Auto merge of #69748 - Mark-Simulacrum:beta-next, r=Mark-Simulacrum

[beta] another round of backports for 1.42

This backports the following pull requests:

* Fix a leak in `DiagnosticBuilder::into_diagnostic`. #69628
* stash API: remove panic to fix ICE. #69623
* Do not ICE on invalid type node after parse recovery #69583
* Backport only: avoid ICE on bad placeholder type #69324
* add regression test for issue #68794 #69168
* Update compiler-builtins to 0.1.25 #69086
* Update RELEASES.md for 1.42.0 #68989

17 files changed, 157 insertions, 770 deletions

diff --git a/src/librustc_errors/diagnostic_builder.rs b/src/librustc_errors/diagnostic_builder.rs
index 3c217c1d643..0796c46e0d5 100644
--- a/src/librustc_errors/diagnostic_builder.rs
+++ b/src/librustc_errors/diagnostic_builder.rs
@@ -132,12 +132,11 @@ impl<'a> DiagnosticBuilder<'a> {
 
         let handler = self.0.handler;
 
-        // We need to use `ptr::read` because `DiagnosticBuilder` implements `Drop`.
-        let diagnostic;
-        unsafe {
-            diagnostic = std::ptr::read(&self.0.diagnostic);
-            std::mem::forget(self);
-        };
+        // We must use `Level::Cancelled` for `dummy` to avoid an ICE about an
+        // unused diagnostic.
+        let dummy = Diagnostic::new(Level::Cancelled, "");
+        let diagnostic = std::mem::replace(&mut self.0.diagnostic, dummy);
+
         // Logging here is useful to help track down where in logs an error was
         // actually emitted.
         debug!("buffer: diagnostic={:?}", diagnostic);
diff --git a/src/librustc_errors/lib.rs b/src/librustc_errors/lib.rs
index 17b293401f8..19f72e3a3e2 100644
--- a/src/librustc_errors/lib.rs
+++ b/src/librustc_errors/lib.rs
@@ -446,22 +446,12 @@ impl Handler {
     }
 
     /// Stash a given diagnostic with the given `Span` and `StashKey` as the key for later stealing.
-    /// If the diagnostic with this `(span, key)` already exists, this will result in an ICE.
     pub fn stash_diagnostic(&self, span: Span, key: StashKey, diag: Diagnostic) {
         let mut inner = self.inner.borrow_mut();
-        if let Some(mut old_diag) = inner.stashed_diagnostics.insert((span, key), diag) {
-            // We are removing a previously stashed diagnostic which should not happen.
-            old_diag.level = Bug;
-            old_diag.note(&format!(
-                "{}:{}: already existing stashed diagnostic with (span = {:?}, key = {:?})",
-                file!(),
-                line!(),
-                span,
-                key
-            ));
-            inner.emit_diag_at_span(old_diag, span);
-            panic!(ExplicitBug);
-        }
+        // FIXME(Centril, #69537): Consider reintroducing panic on overwriting a stashed diagnostic
+        // if/when we have a more robust macro-friendly replacement for `(span, key)` as a key.
+        // See the PR for a discussion.
+        inner.stashed_diagnostics.insert((span, key), diag);
     }
 
     /// Steal a previously stashed diagnostic with the given `Span` and `StashKey` as the key.
diff --git a/src/librustc_typeck/check/expr.rs b/src/librustc_typeck/check/expr.rs
index b4c2b85241f..2d704145e96 100644
--- a/src/librustc_typeck/check/expr.rs
+++ b/src/librustc_typeck/check/expr.rs
@@ -1311,6 +1311,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         ty_span: Span,
     ) {
         if variant.recovered {
+            self.set_tainted_by_errors();
             return;
         }
         let mut err = self.type_error_struct_with_diag(
diff --git a/src/librustc_typeck/collect.rs b/src/librustc_typeck/collect.rs
index 843872d0ff9..cdf2304b839 100644
--- a/src/librustc_typeck/collect.rs
+++ b/src/librustc_typeck/collect.rs
@@ -316,7 +316,7 @@ impl AstConv<'tcx> for ItemCtxt<'tcx> {
     }
 
     fn ty_infer(&self, _: Option<&ty::GenericParamDef>, span: Span) -> Ty<'tcx> {
-        self.tcx().sess.delay_span_bug(span, "bad placeholder type");
+        placeholder_type_error(self.tcx(), span, &[], vec![span], false);
         self.tcx().types.err
     }
 
diff --git a/src/test/run-make-fulldeps/issue-68794-textrel-on-minimal-lib/Makefile b/src/test/run-make-fulldeps/issue-68794-textrel-on-minimal-lib/Makefile
new file mode 100644
index 00000000000..2f16ad32859
--- /dev/null
+++ b/src/test/run-make-fulldeps/issue-68794-textrel-on-minimal-lib/Makefile
@@ -0,0 +1,17 @@
+# Regression test for issue #68794
+#
+# Verify that no text relocations are accidentally introduced by linking a
+# minimal rust staticlib.
+#
+# The test links a rust static library into a shared library, and checks that
+# the linker doesn't have to flag the resulting file as containing TEXTRELs.
+
+-include ../tools.mk
+
+# only-linux
+
+all:
+	$(RUSTC) foo.rs
+	$(CC) bar.c $(call STATICLIB,foo) -fPIC -shared -o $(call DYLIB,bar) \
+		$(EXTRACFLAGS) $(EXTRACXXFLAGS)
+	readelf -d $(call DYLIB,bar) | grep TEXTREL; test $$? -eq 1
diff --git a/src/test/run-make-fulldeps/issue-68794-textrel-on-minimal-lib/bar.c b/src/test/run-make-fulldeps/issue-68794-textrel-on-minimal-lib/bar.c
new file mode 100644
index 00000000000..bb4036b06e1
--- /dev/null
+++ b/src/test/run-make-fulldeps/issue-68794-textrel-on-minimal-lib/bar.c
@@ -0,0 +1,6 @@
+void foo();
+
+int main() {
+    foo();
+    return 0;
+}
diff --git a/src/test/run-make-fulldeps/issue-68794-textrel-on-minimal-lib/foo.rs b/src/test/run-make-fulldeps/issue-68794-textrel-on-minimal-lib/foo.rs
new file mode 100644
index 00000000000..a3e865b638e
--- /dev/null
+++ b/src/test/run-make-fulldeps/issue-68794-textrel-on-minimal-lib/foo.rs
@@ -0,0 +1,8 @@
+#![crate_type = "staticlib"]
+
+#[no_mangle]
+pub extern "C" fn foo(x: u32) {
+    // using the println! makes it so that enough code from the standard
+    // library is included (see issue #68794)
+    println!("foo: {}", x);
+}
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 fccfb7911ce..f02931eeb6f 100644
--- a/src/test/ui/did_you_mean/bad-assoc-ty.rs
+++ b/src/test/ui/did_you_mean/bad-assoc-ty.rs
@@ -17,6 +17,7 @@ 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
+//~| ERROR the type placeholder `_` is not allowed within types on item signatures
 
 type F = &'static (u8)::AssocTy;
 //~^ ERROR missing angle brackets in associated item path
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 7d3c99bda6b..4fdd407bff3 100644
--- a/src/test/ui/did_you_mean/bad-assoc-ty.stderr
+++ b/src/test/ui/did_you_mean/bad-assoc-ty.stderr
@@ -29,25 +29,25 @@ LL | type E = _::AssocTy;
    |          ^^^^^^^^^^ help: try: `<_>::AssocTy`
 
 error: missing angle brackets in associated item path
-  --> $DIR/bad-assoc-ty.rs:21:19
+  --> $DIR/bad-assoc-ty.rs:22:19
    |
 LL | type F = &'static (u8)::AssocTy;
    |                   ^^^^^^^^^^^^^ help: try: `<(u8)>::AssocTy`
 
 error: missing angle brackets in associated item path
-  --> $DIR/bad-assoc-ty.rs:27:10
+  --> $DIR/bad-assoc-ty.rs:28:10
    |
 LL | type G = dyn 'static + (Send)::AssocTy;
    |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `<dyn 'static + (Send)>::AssocTy`
 
 error: missing angle brackets in associated item path
-  --> $DIR/bad-assoc-ty.rs:44:10
+  --> $DIR/bad-assoc-ty.rs:45:10
    |
 LL | type I = ty!()::AssocTy;
    |          ^^^^^^^^^^^^^^ help: try: `<ty!()>::AssocTy`
 
 error: missing angle brackets in associated item path
-  --> $DIR/bad-assoc-ty.rs:37:19
+  --> $DIR/bad-assoc-ty.rs:38:19
    |
 LL |     ($ty: ty) => ($ty::AssocTy);
    |                   ^^^^^^^^^^^^ help: try: `<$ty>::AssocTy`
@@ -85,26 +85,32 @@ error[E0121]: the type placeholder `_` is not allowed within types on item signa
 LL | type E = _::AssocTy;
    |          ^ not allowed in type signatures
 
+error[E0121]: the type placeholder `_` is not allowed within types on item signatures
+  --> $DIR/bad-assoc-ty.rs:17:10
+   |
+LL | type E = _::AssocTy;
+   |          ^ not allowed in type signatures
+
 error[E0223]: ambiguous associated type
-  --> $DIR/bad-assoc-ty.rs:21:19
+  --> $DIR/bad-assoc-ty.rs:22:19
    |
 LL | type F = &'static (u8)::AssocTy;
    |                   ^^^^^^^^^^^^^ help: use fully-qualified syntax: `<u8 as Trait>::AssocTy`
 
 error[E0223]: ambiguous associated type
-  --> $DIR/bad-assoc-ty.rs:27:10
+  --> $DIR/bad-assoc-ty.rs:28:10
    |
 LL | type G = dyn 'static + (Send)::AssocTy;
    |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use fully-qualified syntax: `<(dyn std::marker::Send + 'static) as Trait>::AssocTy`
 
 error[E0223]: ambiguous associated type
-  --> $DIR/bad-assoc-ty.rs:33:10
+  --> $DIR/bad-assoc-ty.rs:34:10
    |
 LL | type H = Fn(u8) -> (u8)::Output;
    |          ^^^^^^^^^^^^^^^^^^^^^^ help: use fully-qualified syntax: `<(dyn std::ops::Fn(u8) -> u8 + 'static) as Trait>::Output`
 
 error[E0223]: ambiguous associated type
-  --> $DIR/bad-assoc-ty.rs:37:19
+  --> $DIR/bad-assoc-ty.rs:38:19
    |
 LL |     ($ty: ty) => ($ty::AssocTy);
    |                   ^^^^^^^^^^^^ help: use fully-qualified syntax: `<u8 as Trait>::AssocTy`
@@ -113,12 +119,12 @@ LL | type J = ty!(u8);
    |          ------- in this macro invocation
 
 error[E0223]: ambiguous associated type
-  --> $DIR/bad-assoc-ty.rs:44:10
+  --> $DIR/bad-assoc-ty.rs:45:10
    |
 LL | type I = ty!()::AssocTy;
    |          ^^^^^^^^^^^^^^ help: use fully-qualified syntax: `<u8 as Trait>::AssocTy`
 
-error: aborting due to 19 previous errors
+error: aborting due to 20 previous errors
 
 Some errors have detailed explanations: E0121, E0223.
 For more information about an error, try `rustc --explain E0121`.
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
new file mode 100644
index 00000000000..69fc0c1cbb9
--- /dev/null
+++ b/src/test/ui/issues/issue-69396-const-no-type-in-macro.rs
@@ -0,0 +1,17 @@
+macro_rules! suite {
+    ( $( $fn:ident; )* ) => {
+        $(
+            const A = "A".$fn();
+            //~^ ERROR the name `A` is defined multiple times
+            //~| ERROR missing type for `const` item
+            //~| ERROR the type placeholder `_` is not allowed within types
+        )*
+    }
+}
+
+suite! {
+    len;
+    is_empty;
+}
+
+fn main() {}
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
new file mode 100644
index 00000000000..c12ce166efe
--- /dev/null
+++ b/src/test/ui/issues/issue-69396-const-no-type-in-macro.stderr
@@ -0,0 +1,48 @@
+error[E0428]: the name `A` is defined multiple times
+  --> $DIR/issue-69396-const-no-type-in-macro.rs:4:13
+   |
+LL |               const A = "A".$fn();
+   |               ^^^^^^^^^^^^^^^^^^^^
+   |               |
+   |               `A` redefined here
+   |               previous definition of the value `A` here
+...
+LL | / suite! {
+LL | |     len;
+LL | |     is_empty;
+LL | | }
+   | |_- in this macro invocation
+   |
+   = note: `A` must be defined only once in the value namespace of this module
+
+error: missing type for `const` item
+  --> $DIR/issue-69396-const-no-type-in-macro.rs:4:19
+   |
+LL |               const A = "A".$fn();
+   |                     ^ help: provide a type for the item: `A: usize`
+...
+LL | / suite! {
+LL | |     len;
+LL | |     is_empty;
+LL | | }
+   | |_- in this macro invocation
+
+error[E0121]: the type placeholder `_` is not allowed within types on item signatures
+  --> $DIR/issue-69396-const-no-type-in-macro.rs:4:19
+   |
+LL |               const A = "A".$fn();
+   |                     ^
+   |                     |
+   |                     not allowed in type signatures
+   |                     help: replace `_` with the correct type: `bool`
+...
+LL | / suite! {
+LL | |     len;
+LL | |     is_empty;
+LL | | }
+   | |_- in this macro invocation
+
+error: aborting due to 3 previous errors
+
+Some errors have detailed explanations: E0121, E0428.
+For more information about an error, try `rustc --explain E0121`.
diff --git a/src/test/ui/self/self-infer.rs b/src/test/ui/self/self-infer.rs
index 0956f2a5691..77c80521236 100644
--- a/src/test/ui/self/self-infer.rs
+++ b/src/test/ui/self/self-infer.rs
@@ -2,7 +2,9 @@ struct S;
 
 impl S {
     fn f(self: _) {} //~ERROR the type placeholder `_` is not allowed within types on item sig
+    //~^ ERROR the type placeholder `_` is not allowed within types on item sig
     fn g(self: &_) {} //~ERROR the type placeholder `_` is not allowed within types on item sig
+    //~^ ERROR the type placeholder `_` is not allowed within types on item sig
 }
 
 fn main() {}
diff --git a/src/test/ui/self/self-infer.stderr b/src/test/ui/self/self-infer.stderr
index 1475b212b56..d6bf8b44d60 100644
--- a/src/test/ui/self/self-infer.stderr
+++ b/src/test/ui/self/self-infer.stderr
@@ -3,6 +3,12 @@ error[E0121]: the type placeholder `_` is not allowed within types on item signa
    |
 LL |     fn f(self: _) {}
    |                ^ not allowed in type signatures
+
+error[E0121]: the type placeholder `_` is not allowed within types on item signatures
+  --> $DIR/self-infer.rs:4:16
+   |
+LL |     fn f(self: _) {}
+   |                ^ not allowed in type signatures
    |
 help: use type parameters instead
    |
@@ -10,7 +16,13 @@ LL |     fn f<T>(self: T) {}
    |         ^^^       ^
 
 error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/self-infer.rs:5:17
+  --> $DIR/self-infer.rs:6:17
+   |
+LL |     fn g(self: &_) {}
+   |                 ^ not allowed in type signatures
+
+error[E0121]: the type placeholder `_` is not allowed within types on item signatures
+  --> $DIR/self-infer.rs:6:17
    |
 LL |     fn g(self: &_) {}
    |                 ^ not allowed in type signatures
@@ -20,6 +32,6 @@ help: use type parameters instead
 LL |     fn g<T>(self: &T) {}
    |         ^^^        ^
 
-error: aborting due to 2 previous errors
+error: aborting due to 4 previous errors
 
 For more information about this error, try `rustc --explain E0121`.
diff --git a/src/test/ui/typeck/issue-69378-ice-on-invalid-type-node-after-recovery.rs b/src/test/ui/typeck/issue-69378-ice-on-invalid-type-node-after-recovery.rs
new file mode 100644
index 00000000000..571692a5374
--- /dev/null
+++ b/src/test/ui/typeck/issue-69378-ice-on-invalid-type-node-after-recovery.rs
@@ -0,0 +1,9 @@
+// Regression test for #69378: no type for node after struct parse recovery
+
+struct Foo { 0: u8 } //~ ERROR expected identifier
+
+fn test(f: Foo) {
+    Foo{foo: 4, ..f};
+}
+
+fn main() {}
diff --git a/src/test/ui/typeck/issue-69378-ice-on-invalid-type-node-after-recovery.stderr b/src/test/ui/typeck/issue-69378-ice-on-invalid-type-node-after-recovery.stderr
new file mode 100644
index 00000000000..6bc9c8498c9
--- /dev/null
+++ b/src/test/ui/typeck/issue-69378-ice-on-invalid-type-node-after-recovery.stderr
@@ -0,0 +1,8 @@
+error: expected identifier, found `0`
+  --> $DIR/issue-69378-ice-on-invalid-type-node-after-recovery.rs:3:14
+   |
+LL | struct Foo { 0: u8 }
+   |              ^ expected identifier
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/typeck/typeck_type_placeholder_item.rs b/src/test/ui/typeck/typeck_type_placeholder_item.rs
deleted file mode 100644
index 86c7c52b271..00000000000
--- a/src/test/ui/typeck/typeck_type_placeholder_item.rs
+++ /dev/null
@@ -1,185 +0,0 @@
-#![feature(type_alias_impl_trait)] // Needed for single test `type Y = impl Trait<_>`
-// This test checks that it is not possible to enable global type
-// inference by using the `_` type placeholder.
-
-fn test() -> _ { 5 }
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-fn test2() -> (_, _) { (5, 5) }
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-static TEST3: _ = "test";
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-static TEST4: _ = 145;
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-static TEST5: (_, _) = (1, 2);
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-fn test6(_: _) { }
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-fn test6_b<T>(_: _, _: T) { }
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-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
-
-fn test7(x: _) { let _x: usize = x; }
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-fn test8(_f: fn() -> _) { }
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-//~| ERROR the type placeholder `_` is not allowed within types on item signatures
-
-struct Test9;
-
-impl Test9 {
-    fn test9(&self) -> _ { () }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-    fn test10(&self, _x : _) { }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-}
-
-fn test11(x: &usize) -> &_ {
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-    &x
-}
-
-unsafe fn test12(x: *const usize) -> *const *const _ {
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-    &x
-}
-
-impl Clone for Test9 {
-    fn clone(&self) -> _ { Test9 }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-    fn clone_from(&mut self, other: _) { *self = Test9; }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-}
-
-struct Test10 {
-    a: _,
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-    b: (_, _),
-}
-
-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
-    static C: Option<_> = Some(42);
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-    fn fn_test() -> _ { 5 }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-    fn fn_test2() -> (_, _) { (5, 5) }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-    static FN_TEST3: _ = "test";
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-    static FN_TEST4: _ = 145;
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-    static FN_TEST5: (_, _) = (1, 2);
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-    fn fn_test6(_: _) { }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-    fn fn_test7(x: _) { let _x: usize = x; }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-    fn fn_test8(_f: fn() -> _) { }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-    //~| ERROR the type placeholder `_` is not allowed within types on item signatures
-
-    struct FnTest9;
-
-    impl FnTest9 {
-        fn fn_test9(&self) -> _ { () }
-        //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-        fn fn_test10(&self, _x : _) { }
-        //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-    }
-
-    impl Clone for FnTest9 {
-        fn clone(&self) -> _ { FnTest9 }
-        //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-        fn clone_from(&mut self, other: _) { *self = FnTest9; }
-        //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-    }
-
-    struct FnTest10 {
-        a: _,
-        //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-        b: (_, _),
-    }
-
-    fn fn_test11(_: _) -> (_, _) { panic!() }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-    //~| ERROR type annotations needed
-
-    fn fn_test12(x: i32) -> (_, _) { (x, x) }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-    fn fn_test13(x: _) -> (i32, _) { (x, x) }
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-}
-
-trait T {
-    fn method_test1(&self, x: _);
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-    fn method_test2(&self, x: _) -> _;
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-    fn method_test3(&self) -> _;
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-    fn assoc_fn_test1(x: _);
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-    fn assoc_fn_test2(x: _) -> _;
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-    fn assoc_fn_test3() -> _;
-    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-}
-
-struct BadStruct<_>(_);
-//~^ ERROR expected identifier, found reserved identifier `_`
-//~| ERROR the type placeholder `_` is not allowed within types on item signatures
-trait BadTrait<_> {}
-//~^ ERROR expected identifier, found reserved identifier `_`
-impl BadTrait<_> for BadStruct<_> {}
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-fn impl_trait() -> impl BadTrait<_> {
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-    unimplemented!()
-}
-
-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
-struct BadStruct2<_, T>(_, T);
-//~^ ERROR expected identifier, found reserved identifier `_`
-//~| ERROR the type placeholder `_` is not allowed within types on item signatures
-
-type X = Box<_>;
-//~^ ERROR the type placeholder `_` is not allowed within types on item signatures
-
-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
-fn foo() -> Y {
-    Struct
-}
diff --git a/src/test/ui/typeck/typeck_type_placeholder_item.stderr b/src/test/ui/typeck/typeck_type_placeholder_item.stderr
deleted file mode 100644
index f740a9f7f34..00000000000
--- a/src/test/ui/typeck/typeck_type_placeholder_item.stderr
+++ /dev/null
@@ -1,552 +0,0 @@
-error: expected identifier, found reserved identifier `_`
-  --> $DIR/typeck_type_placeholder_item.rs:153:18
-   |
-LL | struct BadStruct<_>(_);
-   |                  ^ expected identifier, found reserved identifier
-
-error: expected identifier, found reserved identifier `_`
-  --> $DIR/typeck_type_placeholder_item.rs:156:16
-   |
-LL | trait BadTrait<_> {}
-   |                ^ expected identifier, found reserved identifier
-
-error: expected identifier, found reserved identifier `_`
-  --> $DIR/typeck_type_placeholder_item.rs:166:19
-   |
-LL | struct BadStruct1<_, _>(_);
-   |                   ^ expected identifier, found reserved identifier
-
-error: expected identifier, found reserved identifier `_`
-  --> $DIR/typeck_type_placeholder_item.rs:166:22
-   |
-LL | struct BadStruct1<_, _>(_);
-   |                      ^ expected identifier, found reserved identifier
-
-error: expected identifier, found reserved identifier `_`
-  --> $DIR/typeck_type_placeholder_item.rs:171:19
-   |
-LL | struct BadStruct2<_, T>(_, T);
-   |                   ^ expected identifier, found reserved identifier
-
-error[E0403]: the name `_` is already used for a generic parameter in this item's generic parameters
-  --> $DIR/typeck_type_placeholder_item.rs:166:22
-   |
-LL | struct BadStruct1<_, _>(_);
-   |                   -  ^ already used
-   |                   |
-   |                   first use of `_`
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:5:14
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:8:16
-   |
-LL | fn test2() -> (_, _) { (5, 5) }
-   |               -^--^-
-   |               ||  |
-   |               ||  not allowed in type signatures
-   |               |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
-  --> $DIR/typeck_type_placeholder_item.rs:11:15
-   |
-LL | static TEST3: _ = "test";
-   |               ^
-   |               |
-   |               not allowed in type signatures
-   |               help: replace `_` with the correct type: `&'static str`
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:14:15
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:17:15
-   |
-LL | static TEST5: (_, _) = (1, 2);
-   |               ^^^^^^ not allowed in type signatures
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:20:13
-   |
-LL | fn test6(_: _) { }
-   |             ^ not allowed in type signatures
-   |
-help: use type parameters instead
-   |
-LL | fn test6<T>(_: T) { }
-   |         ^^^    ^
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:23:18
-   |
-LL | fn test6_b<T>(_: _, _: T) { }
-   |                  ^ not allowed in type signatures
-   |
-help: use type parameters instead
-   |
-LL | fn test6_b<T, K>(_: K, _: T) { }
-   |             ^^^     ^
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:26:30
-   |
-LL | fn test6_c<T, K, L, A, B>(_: _, _: (T, K, L, A, B)) { }
-   |                              ^ not allowed in type signatures
-   |
-help: use type parameters instead
-   |
-LL | fn test6_c<T, K, L, A, B, C>(_: C, _: (T, K, L, A, B)) { }
-   |                         ^^^     ^
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:29:13
-   |
-LL | fn test7(x: _) { let _x: usize = x; }
-   |             ^ not allowed in type signatures
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:32:22
-   |
-LL | fn test8(_f: fn() -> _) { }
-   |                      ^ not allowed in type signatures
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:32:22
-   |
-LL | fn test8(_f: fn() -> _) { }
-   |                      ^ not allowed in type signatures
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:46:26
-   |
-LL | fn test11(x: &usize) -> &_ {
-   |                         -^
-   |                         ||
-   |                         |not allowed in type signatures
-   |                         help: replace with the correct return type: `&&usize`
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:51:52
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:65:8
-   |
-LL |     a: _,
-   |        ^ not allowed in type signatures
-LL |
-LL |     b: (_, _),
-   |         ^  ^ not allowed in type signatures
-   |         |
-   |         not allowed in type signatures
-   |
-help: use type parameters instead
-   |
-LL | struct Test10<T> {
-LL |     a: T,
-LL |
-LL |     b: (T, T),
-   |
-
-error: missing type for `static` item
-  --> $DIR/typeck_type_placeholder_item.rs:71:12
-   |
-LL |     static A = 42;
-   |            ^ help: provide a type for the item: `A: i32`
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:73:15
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:75:15
-   |
-LL |     static C: Option<_> = Some(42);
-   |               ^^^^^^^^^ not allowed in type signatures
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:78:21
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:81:23
-   |
-LL |     fn fn_test2() -> (_, _) { (5, 5) }
-   |                      -^--^-
-   |                      ||  |
-   |                      ||  not allowed in type signatures
-   |                      |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
-  --> $DIR/typeck_type_placeholder_item.rs:84:22
-   |
-LL |     static FN_TEST3: _ = "test";
-   |                      ^
-   |                      |
-   |                      not allowed in type signatures
-   |                      help: replace `_` with the correct type: `&'static str`
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:87:22
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:90:22
-   |
-LL |     static FN_TEST5: (_, _) = (1, 2);
-   |                      ^^^^^^ not allowed in type signatures
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:93:20
-   |
-LL |     fn fn_test6(_: _) { }
-   |                    ^ not allowed in type signatures
-   |
-help: use type parameters instead
-   |
-LL |     fn fn_test6<T>(_: T) { }
-   |                ^^^    ^
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:96:20
-   |
-LL |     fn fn_test7(x: _) { let _x: usize = x; }
-   |                    ^ not allowed in type signatures
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:99:29
-   |
-LL |     fn fn_test8(_f: fn() -> _) { }
-   |                             ^ not allowed in type signatures
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:99:29
-   |
-LL |     fn fn_test8(_f: fn() -> _) { }
-   |                             ^ not allowed in type signatures
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:122:12
-   |
-LL |         a: _,
-   |            ^ not allowed in type signatures
-LL |
-LL |         b: (_, _),
-   |             ^  ^ not allowed in type signatures
-   |             |
-   |             not allowed in type signatures
-   |
-help: use type parameters instead
-   |
-LL |     struct FnTest10<T> {
-LL |         a: T,
-LL |
-LL |         b: (T, T),
-   |
-
-error[E0282]: type annotations needed
-  --> $DIR/typeck_type_placeholder_item.rs:127:27
-   |
-LL |     fn fn_test11(_: _) -> (_, _) { panic!() }
-   |                           ^^^^^^ cannot infer type
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:127:28
-   |
-LL |     fn fn_test11(_: _) -> (_, _) { panic!() }
-   |                            ^  ^ not allowed in type signatures
-   |                            |
-   |                            not allowed in type signatures
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:131:30
-   |
-LL |     fn fn_test12(x: i32) -> (_, _) { (x, x) }
-   |                             -^--^-
-   |                             ||  |
-   |                             ||  not allowed in type signatures
-   |                             |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
-  --> $DIR/typeck_type_placeholder_item.rs:134:33
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:153:21
-   |
-LL | struct BadStruct<_>(_);
-   |                     ^ not allowed in type signatures
-   |
-help: use type parameters instead
-   |
-LL | struct BadStruct<T>(T);
-   |                  ^  ^
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:158:15
-   |
-LL | impl BadTrait<_> for BadStruct<_> {}
-   |               ^                ^ not allowed in type signatures
-   |               |
-   |               not allowed in type signatures
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:161:34
-   |
-LL | fn impl_trait() -> impl BadTrait<_> {
-   |                                  ^ not allowed in type signatures
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:166:25
-   |
-LL | struct BadStruct1<_, _>(_);
-   |                         ^ not allowed in type signatures
-   |
-help: use type parameters instead
-   |
-LL | struct BadStruct1<T, _>(T);
-   |                   ^     ^
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:171:25
-   |
-LL | struct BadStruct2<_, T>(_, T);
-   |                         ^ not allowed in type signatures
-   |
-help: use type parameters instead
-   |
-LL | struct BadStruct2<K, T>(K, T);
-   |                   ^     ^
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:175:14
-   |
-LL | type X = Box<_>;
-   |              ^ not allowed in type signatures
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:42:27
-   |
-LL |     fn test10(&self, _x : _) { }
-   |                           ^ not allowed in type signatures
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:139:31
-   |
-LL |     fn method_test1(&self, x: _);
-   |                               ^ not allowed in type signatures
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:141:31
-   |
-LL |     fn method_test2(&self, x: _) -> _;
-   |                               ^     ^ not allowed in type signatures
-   |                               |
-   |                               not allowed in type signatures
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:143:31
-   |
-LL |     fn method_test3(&self) -> _;
-   |                               ^ not allowed in type signatures
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:145:26
-   |
-LL |     fn assoc_fn_test1(x: _);
-   |                          ^ not allowed in type signatures
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:147:26
-   |
-LL |     fn assoc_fn_test2(x: _) -> _;
-   |                          ^     ^ not allowed in type signatures
-   |                          |
-   |                          not allowed in type signatures
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:149:28
-   |
-LL |     fn assoc_fn_test3() -> _;
-   |                            ^ not allowed in type signatures
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:60:37
-   |
-LL |     fn clone_from(&mut self, other: _) { *self = Test9; }
-   |                                     ^ not allowed in type signatures
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:109:34
-   |
-LL |         fn fn_test10(&self, _x : _) { }
-   |                                  ^ not allowed in type signatures
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:117:41
-   |
-LL |         fn clone_from(&mut self, other: _) { *self = FnTest9; }
-   |                                         ^ not allowed in type signatures
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:181:21
-   |
-LL | type Y = impl Trait<_>;
-   |                     ^ not allowed in type signatures
-
-error[E0121]: the type placeholder `_` is not allowed within types on item signatures
-  --> $DIR/typeck_type_placeholder_item.rs:39:24
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:57:24
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:106:31
-   |
-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
-  --> $DIR/typeck_type_placeholder_item.rs:114:28
-   |
-LL |         fn clone(&self) -> _ { FnTest9 }
-   |                            ^
-   |                            |
-   |                            not allowed in type signatures
-   |                            help: replace with the correct return type: `main::FnTest9`
-
-error: aborting due to 58 previous errors
-
-Some errors have detailed explanations: E0121, E0282, E0403.
-For more information about an error, try `rustc --explain E0121`.