Rollup merge of #70906 - gizmondo:66107, r=estebank

Suggest move for closures and async blocks in more cases.

Fixes #66107, also improves #67577
Related PR https://github.com/rust-lang/rust/pull/65166

6 files changed, 56 insertions, 25 deletions

diff --git a/src/test/ui/async-await/async-borrowck-escaping-block-error.fixed b/src/test/ui/async-await/async-borrowck-escaping-block-error.fixed
index f004b4180dd..605cfdfe747 100644
--- a/src/test/ui/async-await/async-borrowck-escaping-block-error.fixed
+++ b/src/test/ui/async-await/async-borrowck-escaping-block-error.fixed
@@ -1,12 +1,18 @@
 // edition:2018
 // run-rustfix
 
-fn foo() -> Box<impl std::future::Future<Output = u32>> {
+fn test_boxed() -> Box<impl std::future::Future<Output = u32>> {
     let x = 0u32;
     Box::new(async move { x } )
     //~^ ERROR E0373
 }
 
+fn test_ref(x: &u32) -> impl std::future::Future<Output = u32> + '_ {
+    async move { *x }
+    //~^ ERROR E0373
+}
+
 fn main() {
-    let _foo = foo();
+    let _ = test_boxed();
+    let _ = test_ref(&0u32);
 }
diff --git a/src/test/ui/async-await/async-borrowck-escaping-block-error.rs b/src/test/ui/async-await/async-borrowck-escaping-block-error.rs
index 4f35fd52ca3..ec752c15fa2 100644
--- a/src/test/ui/async-await/async-borrowck-escaping-block-error.rs
+++ b/src/test/ui/async-await/async-borrowck-escaping-block-error.rs
@@ -1,12 +1,18 @@
 // edition:2018
 // run-rustfix
 
-fn foo() -> Box<impl std::future::Future<Output = u32>> {
+fn test_boxed() -> Box<impl std::future::Future<Output = u32>> {
     let x = 0u32;
     Box::new(async { x } )
     //~^ ERROR E0373
 }
 
+fn test_ref(x: &u32) -> impl std::future::Future<Output = u32> + '_ {
+    async { *x }
+    //~^ ERROR E0373
+}
+
 fn main() {
-    let _foo = foo();
+    let _ = test_boxed();
+    let _ = test_ref(&0u32);
 }
diff --git a/src/test/ui/async-await/async-borrowck-escaping-block-error.stderr b/src/test/ui/async-await/async-borrowck-escaping-block-error.stderr
index 0eb3971d14a..193026541d0 100644
--- a/src/test/ui/async-await/async-borrowck-escaping-block-error.stderr
+++ b/src/test/ui/async-await/async-borrowck-escaping-block-error.stderr
@@ -1,4 +1,4 @@
-error[E0373]: closure may outlive the current function, but it borrows `x`, which is owned by the current function
+error[E0373]: async block may outlive the current function, but it borrows `x`, which is owned by the current function
   --> $DIR/async-borrowck-escaping-block-error.rs:6:20
    |
 LL |     Box::new(async { x } )
@@ -7,16 +7,35 @@ LL |     Box::new(async { x } )
    |                    | `x` is borrowed here
    |                    may outlive borrowed value `x`
    |
-note: generator is returned here
-  --> $DIR/async-borrowck-escaping-block-error.rs:4:13
+note: async block is returned here
+  --> $DIR/async-borrowck-escaping-block-error.rs:4:20
    |
-LL | fn foo() -> Box<impl std::future::Future<Output = u32>> {
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | fn test_boxed() -> Box<impl std::future::Future<Output = u32>> {
+   |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 help: to force the async block to take ownership of `x` (and any other referenced variables), use the `move` keyword
    |
 LL |     Box::new(async move { x } )
    |                    ^^^^^^^^^^
 
-error: aborting due to previous error
+error[E0373]: async block may outlive the current function, but it borrows `x`, which is owned by the current function
+  --> $DIR/async-borrowck-escaping-block-error.rs:11:11
+   |
+LL |     async { *x }
+   |           ^^^-^^
+   |           |  |
+   |           |  `x` is borrowed here
+   |           may outlive borrowed value `x`
+   |
+note: async block is returned here
+  --> $DIR/async-borrowck-escaping-block-error.rs:11:5
+   |
+LL |     async { *x }
+   |     ^^^^^^^^^^^^
+help: to force the async block to take ownership of `x` (and any other referenced variables), use the `move` keyword
+   |
+LL |     async move { *x }
+   |           ^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0373`.
diff --git a/src/test/ui/async-await/async-borrowck-escaping-closure-error.rs b/src/test/ui/async-await/async-borrowck-escaping-closure-error.rs
index d2fa5d0a3d0..e667b72aee5 100644
--- a/src/test/ui/async-await/async-borrowck-escaping-closure-error.rs
+++ b/src/test/ui/async-await/async-borrowck-escaping-closure-error.rs
@@ -1,5 +1,5 @@
 // edition:2018
-#![feature(async_closure,async_await)]
+#![feature(async_closure)]
 fn foo() -> Box<dyn std::future::Future<Output = u32>> {
     let x = 0u32;
     Box::new((async || x)())
diff --git a/src/test/ui/impl-trait/does-not-live-long-enough.rs b/src/test/ui/impl-trait/does-not-live-long-enough.rs
index 6179132b3f6..d2a345231eb 100644
--- a/src/test/ui/impl-trait/does-not-live-long-enough.rs
+++ b/src/test/ui/impl-trait/does-not-live-long-enough.rs
@@ -4,7 +4,7 @@ struct List {
 impl List {
     fn started_with<'a>(&'a self, prefix: &'a str) -> impl Iterator<Item=&'a str> {
         self.data.iter().filter(|s| s.starts_with(prefix)).map(|s| s.as_ref())
-        //~^ ERROR does not live long enough
+        //~^ ERROR E0373
     }
 }
 
diff --git a/src/test/ui/impl-trait/does-not-live-long-enough.stderr b/src/test/ui/impl-trait/does-not-live-long-enough.stderr
index 9cff4bcd8b5..468c2f36629 100644
--- a/src/test/ui/impl-trait/does-not-live-long-enough.stderr
+++ b/src/test/ui/impl-trait/does-not-live-long-enough.stderr
@@ -1,21 +1,21 @@
-error[E0597]: `prefix` does not live long enough
-  --> $DIR/does-not-live-long-enough.rs:6:51
+error[E0373]: closure may outlive the current function, but it borrows `prefix`, which is owned by the current function
+  --> $DIR/does-not-live-long-enough.rs:6:33
    |
-LL |     fn started_with<'a>(&'a self, prefix: &'a str) -> impl Iterator<Item=&'a str> {
-   |                     -- lifetime `'a` defined here     --------------------------- opaque type requires that `prefix` is borrowed for `'a`
 LL |         self.data.iter().filter(|s| s.starts_with(prefix)).map(|s| s.as_ref())
-   |                                 ---               ^^^^^^ borrowed value does not live long enough
+   |                                 ^^^               ------ `prefix` is borrowed here
    |                                 |
-   |                                 value captured here
-LL |
-LL |     }
-   |     - `prefix` dropped here while still borrowed
+   |                                 may outlive borrowed value `prefix`
+   |
+note: closure is returned here
+  --> $DIR/does-not-live-long-enough.rs:5:55
    |
-help: you can add a bound to the opaque type to make it last less than `'static` and match `'a`
+LL |     fn started_with<'a>(&'a self, prefix: &'a str) -> impl Iterator<Item=&'a str> {
+   |                                                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+help: to force the closure to take ownership of `prefix` (and any other referenced variables), use the `move` keyword
    |
-LL |     fn started_with<'a>(&'a self, prefix: &'a str) -> impl Iterator<Item=&'a str> + 'a {
-   |                                                                                   ^^^^
+LL |         self.data.iter().filter(move |s| s.starts_with(prefix)).map(|s| s.as_ref())
+   |                                 ^^^^^^^^
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0597`.
+For more information about this error, try `rustc --explain E0373`.