Auto merge of #80960 - Dylan-DPC:rollup-89tri8x, r=Dylan-DPC

Rollup of 10 pull requests

Successful merges:

 - #78901 (diagnostics: Note capturing closures can't be coerced to fns)
 - #79588 (Provide more information for HRTB lifetime errors involving closures)
 - #80232 (Remove redundant def_id lookups)
 - #80662 (Added support for i386-unknown-linux-gnu and i486-unknown-linux-gnu)
 - #80736 (use Once instead of Mutex to manage capture resolution)
 - #80796 (Update to LLVM 11.0.1)
 - #80859 (Fix --pretty=expanded with --remap-path-prefix)
 - #80922 (Revert "Auto merge of #76896 - spastorino:codegen-inline-fns2)
 - #80924 (Fix rustdoc --test-builder argument parsing)
 - #80935 (Rename `rustc_middle::lint::LevelSource` to `LevelAndSource`)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

33 files changed, 449 insertions, 41 deletions

diff --git a/src/librustdoc/lib.rs b/src/librustdoc/lib.rs
index 7ed64c5813f..efcb006870c 100644
--- a/src/librustdoc/lib.rs
+++ b/src/librustdoc/lib.rs
@@ -412,11 +412,7 @@ fn opts() -> Vec<RustcOptGroup> {
             )
         }),
         unstable("test-builder", |o| {
-            o.optflag(
-                "",
-                "test-builder",
-                "specified the rustc-like binary to use as the test builder",
-            )
+            o.optopt("", "test-builder", "The rustc-like binary to use as the test builder", "PATH")
         }),
         unstable("check", |o| o.optflag("", "check", "Run rustdoc checks")),
     ]
diff --git a/src/llvm-project b/src/llvm-project
-Subproject fb115ee43b77601b237717c21ab0a8f5b5b9d50
+Subproject f9a8d70b6e0365ac2172ca6b7f1de0341297458
diff --git a/src/test/incremental/hygiene/load_cached_hygiene.rs b/src/test/incremental/hygiene/load_cached_hygiene.rs
index d6a5cb993a4..8124141418b 100644
--- a/src/test/incremental/hygiene/load_cached_hygiene.rs
+++ b/src/test/incremental/hygiene/load_cached_hygiene.rs
@@ -1,5 +1,5 @@
 // revisions:rpass1 rpass2
-// compile-flags: -Z query-dep-graph -O
+// compile-flags: -Z query-dep-graph
 // aux-build:cached_hygiene.rs
 
 // This tests the folllowing scenario
@@ -19,12 +19,7 @@
 // the metadata. Specifically, we were not resetting `orig_id`
 // for an `EpxnData` generate in the current crate, which would cause
 // us to serialize the `ExpnId` pointing to a garbage location in
-// the metadata.o
-
-// NOTE: We're explicitly passing the `-O` optimization flag because if optimizations are not
-// enabled, then rustc will ignore the `#[inline(always)]` attribute which means we do not load
-// the optimized mir for the unmodified function to be loaded and so the CGU containing that
-// function will be reused.
+// the metadata.
 
 #![feature(rustc_attrs)]
 
diff --git a/src/test/incremental/remapped_paths_cc/main.rs b/src/test/incremental/remapped_paths_cc/main.rs
index 735635029da..b01f02444ea 100644
--- a/src/test/incremental/remapped_paths_cc/main.rs
+++ b/src/test/incremental/remapped_paths_cc/main.rs
@@ -1,18 +1,11 @@
 // revisions:rpass1 rpass2 rpass3
-// compile-flags: -Z query-dep-graph -g -O
+// compile-flags: -Z query-dep-graph -g
 // aux-build:extern_crate.rs
 
 // ignore-asmjs wasm2js does not support source maps yet
-
 // This test case makes sure that we detect if paths emitted into debuginfo
 // are changed, even when the change happens in an external crate.
 
-// NOTE: We're explicitly passing the `-O` optimization flag because if no optimizations are
-// requested, rustc will ignore the `#[inline]` attribute. This is a performance optimization for
-// non-optimized builds which causes us to generate fewer copies of inlined functions when
-// runtime performance doesn't matter. Without this flag, the function will go into a different
-// CGU which can be reused by this crate.
-
 #![feature(rustc_attrs)]
 
 #![rustc_partition_reused(module="main", cfg="rpass2")]
diff --git a/src/test/pretty/expanded-and-path-remap-80832.pp b/src/test/pretty/expanded-and-path-remap-80832.pp
new file mode 100644
index 00000000000..6dbc19e9d9c
--- /dev/null
+++ b/src/test/pretty/expanded-and-path-remap-80832.pp
@@ -0,0 +1,13 @@
+#![feature(prelude_import)]
+#![no_std]
+#[prelude_import]
+use ::std::prelude::v1::*;
+#[macro_use]
+extern crate std;
+// Test for issue 80832
+//
+// pretty-mode:expanded
+// pp-exact:expanded-and-path-remap-80832.pp
+// compile-flags: --remap-path-prefix {{src-base}}=the/src
+
+fn main() { }
diff --git a/src/test/pretty/expanded-and-path-remap-80832.rs b/src/test/pretty/expanded-and-path-remap-80832.rs
new file mode 100644
index 00000000000..f48441fbc57
--- /dev/null
+++ b/src/test/pretty/expanded-and-path-remap-80832.rs
@@ -0,0 +1,7 @@
+// Test for issue 80832
+//
+// pretty-mode:expanded
+// pp-exact:expanded-and-path-remap-80832.pp
+// compile-flags: --remap-path-prefix {{src-base}}=the/src
+
+fn main() {}
diff --git a/src/test/run-make-fulldeps/inline-always-many-cgu/Makefile b/src/test/run-make-fulldeps/inline-always-many-cgu/Makefile
index d12a23fbbf0..0cab955f644 100644
--- a/src/test/run-make-fulldeps/inline-always-many-cgu/Makefile
+++ b/src/test/run-make-fulldeps/inline-always-many-cgu/Makefile
@@ -1,12 +1,7 @@
 -include ../tools.mk
 
 all:
-	$(RUSTC) foo.rs --emit llvm-ir -C codegen-units=2 -C opt-level=0
-	if ![cat $(TMPDIR)/*.ll | $(CGREP) -e '\bcall\b']; then \
-		echo "not found call instruction when one was expected"; \
-		exit 1; \
-	fi
-	$(RUSTC) foo.rs --emit llvm-ir -C codegen-units=2 -C opt-level=1
+	$(RUSTC) foo.rs --emit llvm-ir -C codegen-units=2
 	if cat $(TMPDIR)/*.ll | $(CGREP) -e '\bcall\b'; then \
 		echo "found call instruction when one wasn't expected"; \
 		exit 1; \
diff --git a/src/test/rustdoc/issue-80893.rs b/src/test/rustdoc/issue-80893.rs
new file mode 100644
index 00000000000..7c958a80be3
--- /dev/null
+++ b/src/test/rustdoc/issue-80893.rs
@@ -0,0 +1,6 @@
+// compile-flags: --test -Z unstable-options --test-builder true
+
+/// ```no_run
+/// This tests that `--test-builder` is accepted as a flag by rustdoc.
+/// ```
+pub struct Foo;
diff --git a/src/test/ui/associated-types/higher-ranked-projection.bad.stderr b/src/test/ui/associated-types/higher-ranked-projection.bad.stderr
index 811c9a8f5e1..e2847b6b72b 100644
--- a/src/test/ui/associated-types/higher-ranked-projection.bad.stderr
+++ b/src/test/ui/associated-types/higher-ranked-projection.bad.stderr
@@ -2,10 +2,15 @@ error[E0308]: mismatched types
   --> $DIR/higher-ranked-projection.rs:25:5
    |
 LL |     foo(());
-   |     ^^^ one type is more general than the other
+   |     ^^^ lifetime mismatch
    |
    = note: expected type `&'a ()`
               found type `&()`
+note: the lifetime requirement is introduced here
+  --> $DIR/higher-ranked-projection.rs:15:33
+   |
+LL |     where for<'a> &'a T: Mirror<Image=U>
+   |                                 ^^^^^^^
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/closures/closure-no-fn-1.stderr b/src/test/ui/closures/closure-no-fn-1.stderr
index 76136315a1b..2b53802fea7 100644
--- a/src/test/ui/closures/closure-no-fn-1.stderr
+++ b/src/test/ui/closures/closure-no-fn-1.stderr
@@ -8,6 +8,11 @@ LL |     let foo: fn(u8) -> u8 = |v: u8| { a += v; a };
    |
    = note: expected fn pointer `fn(u8) -> u8`
                  found closure `[closure@$DIR/closure-no-fn-1.rs:6:29: 6:50]`
+note: closures can only be coerced to `fn` types if they do not capture any variables
+  --> $DIR/closure-no-fn-1.rs:6:39
+   |
+LL |     let foo: fn(u8) -> u8 = |v: u8| { a += v; a };
+   |                                       ^ `a` captured here
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/closures/closure-no-fn-2.stderr b/src/test/ui/closures/closure-no-fn-2.stderr
index 85cbdbe7c18..ed9f87a2c94 100644
--- a/src/test/ui/closures/closure-no-fn-2.stderr
+++ b/src/test/ui/closures/closure-no-fn-2.stderr
@@ -8,6 +8,11 @@ LL |     let bar: fn() -> u8 = || { b };
    |
    = note: expected fn pointer `fn() -> u8`
                  found closure `[closure@$DIR/closure-no-fn-2.rs:6:27: 6:35]`
+note: closures can only be coerced to `fn` types if they do not capture any variables
+  --> $DIR/closure-no-fn-2.rs:6:32
+   |
+LL |     let bar: fn() -> u8 = || { b };
+   |                                ^ `b` captured here
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/closures/closure-no-fn-4.rs b/src/test/ui/closures/closure-no-fn-4.rs
new file mode 100644
index 00000000000..275bff645db
--- /dev/null
+++ b/src/test/ui/closures/closure-no-fn-4.rs
@@ -0,0 +1,8 @@
+fn main() {
+    let b = 2;
+    let _: fn(usize) -> usize = match true {
+        true => |a| a + 1,
+        false => |a| a - b,
+        //~^ ERROR `match` arms have incompatible types
+    };
+}
diff --git a/src/test/ui/closures/closure-no-fn-4.stderr b/src/test/ui/closures/closure-no-fn-4.stderr
new file mode 100644
index 00000000000..89798ec5dd3
--- /dev/null
+++ b/src/test/ui/closures/closure-no-fn-4.stderr
@@ -0,0 +1,24 @@
+error[E0308]: `match` arms have incompatible types
+  --> $DIR/closure-no-fn-4.rs:5:18
+   |
+LL |       let _: fn(usize) -> usize = match true {
+   |  _________________________________-
+LL | |         true => |a| a + 1,
+   | |                 --------- this is found to be of type `fn(usize) -> usize`
+LL | |         false => |a| a - b,
+   | |                  ^^^^^^^^^ expected fn pointer, found closure
+LL | |
+LL | |     };
+   | |_____- `match` arms have incompatible types
+   |
+   = note: expected fn pointer `fn(usize) -> usize`
+                 found closure `[closure@$DIR/closure-no-fn-4.rs:5:18: 5:27]`
+note: closures can only be coerced to `fn` types if they do not capture any variables
+  --> $DIR/closure-no-fn-4.rs:5:26
+   |
+LL |         false => |a| a - b,
+   |                          ^ `b` captured here
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/src/test/ui/closures/closure-no-fn-5.rs b/src/test/ui/closures/closure-no-fn-5.rs
new file mode 100644
index 00000000000..43e3e977e34
--- /dev/null
+++ b/src/test/ui/closures/closure-no-fn-5.rs
@@ -0,0 +1,12 @@
+// When providing diagnostics about not being able to coerce a capturing-closure
+// to fn type, we want to report only upto 4 captures.
+
+fn main() {
+    let a = 0u8;
+    let b = 0u8;
+    let c = 0u8;
+    let d = 0u8;
+    let e = 0u8;
+    let bar: fn() -> u8 = || { a; b; c; d; e };
+    //~^ ERROR mismatched types
+}
diff --git a/src/test/ui/closures/closure-no-fn-5.stderr b/src/test/ui/closures/closure-no-fn-5.stderr
new file mode 100644
index 00000000000..1f373f10489
--- /dev/null
+++ b/src/test/ui/closures/closure-no-fn-5.stderr
@@ -0,0 +1,23 @@
+error[E0308]: mismatched types
+  --> $DIR/closure-no-fn-5.rs:10:27
+   |
+LL |     let bar: fn() -> u8 = || { a; b; c; d; e };
+   |              ----------   ^^^^^^^^^^^^^^^^^^^^ expected fn pointer, found closure
+   |              |
+   |              expected due to this
+   |
+   = note: expected fn pointer `fn() -> u8`
+                 found closure `[closure@$DIR/closure-no-fn-5.rs:10:27: 10:47]`
+note: closures can only be coerced to `fn` types if they do not capture any variables
+  --> $DIR/closure-no-fn-5.rs:10:32
+   |
+LL |     let bar: fn() -> u8 = || { a; b; c; d; e };
+   |                                ^  ^  ^  ^ `d` captured here
+   |                                |  |  |
+   |                                |  |  `c` captured here
+   |                                |  `b` captured here
+   |                                `a` captured here
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/src/test/ui/closures/closure-reform-bad.stderr b/src/test/ui/closures/closure-reform-bad.stderr
index 77c8c7ab794..37813879ce7 100644
--- a/src/test/ui/closures/closure-reform-bad.stderr
+++ b/src/test/ui/closures/closure-reform-bad.stderr
@@ -8,6 +8,11 @@ LL |     call_bare(f)
    |
    = note: expected fn pointer `for<'r> fn(&'r str)`
                  found closure `[closure@$DIR/closure-reform-bad.rs:10:13: 10:50]`
+note: closures can only be coerced to `fn` types if they do not capture any variables
+  --> $DIR/closure-reform-bad.rs:10:43
+   |
+LL |     let f = |s: &str| println!("{}{}", s, string);
+   |                                           ^^^^^^ `string` captured here
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/closures/print/closure-print-verbose.stderr b/src/test/ui/closures/print/closure-print-verbose.stderr
index 9e07137a241..d19b07acbf1 100644
--- a/src/test/ui/closures/print/closure-print-verbose.stderr
+++ b/src/test/ui/closures/print/closure-print-verbose.stderr
@@ -8,6 +8,11 @@ LL |     let foo: fn(u8) -> u8 = |v: u8| { a += v; a };
    |
    = note: expected fn pointer `fn(u8) -> u8`
                  found closure `[main::{closure#0} closure_substs=(unavailable)]`
+note: closures can only be coerced to `fn` types if they do not capture any variables
+  --> $DIR/closure-print-verbose.rs:10:39
+   |
+LL |     let foo: fn(u8) -> u8 = |v: u8| { a += v; a };
+   |                                       ^ `a` captured here
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/extern/extern-compare-with-return-type.rs b/src/test/ui/extern/extern-compare-with-return-type.rs
index 6c9ed3760f6..52b51bb943a 100644
--- a/src/test/ui/extern/extern-compare-with-return-type.rs
+++ b/src/test/ui/extern/extern-compare-with-return-type.rs
@@ -2,8 +2,9 @@
 // Tests that we can compare various kinds of extern fn signatures.
 #![allow(non_camel_case_types)]
 
-extern fn voidret1() {}
-extern fn voidret2() {}
+// `dbg!()` differentiates these functions to ensure they won't be merged.
+extern fn voidret1() { dbg!() }
+extern fn voidret2() { dbg!() }
 
 extern fn uintret() -> usize { 22 }
 
diff --git a/src/test/ui/generator/resume-arg-late-bound.stderr b/src/test/ui/generator/resume-arg-late-bound.stderr
index dc0864165ab..63411b59280 100644
--- a/src/test/ui/generator/resume-arg-late-bound.stderr
+++ b/src/test/ui/generator/resume-arg-late-bound.stderr
@@ -2,19 +2,47 @@ error[E0308]: mismatched types
   --> $DIR/resume-arg-late-bound.rs:15:5
    |
 LL |     test(gen);
-   |     ^^^^ one type is more general than the other
+   |     ^^^^ lifetime mismatch
    |
    = note: expected type `for<'a> Generator<&'a mut bool>`
               found type `Generator<&mut bool>`
+note: the required lifetime does not necessarily outlive the anonymous lifetime #1 defined on the body at 11:15
+  --> $DIR/resume-arg-late-bound.rs:11:15
+   |
+LL |       let gen = |arg: &mut bool| {
+   |  _______________^
+LL | |         yield ();
+LL | |         *arg = true;
+LL | |     };
+   | |_____^
+note: the lifetime requirement is introduced here
+  --> $DIR/resume-arg-late-bound.rs:8:17
+   |
+LL | fn test(a: impl for<'a> Generator<&'a mut bool>) {}
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
   --> $DIR/resume-arg-late-bound.rs:15:5
    |
 LL |     test(gen);
-   |     ^^^^ one type is more general than the other
+   |     ^^^^ lifetime mismatch
    |
    = note: expected type `for<'a> Generator<&'a mut bool>`
               found type `Generator<&mut bool>`
+note: the anonymous lifetime #1 defined on the body at 11:15 doesn't meet the lifetime requirements
+  --> $DIR/resume-arg-late-bound.rs:11:15
+   |
+LL |       let gen = |arg: &mut bool| {
+   |  _______________^
+LL | |         yield ();
+LL | |         *arg = true;
+LL | |     };
+   | |_____^
+note: the lifetime requirement is introduced here
+  --> $DIR/resume-arg-late-bound.rs:8:17
+   |
+LL | fn test(a: impl for<'a> Generator<&'a mut bool>) {}
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/hrtb/hrtb-perfect-forwarding.stderr b/src/test/ui/hrtb/hrtb-perfect-forwarding.stderr
index 1ceb0c99e90..ed810d443be 100644
--- a/src/test/ui/hrtb/hrtb-perfect-forwarding.stderr
+++ b/src/test/ui/hrtb/hrtb-perfect-forwarding.stderr
@@ -2,19 +2,39 @@ error[E0308]: mismatched types
   --> $DIR/hrtb-perfect-forwarding.rs:46:5
    |
 LL |     foo_hrtb_bar_not(&mut t);
-   |     ^^^^^^^^^^^^^^^^ one type is more general than the other
+   |     ^^^^^^^^^^^^^^^^ lifetime mismatch
    |
    = note: expected type `Bar<&'a isize>`
               found type `Bar<&'b isize>`
+note: the required lifetime does not necessarily outlive the lifetime `'b` as defined on the function body at 39:21
+  --> $DIR/hrtb-perfect-forwarding.rs:39:21
+   |
+LL | fn foo_hrtb_bar_not<'b,T>(mut t: T)
+   |                     ^^
+note: the lifetime requirement is introduced here
+  --> $DIR/hrtb-perfect-forwarding.rs:40:15
+   |
+LL |     where T : for<'a> Foo<&'a isize> + Bar<&'b isize>
+   |               ^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
   --> $DIR/hrtb-perfect-forwarding.rs:46:5
    |
 LL |     foo_hrtb_bar_not(&mut t);
-   |     ^^^^^^^^^^^^^^^^ one type is more general than the other
+   |     ^^^^^^^^^^^^^^^^ lifetime mismatch
    |
    = note: expected type `Bar<&'a isize>`
               found type `Bar<&'b isize>`
+note: the lifetime `'b` as defined on the function body at 39:21 doesn't meet the lifetime requirements
+  --> $DIR/hrtb-perfect-forwarding.rs:39:21
+   |
+LL | fn foo_hrtb_bar_not<'b,T>(mut t: T)
+   |                     ^^
+note: the lifetime requirement is introduced here
+  --> $DIR/hrtb-perfect-forwarding.rs:40:15
+   |
+LL |     where T : for<'a> Foo<&'a isize> + Bar<&'b isize>
+   |               ^^^^^^^^^^^^^^^^^^^^^^
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/issues/issue-26217.stderr b/src/test/ui/issues/issue-26217.stderr
index b1625536d42..f5c641be2d4 100644
--- a/src/test/ui/issues/issue-26217.stderr
+++ b/src/test/ui/issues/issue-26217.stderr
@@ -3,8 +3,6 @@ error[E0477]: the type `&'a i32` does not fulfill the required lifetime
    |
 LL |     foo::<&'a i32>();
    |     ^^^^^^^^^^^^^^
-   |
-   = note: type must outlive any other region
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-57843.stderr b/src/test/ui/issues/issue-57843.stderr
index 01edb9507a3..7699e97da99 100644
--- a/src/test/ui/issues/issue-57843.stderr
+++ b/src/test/ui/issues/issue-57843.stderr
@@ -6,6 +6,11 @@ LL |     Foo(Box::new(|_| ()));
    |
    = note: expected type `FnOnce<(&'a bool,)>`
               found type `FnOnce<(&bool,)>`
+note: this closure does not fulfill the lifetime requirements
+  --> $DIR/issue-57843.rs:23:18
+   |
+LL |     Foo(Box::new(|_| ()));
+   |                  ^^^^^^
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/lifetimes/issue-79187-2.nll.stderr b/src/test/ui/lifetimes/issue-79187-2.nll.stderr
new file mode 100644
index 00000000000..4970c579e7b
--- /dev/null
+++ b/src/test/ui/lifetimes/issue-79187-2.nll.stderr
@@ -0,0 +1,44 @@
+error: lifetime may not live long enough
+  --> $DIR/issue-79187-2.rs:9:24
+   |
+LL |     take_foo(|a: &i32| a);
+   |                  -   - ^ returning this value requires that `'1` must outlive `'2`
+   |                  |   |
+   |                  |   return type of closure is &'2 i32
+   |                  let's call the lifetime of this reference `'1`
+
+error: lifetime may not live long enough
+  --> $DIR/issue-79187-2.rs:10:34
+   |
+LL |     take_foo(|a: &i32| -> &i32 { a });
+   |                  -        -      ^ returning this value requires that `'1` must outlive `'2`
+   |                  |        |
+   |                  |        let's call the lifetime of this reference `'2`
+   |                  let's call the lifetime of this reference `'1`
+
+error: higher-ranked subtype error
+  --> $DIR/issue-79187-2.rs:8:5
+   |
+LL |     take_foo(|a| a);
+   |     ^^^^^^^^^^^^^^^
+
+error: higher-ranked subtype error
+  --> $DIR/issue-79187-2.rs:8:5
+   |
+LL |     take_foo(|a| a);
+   |     ^^^^^^^^^^^^^^^
+
+error: higher-ranked subtype error
+  --> $DIR/issue-79187-2.rs:9:5
+   |
+LL |     take_foo(|a: &i32| a);
+   |     ^^^^^^^^^^^^^^^^^^^^^
+
+error: higher-ranked subtype error
+  --> $DIR/issue-79187-2.rs:10:5
+   |
+LL |     take_foo(|a: &i32| -> &i32 { a });
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 6 previous errors
+
diff --git a/src/test/ui/lifetimes/issue-79187-2.rs b/src/test/ui/lifetimes/issue-79187-2.rs
new file mode 100644
index 00000000000..29d108facab
--- /dev/null
+++ b/src/test/ui/lifetimes/issue-79187-2.rs
@@ -0,0 +1,23 @@
+trait Foo {}
+
+impl<F> Foo for F where F: Fn(&i32) -> &i32 {}
+
+fn take_foo(_: impl Foo) {}
+
+fn main() {
+    take_foo(|a| a); //~ ERROR mismatched types
+    take_foo(|a: &i32| a); //~ ERROR mismatched types
+    take_foo(|a: &i32| -> &i32 { a }); //~ ERROR mismatched types
+
+    // OK
+    take_foo(identity(|a| a));
+    take_foo(identity(|a: &i32| a));
+    take_foo(identity(|a: &i32| -> &i32 { a }));
+
+    fn identity<F>(t: F) -> F
+    where
+        F: Fn(&i32) -> &i32,
+    {
+        t
+    }
+}
diff --git a/src/test/ui/lifetimes/issue-79187-2.stderr b/src/test/ui/lifetimes/issue-79187-2.stderr
new file mode 100644
index 00000000000..a156c74fb33
--- /dev/null
+++ b/src/test/ui/lifetimes/issue-79187-2.stderr
@@ -0,0 +1,60 @@
+error[E0308]: mismatched types
+  --> $DIR/issue-79187-2.rs:8:5
+   |
+LL |     take_foo(|a| a);
+   |     ^^^^^^^^ lifetime mismatch
+   |
+   = note: expected type `for<'r> Fn<(&'r i32,)>`
+              found type `Fn<(&i32,)>`
+note: this closure does not fulfill the lifetime requirements
+  --> $DIR/issue-79187-2.rs:8:14
+   |
+LL |     take_foo(|a| a);
+   |              ^^^^^
+note: the lifetime requirement is introduced here
+  --> $DIR/issue-79187-2.rs:5:21
+   |
+LL | fn take_foo(_: impl Foo) {}
+   |                     ^^^
+
+error[E0308]: mismatched types
+  --> $DIR/issue-79187-2.rs:9:5
+   |
+LL |     take_foo(|a: &i32| a);
+   |     ^^^^^^^^ lifetime mismatch
+   |
+   = note: expected reference `&i32`
+              found reference `&i32`
+note: the anonymous lifetime #1 defined on the body at 9:14 doesn't meet the lifetime requirements
+  --> $DIR/issue-79187-2.rs:9:14
+   |
+LL |     take_foo(|a: &i32| a);
+   |              ^^^^^^^^^^^
+note: the lifetime requirement is introduced here
+  --> $DIR/issue-79187-2.rs:5:21
+   |
+LL | fn take_foo(_: impl Foo) {}
+   |                     ^^^
+
+error[E0308]: mismatched types
+  --> $DIR/issue-79187-2.rs:10:5
+   |
+LL |     take_foo(|a: &i32| -> &i32 { a });
+   |     ^^^^^^^^ lifetime mismatch
+   |
+   = note: expected reference `&i32`
+              found reference `&i32`
+note: the anonymous lifetime #1 defined on the body at 10:14 doesn't meet the lifetime requirements
+  --> $DIR/issue-79187-2.rs:10:14
+   |
+LL |     take_foo(|a: &i32| -> &i32 { a });
+   |              ^^^^^^^^^^^^^^^^^^^^^^^
+note: the lifetime requirement is introduced here
+  --> $DIR/issue-79187-2.rs:5:21
+   |
+LL | fn take_foo(_: impl Foo) {}
+   |                     ^^^
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/src/test/ui/lifetimes/issue-79187.nll.stderr b/src/test/ui/lifetimes/issue-79187.nll.stderr
new file mode 100644
index 00000000000..aa8809dbc95
--- /dev/null
+++ b/src/test/ui/lifetimes/issue-79187.nll.stderr
@@ -0,0 +1,14 @@
+error: higher-ranked subtype error
+  --> $DIR/issue-79187.rs:5:5
+   |
+LL |     thing(f);
+   |     ^^^^^^^^
+
+error: higher-ranked subtype error
+  --> $DIR/issue-79187.rs:5:5
+   |
+LL |     thing(f);
+   |     ^^^^^^^^
+
+error: aborting due to 2 previous errors
+
diff --git a/src/test/ui/lifetimes/issue-79187.rs b/src/test/ui/lifetimes/issue-79187.rs
new file mode 100644
index 00000000000..bf331d8a606
--- /dev/null
+++ b/src/test/ui/lifetimes/issue-79187.rs
@@ -0,0 +1,6 @@
+fn thing(x: impl FnOnce(&u32)) {}
+
+fn main() {
+    let f = |_| ();
+    thing(f); //~ERROR mismatched types
+}
diff --git a/src/test/ui/lifetimes/issue-79187.stderr b/src/test/ui/lifetimes/issue-79187.stderr
new file mode 100644
index 00000000000..63f501e08fc
--- /dev/null
+++ b/src/test/ui/lifetimes/issue-79187.stderr
@@ -0,0 +1,22 @@
+error[E0308]: mismatched types
+  --> $DIR/issue-79187.rs:5:5
+   |
+LL |     thing(f);
+   |     ^^^^^ lifetime mismatch
+   |
+   = note: expected type `FnOnce<(&u32,)>`
+              found type `FnOnce<(&u32,)>`
+note: this closure does not fulfill the lifetime requirements
+  --> $DIR/issue-79187.rs:4:13
+   |
+LL |     let f = |_| ();
+   |             ^^^^^^
+note: the lifetime requirement is introduced here
+  --> $DIR/issue-79187.rs:1:18
+   |
+LL | fn thing(x: impl FnOnce(&u32)) {}
+   |                  ^^^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/src/test/ui/mismatched_types/closure-arg-type-mismatch.stderr b/src/test/ui/mismatched_types/closure-arg-type-mismatch.stderr
index 0af44d21196..02ba60f7f4b 100644
--- a/src/test/ui/mismatched_types/closure-arg-type-mismatch.stderr
+++ b/src/test/ui/mismatched_types/closure-arg-type-mismatch.stderr
@@ -26,37 +26,77 @@ error[E0308]: mismatched types
   --> $DIR/closure-arg-type-mismatch.rs:10:5
    |
 LL |     baz(f);
-   |     ^^^ one type is more general than the other
+   |     ^^^ lifetime mismatch
    |
    = note: expected type `for<'r> Fn<(*mut &'r u32,)>`
               found type `Fn<(*mut &'a u32,)>`
+note: the required lifetime does not necessarily outlive the lifetime `'a` as defined on the function body at 9:10
+  --> $DIR/closure-arg-type-mismatch.rs:9:10
+   |
+LL | fn _test<'a>(f: fn(*mut &'a u32)) {
+   |          ^^
+note: the lifetime requirement is introduced here
+  --> $DIR/closure-arg-type-mismatch.rs:8:11
+   |
+LL | fn baz<F: Fn(*mut &u32)>(_: F) {}
+   |           ^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
   --> $DIR/closure-arg-type-mismatch.rs:10:5
    |
 LL |     baz(f);
-   |     ^^^ one type is more general than the other
+   |     ^^^ lifetime mismatch
    |
    = note: expected type `FnOnce<(*mut &u32,)>`
               found type `FnOnce<(*mut &'a u32,)>`
+note: the required lifetime does not necessarily outlive the lifetime `'a` as defined on the function body at 9:10
+  --> $DIR/closure-arg-type-mismatch.rs:9:10
+   |
+LL | fn _test<'a>(f: fn(*mut &'a u32)) {
+   |          ^^
+note: the lifetime requirement is introduced here
+  --> $DIR/closure-arg-type-mismatch.rs:8:11
+   |
+LL | fn baz<F: Fn(*mut &u32)>(_: F) {}
+   |           ^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
   --> $DIR/closure-arg-type-mismatch.rs:10:5
    |
 LL |     baz(f);
-   |     ^^^ one type is more general than the other
+   |     ^^^ lifetime mismatch
    |
    = note: expected type `for<'r> Fn<(*mut &'r u32,)>`
               found type `Fn<(*mut &'a u32,)>`
+note: the lifetime `'a` as defined on the function body at 9:10 doesn't meet the lifetime requirements
+  --> $DIR/closure-arg-type-mismatch.rs:9:10
+   |
+LL | fn _test<'a>(f: fn(*mut &'a u32)) {
+   |          ^^
+note: the lifetime requirement is introduced here
+  --> $DIR/closure-arg-type-mismatch.rs:8:11
+   |
+LL | fn baz<F: Fn(*mut &u32)>(_: F) {}
+   |           ^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
   --> $DIR/closure-arg-type-mismatch.rs:10:5
    |
 LL |     baz(f);
-   |     ^^^ one type is more general than the other
+   |     ^^^ lifetime mismatch
    |
    = note: expected type `FnOnce<(*mut &u32,)>`
               found type `FnOnce<(*mut &'a u32,)>`
+note: the lifetime `'a` as defined on the function body at 9:10 doesn't meet the lifetime requirements
+  --> $DIR/closure-arg-type-mismatch.rs:9:10
+   |
+LL | fn _test<'a>(f: fn(*mut &'a u32)) {
+   |          ^^
+note: the lifetime requirement is introduced here
+  --> $DIR/closure-arg-type-mismatch.rs:8:11
+   |
+LL | fn baz<F: Fn(*mut &u32)>(_: F) {}
+   |           ^^^^^^^^^^^^^
 
 error: aborting due to 7 previous errors
 
diff --git a/src/test/ui/mismatched_types/closure-mismatch.stderr b/src/test/ui/mismatched_types/closure-mismatch.stderr
index 149f505dc6f..c41bece3c19 100644
--- a/src/test/ui/mismatched_types/closure-mismatch.stderr
+++ b/src/test/ui/mismatched_types/closure-mismatch.stderr
@@ -2,10 +2,20 @@ error[E0308]: mismatched types
   --> $DIR/closure-mismatch.rs:8:5
    |
 LL |     baz(|_| ());
-   |     ^^^ one type is more general than the other
+   |     ^^^ lifetime mismatch
    |
    = note: expected type `for<'r> Fn<(&'r (),)>`
               found type `Fn<(&(),)>`
+note: this closure does not fulfill the lifetime requirements
+  --> $DIR/closure-mismatch.rs:8:9
+   |
+LL |     baz(|_| ());
+   |         ^^^^^^
+note: the lifetime requirement is introduced here
+  --> $DIR/closure-mismatch.rs:5:11
+   |
+LL | fn baz<T: Foo>(_: T) {}
+   |           ^^^
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/type-alias-impl-trait/issue-57611-trait-alias.nll.stderr b/src/test/ui/type-alias-impl-trait/issue-57611-trait-alias.nll.stderr
index 790aea87510..be1dd1a8524 100644
--- a/src/test/ui/type-alias-impl-trait/issue-57611-trait-alias.nll.stderr
+++ b/src/test/ui/type-alias-impl-trait/issue-57611-trait-alias.nll.stderr
@@ -18,6 +18,11 @@ LL |     type Bar = impl Baz<Self, Self>;
    |
    = note: expected type `for<'r> Fn<(&'r X,)>`
               found type `Fn<(&'static X,)>`
+note: this closure does not fulfill the lifetime requirements
+  --> $DIR/issue-57611-trait-alias.rs:25:9
+   |
+LL |         |x| x
+   |         ^^^^^
 
 error[E0308]: mismatched types
   --> $DIR/issue-57611-trait-alias.rs:17:16
@@ -27,6 +32,11 @@ LL |     type Bar = impl Baz<Self, Self>;
    |
    = note: expected type `FnOnce<(&X,)>`
               found type `FnOnce<(&'static X,)>`
+note: this closure does not fulfill the lifetime requirements
+  --> $DIR/issue-57611-trait-alias.rs:25:9
+   |
+LL |         |x| x
+   |         ^^^^^
 
 error: aborting due to 4 previous errors
 
diff --git a/src/test/ui/type-alias-impl-trait/issue-57611-trait-alias.stderr b/src/test/ui/type-alias-impl-trait/issue-57611-trait-alias.stderr
index 5e2a8db0286..9d9293e958e 100644
--- a/src/test/ui/type-alias-impl-trait/issue-57611-trait-alias.stderr
+++ b/src/test/ui/type-alias-impl-trait/issue-57611-trait-alias.stderr
@@ -6,6 +6,11 @@ LL |     type Bar = impl Baz<Self, Self>;
    |
    = note: expected type `FnOnce<(&X,)>`
               found type `FnOnce<(&X,)>`
+note: this closure does not fulfill the lifetime requirements
+  --> $DIR/issue-57611-trait-alias.rs:25:9
+   |
+LL |         |x| x
+   |         ^^^^^
 
 error[E0308]: mismatched types
   --> $DIR/issue-57611-trait-alias.rs:17:16
@@ -15,6 +20,11 @@ LL |     type Bar = impl Baz<Self, Self>;
    |
    = note: expected type `for<'r> Fn<(&'r X,)>`
               found type `Fn<(&'<empty> X,)>`
+note: this closure does not fulfill the lifetime requirements
+  --> $DIR/issue-57611-trait-alias.rs:25:9
+   |
+LL |         |x| x
+   |         ^^^^^
 
 error[E0308]: mismatched types
   --> $DIR/issue-57611-trait-alias.rs:17:16
@@ -24,6 +34,11 @@ LL |     type Bar = impl Baz<Self, Self>;
    |
    = note: expected type `FnOnce<(&X,)>`
               found type `FnOnce<(&'<empty> X,)>`
+note: this closure does not fulfill the lifetime requirements
+  --> $DIR/issue-57611-trait-alias.rs:25:9
+   |
+LL |         |x| x
+   |         ^^^^^
 
 error[E0308]: mismatched types
   --> $DIR/issue-57611-trait-alias.rs:17:16
@@ -33,6 +48,11 @@ LL |     type Bar = impl Baz<Self, Self>;
    |
    = note: expected type `for<'r> Fn<(&'r X,)>`
               found type `Fn<(&'<empty> X,)>`
+note: this closure does not fulfill the lifetime requirements
+  --> $DIR/issue-57611-trait-alias.rs:25:9
+   |
+LL |         |x| x
+   |         ^^^^^
 
 error[E0308]: mismatched types
   --> $DIR/issue-57611-trait-alias.rs:17:16
@@ -42,6 +62,11 @@ LL |     type Bar = impl Baz<Self, Self>;
    |
    = note: expected type `FnOnce<(&X,)>`
               found type `FnOnce<(&'<empty> X,)>`
+note: this closure does not fulfill the lifetime requirements
+  --> $DIR/issue-57611-trait-alias.rs:25:9
+   |
+LL |         |x| x
+   |         ^^^^^
 
 error: aborting due to 5 previous errors
 
diff --git a/src/test/ui/unboxed-closures/issue-30906.stderr b/src/test/ui/unboxed-closures/issue-30906.stderr
index 5f343ff74a1..ecf3a96b5a8 100644
--- a/src/test/ui/unboxed-closures/issue-30906.stderr
+++ b/src/test/ui/unboxed-closures/issue-30906.stderr
@@ -2,10 +2,15 @@ error[E0308]: mismatched types
   --> $DIR/issue-30906.rs:15:5
    |
 LL |     test(Compose(f, |_| {}));
-   |     ^^^^ one type is more general than the other
+   |     ^^^^ lifetime mismatch
    |
    = note: expected type `FnOnce<(&'x str,)>`
               found type `FnOnce<(&str,)>`
+note: the lifetime requirement is introduced here
+  --> $DIR/issue-30906.rs:3:12
+   |
+LL | fn test<F: for<'x> FnOnce<(&'x str,)>>(_: F) {}
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: aborting due to previous error