ help: use type parameters instead
 LL | enum N<F, T> where F: Fn() -> T {
    |         +++                   ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for unions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for unions
   --> $DIR/bad-assoc-ty.rs:71:29
    |
 LL | union O<F> where F: Fn() -> _ {
@@ -215,7 +215,7 @@ help: use type parameters instead
 LL | union O<F, T> where F: Fn() -> T {
    |          +++                   ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for traits
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for traits
   --> $DIR/bad-assoc-ty.rs:76:29
    |
 LL | trait P<F> where F: Fn() -> _ {
@@ -226,7 +226,7 @@ help: use type parameters instead
 LL | trait P<F, T> where F: Fn() -> T {
    |          +++                   ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/bad-assoc-ty.rs:81:38
    |
 LL |     fn foo<F>(_: F) where F: Fn() -> _ {}
diff --git a/src/test/ui/error-codes/E0121.stderr b/src/test/ui/error-codes/E0121.stderr
index cc0c2df72ea..023d7e011bf 100644
--- a/src/test/ui/error-codes/E0121.stderr
+++ b/src/test/ui/error-codes/E0121.stderr
@@ -1,4 +1,4 @@
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/E0121.rs:1:13
    |
 LL | fn foo() -> _ { 5 }
@@ -7,7 +7,7 @@ LL | fn foo() -> _ { 5 }
    |             not allowed in type signatures
    |             help: replace with the correct return type: `i32`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for static variables
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for static variables
   --> $DIR/E0121.rs:3:13
    |
 LL | static BAR: _ = "test";
diff --git a/src/test/ui/fn/issue-80179.rs b/src/test/ui/fn/issue-80179.rs
index 550974bf778..fcef6f1b60e 100644
--- a/src/test/ui/fn/issue-80179.rs
+++ b/src/test/ui/fn/issue-80179.rs
@@ -8,7 +8,7 @@ fn returns_i32() -> i32 {
 }
 
 fn returns_fn_ptr() -> _ {
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for return types [E0121]
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types [E0121]
 //~| NOTE not allowed in type signatures
 //~| HELP replace with the correct return type
 //~| SUGGESTION fn() -> i32
@@ -16,7 +16,7 @@ fn returns_fn_ptr() -> _ {
 }
 
 fn returns_closure() -> _ {
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for return types [E0121]
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types [E0121]
 //~| NOTE not allowed in type signatures
 //~| HELP consider using an `Fn`, `FnMut`, or `FnOnce` trait bound
 //~| NOTE for more information on `Fn` traits and closure types, see
diff --git a/src/test/ui/fn/issue-80179.stderr b/src/test/ui/fn/issue-80179.stderr
index 96d0f02b01a..2ca4ae982d9 100644
--- a/src/test/ui/fn/issue-80179.stderr
+++ b/src/test/ui/fn/issue-80179.stderr
@@ -1,4 +1,4 @@
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/issue-80179.rs:10:24
    |
 LL | fn returns_fn_ptr() -> _ {
@@ -7,7 +7,7 @@ LL | fn returns_fn_ptr() -> _ {
    |                        not allowed in type signatures
    |                        help: replace with the correct return type: `fn() -> i32`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/issue-80179.rs:18:25
    |
 LL | fn returns_closure() -> _ {
diff --git a/src/test/ui/issues/issue-69396-const-no-type-in-macro.rs b/src/test/ui/issues/issue-69396-const-no-type-in-macro.rs
index 6880e1a4629..45a30857413 100644
--- a/src/test/ui/issues/issue-69396-const-no-type-in-macro.rs
+++ b/src/test/ui/issues/issue-69396-const-no-type-in-macro.rs
@@ -4,7 +4,7 @@ macro_rules! suite {
             const A = "A".$fn();
             //~^ ERROR the name `A` is defined multiple times
             //~| ERROR missing type for `const` item
-            //~| ERROR the type placeholder `_` is not allowed within types on item signatures for constants
+            //~| ERROR the placeholder `_` is not allowed within types on item signatures for constants
         )*
     }
 }
diff --git a/src/test/ui/issues/issue-69396-const-no-type-in-macro.stderr b/src/test/ui/issues/issue-69396-const-no-type-in-macro.stderr
index 34c2073db04..e5ab65169ce 100644
--- a/src/test/ui/issues/issue-69396-const-no-type-in-macro.stderr
+++ b/src/test/ui/issues/issue-69396-const-no-type-in-macro.stderr
@@ -30,7 +30,7 @@ LL | | }
    |
    = note: this error originates in the macro `suite` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for constants
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
   --> $DIR/issue-69396-const-no-type-in-macro.rs:4:19
    |
 LL |               const A = "A".$fn();
diff --git a/src/test/ui/self/self-infer.rs b/src/test/ui/self/self-infer.rs
index cc17d8f8e39..9839b8880e9 100644
--- a/src/test/ui/self/self-infer.rs
+++ b/src/test/ui/self/self-infer.rs
@@ -1,8 +1,8 @@
 struct S;
 
 impl S {
-    fn f(self: _) {} //~ERROR the type placeholder `_` is not allowed within types on item signatures for functions
-    fn g(self: &_) {} //~ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+    fn f(self: _) {} //~ERROR the placeholder `_` is not allowed within types on item signatures for functions
+    fn g(self: &_) {} //~ERROR the placeholder `_` is not allowed within types on item signatures for functions
 }
 
 fn main() {}
diff --git a/src/test/ui/self/self-infer.stderr b/src/test/ui/self/self-infer.stderr
index d3bf63efa40..4f9e3f21dca 100644
--- a/src/test/ui/self/self-infer.stderr
+++ b/src/test/ui/self/self-infer.stderr
@@ -1,4 +1,4 @@
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/self-infer.rs:4:16
    |
 LL |     fn f(self: _) {}
@@ -9,7 +9,7 @@ help: use type parameters instead
 LL |     fn f<T>(self: T) {}
    |         +++       ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/self-infer.rs:5:17
    |
 LL |     fn g(self: &_) {}
diff --git a/src/test/ui/suggestions/unnamable-types.rs b/src/test/ui/suggestions/unnamable-types.rs
index 483f9bbb48c..f2485041d9b 100644
--- a/src/test/ui/suggestions/unnamable-types.rs
+++ b/src/test/ui/suggestions/unnamable-types.rs
@@ -8,14 +8,14 @@ const A = 5;
 //~| HELP: provide a type for the constant
 
 static B: _ = "abc";
-//~^ ERROR: the type placeholder `_` is not allowed within types on item signatures for static variables
+//~^ ERROR: the placeholder `_` is not allowed within types on item signatures for static variables
 //~| NOTE: not allowed in type signatures
 //~| HELP: replace with the correct type
 
 
 // FIXME: this should also suggest a function pointer, as the closure is non-capturing
 const C: _ = || 42;
-//~^ ERROR: the type placeholder `_` is not allowed within types on item signatures for constants
+//~^ ERROR: the placeholder `_` is not allowed within types on item signatures for constants
 //~| NOTE: not allowed in type signatures
 //~| NOTE: however, the inferred type
 
diff --git a/src/test/ui/suggestions/unnamable-types.stderr b/src/test/ui/suggestions/unnamable-types.stderr
index 3a489a6e943..6127446c83e 100644
--- a/src/test/ui/suggestions/unnamable-types.stderr
+++ b/src/test/ui/suggestions/unnamable-types.stderr
@@ -4,7 +4,7 @@ error: missing type for `const` item
 LL | const A = 5;
    |       ^ help: provide a type for the constant: `A: i32`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for static variables
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for static variables
   --> $DIR/unnamable-types.rs:10:11
    |
 LL | static B: _ = "abc";
@@ -13,7 +13,7 @@ LL | static B: _ = "abc";
    |           not allowed in type signatures
    |           help: replace with the correct type: `&str`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for constants
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
   --> $DIR/unnamable-types.rs:17:10
    |
 LL | const C: _ = || 42;
diff --git a/src/test/ui/type-alias-impl-trait/issue-77179.rs b/src/test/ui/type-alias-impl-trait/issue-77179.rs
index 31c45a2093a..8d818d4a387 100644
--- a/src/test/ui/type-alias-impl-trait/issue-77179.rs
+++ b/src/test/ui/type-alias-impl-trait/issue-77179.rs
@@ -5,7 +5,7 @@
 type Pointer<T> = impl std::ops::Deref<Target=T>;
 
 fn test() -> Pointer<_> {
-    //~^ ERROR: the type placeholder `_` is not allowed within types
+    //~^ ERROR: the placeholder `_` is not allowed within types
     Box::new(1)
 }
 
diff --git a/src/test/ui/type-alias-impl-trait/issue-77179.stderr b/src/test/ui/type-alias-impl-trait/issue-77179.stderr
index 593aeeacb83..15205ba9b41 100644
--- a/src/test/ui/type-alias-impl-trait/issue-77179.stderr
+++ b/src/test/ui/type-alias-impl-trait/issue-77179.stderr
@@ -1,4 +1,4 @@
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/issue-77179.rs:7:22
    |
 LL | fn test() -> Pointer<_> {
diff --git a/src/test/ui/typeck/issue-74086.rs b/src/test/ui/typeck/issue-74086.rs
index 1de9cd8007c..44ca256b051 100644
--- a/src/test/ui/typeck/issue-74086.rs
+++ b/src/test/ui/typeck/issue-74086.rs
@@ -1,4 +1,4 @@
 fn main() {
     static BUG: fn(_) -> u8 = |_| 8;
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions [E0121]
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions [E0121]
 }
diff --git a/src/test/ui/typeck/issue-74086.stderr b/src/test/ui/typeck/issue-74086.stderr
index ac1752e17df..e7aea33758c 100644
--- a/src/test/ui/typeck/issue-74086.stderr
+++ b/src/test/ui/typeck/issue-74086.stderr
@@ -1,4 +1,4 @@
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/issue-74086.rs:2:20
    |
 LL |     static BUG: fn(_) -> u8 = |_| 8;
diff --git a/src/test/ui/typeck/issue-75883.rs b/src/test/ui/typeck/issue-75883.rs
index 0d1534df091..885acc48231 100644
--- a/src/test/ui/typeck/issue-75883.rs
+++ b/src/test/ui/typeck/issue-75883.rs
@@ -5,7 +5,7 @@ pub struct UI {}
 impl UI {
     pub fn run() -> Result<_> {
         //~^ ERROR: this enum takes 2 generic arguments but 1 generic argument was supplied
-        //~| ERROR: the type placeholder `_` is not allowed within types on item signatures for return types
+        //~| ERROR: the placeholder `_` is not allowed within types on item signatures for return types
         let mut ui = UI {};
         ui.interact();
 
@@ -14,7 +14,7 @@ impl UI {
 
     pub fn interact(&mut self) -> Result<_> {
         //~^ ERROR: this enum takes 2 generic arguments but 1 generic argument was supplied
-        //~| ERROR: the type placeholder `_` is not allowed within types on item signatures for return types
+        //~| ERROR: the placeholder `_` is not allowed within types on item signatures for return types
         unimplemented!();
     }
 }
diff --git a/src/test/ui/typeck/issue-75883.stderr b/src/test/ui/typeck/issue-75883.stderr
index 5e42c817e03..3861e0507f6 100644
--- a/src/test/ui/typeck/issue-75883.stderr
+++ b/src/test/ui/typeck/issue-75883.stderr
@@ -34,13 +34,13 @@ help: add missing generic argument
 LL |     pub fn interact(&mut self) -> Result<_, E> {
    |                                           +++
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/issue-75883.rs:15:42
    |
 LL |     pub fn interact(&mut self) -> Result<_> {
    |                                          ^ not allowed in type signatures
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/issue-75883.rs:6:28
    |
 LL |     pub fn run() -> Result<_> {
diff --git a/src/test/ui/typeck/issue-75889.stderr b/src/test/ui/typeck/issue-75889.stderr
index de4bdf4e6d9..1438f481ec7 100644
--- a/src/test/ui/typeck/issue-75889.stderr
+++ b/src/test/ui/typeck/issue-75889.stderr
@@ -1,10 +1,10 @@
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for constant items
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for constant items
   --> $DIR/issue-75889.rs:3:24
    |
 LL | const FOO: dyn Fn() -> _ = "";
    |                        ^ not allowed in type signatures
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for static items
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for static items
   --> $DIR/issue-75889.rs:4:25
    |
 LL | static BOO: dyn Fn() -> _ = "";
diff --git a/src/test/ui/typeck/issue-80779.rs b/src/test/ui/typeck/issue-80779.rs
index 99a93b1863d..1624f6b7742 100644
--- a/src/test/ui/typeck/issue-80779.rs
+++ b/src/test/ui/typeck/issue-80779.rs
@@ -3,11 +3,11 @@
 pub struct T<'a>(&'a str);
 
 pub fn f<'a>(val: T<'a>) -> _ {
-    //~^ ERROR: the type placeholder `_` is not allowed within types on item signatures for return types
+    //~^ ERROR: the placeholder `_` is not allowed within types on item signatures for return types
     g(val)
 }
 
 pub fn g(_: T<'static>) -> _ {}
-//~^ ERROR: the type placeholder `_` is not allowed within types on item signatures for return types
+//~^ ERROR: the placeholder `_` is not allowed within types on item signatures for return types
 
 fn main() {}
diff --git a/src/test/ui/typeck/issue-80779.stderr b/src/test/ui/typeck/issue-80779.stderr
index 5a695fecc29..2261ba61654 100644
--- a/src/test/ui/typeck/issue-80779.stderr
+++ b/src/test/ui/typeck/issue-80779.stderr
@@ -1,4 +1,4 @@
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/issue-80779.rs:10:28
    |
 LL | pub fn g(_: T<'static>) -> _ {}
@@ -7,7 +7,7 @@ LL | pub fn g(_: T<'static>) -> _ {}
    |                            not allowed in type signatures
    |                            help: replace with the correct return type: `()`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/issue-80779.rs:5:29
    |
 LL | pub fn f<'a>(val: T<'a>) -> _ {
diff --git a/src/test/ui/typeck/issue-81885.rs b/src/test/ui/typeck/issue-81885.rs
index 5117f250fe5..8935535fb7e 100644
--- a/src/test/ui/typeck/issue-81885.rs
+++ b/src/test/ui/typeck/issue-81885.rs
@@ -1,8 +1,8 @@
 const TEST4: fn() -> _ = 42;
-                  //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+                  //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
 
 fn main() {
     const TEST5: fn() -> _ = 42;
-                      //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+                      //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
 
 }
diff --git a/src/test/ui/typeck/issue-81885.stderr b/src/test/ui/typeck/issue-81885.stderr
index 8206156a618..3ff4375cd8d 100644
--- a/src/test/ui/typeck/issue-81885.stderr
+++ b/src/test/ui/typeck/issue-81885.stderr
@@ -1,10 +1,10 @@
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/issue-81885.rs:1:22
    |
 LL | const TEST4: fn() -> _ = 42;
    |                      ^ not allowed in type signatures
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/issue-81885.rs:5:26
    |
 LL |     const TEST5: fn() -> _ = 42;
diff --git a/src/test/ui/typeck/issue-83621-placeholder-static-in-extern.stderr b/src/test/ui/typeck/issue-83621-placeholder-static-in-extern.stderr
index 7c5cf1082be..9376e8bcf80 100644
--- a/src/test/ui/typeck/issue-83621-placeholder-static-in-extern.stderr
+++ b/src/test/ui/typeck/issue-83621-placeholder-static-in-extern.stderr
@@ -1,4 +1,4 @@
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for static variables
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for static variables
   --> $DIR/issue-83621-placeholder-static-in-extern.rs:4:15
    |
 LL |     static x: _;
diff --git a/src/test/ui/typeck/issue-91450-inner-ty-error.rs b/src/test/ui/typeck/issue-91450-inner-ty-error.rs
index 0b942d6d94f..3c7c990d4e2 100644
--- a/src/test/ui/typeck/issue-91450-inner-ty-error.rs
+++ b/src/test/ui/typeck/issue-91450-inner-ty-error.rs
@@ -2,6 +2,6 @@
 // This test ensures that the compiler does not suggest `Foo<[type error]>` in diagnostic messages.
 
 fn foo() -> Option<_> {} //~ ERROR: [E0308]
-//~^ ERROR: the type placeholder `_` is not allowed
+//~^ ERROR: the placeholder `_` is not allowed
 
 fn main() {}
diff --git a/src/test/ui/typeck/issue-91450-inner-ty-error.stderr b/src/test/ui/typeck/issue-91450-inner-ty-error.stderr
index 314fe561803..32f4c8f6fdf 100644
--- a/src/test/ui/typeck/issue-91450-inner-ty-error.stderr
+++ b/src/test/ui/typeck/issue-91450-inner-ty-error.stderr
@@ -9,7 +9,7 @@ LL | fn foo() -> Option<_> {}
    = note:   expected enum `Option<_>`
            found unit type `()`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/issue-91450-inner-ty-error.rs:4:20
    |
 LL | fn foo() -> Option<_> {}
diff --git a/src/test/ui/typeck/type-placeholder-fn-in-const.rs b/src/test/ui/typeck/type-placeholder-fn-in-const.rs
index f657bea1648..ab2e2d8c53a 100644
--- a/src/test/ui/typeck/type-placeholder-fn-in-const.rs
+++ b/src/test/ui/typeck/type-placeholder-fn-in-const.rs
@@ -2,13 +2,13 @@ struct MyStruct;
 
 trait Test {
     const TEST: fn() -> _;
-    //~^ ERROR: the type placeholder `_` is not allowed within types on item signatures for functions [E0121]
-    //~| ERROR: the type placeholder `_` is not allowed within types on item signatures for constants [E0121]
+    //~^ ERROR: the placeholder `_` is not allowed within types on item signatures for functions [E0121]
+    //~| ERROR: the placeholder `_` is not allowed within types on item signatures for constants [E0121]
 }
 
 impl Test for MyStruct {
     const TEST: fn() -> _ = 42;
-    //~^ ERROR: the type placeholder `_` is not allowed within types on item signatures for functions [E0121]
+    //~^ ERROR: the placeholder `_` is not allowed within types on item signatures for functions [E0121]
 }
 
 fn main() {}
diff --git a/src/test/ui/typeck/type-placeholder-fn-in-const.stderr b/src/test/ui/typeck/type-placeholder-fn-in-const.stderr
index 62f4db8638f..e7b2e554a8d 100644
--- a/src/test/ui/typeck/type-placeholder-fn-in-const.stderr
+++ b/src/test/ui/typeck/type-placeholder-fn-in-const.stderr
@@ -1,16 +1,16 @@
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/type-placeholder-fn-in-const.rs:4:25
    |
 LL |     const TEST: fn() -> _;
    |                         ^ not allowed in type signatures
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for constants
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
   --> $DIR/type-placeholder-fn-in-const.rs:4:25
    |
 LL |     const TEST: fn() -> _;
    |                         ^ not allowed in type signatures
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/type-placeholder-fn-in-const.rs:10:25
    |
 LL |     const TEST: fn() -> _ = 42;
diff --git a/src/test/ui/typeck/typeck_type_placeholder_item.rs b/src/test/ui/typeck/typeck_type_placeholder_item.rs
index a3b75543510..ca0876be58d 100644
--- a/src/test/ui/typeck/typeck_type_placeholder_item.rs
+++ b/src/test/ui/typeck/typeck_type_placeholder_item.rs
@@ -5,67 +5,67 @@
 // inference by using the `_` type placeholder.
 
 fn test() -> _ { 5 }
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for return types
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
 
 fn test2() -> (_, _) { (5, 5) }
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for return types
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
 
 static TEST3: _ = "test";
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for static variables
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for static variables
 
 static TEST4: _ = 145;
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for static variables
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for static variables
 
 static TEST5: (_, _) = (1, 2);
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for static variables
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for static variables
 
 fn test6(_: _) { }
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
 
 fn test6_b<T>(_: _, _: T) { }
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
 
 fn test6_c<T, K, L, A, B>(_: _, _: (T, K, L, A, B)) { }
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
 
 fn test7(x: _) { let _x: usize = x; }
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
 
 fn test8(_f: fn() -> _) { }
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
-//~^^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
+//~^^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
 
 struct Test9;
 
 impl Test9 {
     fn test9(&self) -> _ { () }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for return types
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
 
     fn test10(&self, _x : _) { }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
 }
 
 fn test11(x: &usize) -> &_ {
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for return types
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
     &x
 }
 
 unsafe fn test12(x: *const usize) -> *const *const _ {
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for return types
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
     &x
 }
 
 impl Clone for Test9 {
     fn clone(&self) -> _ { Test9 }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for return types
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
 
     fn clone_from(&mut self, other: _) { *self = Test9; }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
 }
 
 struct Test10 {
     a: _,
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for structs
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for structs
     b: (_, _),
 }
 
@@ -73,94 +73,94 @@ pub fn main() {
     static A = 42;
     //~^ ERROR missing type for `static` item
     static B: _ = 42;
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for static variables
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for static variables
     static C: Option<_> = Some(42);
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for static variables
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for static variables
     fn fn_test() -> _ { 5 }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for return types
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
 
     fn fn_test2() -> (_, _) { (5, 5) }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for return types
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
 
     static FN_TEST3: _ = "test";
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for static variables
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for static variables
 
     static FN_TEST4: _ = 145;
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for static variables
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for static variables
 
     static FN_TEST5: (_, _) = (1, 2);
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for static variables
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for static variables
 
     fn fn_test6(_: _) { }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
 
     fn fn_test7(x: _) { let _x: usize = x; }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
 
     fn fn_test8(_f: fn() -> _) { }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
-    //~^^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
+    //~^^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
 
     struct FnTest9;
 
     impl FnTest9 {
         fn fn_test9(&self) -> _ { () }
-        //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for return types
+        //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
 
         fn fn_test10(&self, _x : _) { }
-        //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+        //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
     }
 
     impl Clone for FnTest9 {
         fn clone(&self) -> _ { FnTest9 }
-        //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for return types
+        //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
 
         fn clone_from(&mut self, other: _) { *self = FnTest9; }
-        //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+        //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
     }
 
     struct FnTest10 {
         a: _,
-        //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for structs
+        //~^ ERROR the placeholder `_` is not allowed within types on item signatures for structs
         b: (_, _),
     }
 
     fn fn_test11(_: _) -> (_, _) { panic!() }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for return types
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
     //~| ERROR type annotations needed
 
     fn fn_test12(x: i32) -> (_, _) { (x, x) }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for return types
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
 
     fn fn_test13(x: _) -> (i32, _) { (x, x) }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for return types
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
 }
 
 trait T {
     fn method_test1(&self, x: _);
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
     fn method_test2(&self, x: _) -> _;
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
     fn method_test3(&self) -> _;
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
     fn assoc_fn_test1(x: _);
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
     fn assoc_fn_test2(x: _) -> _;
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
     fn assoc_fn_test3() -> _;
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
 }
 
 struct BadStruct<_>(_);
 //~^ ERROR expected identifier, found reserved identifier `_`
-//~| ERROR the type placeholder `_` is not allowed within types on item signatures for structs
+//~| ERROR the placeholder `_` is not allowed within types on item signatures for structs
 trait BadTrait<_> {}
 //~^ ERROR expected identifier, found reserved identifier `_`
 impl BadTrait<_> for BadStruct<_> {}
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for implementations
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for implementations
 
 fn impl_trait() -> impl BadTrait<_> {
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for opaque types
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for opaque types
     unimplemented!()
 }
 
@@ -168,19 +168,19 @@ struct BadStruct1<_, _>(_);
 //~^ ERROR expected identifier, found reserved identifier `_`
 //~| ERROR expected identifier, found reserved identifier `_`
 //~| ERROR the name `_` is already used
-//~| ERROR the type placeholder `_` is not allowed within types on item signatures for structs
+//~| ERROR the placeholder `_` is not allowed within types on item signatures for structs
 struct BadStruct2<_, T>(_, T);
 //~^ ERROR expected identifier, found reserved identifier `_`
-//~| ERROR the type placeholder `_` is not allowed within types on item signatures for structs
+//~| ERROR the placeholder `_` is not allowed within types on item signatures for structs
 
 type X = Box<_>;
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for type aliases
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for type aliases
 
 struct Struct;
 trait Trait<T> {}
 impl Trait<usize> for Struct {}
 type Y = impl Trait<_>;
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for opaque types
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for opaque types
 fn foo() -> Y {
     Struct
 }
@@ -188,25 +188,25 @@ fn foo() -> Y {
 trait Qux {
     type A;
     type B = _;
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for associated types
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for associated types
     const C: _;
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for constants
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for constants
     const D: _ = 42;
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for constants
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for constants
     // type E: _; // FIXME: make the parser propagate the existence of `B`
     type F: std::ops::Fn(_);
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for associated types
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for associated types
 }
 impl Qux for Struct {
     type A = _;
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for associated types
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for associated types
     type B = _;
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for associated types
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for associated types
     const C: _;
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for constants
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for constants
     //~| ERROR associated constant in `impl` without body
     const D: _ = 42;
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for constants
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for constants
 }
 
 fn map<T>(_: fn() -> Option<&'static T>) -> Option<T> {
@@ -214,9 +214,9 @@ fn map<T>(_: fn() -> Option<&'static T>) -> Option<T> {
 }
 
 fn value() -> Option<&'static _> {
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for return types
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
     Option::<&'static u8>::None
 }
 
 const _: Option<_> = map(value);
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for constants
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for constants
diff --git a/src/test/ui/typeck/typeck_type_placeholder_item.stderr b/src/test/ui/typeck/typeck_type_placeholder_item.stderr
index e1f66afdacc..c07b96f9a97 100644
--- a/src/test/ui/typeck/typeck_type_placeholder_item.stderr
+++ b/src/test/ui/typeck/typeck_type_placeholder_item.stderr
@@ -44,7 +44,7 @@ LL | struct BadStruct1<_, _>(_);
    |                   |
    |                   first use of `_`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/typeck_type_placeholder_item.rs:7:14
    |
 LL | fn test() -> _ { 5 }
@@ -53,7 +53,7 @@ LL | fn test() -> _ { 5 }
    |              not allowed in type signatures
    |              help: replace with the correct return type: `i32`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/typeck_type_placeholder_item.rs:10:16
    |
 LL | fn test2() -> (_, _) { (5, 5) }
@@ -63,7 +63,7 @@ LL | fn test2() -> (_, _) { (5, 5) }
    |               |not allowed in type signatures
    |               help: replace with the correct return type: `(i32, i32)`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for static variables
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for static variables
   --> $DIR/typeck_type_placeholder_item.rs:13:15
    |
 LL | static TEST3: _ = "test";
@@ -72,7 +72,7 @@ LL | static TEST3: _ = "test";
    |               not allowed in type signatures
    |               help: replace with the correct type: `&str`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for static variables
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for static variables
   --> $DIR/typeck_type_placeholder_item.rs:16:15
    |
 LL | static TEST4: _ = 145;
@@ -81,13 +81,13 @@ LL | static TEST4: _ = 145;
    |               not allowed in type signatures
    |               help: replace with the correct type: `i32`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for static variables
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for static variables
   --> $DIR/typeck_type_placeholder_item.rs:19:15
    |
 LL | static TEST5: (_, _) = (1, 2);
    |               ^^^^^^ not allowed in type signatures
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/typeck_type_placeholder_item.rs:22:13
    |
 LL | fn test6(_: _) { }
@@ -98,7 +98,7 @@ help: use type parameters instead
 LL | fn test6<T>(_: T) { }
    |         +++    ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/typeck_type_placeholder_item.rs:25:18
    |
 LL | fn test6_b<T>(_: _, _: T) { }
@@ -109,7 +109,7 @@ help: use type parameters instead
 LL | fn test6_b<T, U>(_: U, _: T) { }
    |             +++     ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/typeck_type_placeholder_item.rs:28:30
    |
 LL | fn test6_c<T, K, L, A, B>(_: _, _: (T, K, L, A, B)) { }
@@ -120,7 +120,7 @@ help: use type parameters instead
 LL | fn test6_c<T, K, L, A, B, U>(_: U, _: (T, K, L, A, B)) { }
    |                         +++     ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/typeck_type_placeholder_item.rs:31:13
    |
 LL | fn test7(x: _) { let _x: usize = x; }
@@ -131,7 +131,7 @@ help: use type parameters instead
 LL | fn test7<T>(x: T) { let _x: usize = x; }
    |         +++    ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/typeck_type_placeholder_item.rs:34:22
    |
 LL | fn test8(_f: fn() -> _) { }
@@ -140,7 +140,7 @@ LL | fn test8(_f: fn() -> _) { }
    |                      not allowed in type signatures
    |                      help: use type parameters instead: `T`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/typeck_type_placeholder_item.rs:34:22
    |
 LL | fn test8(_f: fn() -> _) { }
@@ -151,7 +151,7 @@ help: use type parameters instead
 LL | fn test8<T>(_f: fn() -> T) { }
    |         +++             ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/typeck_type_placeholder_item.rs:48:26
    |
 LL | fn test11(x: &usize) -> &_ {
@@ -160,7 +160,7 @@ LL | fn test11(x: &usize) -> &_ {
    |                         |not allowed in type signatures
    |                         help: replace with the correct return type: `&'static &'static usize`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/typeck_type_placeholder_item.rs:53:52
    |
 LL | unsafe fn test12(x: *const usize) -> *const *const _ {
@@ -169,7 +169,7 @@ LL | unsafe fn test12(x: *const usize) -> *const *const _ {
    |                                      |             not allowed in type signatures
    |                                      help: replace with the correct return type: `*const *const usize`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for structs
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for structs
   --> $DIR/typeck_type_placeholder_item.rs:67:8
    |
 LL |     a: _,
@@ -194,7 +194,7 @@ error: missing type for `static` item
 LL |     static A = 42;
    |            ^ help: provide a type for the static variable: `A: i32`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for static variables
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for static variables
   --> $DIR/typeck_type_placeholder_item.rs:75:15
    |
 LL |     static B: _ = 42;
@@ -203,13 +203,13 @@ LL |     static B: _ = 42;
    |               not allowed in type signatures
    |               help: replace with the correct type: `i32`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for static variables
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for static variables
   --> $DIR/typeck_type_placeholder_item.rs:77:15
    |
 LL |     static C: Option<_> = Some(42);
    |               ^^^^^^^^^ not allowed in type signatures
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/typeck_type_placeholder_item.rs:79:21
    |
 LL |     fn fn_test() -> _ { 5 }
@@ -218,7 +218,7 @@ LL |     fn fn_test() -> _ { 5 }
    |                     not allowed in type signatures
    |                     help: replace with the correct return type: `i32`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/typeck_type_placeholder_item.rs:82:23
    |
 LL |     fn fn_test2() -> (_, _) { (5, 5) }
@@ -228,7 +228,7 @@ LL |     fn fn_test2() -> (_, _) { (5, 5) }
    |                      |not allowed in type signatures
    |                      help: replace with the correct return type: `(i32, i32)`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for static variables
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for static variables
   --> $DIR/typeck_type_placeholder_item.rs:85:22
    |
 LL |     static FN_TEST3: _ = "test";
@@ -237,7 +237,7 @@ LL |     static FN_TEST3: _ = "test";
    |                      not allowed in type signatures
    |                      help: replace with the correct type: `&str`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for static variables
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for static variables
   --> $DIR/typeck_type_placeholder_item.rs:88:22
    |
 LL |     static FN_TEST4: _ = 145;
@@ -246,13 +246,13 @@ LL |     static FN_TEST4: _ = 145;
    |                      not allowed in type signatures
    |                      help: replace with the correct type: `i32`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for static variables
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for static variables
   --> $DIR/typeck_type_placeholder_item.rs:91:22
    |
 LL |     static FN_TEST5: (_, _) = (1, 2);
    |                      ^^^^^^ not allowed in type signatures
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/typeck_type_placeholder_item.rs:94:20
    |
 LL |     fn fn_test6(_: _) { }
@@ -263,7 +263,7 @@ help: use type parameters instead
 LL |     fn fn_test6<T>(_: T) { }
    |                +++    ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/typeck_type_placeholder_item.rs:97:20
    |
 LL |     fn fn_test7(x: _) { let _x: usize = x; }
@@ -274,7 +274,7 @@ help: use type parameters instead
 LL |     fn fn_test7<T>(x: T) { let _x: usize = x; }
    |                +++    ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/typeck_type_placeholder_item.rs:100:29
    |
 LL |     fn fn_test8(_f: fn() -> _) { }
@@ -283,7 +283,7 @@ LL |     fn fn_test8(_f: fn() -> _) { }
    |                             not allowed in type signatures
    |                             help: use type parameters instead: `T`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/typeck_type_placeholder_item.rs:100:29
    |
 LL |     fn fn_test8(_f: fn() -> _) { }
@@ -294,7 +294,7 @@ help: use type parameters instead
 LL |     fn fn_test8<T>(_f: fn() -> T) { }
    |                +++             ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for structs
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for structs
   --> $DIR/typeck_type_placeholder_item.rs:123:12
    |
 LL |         a: _,
@@ -319,7 +319,7 @@ error[E0282]: type annotations needed
 LL |     fn fn_test11(_: _) -> (_, _) { panic!() }
    |                  ^ cannot infer type
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/typeck_type_placeholder_item.rs:128:28
    |
 LL |     fn fn_test11(_: _) -> (_, _) { panic!() }
@@ -327,7 +327,7 @@ LL |     fn fn_test11(_: _) -> (_, _) { panic!() }
    |                            |
    |                            not allowed in type signatures
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/typeck_type_placeholder_item.rs:132:30
    |
 LL |     fn fn_test12(x: i32) -> (_, _) { (x, x) }
@@ -337,7 +337,7 @@ LL |     fn fn_test12(x: i32) -> (_, _) { (x, x) }
    |                             |not allowed in type signatures
    |                             help: replace with the correct return type: `(i32, i32)`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/typeck_type_placeholder_item.rs:135:33
    |
 LL |     fn fn_test13(x: _) -> (i32, _) { (x, x) }
@@ -346,7 +346,7 @@ LL |     fn fn_test13(x: _) -> (i32, _) { (x, x) }
    |                           |     not allowed in type signatures
    |                           help: replace with the correct return type: `(i32, i32)`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for structs
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for structs
   --> $DIR/typeck_type_placeholder_item.rs:154:21
    |
 LL | struct BadStruct<_>(_);
@@ -357,7 +357,7 @@ help: use type parameters instead
 LL | struct BadStruct<T>(T);
    |                  ~  ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for implementations
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for implementations
   --> $DIR/typeck_type_placeholder_item.rs:159:15
    |
 LL | impl BadTrait<_> for BadStruct<_> {}
@@ -370,13 +370,13 @@ help: use type parameters instead
 LL | impl<T> BadTrait<T> for BadStruct<T> {}
    |     +++          ~                ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for opaque types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for opaque types
   --> $DIR/typeck_type_placeholder_item.rs:162:34
    |
 LL | fn impl_trait() -> impl BadTrait<_> {
    |                                  ^ not allowed in type signatures
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for structs
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for structs
   --> $DIR/typeck_type_placeholder_item.rs:167:25
    |
 LL | struct BadStruct1<_, _>(_);
@@ -387,7 +387,7 @@ help: use type parameters instead
 LL | struct BadStruct1<T, _>(T);
    |                   ~     ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for structs
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for structs
   --> $DIR/typeck_type_placeholder_item.rs:172:25
    |
 LL | struct BadStruct2<_, T>(_, T);
@@ -398,19 +398,19 @@ help: use type parameters instead
 LL | struct BadStruct2<U, T>(U, T);
    |                   ~     ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for type aliases
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for type aliases
   --> $DIR/typeck_type_placeholder_item.rs:176:14
    |
 LL | type X = Box<_>;
    |              ^ not allowed in type signatures
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for opaque types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for opaque types
   --> $DIR/typeck_type_placeholder_item.rs:182:21
    |
 LL | type Y = impl Trait<_>;
    |                     ^ not allowed in type signatures
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/typeck_type_placeholder_item.rs:216:31
    |
 LL | fn value() -> Option<&'static _> {
@@ -419,7 +419,7 @@ LL | fn value() -> Option<&'static _> {
    |               |               not allowed in type signatures
    |               help: replace with the correct return type: `Option<&'static u8>`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for constants
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
   --> $DIR/typeck_type_placeholder_item.rs:221:10
    |
 LL | const _: Option<_> = map(value);
@@ -428,7 +428,7 @@ LL | const _: Option<_> = map(value);
    |          not allowed in type signatures
    |          help: replace with the correct type: `Option<u8>`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/typeck_type_placeholder_item.rs:140:31
    |
 LL |     fn method_test1(&self, x: _);
@@ -439,7 +439,7 @@ help: use type parameters instead
 LL |     fn method_test1<T>(&self, x: T);
    |                    +++           ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/typeck_type_placeholder_item.rs:142:31
    |
 LL |     fn method_test2(&self, x: _) -> _;
@@ -452,7 +452,7 @@ help: use type parameters instead
 LL |     fn method_test2<T>(&self, x: T) -> T;
    |                    +++           ~     ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/typeck_type_placeholder_item.rs:144:31
    |
 LL |     fn method_test3(&self) -> _;
@@ -463,7 +463,7 @@ help: use type parameters instead
 LL |     fn method_test3<T>(&self) -> T;
    |                    +++           ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/typeck_type_placeholder_item.rs:146:26
    |
 LL |     fn assoc_fn_test1(x: _);
@@ -474,7 +474,7 @@ help: use type parameters instead
 LL |     fn assoc_fn_test1<T>(x: T);
    |                      +++    ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/typeck_type_placeholder_item.rs:148:26
    |
 LL |     fn assoc_fn_test2(x: _) -> _;
@@ -487,7 +487,7 @@ help: use type parameters instead
 LL |     fn assoc_fn_test2<T>(x: T) -> T;
    |                      +++    ~     ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/typeck_type_placeholder_item.rs:150:28
    |
 LL |     fn assoc_fn_test3() -> _;
@@ -498,19 +498,19 @@ help: use type parameters instead
 LL |     fn assoc_fn_test3<T>() -> T;
    |                      +++      ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for associated types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for associated types
   --> $DIR/typeck_type_placeholder_item.rs:190:14
    |
 LL |     type B = _;
    |              ^ not allowed in type signatures
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for constants
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
   --> $DIR/typeck_type_placeholder_item.rs:192:14
    |
 LL |     const C: _;
    |              ^ not allowed in type signatures
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for constants
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
   --> $DIR/typeck_type_placeholder_item.rs:194:14
    |
 LL |     const D: _ = 42;
@@ -519,13 +519,13 @@ LL |     const D: _ = 42;
    |              not allowed in type signatures
    |              help: replace with the correct type: `i32`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for associated types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for associated types
   --> $DIR/typeck_type_placeholder_item.rs:197:26
    |
 LL |     type F: std::ops::Fn(_);
    |                          ^ not allowed in type signatures
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/typeck_type_placeholder_item.rs:41:24
    |
 LL |     fn test9(&self) -> _ { () }
@@ -534,7 +534,7 @@ LL |     fn test9(&self) -> _ { () }
    |                        not allowed in type signatures
    |                        help: replace with the correct return type: `()`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/typeck_type_placeholder_item.rs:44:27
    |
 LL |     fn test10(&self, _x : _) { }
@@ -545,7 +545,7 @@ help: use type parameters instead
 LL |     fn test10<T>(&self, _x : T) { }
    |              +++             ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/typeck_type_placeholder_item.rs:59:24
    |
 LL |     fn clone(&self) -> _ { Test9 }
@@ -554,7 +554,7 @@ LL |     fn clone(&self) -> _ { Test9 }
    |                        not allowed in type signatures
    |                        help: replace with the correct return type: `Test9`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/typeck_type_placeholder_item.rs:62:37
    |
 LL |     fn clone_from(&mut self, other: _) { *self = Test9; }
@@ -565,7 +565,7 @@ help: use type parameters instead
 LL |     fn clone_from<T>(&mut self, other: T) { *self = Test9; }
    |                  +++                   ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/typeck_type_placeholder_item.rs:107:31
    |
 LL |         fn fn_test9(&self) -> _ { () }
@@ -574,7 +574,7 @@ LL |         fn fn_test9(&self) -> _ { () }
    |                               not allowed in type signatures
    |                               help: replace with the correct return type: `()`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/typeck_type_placeholder_item.rs:110:34
    |
 LL |         fn fn_test10(&self, _x : _) { }
@@ -585,7 +585,7 @@ help: use type parameters instead
 LL |         fn fn_test10<T>(&self, _x : T) { }
    |                     +++             ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/typeck_type_placeholder_item.rs:115:28
    |
 LL |         fn clone(&self) -> _ { FnTest9 }
@@ -594,7 +594,7 @@ LL |         fn clone(&self) -> _ { FnTest9 }
    |                            not allowed in type signatures
    |                            help: replace with the correct return type: `FnTest9`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/typeck_type_placeholder_item.rs:118:41
    |
 LL |         fn clone_from(&mut self, other: _) { *self = FnTest9; }
@@ -605,25 +605,25 @@ help: use type parameters instead
 LL |         fn clone_from<T>(&mut self, other: T) { *self = FnTest9; }
    |                      +++                   ~
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for associated types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for associated types
   --> $DIR/typeck_type_placeholder_item.rs:201:14
    |
 LL |     type A = _;
    |              ^ not allowed in type signatures
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for associated types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for associated types
   --> $DIR/typeck_type_placeholder_item.rs:203:14
    |
 LL |     type B = _;
    |              ^ not allowed in type signatures
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for constants
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
   --> $DIR/typeck_type_placeholder_item.rs:205:14
    |
 LL |     const C: _;
    |              ^ not allowed in type signatures
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for constants
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
   --> $DIR/typeck_type_placeholder_item.rs:208:14
    |
 LL |     const D: _ = 42;
diff --git a/src/test/ui/typeck/typeck_type_placeholder_item_help.rs b/src/test/ui/typeck/typeck_type_placeholder_item_help.rs
index 3af5cf926ab..53f31b683c1 100644
--- a/src/test/ui/typeck/typeck_type_placeholder_item_help.rs
+++ b/src/test/ui/typeck/typeck_type_placeholder_item_help.rs
@@ -2,27 +2,27 @@
 // using the `_` type placeholder.
 
 fn test1() -> _ { Some(42) }
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for return types
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
 
 const TEST2: _ = 42u32;
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for constants
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for constants
 
 const TEST3: _ = Some(42);
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for constants
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for constants
 
 const TEST4: fn() -> _ = 42;
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures for functions
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
 
 trait Test5 {
     const TEST5: _ = 42;
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for constants
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for constants
 }
 
 struct Test6;
 
 impl Test6 {
     const TEST6: _ = 13;
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures for constants
+    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for constants
 }
 
 pub fn main() {
diff --git a/src/test/ui/typeck/typeck_type_placeholder_item_help.stderr b/src/test/ui/typeck/typeck_type_placeholder_item_help.stderr
index 1b56b1033a8..e8191832318 100644
--- a/src/test/ui/typeck/typeck_type_placeholder_item_help.stderr
+++ b/src/test/ui/typeck/typeck_type_placeholder_item_help.stderr
@@ -1,4 +1,4 @@
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for return types
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/typeck_type_placeholder_item_help.rs:4:15
    |
 LL | fn test1() -> _ { Some(42) }
@@ -7,7 +7,7 @@ LL | fn test1() -> _ { Some(42) }
    |               not allowed in type signatures
    |               help: replace with the correct return type: `Option<i32>`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for constants
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
   --> $DIR/typeck_type_placeholder_item_help.rs:7:14
    |
 LL | const TEST2: _ = 42u32;
@@ -16,7 +16,7 @@ LL | const TEST2: _ = 42u32;
    |              not allowed in type signatures
    |              help: replace with the correct type: `u32`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for constants
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
   --> $DIR/typeck_type_placeholder_item_help.rs:10:14
    |
 LL | const TEST3: _ = Some(42);
@@ -25,13 +25,13 @@ LL | const TEST3: _ = Some(42);
    |              not allowed in type signatures
    |              help: replace with the correct type: `Option<i32>`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for functions
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
   --> $DIR/typeck_type_placeholder_item_help.rs:13:22
    |
 LL | const TEST4: fn() -> _ = 42;
    |                      ^ not allowed in type signatures
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for constants
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
   --> $DIR/typeck_type_placeholder_item_help.rs:17:18
    |
 LL |     const TEST5: _ = 42;
@@ -40,7 +40,7 @@ LL |     const TEST5: _ = 42;
    |                  not allowed in type signatures
    |                  help: replace with the correct type: `i32`
 
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures for constants
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
   --> $DIR/typeck_type_placeholder_item_help.rs:24:18
    |
 LL |     const TEST6: _ = 13;
-- 
cgit 1.4.1-3-g733a5


From 29a2d6b50536cee777ca5454b5f9bd1a58b5fc17 Mon Sep 17 00:00:00 2001
From: Noah Lev <camelidcamel@gmail.com>
Date: Sat, 8 Jan 2022 14:48:25 -0800
Subject: intra-doc: Use the impl's assoc item where possible

Before, the trait's associated item would be used. Now, the impl's
associated item is used. The only exception is for impls that use
default values for associated items set by the trait. In that case,
the trait's associated item is still used.

As an example of the old and new behavior, take this code:

    trait MyTrait {
        type AssocTy;
    }

    impl MyTrait for String {
        type AssocTy = u8;
    }

Before, when resolving a link to `String::AssocTy`,
`resolve_associated_trait_item` would return the associated item for
`MyTrait::AssocTy`. Now, it would return the associated item for
`<String as MyTrait>::AssocTy`, as it claims in its docs.
---
 src/librustdoc/passes/collect_intra_doc_links.rs | 88 ++++++++++++++----------
 1 file changed, 53 insertions(+), 35 deletions(-)

(limited to 'src')

diff --git a/src/librustdoc/passes/collect_intra_doc_links.rs b/src/librustdoc/passes/collect_intra_doc_links.rs
index 1a9794e75bc..7dbf00420de 100644
--- a/src/librustdoc/passes/collect_intra_doc_links.rs
+++ b/src/librustdoc/passes/collect_intra_doc_links.rs
@@ -305,16 +305,15 @@ crate enum FragmentKind {
 
 impl ItemFragment {
     /// Create a fragment for an associated item.
-    ///
-    /// `is_prototype` is whether this associated item is a trait method
-    /// without a default definition.
-    fn from_assoc_item(def_id: DefId, kind: ty::AssocKind, is_prototype: bool) -> Self {
-        match kind {
+    #[instrument(level = "debug")]
+    fn from_assoc_item(item: &ty::AssocItem) -> Self {
+        let def_id = item.def_id;
+        match item.kind {
             ty::AssocKind::Fn => {
-                if is_prototype {
-                    ItemFragment(FragmentKind::TyMethod, def_id)
-                } else {
+                if item.defaultness.has_value() {
                     ItemFragment(FragmentKind::Method, def_id)
+                } else {
+                    ItemFragment(FragmentKind::TyMethod, def_id)
                 }
             }
             ty::AssocKind::Const => ItemFragment(FragmentKind::AssociatedConstant, def_id),
@@ -473,8 +472,7 @@ impl<'a, 'tcx> LinkCollector<'a, 'tcx> {
             tcx.associated_items(impl_)
                 .find_by_name_and_namespace(tcx, Ident::with_dummy_span(item_name), ns, impl_)
                 .map(|item| {
-                    let kind = item.kind;
-                    let fragment = ItemFragment::from_assoc_item(item.def_id, kind, false);
+                    let fragment = ItemFragment::from_assoc_item(item);
                     (Res::Primitive(prim_ty), fragment)
                 })
         })
@@ -726,8 +724,7 @@ impl<'a, 'tcx> LinkCollector<'a, 'tcx> {
                         .flatten();
 
                     assoc_item.map(|item| {
-                        let kind = item.kind;
-                        let fragment = ItemFragment::from_assoc_item(item.def_id, kind, false);
+                        let fragment = ItemFragment::from_assoc_item(&item);
                         (root_res, fragment)
                     })
                 })
@@ -765,20 +762,19 @@ impl<'a, 'tcx> LinkCollector<'a, 'tcx> {
                     // To handle that properly resolve() would have to support
                     // something like [`ambi_fn`](<SomeStruct as SomeTrait>::ambi_fn)
                     .or_else(|| {
-                        let item = resolve_associated_trait_item(
+                        resolve_associated_trait_item(
                             tcx.type_of(did),
                             module_id,
                             item_name,
                             ns,
                             self.cx,
-                        );
-                        debug!("got associated item {:?}", item);
-                        item
+                        )
                     });
 
+                debug!("got associated item {:?}", assoc_item);
+
                 if let Some(item) = assoc_item {
-                    let kind = item.kind;
-                    let fragment = ItemFragment::from_assoc_item(item.def_id, kind, false);
+                    let fragment = ItemFragment::from_assoc_item(&item);
                     return Some((root_res, fragment));
                 }
 
@@ -813,11 +809,7 @@ impl<'a, 'tcx> LinkCollector<'a, 'tcx> {
                 .associated_items(did)
                 .find_by_name_and_namespace(tcx, Ident::with_dummy_span(item_name), ns, did)
                 .map(|item| {
-                    let fragment = ItemFragment::from_assoc_item(
-                        item.def_id,
-                        item.kind,
-                        !item.defaultness.has_value(),
-                    );
+                    let fragment = ItemFragment::from_assoc_item(item);
                     let res = Res::Def(item.kind.as_def_kind(), item.def_id);
                     (res, fragment)
                 }),
@@ -883,30 +875,56 @@ fn resolve_associated_trait_item<'a>(
 
     // Next consider explicit impls: `impl MyTrait for MyType`
     // Give precedence to inherent impls.
-    let traits = traits_implemented_by(cx, ty, module);
+    let traits = trait_impls_for(cx, ty, module);
     debug!("considering traits {:?}", traits);
-    let mut candidates = traits.iter().filter_map(|&trait_| {
-        cx.tcx.associated_items(trait_).find_by_name_and_namespace(
-            cx.tcx,
-            Ident::with_dummy_span(item_name),
-            ns,
-            trait_,
-        )
+    let mut candidates = traits.iter().filter_map(|&(impl_, trait_)| {
+        cx.tcx
+            .associated_items(trait_)
+            .find_by_name_and_namespace(cx.tcx, Ident::with_dummy_span(item_name), ns, trait_)
+            .map(|trait_assoc| {
+                trait_assoc_to_impl_assoc_item(cx.tcx, impl_, trait_assoc.def_id)
+                    .unwrap_or(trait_assoc)
+            })
     });
     // FIXME(#74563): warn about ambiguity
     debug!("the candidates were {:?}", candidates.clone().collect::<Vec<_>>());
     candidates.next().copied()
 }
 
-/// Given a type, return all traits in scope in `module` implemented by that type.
+/// Find the associated item in the impl `impl_id` that corresponds to the
+/// trait associated item `trait_assoc_id`.
+///
+/// This function returns `None` if no associated item was found in the impl.
+/// This can occur when the trait associated item has a default value that is
+/// not overriden in the impl.
+///
+/// This is just a wrapper around [`TyCtxt::impl_item_implementor_ids()`] and
+/// [`TyCtxt::associated_item()`] (with some helpful logging added).
+#[instrument(level = "debug", skip(tcx))]
+fn trait_assoc_to_impl_assoc_item<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    impl_id: DefId,
+    trait_assoc_id: DefId,
+) -> Option<&'tcx ty::AssocItem> {
+    let trait_to_impl_assoc_map = tcx.impl_item_implementor_ids(impl_id);
+    debug!(?trait_to_impl_assoc_map);
+    let impl_assoc_id = *trait_to_impl_assoc_map.get(&trait_assoc_id)?;
+    debug!(?impl_assoc_id);
+    let impl_assoc = tcx.associated_item(impl_assoc_id);
+    debug!(?impl_assoc);
+    Some(impl_assoc)
+}
+
+/// Given a type, return all trait impls in scope in `module` for that type.
+/// Returns a set of pairs of `(impl_id, trait_id)`.
 ///
 /// NOTE: this cannot be a query because more traits could be available when more crates are compiled!
 /// So it is not stable to serialize cross-crate.
-fn traits_implemented_by<'a>(
+fn trait_impls_for<'a>(
     cx: &mut DocContext<'a>,
     ty: Ty<'a>,
     module: DefId,
-) -> FxHashSet<DefId> {
+) -> FxHashSet<(DefId, DefId)> {
     let mut resolver = cx.resolver.borrow_mut();
     let in_scope_traits = cx.module_trait_cache.entry(module).or_insert_with(|| {
         resolver.access(|resolver| {
@@ -948,7 +966,7 @@ fn traits_implemented_by<'a>(
                     _ => false,
                 };
 
-            if saw_impl { Some(trait_) } else { None }
+            if saw_impl { Some((impl_, trait_)) } else { None }
         })
     });
     iter.collect()
-- 
cgit 1.4.1-3-g733a5


From 2938be612dce1d2976bebf80812d713257a3b501 Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <guillaume.gomez@huawei.com>
Date: Tue, 18 Jan 2022 16:56:16 +0100
Subject: Correctly handle starts in block doc comments

---
 compiler/rustc_ast/src/attr/mod.rs            | 11 ++++++++++
 compiler/rustc_ast/src/util/comments.rs       | 29 +++++++++++++++++++++++----
 compiler/rustc_ast/src/util/comments/tests.rs | 14 ++++++-------
 compiler/rustc_save_analysis/src/lib.rs       |  4 ++--
 src/librustdoc/clean/types.rs                 |  4 ++--
 5 files changed, 47 insertions(+), 15 deletions(-)

(limited to 'src')

diff --git a/compiler/rustc_ast/src/attr/mod.rs b/compiler/rustc_ast/src/attr/mod.rs
index d66774040f7..6a0ace04d4b 100644
--- a/compiler/rustc_ast/src/attr/mod.rs
+++ b/compiler/rustc_ast/src/attr/mod.rs
@@ -242,6 +242,17 @@ impl Attribute {
         }
     }
 
+    pub fn doc_str_and_comment_kind(&self) -> Option<(Symbol, CommentKind)> {
+        match self.kind {
+            AttrKind::DocComment(kind, data) => Some((data, kind)),
+            AttrKind::Normal(ref item, _) if item.path == sym::doc => item
+                .meta_kind()
+                .and_then(|kind| kind.value_str())
+                .map(|data| (data, CommentKind::Line)),
+            _ => None,
+        }
+    }
+
     pub fn doc_str(&self) -> Option<Symbol> {
         match self.kind {
             AttrKind::DocComment(.., data) => Some(data),
diff --git a/compiler/rustc_ast/src/util/comments.rs b/compiler/rustc_ast/src/util/comments.rs
index 0a391123dd3..612ee71f350 100644
--- a/compiler/rustc_ast/src/util/comments.rs
+++ b/compiler/rustc_ast/src/util/comments.rs
@@ -1,3 +1,4 @@
+use crate::token::CommentKind;
 use rustc_span::source_map::SourceMap;
 use rustc_span::{BytePos, CharPos, FileName, Pos, Symbol};
 
@@ -25,7 +26,7 @@ pub struct Comment {
 
 /// Makes a doc string more presentable to users.
 /// Used by rustdoc and perhaps other tools, but not by rustc.
-pub fn beautify_doc_string(data: Symbol) -> Symbol {
+pub fn beautify_doc_string(data: Symbol, kind: CommentKind) -> Symbol {
     fn get_vertical_trim(lines: &[&str]) -> Option<(usize, usize)> {
         let mut i = 0;
         let mut j = lines.len();
@@ -42,10 +43,28 @@ pub fn beautify_doc_string(data: Symbol) -> Symbol {
         if i != 0 || j != lines.len() { Some((i, j)) } else { None }
     }
 
-    fn get_horizontal_trim(lines: &[&str]) -> Option<usize> {
+    fn get_horizontal_trim(lines: &[&str], kind: CommentKind) -> Option<usize> {
         let mut i = usize::MAX;
         let mut first = true;
 
+        // In case we have doc comments like `/**` or `/*!`, we want to remove stars if they are
+        // present. However, we first need to strip the empty lines so they don't get in the middle
+        // when we try to compute the "horizontal trim".
+        let lines = if kind == CommentKind::Block {
+            let mut i = 0;
+            let mut j = lines.len();
+
+            while i < j && lines[i].trim().is_empty() {
+                i += 1;
+            }
+            while j > i && lines[j - 1].trim().is_empty() {
+                j -= 1;
+            }
+            &lines[i..j]
+        } else {
+            lines
+        };
+
         for line in lines {
             for (j, c) in line.chars().enumerate() {
                 if j > i || !"* \t".contains(c) {
@@ -79,11 +98,13 @@ pub fn beautify_doc_string(data: Symbol) -> Symbol {
         } else {
             &mut lines
         };
-        if let Some(horizontal) = get_horizontal_trim(&lines) {
+        if let Some(horizontal) = get_horizontal_trim(&lines, kind) {
             changes = true;
             // remove a "[ \t]*\*" block from each line, if possible
             for line in lines.iter_mut() {
-                *line = &line[horizontal + 1..];
+                if horizontal + 1 < line.len() {
+                    *line = &line[horizontal + 1..];
+                }
             }
         }
         if changes {
diff --git a/compiler/rustc_ast/src/util/comments/tests.rs b/compiler/rustc_ast/src/util/comments/tests.rs
index 6d137f3774f..98f692a7724 100644
--- a/compiler/rustc_ast/src/util/comments/tests.rs
+++ b/compiler/rustc_ast/src/util/comments/tests.rs
@@ -5,7 +5,7 @@ use rustc_span::create_default_session_globals_then;
 fn test_block_doc_comment_1() {
     create_default_session_globals_then(|| {
         let comment = "\n * Test \n **  Test\n *   Test\n";
-        let stripped = beautify_doc_string(Symbol::intern(comment));
+        let stripped = beautify_doc_string(Symbol::intern(comment), CommentKind::Block);
         assert_eq!(stripped.as_str(), " Test \n*  Test\n   Test");
     })
 }
@@ -14,7 +14,7 @@ fn test_block_doc_comment_1() {
 fn test_block_doc_comment_2() {
     create_default_session_globals_then(|| {
         let comment = "\n * Test\n *  Test\n";
-        let stripped = beautify_doc_string(Symbol::intern(comment));
+        let stripped = beautify_doc_string(Symbol::intern(comment), CommentKind::Block);
         assert_eq!(stripped.as_str(), " Test\n  Test");
     })
 }
@@ -23,7 +23,7 @@ fn test_block_doc_comment_2() {
 fn test_block_doc_comment_3() {
     create_default_session_globals_then(|| {
         let comment = "\n let a: *i32;\n *a = 5;\n";
-        let stripped = beautify_doc_string(Symbol::intern(comment));
+        let stripped = beautify_doc_string(Symbol::intern(comment), CommentKind::Block);
         assert_eq!(stripped.as_str(), " let a: *i32;\n *a = 5;");
     })
 }
@@ -31,13 +31,13 @@ fn test_block_doc_comment_3() {
 #[test]
 fn test_line_doc_comment() {
     create_default_session_globals_then(|| {
-        let stripped = beautify_doc_string(Symbol::intern(" test"));
+        let stripped = beautify_doc_string(Symbol::intern(" test"), CommentKind::Line);
         assert_eq!(stripped.as_str(), " test");
-        let stripped = beautify_doc_string(Symbol::intern("! test"));
+        let stripped = beautify_doc_string(Symbol::intern("! test"), CommentKind::Line);
         assert_eq!(stripped.as_str(), "! test");
-        let stripped = beautify_doc_string(Symbol::intern("test"));
+        let stripped = beautify_doc_string(Symbol::intern("test"), CommentKind::Line);
         assert_eq!(stripped.as_str(), "test");
-        let stripped = beautify_doc_string(Symbol::intern("!test"));
+        let stripped = beautify_doc_string(Symbol::intern("!test"), CommentKind::Line);
         assert_eq!(stripped.as_str(), "!test");
     })
 }
diff --git a/compiler/rustc_save_analysis/src/lib.rs b/compiler/rustc_save_analysis/src/lib.rs
index 21cb93cc5f4..b95fe1b0549 100644
--- a/compiler/rustc_save_analysis/src/lib.rs
+++ b/compiler/rustc_save_analysis/src/lib.rs
@@ -821,9 +821,9 @@ impl<'tcx> SaveContext<'tcx> {
         let mut result = String::new();
 
         for attr in attrs {
-            if let Some(val) = attr.doc_str() {
+            if let Some((val, kind)) = attr.doc_str_and_comment_kind() {
                 // FIXME: Should save-analysis beautify doc strings itself or leave it to users?
-                result.push_str(beautify_doc_string(val).as_str());
+                result.push_str(beautify_doc_string(val, kind).as_str());
                 result.push('\n');
             }
         }
diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index 00c6e38839f..8e60473140a 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -1040,9 +1040,9 @@ impl Attributes {
     ) -> Attributes {
         let mut doc_strings: Vec<DocFragment> = vec![];
         let clean_attr = |(attr, parent_module): (&ast::Attribute, Option<DefId>)| {
-            if let Some(value) = attr.doc_str() {
+            if let Some((value, kind)) = attr.doc_str_and_comment_kind() {
                 trace!("got doc_str={:?}", value);
-                let value = beautify_doc_string(value);
+                let value = beautify_doc_string(value, kind);
                 let kind = if attr.is_doc_comment() {
                     DocFragmentKind::SugaredDoc
                 } else {
-- 
cgit 1.4.1-3-g733a5


From 06b00ad19972c18150fe25a9b3716ffdf5300a83 Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <guillaume.gomez@huawei.com>
Date: Tue, 18 Jan 2022 16:56:37 +0100
Subject: Add test for block doc comments

---
 src/test/rustdoc/strip-block-doc-comments-stars.docblock.html |  2 ++
 src/test/rustdoc/strip-block-doc-comments-stars.rs            | 11 +++++++++++
 2 files changed, 13 insertions(+)
 create mode 100644 src/test/rustdoc/strip-block-doc-comments-stars.docblock.html
 create mode 100644 src/test/rustdoc/strip-block-doc-comments-stars.rs

(limited to 'src')

diff --git a/src/test/rustdoc/strip-block-doc-comments-stars.docblock.html b/src/test/rustdoc/strip-block-doc-comments-stars.docblock.html
new file mode 100644
index 00000000000..22b0b5dc47e
--- /dev/null
+++ b/src/test/rustdoc/strip-block-doc-comments-stars.docblock.html
@@ -0,0 +1,2 @@
+<div class="docblock"><p>a</p>
+</div>
\ No newline at end of file
diff --git a/src/test/rustdoc/strip-block-doc-comments-stars.rs b/src/test/rustdoc/strip-block-doc-comments-stars.rs
new file mode 100644
index 00000000000..ed2297b4fac
--- /dev/null
+++ b/src/test/rustdoc/strip-block-doc-comments-stars.rs
@@ -0,0 +1,11 @@
+#![crate_name = "foo"]
+
+// The goal of this test is to answer that it won't be generated as a list because
+// block doc comments can have their lines starting with a star.
+
+// @has foo/fn.foo.html
+// @snapshot docblock - '//*[@class="rustdoc-toggle top-doc"]//*[@class="docblock"]'
+/**
+ *     a
+ */
+pub fn foo() {}
-- 
cgit 1.4.1-3-g733a5


From 5c15ad7fca5140362fe459d7c72661ea59a66b10 Mon Sep 17 00:00:00 2001
From: Tyler Mandry <tmandry@gmail.com>
Date: Sat, 20 Nov 2021 02:48:29 +0000
Subject: NiceRegionError: Use written return type for async fn

---
 compiler/rustc_hir/src/hir.rs                      | 15 +++++-
 .../rustc_infer/src/infer/error_reporting/mod.rs   |  2 +-
 .../nice_region_error/different_lifetimes.rs       |  1 +
 .../nice_region_error/find_anon_type.rs            | 19 +++-----
 .../error_reporting/nice_region_error/util.rs      | 37 +++++++++-----
 src/test/ui/async-await/issue-76547.stderr         | 14 ++----
 .../ui/async-await/issues/issue-63388-1.stderr     |  2 +-
 ...y_self_types_pin_lifetime_mismatch-async.stderr | 24 +++++-----
 src/test/ui/self/elision/lt-ref-self-async.stderr  | 48 +++++++++----------
 src/test/ui/self/elision/ref-mut-self-async.stderr | 48 +++++++++----------
 .../ui/self/elision/ref-mut-struct-async.stderr    | 40 ++++++++--------
 src/test/ui/self/elision/ref-self-async.stderr     | 56 +++++++++++-----------
 src/test/ui/self/elision/ref-struct-async.stderr   | 40 ++++++++--------
 13 files changed, 181 insertions(+), 165 deletions(-)

(limited to 'src')

diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs
index 43aa0ae265a..a9dbdd483fe 100644
--- a/compiler/rustc_hir/src/hir.rs
+++ b/compiler/rustc_hir/src/hir.rs
@@ -2726,6 +2726,10 @@ pub struct FnHeader {
 }
 
 impl FnHeader {
+    pub fn is_async(&self) -> bool {
+        matches!(&self.asyncness, IsAsync::Async)
+    }
+
     pub fn is_const(&self) -> bool {
         matches!(&self.constness, Constness::Const)
     }
@@ -3169,7 +3173,7 @@ impl<'hir> Node<'hir> {
         }
     }
 
-    pub fn fn_decl(&self) -> Option<&FnDecl<'hir>> {
+    pub fn fn_decl(&self) -> Option<&'hir FnDecl<'hir>> {
         match self {
             Node::TraitItem(TraitItem { kind: TraitItemKind::Fn(fn_sig, _), .. })
             | Node::ImplItem(ImplItem { kind: ImplItemKind::Fn(fn_sig, _), .. })
@@ -3181,6 +3185,15 @@ impl<'hir> Node<'hir> {
         }
     }
 
+    pub fn fn_sig(&self) -> Option<&'hir FnSig<'hir>> {
+        match self {
+            Node::TraitItem(TraitItem { kind: TraitItemKind::Fn(fn_sig, _), .. })
+            | Node::ImplItem(ImplItem { kind: ImplItemKind::Fn(fn_sig, _), .. })
+            | Node::Item(Item { kind: ItemKind::Fn(fn_sig, _, _), .. }) => Some(fn_sig),
+            _ => None,
+        }
+    }
+
     pub fn body_id(&self) -> Option<BodyId> {
         match self {
             Node::TraitItem(TraitItem {
diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
index 75472faeeba..14ab635a2ae 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
@@ -65,9 +65,9 @@ use rustc_hir::def_id::DefId;
 use rustc_hir::lang_items::LangItem;
 use rustc_hir::{Item, ItemKind, Node};
 use rustc_middle::dep_graph::DepContext;
-use rustc_middle::ty::error::TypeError;
 use rustc_middle::ty::{
     self,
+    error::TypeError,
     subst::{GenericArgKind, Subst, SubstsRef},
     Binder, Region, Ty, TyCtxt, TypeFoldable,
 };
diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/different_lifetimes.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/different_lifetimes.rs
index ac57796763f..5d33d2b4f9b 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/different_lifetimes.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/different_lifetimes.rs
@@ -171,6 +171,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
 
         self.suggest_adding_lifetime_params(sub, ty_sup, ty_sub, &mut err);
 
+        // TODO: This is only helpful if the lifetime more visible in the impl Future type than in the signature.
         if let Some(t) = future_return_type {
             let snip = self
                 .tcx()
diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/find_anon_type.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/find_anon_type.rs
index 07bba000566..b1535701bb3 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/find_anon_type.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/find_anon_type.rs
@@ -1,6 +1,5 @@
 use rustc_hir as hir;
 use rustc_hir::intravisit::{self, Visitor};
-use rustc_hir::Node;
 use rustc_middle::hir::map::Map;
 use rustc_middle::hir::nested_filter;
 use rustc_middle::middle::resolve_lifetime as rl;
@@ -25,25 +24,19 @@ pub(crate) fn find_anon_type<'tcx>(
     tcx: TyCtxt<'tcx>,
     region: Region<'tcx>,
     br: &ty::BoundRegionKind,
-) -> Option<(&'tcx hir::Ty<'tcx>, &'tcx hir::FnDecl<'tcx>)> {
+) -> Option<(&'tcx hir::Ty<'tcx>, &'tcx hir::FnSig<'tcx>)> {
     if let Some(anon_reg) = tcx.is_suitable_region(region) {
         let hir_id = tcx.hir().local_def_id_to_hir_id(anon_reg.def_id);
-        let fndecl = match tcx.hir().get(hir_id) {
-            Node::Item(&hir::Item { kind: hir::ItemKind::Fn(ref m, ..), .. })
-            | Node::TraitItem(&hir::TraitItem {
-                kind: hir::TraitItemKind::Fn(ref m, ..), ..
-            })
-            | Node::ImplItem(&hir::ImplItem { kind: hir::ImplItemKind::Fn(ref m, ..), .. }) => {
-                &m.decl
-            }
-            _ => return None,
+        let Some(fn_sig) = tcx.hir().get(hir_id).fn_sig() else {
+            return None
         };
 
-        fndecl
+        fn_sig
+            .decl
             .inputs
             .iter()
             .find_map(|arg| find_component_for_bound_region(tcx, arg, br))
-            .map(|ty| (ty, &**fndecl))
+            .map(|ty| (ty, fn_sig))
     } else {
         None
     }
diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs
index 3fa71d1a3d8..3e87f97f496 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs
@@ -4,7 +4,7 @@
 use crate::infer::error_reporting::nice_region_error::NiceRegionError;
 use rustc_hir as hir;
 use rustc_hir::def_id::LocalDefId;
-use rustc_middle::ty::{self, DefIdTree, Region, Ty};
+use rustc_middle::ty::{self, Binder, DefIdTree, Region, Ty, TypeFoldable};
 use rustc_span::Span;
 
 /// Information about the anonymous region we are searching for.
@@ -149,26 +149,41 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
     }
 
     // Here, we check for the case where the anonymous region
-    // is in the return type.
+    // is in the return type as written by the user.
     // FIXME(#42703) - Need to handle certain cases here.
     pub(super) fn is_return_type_anon(
         &self,
         scope_def_id: LocalDefId,
         br: ty::BoundRegionKind,
-        decl: &hir::FnDecl<'_>,
+        hir_sig: &hir::FnSig<'_>,
     ) -> Option<Span> {
-        let ret_ty = self.tcx().type_of(scope_def_id);
-        if let ty::FnDef(_, _) = ret_ty.kind() {
-            let sig = ret_ty.fn_sig(self.tcx());
-            let late_bound_regions =
-                self.tcx().collect_referenced_late_bound_regions(&sig.output());
-            if late_bound_regions.iter().any(|r| *r == br) {
-                return Some(decl.output.span());
-            }
+        let fn_ty = self.tcx().type_of(scope_def_id);
+        if let ty::FnDef(_, _) = fn_ty.kind() {
+            let ret_ty = fn_ty.fn_sig(self.tcx()).output();
+            let span = hir_sig.decl.output.span();
+            let future_output = if hir_sig.header.is_async() {
+                ret_ty.map_bound(|ty| self.infcx.get_impl_future_output_ty(ty)).transpose()
+            } else {
+                None
+            };
+            return match future_output {
+                Some(output) if self.includes_region(output, br) => Some(span),
+                None if self.includes_region(ret_ty, br) => Some(span),
+                _ => None,
+            };
         }
         None
     }
 
+    fn includes_region(
+        &self,
+        ty: Binder<'tcx, impl TypeFoldable<'tcx>>,
+        region: ty::BoundRegionKind,
+    ) -> bool {
+        let late_bound_regions = self.tcx().collect_referenced_late_bound_regions(&ty);
+        late_bound_regions.iter().any(|r| *r == region)
+    }
+
     // Here we check for the case where anonymous region
     // corresponds to self and if yes, we display E0312.
     // FIXME(#42700) - Need to format self properly to
diff --git a/src/test/ui/async-await/issue-76547.stderr b/src/test/ui/async-await/issue-76547.stderr
index 9bfb0f28028..ac5f99970c8 100644
--- a/src/test/ui/async-await/issue-76547.stderr
+++ b/src/test/ui/async-await/issue-76547.stderr
@@ -2,23 +2,17 @@ error[E0623]: lifetime mismatch
   --> $DIR/issue-76547.rs:20:13
    |
 LL | async fn fut(bufs: &mut [&mut [u8]]) {
-   |                          ---------   -
-   |                          |           |
-   |                          |           this `async fn` implicitly returns an `impl Future<Output = ()>`
-   |                          this parameter and the returned future are declared with different lifetimes...
+   |                    ---------------- these two types are declared with different lifetimes...
 LL |     ListFut(bufs).await
-   |             ^^^^ ...but data from `bufs` is held across an await point here
+   |             ^^^^ ...but data from `bufs` flows into `bufs` here
 
 error[E0623]: lifetime mismatch
   --> $DIR/issue-76547.rs:34:14
    |
 LL | async fn fut2(bufs: &mut [&mut [u8]]) -> i32 {
-   |                           ---------      ---
-   |                           |              |
-   |                           |              this `async fn` implicitly returns an `impl Future<Output = i32>`
-   |                           this parameter and the returned future are declared with different lifetimes...
+   |                     ---------------- these two types are declared with different lifetimes...
 LL |     ListFut2(bufs).await
-   |              ^^^^ ...but data from `bufs` is held across an await point here
+   |              ^^^^ ...but data from `bufs` flows into `bufs` here
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/async-await/issues/issue-63388-1.stderr b/src/test/ui/async-await/issues/issue-63388-1.stderr
index ac29cca9d3f..32ca7afd82d 100644
--- a/src/test/ui/async-await/issues/issue-63388-1.stderr
+++ b/src/test/ui/async-await/issues/issue-63388-1.stderr
@@ -2,7 +2,7 @@ error[E0623]: lifetime mismatch
   --> $DIR/issue-63388-1.rs:14:9
    |
 LL |         &'a self, foo: &dyn Foo
-   |         -------- this parameter and the returned future are declared with different lifetimes...
+   |                        -------- this parameter and the returned future are declared with different lifetimes...
 LL |     ) -> &dyn Foo
    |          --------
    |          |
diff --git a/src/test/ui/self/arbitrary_self_types_pin_lifetime_mismatch-async.stderr b/src/test/ui/self/arbitrary_self_types_pin_lifetime_mismatch-async.stderr
index e6846fb4049..6986cd1a5fd 100644
--- a/src/test/ui/self/arbitrary_self_types_pin_lifetime_mismatch-async.stderr
+++ b/src/test/ui/self/arbitrary_self_types_pin_lifetime_mismatch-async.stderr
@@ -2,28 +2,28 @@ error[E0623]: lifetime mismatch
   --> $DIR/arbitrary_self_types_pin_lifetime_mismatch-async.rs:8:52
    |
 LL |     async fn a(self: Pin<&Foo>, f: &Foo) -> &Foo { f }
-   |                          ----               ----   ^ ...but data from `f` is held across an await point here
-   |                          |                  |
-   |                          |                  this `async fn` implicitly returns an `impl Future<Output = &Foo>`
-   |                          this parameter and the returned future are declared with different lifetimes...
+   |                                    ----     ----   ^ ...but data from `f` is held across an await point here
+   |                                    |        |
+   |                                    |        this `async fn` implicitly returns an `impl Future<Output = &Foo>`
+   |                                    this parameter and the returned future are declared with different lifetimes...
 
 error[E0623]: lifetime mismatch
   --> $DIR/arbitrary_self_types_pin_lifetime_mismatch-async.rs:11:82
    |
 LL |     async fn c(self: Pin<&Self>, f: &Foo, g: &Foo) -> (Pin<&Foo>, &Foo) { (self, f) }
-   |                          -----                        -----------------          ^ ...but data from `f` is held across an await point here
-   |                          |                            |
-   |                          |                            this `async fn` implicitly returns an `impl Future<Output = (Pin<&Foo>, &Foo)>`
-   |                          this parameter and the returned future are declared with different lifetimes...
+   |                                     ----              -----------------          ^ ...but data from `f` is held across an await point here
+   |                                     |                 |
+   |                                     |                 this `async fn` implicitly returns an `impl Future<Output = (Pin<&Foo>, &Foo)>`
+   |                                     this parameter and the returned future are declared with different lifetimes...
 
 error[E0623]: lifetime mismatch
   --> $DIR/arbitrary_self_types_pin_lifetime_mismatch-async.rs:17:64
    |
 LL |     async fn bar<'a>(self: Alias<&Self>, arg: &'a ()) -> &() { arg }
-   |                                  -----                   ---   ^^^ ...but data from `arg` is held across an await point here
-   |                                  |                       |
-   |                                  |                       this `async fn` implicitly returns an `impl Future<Output = &()>`
-   |                                  this parameter and the returned future are declared with different lifetimes...
+   |                                               ------     ---   ^^^ ...but data from `arg` is held across an await point here
+   |                                               |          |
+   |                                               |          this `async fn` implicitly returns an `impl Future<Output = &()>`
+   |                                               this parameter and the returned future are declared with different lifetimes...
 
 error: aborting due to 3 previous errors
 
diff --git a/src/test/ui/self/elision/lt-ref-self-async.stderr b/src/test/ui/self/elision/lt-ref-self-async.stderr
index 3221d270850..d65a6ade037 100644
--- a/src/test/ui/self/elision/lt-ref-self-async.stderr
+++ b/src/test/ui/self/elision/lt-ref-self-async.stderr
@@ -2,10 +2,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/lt-ref-self-async.rs:13:9
    |
 LL |     async fn ref_self(&self, f: &u32) -> &u32 {
-   |                       -----              ----
-   |                       |                  |
-   |                       |                  this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                       this parameter and the returned future are declared with different lifetimes...
+   |                                 ----     ----
+   |                                 |        |
+   |                                 |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                 this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -13,10 +13,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/lt-ref-self-async.rs:19:9
    |
 LL |     async fn ref_Self(self: &Self, f: &u32) -> &u32 {
-   |                             -----              ----
-   |                             |                  |
-   |                             |                  this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                             this parameter and the returned future are declared with different lifetimes...
+   |                                       ----     ----
+   |                                       |        |
+   |                                       |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                       this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -24,10 +24,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/lt-ref-self-async.rs:23:9
    |
 LL |     async fn box_ref_Self(self: Box<&Self>, f: &u32) -> &u32 {
-   |                                     -----               ----
-   |                                     |                   |
-   |                                     |                   this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                     this parameter and the returned future are declared with different lifetimes...
+   |                                                ----     ----
+   |                                                |        |
+   |                                                |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                                this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -35,10 +35,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/lt-ref-self-async.rs:27:9
    |
 LL |     async fn pin_ref_Self(self: Pin<&Self>, f: &u32) -> &u32 {
-   |                                     -----               ----
-   |                                     |                   |
-   |                                     |                   this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                     this parameter and the returned future are declared with different lifetimes...
+   |                                                ----     ----
+   |                                                |        |
+   |                                                |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                                this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -46,10 +46,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/lt-ref-self-async.rs:31:9
    |
 LL |     async fn box_box_ref_Self(self: Box<Box<&Self>>, f: &u32) -> &u32 {
-   |                                             -----                ----
-   |                                             |                    |
-   |                                             |                    this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                             this parameter and the returned future are declared with different lifetimes...
+   |                                                         ----     ----
+   |                                                         |        |
+   |                                                         |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                                         this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -57,10 +57,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/lt-ref-self-async.rs:35:9
    |
 LL |     async fn box_pin_Self(self: Box<Pin<&Self>>, f: &u32) -> &u32 {
-   |                                         -----                ----
-   |                                         |                    |
-   |                                         |                    this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                         this parameter and the returned future are declared with different lifetimes...
+   |                                                     ----     ----
+   |                                                     |        |
+   |                                                     |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                                     this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
diff --git a/src/test/ui/self/elision/ref-mut-self-async.stderr b/src/test/ui/self/elision/ref-mut-self-async.stderr
index b6ca986923d..c4f7b7eb625 100644
--- a/src/test/ui/self/elision/ref-mut-self-async.stderr
+++ b/src/test/ui/self/elision/ref-mut-self-async.stderr
@@ -2,10 +2,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-mut-self-async.rs:13:9
    |
 LL |     async fn ref_self(&mut self, f: &u32) -> &u32 {
-   |                       ---------              ----
-   |                       |                      |
-   |                       |                      this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                       this parameter and the returned future are declared with different lifetimes...
+   |                                     ----     ----
+   |                                     |        |
+   |                                     |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                     this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -13,10 +13,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-mut-self-async.rs:19:9
    |
 LL |     async fn ref_Self(self: &mut Self, f: &u32) -> &u32 {
-   |                             ---------              ----
-   |                             |                      |
-   |                             |                      this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                             this parameter and the returned future are declared with different lifetimes...
+   |                                           ----     ----
+   |                                           |        |
+   |                                           |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                           this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -24,10 +24,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-mut-self-async.rs:23:9
    |
 LL |     async fn box_ref_Self(self: Box<&mut Self>, f: &u32) -> &u32 {
-   |                                     ---------               ----
-   |                                     |                       |
-   |                                     |                       this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                     this parameter and the returned future are declared with different lifetimes...
+   |                                                    ----     ----
+   |                                                    |        |
+   |                                                    |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                                    this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -35,10 +35,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-mut-self-async.rs:27:9
    |
 LL |     async fn pin_ref_Self(self: Pin<&mut Self>, f: &u32) -> &u32 {
-   |                                     ---------               ----
-   |                                     |                       |
-   |                                     |                       this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                     this parameter and the returned future are declared with different lifetimes...
+   |                                                    ----     ----
+   |                                                    |        |
+   |                                                    |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                                    this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -46,10 +46,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-mut-self-async.rs:31:9
    |
 LL |     async fn box_box_ref_Self(self: Box<Box<&mut Self>>, f: &u32) -> &u32 {
-   |                                             ---------                ----
-   |                                             |                        |
-   |                                             |                        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                             this parameter and the returned future are declared with different lifetimes...
+   |                                                             ----     ----
+   |                                                             |        |
+   |                                                             |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                                             this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -57,10 +57,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-mut-self-async.rs:35:9
    |
 LL |     async fn box_pin_ref_Self(self: Box<Pin<&mut Self>>, f: &u32) -> &u32 {
-   |                                             ---------                ----
-   |                                             |                        |
-   |                                             |                        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                             this parameter and the returned future are declared with different lifetimes...
+   |                                                             ----     ----
+   |                                                             |        |
+   |                                                             |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                                             this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
diff --git a/src/test/ui/self/elision/ref-mut-struct-async.stderr b/src/test/ui/self/elision/ref-mut-struct-async.stderr
index eda15d76390..6c5edcb2b36 100644
--- a/src/test/ui/self/elision/ref-mut-struct-async.stderr
+++ b/src/test/ui/self/elision/ref-mut-struct-async.stderr
@@ -2,10 +2,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-mut-struct-async.rs:13:9
    |
 LL |     async fn ref_Struct(self: &mut Struct, f: &u32) -> &u32 {
-   |                               -----------              ----
-   |                               |                        |
-   |                               |                        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                               this parameter and the returned future are declared with different lifetimes...
+   |                                               ----     ----
+   |                                               |        |
+   |                                               |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                               this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -13,10 +13,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-mut-struct-async.rs:17:9
    |
 LL |     async fn box_ref_Struct(self: Box<&mut Struct>, f: &u32) -> &u32 {
-   |                                       -----------               ----
-   |                                       |                         |
-   |                                       |                         this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                       this parameter and the returned future are declared with different lifetimes...
+   |                                                        ----     ----
+   |                                                        |        |
+   |                                                        |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                                        this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -24,10 +24,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-mut-struct-async.rs:21:9
    |
 LL |     async fn pin_ref_Struct(self: Pin<&mut Struct>, f: &u32) -> &u32 {
-   |                                       -----------               ----
-   |                                       |                         |
-   |                                       |                         this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                       this parameter and the returned future are declared with different lifetimes...
+   |                                                        ----     ----
+   |                                                        |        |
+   |                                                        |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                                        this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -35,10 +35,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-mut-struct-async.rs:25:9
    |
 LL |     async fn box_box_ref_Struct(self: Box<Box<&mut Struct>>, f: &u32) -> &u32 {
-   |                                               -----------                ----
-   |                                               |                          |
-   |                                               |                          this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                               this parameter and the returned future are declared with different lifetimes...
+   |                                                                 ----     ----
+   |                                                                 |        |
+   |                                                                 |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                                                 this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -46,10 +46,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-mut-struct-async.rs:29:9
    |
 LL |     async fn box_pin_ref_Struct(self: Box<Pin<&mut Struct>>, f: &u32) -> &u32 {
-   |                                               -----------                ----
-   |                                               |                          |
-   |                                               |                          this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                               this parameter and the returned future are declared with different lifetimes...
+   |                                                                 ----     ----
+   |                                                                 |        |
+   |                                                                 |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                                                 this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
diff --git a/src/test/ui/self/elision/ref-self-async.stderr b/src/test/ui/self/elision/ref-self-async.stderr
index b42caa88c6f..fef346b4d2a 100644
--- a/src/test/ui/self/elision/ref-self-async.stderr
+++ b/src/test/ui/self/elision/ref-self-async.stderr
@@ -2,10 +2,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-self-async.rs:23:9
    |
 LL |     async fn ref_self(&self, f: &u32) -> &u32 {
-   |                       -----              ----
-   |                       |                  |
-   |                       |                  this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                       this parameter and the returned future are declared with different lifetimes...
+   |                                 ----     ----
+   |                                 |        |
+   |                                 |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                 this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -13,10 +13,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-self-async.rs:29:9
    |
 LL |     async fn ref_Self(self: &Self, f: &u32) -> &u32 {
-   |                             -----              ----
-   |                             |                  |
-   |                             |                  this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                             this parameter and the returned future are declared with different lifetimes...
+   |                                       ----     ----
+   |                                       |        |
+   |                                       |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                       this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -24,10 +24,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-self-async.rs:33:9
    |
 LL |     async fn box_ref_Self(self: Box<&Self>, f: &u32) -> &u32 {
-   |                                     -----               ----
-   |                                     |                   |
-   |                                     |                   this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                     this parameter and the returned future are declared with different lifetimes...
+   |                                                ----     ----
+   |                                                |        |
+   |                                                |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                                this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -35,10 +35,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-self-async.rs:37:9
    |
 LL |     async fn pin_ref_Self(self: Pin<&Self>, f: &u32) -> &u32 {
-   |                                     -----               ----
-   |                                     |                   |
-   |                                     |                   this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                     this parameter and the returned future are declared with different lifetimes...
+   |                                                ----     ----
+   |                                                |        |
+   |                                                |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                                this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -46,10 +46,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-self-async.rs:41:9
    |
 LL |     async fn box_box_ref_Self(self: Box<Box<&Self>>, f: &u32) -> &u32 {
-   |                                             -----                ----
-   |                                             |                    |
-   |                                             |                    this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                             this parameter and the returned future are declared with different lifetimes...
+   |                                                         ----     ----
+   |                                                         |        |
+   |                                                         |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                                         this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -57,10 +57,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-self-async.rs:45:9
    |
 LL |     async fn box_pin_ref_Self(self: Box<Pin<&Self>>, f: &u32) -> &u32 {
-   |                                             -----                ----
-   |                                             |                    |
-   |                                             |                    this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                             this parameter and the returned future are declared with different lifetimes...
+   |                                                         ----     ----
+   |                                                         |        |
+   |                                                         |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                                         this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -68,10 +68,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-self-async.rs:49:9
    |
 LL |     async fn wrap_ref_Self_Self(self: Wrap<&Self, Self>, f: &u8) -> &u8 {
-   |                                            -----                    ---
-   |                                            |                        |
-   |                                            |                        this `async fn` implicitly returns an `impl Future<Output = &u8>`
-   |                                            this parameter and the returned future are declared with different lifetimes...
+   |                                                             ---     ---
+   |                                                             |       |
+   |                                                             |       this `async fn` implicitly returns an `impl Future<Output = &u8>`
+   |                                                             this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
diff --git a/src/test/ui/self/elision/ref-struct-async.stderr b/src/test/ui/self/elision/ref-struct-async.stderr
index 599becd3080..cc269c0e7aa 100644
--- a/src/test/ui/self/elision/ref-struct-async.stderr
+++ b/src/test/ui/self/elision/ref-struct-async.stderr
@@ -2,10 +2,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-struct-async.rs:13:9
    |
 LL |     async fn ref_Struct(self: &Struct, f: &u32) -> &u32 {
-   |                               -------              ----
-   |                               |                    |
-   |                               |                    this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                               this parameter and the returned future are declared with different lifetimes...
+   |                                           ----     ----
+   |                                           |        |
+   |                                           |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                           this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -13,10 +13,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-struct-async.rs:17:9
    |
 LL |     async fn box_ref_Struct(self: Box<&Struct>, f: &u32) -> &u32 {
-   |                                       -------               ----
-   |                                       |                     |
-   |                                       |                     this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                       this parameter and the returned future are declared with different lifetimes...
+   |                                                    ----     ----
+   |                                                    |        |
+   |                                                    |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                                    this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -24,10 +24,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-struct-async.rs:21:9
    |
 LL |     async fn pin_ref_Struct(self: Pin<&Struct>, f: &u32) -> &u32 {
-   |                                       -------               ----
-   |                                       |                     |
-   |                                       |                     this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                       this parameter and the returned future are declared with different lifetimes...
+   |                                                    ----     ----
+   |                                                    |        |
+   |                                                    |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                                    this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -35,10 +35,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-struct-async.rs:25:9
    |
 LL |     async fn box_box_ref_Struct(self: Box<Box<&Struct>>, f: &u32) -> &u32 {
-   |                                               -------                ----
-   |                                               |                      |
-   |                                               |                      this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                               this parameter and the returned future are declared with different lifetimes...
+   |                                                             ----     ----
+   |                                                             |        |
+   |                                                             |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                                             this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
@@ -46,10 +46,10 @@ error[E0623]: lifetime mismatch
   --> $DIR/ref-struct-async.rs:29:9
    |
 LL |     async fn box_pin_Struct(self: Box<Pin<&Struct>>, f: &u32) -> &u32 {
-   |                                           -------                ----
-   |                                           |                      |
-   |                                           |                      this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                           this parameter and the returned future are declared with different lifetimes...
+   |                                                         ----     ----
+   |                                                         |        |
+   |                                                         |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
+   |                                                         this parameter and the returned future are declared with different lifetimes...
 LL |         f
    |         ^ ...but data from `f` is held across an await point here
 
-- 
cgit 1.4.1-3-g733a5


From 698631e16c390c29bacc778e35aba1dc27bed57f Mon Sep 17 00:00:00 2001
From: Tyler Mandry <tmandry@gmail.com>
Date: Fri, 10 Dec 2021 00:01:05 +0000
Subject: Simplify error reporting code, remove await point wording

---
 .../nice_region_error/different_lifetimes.rs       | 110 +++++++--------------
 .../error_reporting/nice_region_error/util.rs      |  54 ----------
 .../ui/async-await/issues/issue-63388-1.stderr     |   6 +-
 .../multiple-lifetimes/ret-impl-trait-one.stderr   |   5 +-
 ...y_self_types_pin_lifetime_mismatch-async.stderr |  21 ++--
 src/test/ui/self/elision/lt-ref-self-async.stderr  |  42 ++++----
 src/test/ui/self/elision/ref-mut-self-async.stderr |  42 ++++----
 .../ui/self/elision/ref-mut-struct-async.stderr    |  35 +++----
 src/test/ui/self/elision/ref-self-async.stderr     |  49 ++++-----
 src/test/ui/self/elision/ref-struct-async.stderr   |  35 +++----
 10 files changed, 133 insertions(+), 266 deletions(-)

(limited to 'src')

diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/different_lifetimes.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/different_lifetimes.rs
index 5d33d2b4f9b..4eec492b3ae 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/different_lifetimes.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/different_lifetimes.rs
@@ -106,91 +106,47 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
             None => String::new(),
         };
 
-        let (span_1, span_2, main_label, span_label, future_return_type) =
-            match (sup_is_ret_type, sub_is_ret_type) {
-                (None, None) => {
-                    let (main_label_1, span_label_1) = if ty_sup.hir_id == ty_sub.hir_id {
-                        (
-                            "this type is declared with multiple lifetimes...".to_owned(),
-                            "...but data with one lifetime flows into the other here".to_owned(),
-                        )
-                    } else {
-                        (
-                            "these two types are declared with different lifetimes...".to_owned(),
-                            format!("...but data{} flows{} here", span_label_var1, span_label_var2),
-                        )
-                    };
-                    (ty_sup.span, ty_sub.span, main_label_1, span_label_1, None)
-                }
+        debug!(
+            "try_report_anon_anon_conflict: sub_is_ret_type={:?} sup_is_ret_type={:?}",
+            sub_is_ret_type, sup_is_ret_type
+        );
 
-                (Some(ret_span), _) => {
-                    let sup_future = self.future_return_type(scope_def_id_sup);
-                    let (return_type, action) = if sup_future.is_some() {
-                        ("returned future", "held across an await point")
-                    } else {
-                        ("return type", "returned")
-                    };
+        let mut err = struct_span_err!(self.tcx().sess, span, E0623, "lifetime mismatch");
 
-                    (
-                        ty_sub.span,
-                        ret_span,
-                        format!(
-                            "this parameter and the {} are declared with different lifetimes...",
-                            return_type
-                        ),
-                        format!("...but data{} is {} here", span_label_var1, action),
-                        sup_future,
-                    )
-                }
-                (_, Some(ret_span)) => {
-                    let sub_future = self.future_return_type(scope_def_id_sub);
-                    let (return_type, action) = if sub_future.is_some() {
-                        ("returned future", "held across an await point")
-                    } else {
-                        ("return type", "returned")
-                    };
+        match (sup_is_ret_type, sub_is_ret_type) {
+            (ret_capture @ Some(ret_span), _) | (_, ret_capture @ Some(ret_span)) => {
+                let param_span =
+                    if sup_is_ret_type == ret_capture { ty_sub.span } else { ty_sup.span };
+
+                err.span_label(
+                    param_span,
+                    "this parameter and the return type are declared with different lifetimes...",
+                );
+                err.span_label(ret_span, "");
+                err.span_label(span, format!("...but data{} is returned here", span_label_var1));
+            }
 
-                    (
+            (None, None) => {
+                if ty_sup.hir_id == ty_sub.hir_id {
+                    err.span_label(ty_sup.span, "this type is declared with multiple lifetimes...");
+                    err.span_label(ty_sub.span, "");
+                    err.span_label(span, "...but data with one lifetime flows into the other here");
+                } else {
+                    err.span_label(
                         ty_sup.span,
-                        ret_span,
-                        format!(
-                            "this parameter and the {} are declared with different lifetimes...",
-                            return_type
-                        ),
-                        format!("...but data{} is {} here", span_label_var1, action),
-                        sub_future,
-                    )
+                        "these two types are declared with different lifetimes...",
+                    );
+                    err.span_label(ty_sub.span, "");
+                    err.span_label(
+                        span,
+                        format!("...but data{} flows{} here", span_label_var1, span_label_var2),
+                    );
                 }
-            };
-
-        let mut err = struct_span_err!(self.tcx().sess, span, E0623, "lifetime mismatch");
-
-        err.span_label(span_1, main_label);
-        err.span_label(span_2, String::new());
-        err.span_label(span, span_label);
+            }
+        }
 
         self.suggest_adding_lifetime_params(sub, ty_sup, ty_sub, &mut err);
 
-        // TODO: This is only helpful if the lifetime more visible in the impl Future type than in the signature.
-        if let Some(t) = future_return_type {
-            let snip = self
-                .tcx()
-                .sess
-                .source_map()
-                .span_to_snippet(t.span)
-                .ok()
-                .and_then(|s| match (&t.kind, s.as_str()) {
-                    (rustc_hir::TyKind::Tup(&[]), "") => Some("()".to_string()),
-                    (_, "") => None,
-                    _ => Some(s),
-                })
-                .unwrap_or_else(|| "{unnamed_type}".to_string());
-
-            err.span_label(
-                t.span,
-                &format!("this `async fn` implicitly returns an `impl Future<Output = {}>`", snip),
-            );
-        }
         err.emit();
         Some(ErrorReported)
     }
diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs
index 3e87f97f496..6d71d702cc8 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs
@@ -94,60 +94,6 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
             })
     }
 
-    pub(super) fn future_return_type(
-        &self,
-        local_def_id: LocalDefId,
-    ) -> Option<&rustc_hir::Ty<'_>> {
-        if let Some(hir::IsAsync::Async) = self.asyncness(local_def_id) {
-            if let rustc_middle::ty::Opaque(def_id, _) =
-                self.tcx().type_of(local_def_id).fn_sig(self.tcx()).output().skip_binder().kind()
-            {
-                match self.tcx().hir().get_if_local(*def_id) {
-                    Some(hir::Node::Item(hir::Item {
-                        kind:
-                            hir::ItemKind::OpaqueTy(hir::OpaqueTy {
-                                bounds,
-                                origin: hir::OpaqueTyOrigin::AsyncFn(..),
-                                ..
-                            }),
-                        ..
-                    })) => {
-                        for b in bounds.iter() {
-                            if let hir::GenericBound::LangItemTrait(
-                                hir::LangItem::Future,
-                                _span,
-                                _hir_id,
-                                generic_args,
-                            ) = b
-                            {
-                                for type_binding in generic_args.bindings.iter() {
-                                    if type_binding.ident.name == rustc_span::sym::Output {
-                                        if let hir::TypeBindingKind::Equality {
-                                            term: hir::Term::Ty(ty),
-                                        } = type_binding.kind
-                                        {
-                                            return Some(ty);
-                                        }
-                                    }
-                                }
-                            }
-                        }
-                    }
-                    _ => {}
-                }
-            }
-        }
-        None
-    }
-
-    pub(super) fn asyncness(&self, local_def_id: LocalDefId) -> Option<hir::IsAsync> {
-        // similar to the asyncness fn in rustc_ty_utils::ty
-        let hir_id = self.tcx().hir().local_def_id_to_hir_id(local_def_id);
-        let node = self.tcx().hir().get(hir_id);
-        let fn_kind = node.fn_kind()?;
-        Some(fn_kind.asyncness())
-    }
-
     // Here, we check for the case where the anonymous region
     // is in the return type as written by the user.
     // FIXME(#42703) - Need to handle certain cases here.
diff --git a/src/test/ui/async-await/issues/issue-63388-1.stderr b/src/test/ui/async-await/issues/issue-63388-1.stderr
index 32ca7afd82d..8f602a1492a 100644
--- a/src/test/ui/async-await/issues/issue-63388-1.stderr
+++ b/src/test/ui/async-await/issues/issue-63388-1.stderr
@@ -2,14 +2,12 @@ error[E0623]: lifetime mismatch
   --> $DIR/issue-63388-1.rs:14:9
    |
 LL |         &'a self, foo: &dyn Foo
-   |                        -------- this parameter and the returned future are declared with different lifetimes...
+   |                        -------- this parameter and the return type are declared with different lifetimes...
 LL |     ) -> &dyn Foo
    |          --------
-   |          |
-   |          this `async fn` implicitly returns an `impl Future<Output = &dyn Foo>`
 LL |     {
 LL |         foo
-   |         ^^^ ...but data from `foo` is held across an await point here
+   |         ^^^ ...but data from `foo` is returned here
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/async-await/multiple-lifetimes/ret-impl-trait-one.stderr b/src/test/ui/async-await/multiple-lifetimes/ret-impl-trait-one.stderr
index 464f283095d..149692a2c69 100644
--- a/src/test/ui/async-await/multiple-lifetimes/ret-impl-trait-one.stderr
+++ b/src/test/ui/async-await/multiple-lifetimes/ret-impl-trait-one.stderr
@@ -4,9 +4,8 @@ error[E0623]: lifetime mismatch
 LL | async fn async_ret_impl_trait3<'a, 'b>(a: &'a u8, b: &'b u8) -> impl Trait<'a> + 'b {
    |                                                      ------     ^^^^^^^^^^^^^^^^^^^
    |                                                      |          |
-   |                                                      |          ...but data from `a` is held across an await point here
-   |                                                      |          this `async fn` implicitly returns an `impl Future<Output = impl Trait<'a> + 'b>`
-   |                                                      this parameter and the returned future are declared with different lifetimes...
+   |                                                      |          ...but data from `a` is returned here
+   |                                                      this parameter and the return type are declared with different lifetimes...
 
 error[E0700]: hidden type for `impl Trait` captures lifetime that does not appear in bounds
   --> $DIR/ret-impl-trait-one.rs:16:65
diff --git a/src/test/ui/self/arbitrary_self_types_pin_lifetime_mismatch-async.stderr b/src/test/ui/self/arbitrary_self_types_pin_lifetime_mismatch-async.stderr
index 6986cd1a5fd..299a2d2f2d3 100644
--- a/src/test/ui/self/arbitrary_self_types_pin_lifetime_mismatch-async.stderr
+++ b/src/test/ui/self/arbitrary_self_types_pin_lifetime_mismatch-async.stderr
@@ -2,28 +2,25 @@ error[E0623]: lifetime mismatch
   --> $DIR/arbitrary_self_types_pin_lifetime_mismatch-async.rs:8:52
    |
 LL |     async fn a(self: Pin<&Foo>, f: &Foo) -> &Foo { f }
-   |                                    ----     ----   ^ ...but data from `f` is held across an await point here
-   |                                    |        |
-   |                                    |        this `async fn` implicitly returns an `impl Future<Output = &Foo>`
-   |                                    this parameter and the returned future are declared with different lifetimes...
+   |                                    ----     ----   ^ ...but data from `f` is returned here
+   |                                    |
+   |                                    this parameter and the return type are declared with different lifetimes...
 
 error[E0623]: lifetime mismatch
   --> $DIR/arbitrary_self_types_pin_lifetime_mismatch-async.rs:11:82
    |
 LL |     async fn c(self: Pin<&Self>, f: &Foo, g: &Foo) -> (Pin<&Foo>, &Foo) { (self, f) }
-   |                                     ----              -----------------          ^ ...but data from `f` is held across an await point here
-   |                                     |                 |
-   |                                     |                 this `async fn` implicitly returns an `impl Future<Output = (Pin<&Foo>, &Foo)>`
-   |                                     this parameter and the returned future are declared with different lifetimes...
+   |                                     ----              -----------------          ^ ...but data from `f` is returned here
+   |                                     |
+   |                                     this parameter and the return type are declared with different lifetimes...
 
 error[E0623]: lifetime mismatch
   --> $DIR/arbitrary_self_types_pin_lifetime_mismatch-async.rs:17:64
    |
 LL |     async fn bar<'a>(self: Alias<&Self>, arg: &'a ()) -> &() { arg }
-   |                                               ------     ---   ^^^ ...but data from `arg` is held across an await point here
-   |                                               |          |
-   |                                               |          this `async fn` implicitly returns an `impl Future<Output = &()>`
-   |                                               this parameter and the returned future are declared with different lifetimes...
+   |                                               ------     ---   ^^^ ...but data from `arg` is returned here
+   |                                               |
+   |                                               this parameter and the return type are declared with different lifetimes...
 
 error: aborting due to 3 previous errors
 
diff --git a/src/test/ui/self/elision/lt-ref-self-async.stderr b/src/test/ui/self/elision/lt-ref-self-async.stderr
index d65a6ade037..7448e8484b4 100644
--- a/src/test/ui/self/elision/lt-ref-self-async.stderr
+++ b/src/test/ui/self/elision/lt-ref-self-async.stderr
@@ -3,66 +3,60 @@ error[E0623]: lifetime mismatch
    |
 LL |     async fn ref_self(&self, f: &u32) -> &u32 {
    |                                 ----     ----
-   |                                 |        |
-   |                                 |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                 this parameter and the returned future are declared with different lifetimes...
+   |                                 |
+   |                                 this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/lt-ref-self-async.rs:19:9
    |
 LL |     async fn ref_Self(self: &Self, f: &u32) -> &u32 {
    |                                       ----     ----
-   |                                       |        |
-   |                                       |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                       this parameter and the returned future are declared with different lifetimes...
+   |                                       |
+   |                                       this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/lt-ref-self-async.rs:23:9
    |
 LL |     async fn box_ref_Self(self: Box<&Self>, f: &u32) -> &u32 {
    |                                                ----     ----
-   |                                                |        |
-   |                                                |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                                this parameter and the returned future are declared with different lifetimes...
+   |                                                |
+   |                                                this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/lt-ref-self-async.rs:27:9
    |
 LL |     async fn pin_ref_Self(self: Pin<&Self>, f: &u32) -> &u32 {
    |                                                ----     ----
-   |                                                |        |
-   |                                                |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                                this parameter and the returned future are declared with different lifetimes...
+   |                                                |
+   |                                                this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/lt-ref-self-async.rs:31:9
    |
 LL |     async fn box_box_ref_Self(self: Box<Box<&Self>>, f: &u32) -> &u32 {
    |                                                         ----     ----
-   |                                                         |        |
-   |                                                         |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                                         this parameter and the returned future are declared with different lifetimes...
+   |                                                         |
+   |                                                         this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/lt-ref-self-async.rs:35:9
    |
 LL |     async fn box_pin_Self(self: Box<Pin<&Self>>, f: &u32) -> &u32 {
    |                                                     ----     ----
-   |                                                     |        |
-   |                                                     |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                                     this parameter and the returned future are declared with different lifetimes...
+   |                                                     |
+   |                                                     this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error: aborting due to 6 previous errors
 
diff --git a/src/test/ui/self/elision/ref-mut-self-async.stderr b/src/test/ui/self/elision/ref-mut-self-async.stderr
index c4f7b7eb625..6056cc46d3d 100644
--- a/src/test/ui/self/elision/ref-mut-self-async.stderr
+++ b/src/test/ui/self/elision/ref-mut-self-async.stderr
@@ -3,66 +3,60 @@ error[E0623]: lifetime mismatch
    |
 LL |     async fn ref_self(&mut self, f: &u32) -> &u32 {
    |                                     ----     ----
-   |                                     |        |
-   |                                     |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                     this parameter and the returned future are declared with different lifetimes...
+   |                                     |
+   |                                     this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/ref-mut-self-async.rs:19:9
    |
 LL |     async fn ref_Self(self: &mut Self, f: &u32) -> &u32 {
    |                                           ----     ----
-   |                                           |        |
-   |                                           |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                           this parameter and the returned future are declared with different lifetimes...
+   |                                           |
+   |                                           this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/ref-mut-self-async.rs:23:9
    |
 LL |     async fn box_ref_Self(self: Box<&mut Self>, f: &u32) -> &u32 {
    |                                                    ----     ----
-   |                                                    |        |
-   |                                                    |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                                    this parameter and the returned future are declared with different lifetimes...
+   |                                                    |
+   |                                                    this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/ref-mut-self-async.rs:27:9
    |
 LL |     async fn pin_ref_Self(self: Pin<&mut Self>, f: &u32) -> &u32 {
    |                                                    ----     ----
-   |                                                    |        |
-   |                                                    |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                                    this parameter and the returned future are declared with different lifetimes...
+   |                                                    |
+   |                                                    this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/ref-mut-self-async.rs:31:9
    |
 LL |     async fn box_box_ref_Self(self: Box<Box<&mut Self>>, f: &u32) -> &u32 {
    |                                                             ----     ----
-   |                                                             |        |
-   |                                                             |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                                             this parameter and the returned future are declared with different lifetimes...
+   |                                                             |
+   |                                                             this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/ref-mut-self-async.rs:35:9
    |
 LL |     async fn box_pin_ref_Self(self: Box<Pin<&mut Self>>, f: &u32) -> &u32 {
    |                                                             ----     ----
-   |                                                             |        |
-   |                                                             |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                                             this parameter and the returned future are declared with different lifetimes...
+   |                                                             |
+   |                                                             this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error: aborting due to 6 previous errors
 
diff --git a/src/test/ui/self/elision/ref-mut-struct-async.stderr b/src/test/ui/self/elision/ref-mut-struct-async.stderr
index 6c5edcb2b36..61034ae4d47 100644
--- a/src/test/ui/self/elision/ref-mut-struct-async.stderr
+++ b/src/test/ui/self/elision/ref-mut-struct-async.stderr
@@ -3,55 +3,50 @@ error[E0623]: lifetime mismatch
    |
 LL |     async fn ref_Struct(self: &mut Struct, f: &u32) -> &u32 {
    |                                               ----     ----
-   |                                               |        |
-   |                                               |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                               this parameter and the returned future are declared with different lifetimes...
+   |                                               |
+   |                                               this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/ref-mut-struct-async.rs:17:9
    |
 LL |     async fn box_ref_Struct(self: Box<&mut Struct>, f: &u32) -> &u32 {
    |                                                        ----     ----
-   |                                                        |        |
-   |                                                        |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                                        this parameter and the returned future are declared with different lifetimes...
+   |                                                        |
+   |                                                        this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/ref-mut-struct-async.rs:21:9
    |
 LL |     async fn pin_ref_Struct(self: Pin<&mut Struct>, f: &u32) -> &u32 {
    |                                                        ----     ----
-   |                                                        |        |
-   |                                                        |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                                        this parameter and the returned future are declared with different lifetimes...
+   |                                                        |
+   |                                                        this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/ref-mut-struct-async.rs:25:9
    |
 LL |     async fn box_box_ref_Struct(self: Box<Box<&mut Struct>>, f: &u32) -> &u32 {
    |                                                                 ----     ----
-   |                                                                 |        |
-   |                                                                 |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                                                 this parameter and the returned future are declared with different lifetimes...
+   |                                                                 |
+   |                                                                 this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/ref-mut-struct-async.rs:29:9
    |
 LL |     async fn box_pin_ref_Struct(self: Box<Pin<&mut Struct>>, f: &u32) -> &u32 {
    |                                                                 ----     ----
-   |                                                                 |        |
-   |                                                                 |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                                                 this parameter and the returned future are declared with different lifetimes...
+   |                                                                 |
+   |                                                                 this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error: aborting due to 5 previous errors
 
diff --git a/src/test/ui/self/elision/ref-self-async.stderr b/src/test/ui/self/elision/ref-self-async.stderr
index fef346b4d2a..0eab16e685d 100644
--- a/src/test/ui/self/elision/ref-self-async.stderr
+++ b/src/test/ui/self/elision/ref-self-async.stderr
@@ -3,77 +3,70 @@ error[E0623]: lifetime mismatch
    |
 LL |     async fn ref_self(&self, f: &u32) -> &u32 {
    |                                 ----     ----
-   |                                 |        |
-   |                                 |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                 this parameter and the returned future are declared with different lifetimes...
+   |                                 |
+   |                                 this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/ref-self-async.rs:29:9
    |
 LL |     async fn ref_Self(self: &Self, f: &u32) -> &u32 {
    |                                       ----     ----
-   |                                       |        |
-   |                                       |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                       this parameter and the returned future are declared with different lifetimes...
+   |                                       |
+   |                                       this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/ref-self-async.rs:33:9
    |
 LL |     async fn box_ref_Self(self: Box<&Self>, f: &u32) -> &u32 {
    |                                                ----     ----
-   |                                                |        |
-   |                                                |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                                this parameter and the returned future are declared with different lifetimes...
+   |                                                |
+   |                                                this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/ref-self-async.rs:37:9
    |
 LL |     async fn pin_ref_Self(self: Pin<&Self>, f: &u32) -> &u32 {
    |                                                ----     ----
-   |                                                |        |
-   |                                                |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                                this parameter and the returned future are declared with different lifetimes...
+   |                                                |
+   |                                                this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/ref-self-async.rs:41:9
    |
 LL |     async fn box_box_ref_Self(self: Box<Box<&Self>>, f: &u32) -> &u32 {
    |                                                         ----     ----
-   |                                                         |        |
-   |                                                         |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                                         this parameter and the returned future are declared with different lifetimes...
+   |                                                         |
+   |                                                         this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/ref-self-async.rs:45:9
    |
 LL |     async fn box_pin_ref_Self(self: Box<Pin<&Self>>, f: &u32) -> &u32 {
    |                                                         ----     ----
-   |                                                         |        |
-   |                                                         |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                                         this parameter and the returned future are declared with different lifetimes...
+   |                                                         |
+   |                                                         this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/ref-self-async.rs:49:9
    |
 LL |     async fn wrap_ref_Self_Self(self: Wrap<&Self, Self>, f: &u8) -> &u8 {
    |                                                             ---     ---
-   |                                                             |       |
-   |                                                             |       this `async fn` implicitly returns an `impl Future<Output = &u8>`
-   |                                                             this parameter and the returned future are declared with different lifetimes...
+   |                                                             |
+   |                                                             this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error: aborting due to 7 previous errors
 
diff --git a/src/test/ui/self/elision/ref-struct-async.stderr b/src/test/ui/self/elision/ref-struct-async.stderr
index cc269c0e7aa..aa1d7453e83 100644
--- a/src/test/ui/self/elision/ref-struct-async.stderr
+++ b/src/test/ui/self/elision/ref-struct-async.stderr
@@ -3,55 +3,50 @@ error[E0623]: lifetime mismatch
    |
 LL |     async fn ref_Struct(self: &Struct, f: &u32) -> &u32 {
    |                                           ----     ----
-   |                                           |        |
-   |                                           |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                           this parameter and the returned future are declared with different lifetimes...
+   |                                           |
+   |                                           this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/ref-struct-async.rs:17:9
    |
 LL |     async fn box_ref_Struct(self: Box<&Struct>, f: &u32) -> &u32 {
    |                                                    ----     ----
-   |                                                    |        |
-   |                                                    |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                                    this parameter and the returned future are declared with different lifetimes...
+   |                                                    |
+   |                                                    this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/ref-struct-async.rs:21:9
    |
 LL |     async fn pin_ref_Struct(self: Pin<&Struct>, f: &u32) -> &u32 {
    |                                                    ----     ----
-   |                                                    |        |
-   |                                                    |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                                    this parameter and the returned future are declared with different lifetimes...
+   |                                                    |
+   |                                                    this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/ref-struct-async.rs:25:9
    |
 LL |     async fn box_box_ref_Struct(self: Box<Box<&Struct>>, f: &u32) -> &u32 {
    |                                                             ----     ----
-   |                                                             |        |
-   |                                                             |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                                             this parameter and the returned future are declared with different lifetimes...
+   |                                                             |
+   |                                                             this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
   --> $DIR/ref-struct-async.rs:29:9
    |
 LL |     async fn box_pin_Struct(self: Box<Pin<&Struct>>, f: &u32) -> &u32 {
    |                                                         ----     ----
-   |                                                         |        |
-   |                                                         |        this `async fn` implicitly returns an `impl Future<Output = &u32>`
-   |                                                         this parameter and the returned future are declared with different lifetimes...
+   |                                                         |
+   |                                                         this parameter and the return type are declared with different lifetimes...
 LL |         f
-   |         ^ ...but data from `f` is held across an await point here
+   |         ^ ...but data from `f` is returned here
 
 error: aborting due to 5 previous errors
 
-- 
cgit 1.4.1-3-g733a5


From 152e8889052adaaa6c12652486292be34059713c Mon Sep 17 00:00:00 2001
From: Jacob Hoffman-Andrews <github@hoffman-andrews.com>
Date: Thu, 13 Jan 2022 09:54:44 -0800
Subject: Rustdoc mobile: put out-of-band on its own line

Before this, the item name and the stability, source link, and "collapse
all docs" would compete for room on a single line, resulting in awkward
wrapping behavior on mobile. This gives a separate line for that
out-of-band information. It also removes the "copy path" icon on mobile
to make a little more room.

Also, switch to flex-wrap: wrap, so anytime there's not enough room for
`source`, it gets bumped to the next line.
---
 src/librustdoc/html/static/css/rustdoc.css   | 29 +++++++++++++++++++---------
 src/test/rustdoc-gui/mobile.goml             | 17 ++++++++++++++++
 src/test/rustdoc-gui/toggle-docs-mobile.goml | 12 ++++++------
 3 files changed, 43 insertions(+), 15 deletions(-)
 create mode 100644 src/test/rustdoc-gui/mobile.goml

(limited to 'src')

diff --git a/src/librustdoc/html/static/css/rustdoc.css b/src/librustdoc/html/static/css/rustdoc.css
index 44a9a571fa1..d0244351b59 100644
--- a/src/librustdoc/html/static/css/rustdoc.css
+++ b/src/librustdoc/html/static/css/rustdoc.css
@@ -148,11 +148,11 @@ h1.fqn {
 }
 .main-heading {
 	display: flex;
+	flex-wrap: wrap;
+	justify-content: space-between;
+	border-bottom: 1px dashed #DDDDDD;
+	padding-bottom: 6px;
 	margin-bottom: 15px;
-
-	/* workaround to keep flex from breaking below 700 px width due to the float: right on the nav
-	   above the h1 */
-	padding-left: 1px;
 }
 .main-heading a:hover {
 	text-decoration: underline;
@@ -623,11 +623,7 @@ nav.sub {
 
 .content .out-of-band {
 	flex-grow: 0;
-	text-align: right;
-	margin-left: auto;
-	margin-right: 0;
 	font-size: 1.15rem;
-	padding: 0 0 0 12px;
 	font-weight: normal;
 	float: right;
 }
@@ -1748,10 +1744,25 @@ details.rustdoc-toggle[open] > summary.hideme::after {
 		padding-top: 0px;
 	}
 
-	.rustdoc {
+	.rustdoc,
+	.main-heading {
 		flex-direction: column;
 	}
 
+	.content .out-of-band {
+		text-align: left;
+		margin-left: initial;
+		padding: initial;
+	}
+
+	.content .out-of-band .since::before {
+		content: "Since ";
+	}
+
+	#copy-path {
+		display: none;
+	}
+
 	/* Hide the logo and item name from the sidebar. Those are displayed
 	   in the mobile-topbar instead. */
 	.sidebar .sidebar-logo,
diff --git a/src/test/rustdoc-gui/mobile.goml b/src/test/rustdoc-gui/mobile.goml
new file mode 100644
index 00000000000..acde1123925
--- /dev/null
+++ b/src/test/rustdoc-gui/mobile.goml
@@ -0,0 +1,17 @@
+// Test various properties of the mobile UI
+goto: file://|DOC_PATH|/staged_api/struct.Foo.html
+size: (400, 600)
+
+// The out-of-band info (source, stable version, collapse) should be below the
+// h1 when the screen gets narrow enough.
+assert-css: (".main-heading", {
+  "display": "flex",
+  "flex-direction": "column"
+})
+
+// Note: We can't use assert-text here because the 'Since' is set by CSS and
+// is therefore not part of the DOM.
+assert-css: (".content .out-of-band .since::before", { "content": "\"Since \"" })
+
+size: (1000, 1000)
+assert-css-false: (".content .out-of-band .since::before", { "content": "\"Since \"" })
diff --git a/src/test/rustdoc-gui/toggle-docs-mobile.goml b/src/test/rustdoc-gui/toggle-docs-mobile.goml
index 4c83fd6c0e3..e7a75b43c5a 100644
--- a/src/test/rustdoc-gui/toggle-docs-mobile.goml
+++ b/src/test/rustdoc-gui/toggle-docs-mobile.goml
@@ -1,12 +1,12 @@
 goto: file://|DOC_PATH|/test_docs/struct.Foo.html
 size: (433, 600)
 assert-attribute: (".top-doc", {"open": ""})
-click: (4, 250) // This is the position of the top doc comment toggle
+click: (4, 270) // This is the position of the top doc comment toggle
 assert-attribute-false: (".top-doc", {"open": ""})
-click: (4, 250)
+click: (4, 270)
 assert-attribute: (".top-doc", {"open": ""})
 // To ensure that the toggle isn't over the text, we check that the toggle isn't clicked.
-click: (3, 250)
+click: (3, 270)
 assert-attribute: (".top-doc", {"open": ""})
 
 // Assert the position of the toggle on the top doc block.
@@ -22,10 +22,10 @@ assert-position: (
 // Now we do the same but with a little bigger width
 size: (600, 600)
 assert-attribute: (".top-doc", {"open": ""})
-click: (4, 250) // New Y position since all search elements are back on one line.
+click: (4, 270) // New Y position since all search elements are back on one line.
 assert-attribute-false: (".top-doc", {"open": ""})
-click: (4, 250)
+click: (4, 270)
 assert-attribute: (".top-doc", {"open": ""})
 // To ensure that the toggle isn't over the text, we check that the toggle isn't clicked.
-click: (3, 250)
+click: (3, 270)
 assert-attribute: (".top-doc", {"open": ""})
-- 
cgit 1.4.1-3-g733a5


From 3b100458c137e2394c0a73f66d37a4ec373d6469 Mon Sep 17 00:00:00 2001
From: Laurențiu Nicola <lnicola@dend.ro>
Date: Thu, 20 Jan 2022 12:14:08 +0200
Subject: :arrow_up: rust-analyzer

---
 src/tools/rust-analyzer | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'src')

diff --git a/src/tools/rust-analyzer b/src/tools/rust-analyzer
index 8e9ccbf97a7..9700addc821 160000
--- a/src/tools/rust-analyzer
+++ b/src/tools/rust-analyzer
@@ -1 +1 @@
-Subproject commit 8e9ccbf97a70259b6c6576e8fd7d77d28238737e
+Subproject commit 9700addc82111200a2150b9a796f62dd8e600ddf
-- 
cgit 1.4.1-3-g733a5