Auto merge of #63575 - Centril:rollup-anlv9g5, r=Centril

Rollup of 11 pull requests

Successful merges:

 - #62984 (Add lint for excess trailing semicolons)
 - #63075 (Miri: Check that a ptr is aligned and inbounds already when evaluating `*`)
 - #63490 (libsyntax: cleanup and refactor `pat.rs`)
 - #63507 (When needing type annotations in local bindings, account for impl Trait and closures)
 - #63509 (Point at the right enclosing scope when using `await` in non-async fn)
 - #63528 (syntax: Remove `DummyResult::expr_only`)
 - #63537 (expand: Unimplement `MutVisitor` on `MacroExpander`)
 - #63542 (Add NodeId for Arm, Field and FieldPat)
 - #63543 (Merge Variant and Variant_)
 - #63560 (move test that shouldn't be in test/run-pass/)
 - #63570 (Adjust tracking issues for `MaybeUninit<T>` gates)

Failed merges:

r? @ghost

src/test/ui/async-await/issues/non-async-enclosing-span.rs

@@ -0,0 +1,12 @@
+// edition:2018
+#![feature(async_await)]
+
+async fn do_the_thing() -> u8 {
+    8
+}
+// #63398: point at the enclosing scope and not the previously seen closure
+fn main() {  //~ NOTE this is not `async`
+    let x = move || {};
+    let y = do_the_thing().await; //~ ERROR `await` is only allowed inside `async` functions
+    //~^ NOTE only allowed inside `async` functions and blocks
+}

src/test/ui/async-await/issues/non-async-enclosing-span.stderr

@@ -0,0 +1,11 @@
+error[E0728]: `await` is only allowed inside `async` functions and blocks
+  --> $DIR/non-async-enclosing-span.rs:10:13
+   |
+LL | fn main() {
+   |    ---- this is not `async`
+LL |     let x = move || {};
+LL |     let y = do_the_thing().await;
+   |             ^^^^^^^^^^^^^^^^^^^^ only allowed inside `async` functions and blocks
+
+error: aborting due to previous error
+

src/test/ui/block-expr-precedence.stderr

@@ -0,0 +1,8 @@
+warning: unnecessary trailing semicolons
+  --> $DIR/block-expr-precedence.rs:60:21
+   |
+LL |   if (true) { 12; };;; -num;
+   |                     ^^ help: remove these semicolons
+   |
+   = note: `#[warn(redundant_semicolon)]` on by default
+

src/test/ui/consts/const-eval/ub-nonnull.rs

@@ -11,10 +11,11 @@ const NON_NULL_PTR: NonNull<u8> = unsafe { mem::transmute(&1) };
 const NULL_PTR: NonNull<u8> = unsafe { mem::transmute(0usize) };
 //~^ ERROR it is undefined behavior to use this value
 
+#[deny(const_err)] // this triggers a `const_err` so validation does not even happen
 const OUT_OF_BOUNDS_PTR: NonNull<u8> = { unsafe {
-//~^ ERROR it is undefined behavior to use this value
-    let ptr: &(u8, u8, u8) = mem::transmute(&0u8); // &0 gets promoted so it does not dangle
-    let out_of_bounds_ptr = &ptr.2; // use address-of-field for pointer arithmetic
+    let ptr: &[u8; 256] = mem::transmute(&0u8); // &0 gets promoted so it does not dangle
+    // Use address-of-element for pointer arithmetic. This could wrap around to NULL!
+    let out_of_bounds_ptr = &ptr[255]; //~ ERROR any use of this value will cause an error
     mem::transmute(out_of_bounds_ptr)
 } };
 

src/test/ui/consts/const-eval/ub-nonnull.stderr

@@ -6,21 +6,26 @@ LL | const NULL_PTR: NonNull<u8> = unsafe { mem::transmute(0usize) };
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
-error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-nonnull.rs:14:1
+error: any use of this value will cause an error
+  --> $DIR/ub-nonnull.rs:18:29
    |
 LL | / const OUT_OF_BOUNDS_PTR: NonNull<u8> = { unsafe {
-LL | |
-LL | |     let ptr: &(u8, u8, u8) = mem::transmute(&0u8); // &0 gets promoted so it does not dangle
-LL | |     let out_of_bounds_ptr = &ptr.2; // use address-of-field for pointer arithmetic
+LL | |     let ptr: &[u8; 256] = mem::transmute(&0u8); // &0 gets promoted so it does not dangle
+LL | |     // Use address-of-element for pointer arithmetic. This could wrap around to NULL!
+LL | |     let out_of_bounds_ptr = &ptr[255];
+   | |                             ^^^^^^^^^ Memory access failed: pointer must be in-bounds at offset 256, but is outside bounds of allocation 6 which has size 1
 LL | |     mem::transmute(out_of_bounds_ptr)
 LL | | } };
-   | |____^ type validation failed: encountered a potentially NULL pointer, but expected something that cannot possibly fail to be greater or equal to 1
+   | |____-
    |
-   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
+note: lint level defined here
+  --> $DIR/ub-nonnull.rs:14:8
+   |
+LL | #[deny(const_err)] // this triggers a `const_err` so validation does not even happen
+   |        ^^^^^^^^^
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-nonnull.rs:21:1
+  --> $DIR/ub-nonnull.rs:22:1
    |
 LL | const NULL_U8: NonZeroU8 = unsafe { mem::transmute(0u8) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered 0, but expected something greater or equal to 1
@@ -28,7 +33,7 @@ LL | const NULL_U8: NonZeroU8 = unsafe { mem::transmute(0u8) };
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-nonnull.rs:23:1
+  --> $DIR/ub-nonnull.rs:24:1
    |
 LL | const NULL_USIZE: NonZeroUsize = unsafe { mem::transmute(0usize) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered 0, but expected something greater or equal to 1
@@ -36,7 +41,7 @@ LL | const NULL_USIZE: NonZeroUsize = unsafe { mem::transmute(0usize) };
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-nonnull.rs:30:1
+  --> $DIR/ub-nonnull.rs:31:1
    |
 LL | const UNINIT: NonZeroU8 = unsafe { Transmute { uninit: () }.out };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered uninitialized bytes, but expected something greater or equal to 1
@@ -44,7 +49,7 @@ LL | const UNINIT: NonZeroU8 = unsafe { Transmute { uninit: () }.out };
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-nonnull.rs:38:1
+  --> $DIR/ub-nonnull.rs:39:1
    |
 LL | const BAD_RANGE1: RestrictedRange1 = unsafe { RestrictedRange1(42) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered 42, but expected something in the range 10..=30
@@ -52,7 +57,7 @@ LL | const BAD_RANGE1: RestrictedRange1 = unsafe { RestrictedRange1(42) };
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
 error[E0080]: it is undefined behavior to use this value
-  --> $DIR/ub-nonnull.rs:44:1
+  --> $DIR/ub-nonnull.rs:45:1
    |
 LL | const BAD_RANGE2: RestrictedRange2 = unsafe { RestrictedRange2(20) };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered 20, but expected something less or equal to 10, or greater or equal to 30

src/test/ui/did_you_mean/issue-46836-identifier-not-instead-of-negation.stderr

@@ -28,7 +28,10 @@ error: expected `{`, found `;`
 LL |     if not  // lack of braces is [sic]
    |     -- this `if` statement has a condition, but no block
 LL |         println!("Then when?");
-   |                               ^ expected `{`
+   |                               ^
+   |                               |
+   |                               expected `{`
+   |                               help: try placing this code inside a block: `{ ; }`
 
 error: unexpected `2` after identifier
   --> $DIR/issue-46836-identifier-not-instead-of-negation.rs:26:24

src/test/ui/error-codes/E0282.stderr

@@ -2,10 +2,7 @@ error[E0282]: type annotations needed
   --> $DIR/E0282.rs:2:9
    |
 LL |     let x = "hello".chars().rev().collect();
-   |         ^
-   |         |
-   |         cannot infer type
-   |         consider giving `x` a type
+   |         ^ consider giving `x` a type
 
 error: aborting due to previous error
 

src/test/ui/for/for-loop-unconstrained-element-type.stderr

@@ -2,10 +2,7 @@ error[E0282]: type annotations needed
   --> $DIR/for-loop-unconstrained-element-type.rs:8:14
    |
 LL |     for i in Vec::new() { }
-   |              ^^^^^^^^^^
-   |              |
-   |              cannot infer type
-   |              the element type for this iterator is not specified
+   |              ^^^^^^^^^^ the element type for this iterator is not specified
 
 error: aborting due to previous error
 

src/test/ui/generator/niche-in-generator.rs

@@ -1,5 +1,7 @@
 // Test that niche finding works with captured generator upvars.
 
+// run-pass
+
 #![feature(generators)]
 
 use std::mem::size_of_val;

src/test/ui/inference/cannot-infer-async-enabled-impl-trait-bindings.rs

@@ -0,0 +1,18 @@
+// edition:2018
+#![feature(async_await)]
+#![feature(impl_trait_in_bindings)]
+//~^ WARN the feature `impl_trait_in_bindings` is incomplete and may cause the compiler to crash
+
+use std::io::Error;
+
+fn make_unit() -> Result<(), Error> {
+    Ok(())
+}
+
+fn main() {
+    let fut = async {
+        make_unit()?; //~ ERROR type annotations needed
+
+        Ok(())
+    };
+}

src/test/ui/inference/cannot-infer-async-enabled-impl-trait-bindings.stderr

@@ -0,0 +1,19 @@
+warning: the feature `impl_trait_in_bindings` is incomplete and may cause the compiler to crash
+  --> $DIR/cannot-infer-async-enabled-impl-trait-bindings.rs:3:12
+   |
+LL | #![feature(impl_trait_in_bindings)]
+   |            ^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(incomplete_features)]` on by default
+
+error[E0282]: type annotations needed for `impl std::future::Future`
+  --> $DIR/cannot-infer-async-enabled-impl-trait-bindings.rs:14:9
+   |
+LL |     let fut = async {
+   |         --- consider giving `fut` the explicit type `impl std::future::Future`, with the type parameters specified
+LL |         make_unit()?;
+   |         ^^^^^^^^^^^^ cannot infer type
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0282`.

src/test/ui/inference/cannot-infer-async.rs

@@ -0,0 +1,16 @@
+// edition:2018
+#![feature(async_await)]
+
+use std::io::Error;
+
+fn make_unit() -> Result<(), Error> {
+    Ok(())
+}
+
+fn main() {
+    let fut = async {
+        make_unit()?; //~ ERROR type annotations needed
+
+        Ok(())
+    };
+}

src/test/ui/inference/cannot-infer-async.stderr

@@ -0,0 +1,11 @@
+error[E0282]: type annotations needed
+  --> $DIR/cannot-infer-async.rs:12:9
+   |
+LL |     let fut = async {
+   |         --- consider giving `fut` a type
+LL |         make_unit()?;
+   |         ^^^^^^^^^^^^ cannot infer type
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0282`.

src/test/ui/inference/cannot-infer-closure.rs

@@ -0,0 +1,6 @@
+fn main() {
+    let x = |a: (), b: ()| {
+        Err(a)?; //~ ERROR type annotations needed for the closure
+        Ok(b)
+    };
+}

src/test/ui/inference/cannot-infer-closure.stderr

@@ -0,0 +1,13 @@
+error[E0282]: type annotations needed for the closure `fn((), ()) -> std::result::Result<(), _>`
+  --> $DIR/cannot-infer-closure.rs:3:9
+   |
+LL |         Err(a)?;
+   |         ^^^^^^^ cannot infer type
+help: give this closure an explicit return type without `_` placeholders
+   |
+LL |     let x = |a: (), b: ()| -> std::result::Result<(), _> {
+   |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0282`.

src/test/ui/issues/issue-18159.stderr

@@ -2,10 +2,7 @@ error[E0282]: type annotations needed
   --> $DIR/issue-18159.rs:2:9
    |
 LL |     let x;
-   |         ^
-   |         |
-   |         cannot infer type
-   |         consider giving `x` a type
+   |         ^ consider giving `x` a type
 
 error: aborting due to previous error
 

src/test/ui/match/match-unresolved-one-arm.stderr

@@ -2,10 +2,7 @@ error[E0282]: type annotations needed
   --> $DIR/match-unresolved-one-arm.rs:4:9
    |
 LL |     let x = match () {
-   |         ^
-   |         |
-   |         cannot infer type
-   |         consider giving `x` a type
+   |         ^ consider giving `x` a type
 
 error: aborting due to previous error
 

src/test/ui/parser/doc-before-semi.rs

@@ -3,4 +3,6 @@ fn main() {
     //~^ ERROR found a documentation comment that doesn't document anything
     //~| HELP maybe a comment was intended
     ;
+    //~^ WARNING unnecessary trailing semicolon
+    //~| HELP remove this semicolon
 }

src/test/ui/parser/doc-before-semi.stderr

@@ -6,6 +6,14 @@ LL |     /// hi
    |
    = help: doc comments must come before what they document, maybe a comment was intended with `//`?
 
+warning: unnecessary trailing semicolon
+  --> $DIR/doc-before-semi.rs:5:5
+   |
+LL |     ;
+   |     ^ help: remove this semicolon
+   |
+   = note: `#[warn(redundant_semicolon)]` on by default
+
 error: aborting due to previous error
 
 For more information about this error, try `rustc --explain E0585`.

src/test/ui/proc-macro/span-preservation.rs

@@ -9,7 +9,7 @@ extern crate test_macros;
 
 #[recollect_attr]
 fn a() {
-    let x: usize = "hello";;;;; //~ ERROR mismatched types
+    let x: usize = "hello"; //~ ERROR mismatched types
 }
 
 #[recollect_attr]

src/test/ui/proc-macro/span-preservation.stderr

@@ -6,7 +6,7 @@ error[E0308]: mismatched types
 error[E0308]: mismatched types
   --> $DIR/span-preservation.rs:12:20
    |
-LL |     let x: usize = "hello";;;;;
+LL |     let x: usize = "hello";
    |                    ^^^^^^^ expected usize, found reference
    |
    = note: expected type `usize`

src/test/ui/suggestions/suggest-box.fixed

@@ -0,0 +1,8 @@
+// run-rustfix
+
+fn main() {
+    let _x: Box<dyn Fn() -> Result<(), ()>> = Box::new(|| { //~ ERROR mismatched types
+        Err(())?;
+        Ok(())
+    });
+}

src/test/ui/suggestions/suggest-box.rs

@@ -0,0 +1,8 @@
+// run-rustfix
+
+fn main() {
+    let _x: Box<dyn Fn() -> Result<(), ()>> = || { //~ ERROR mismatched types
+        Err(())?;
+        Ok(())
+    };
+}

src/test/ui/suggestions/suggest-box.stderr

@@ -0,0 +1,24 @@
+error[E0308]: mismatched types
+  --> $DIR/suggest-box.rs:4:47
+   |
+LL |       let _x: Box<dyn Fn() -> Result<(), ()>> = || {
+   |  _______________________________________________^
+LL | |         Err(())?;
+LL | |         Ok(())
+LL | |     };
+   | |_____^ expected struct `std::boxed::Box`, found closure
+   |
+   = note: expected type `std::boxed::Box<dyn std::ops::Fn() -> std::result::Result<(), ()>>`
+              found type `[closure@$DIR/suggest-box.rs:4:47: 7:6]`
+   = note: for more on the distinction between the stack and the heap, read https://doc.rust-lang.org/book/ch15-01-box.html, https://doc.rust-lang.org/rust-by-example/std/box.html, and https://doc.rust-lang.org/std/boxed/index.html
+help: store this in the heap by calling `Box::new`
+   |
+LL |     let _x: Box<dyn Fn() -> Result<(), ()>> = Box::new(|| {
+LL |         Err(())?;
+LL |         Ok(())
+LL |     });
+   |
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0308`.

src/test/ui/suggestions/suggest-closure-return-type-1.rs

@@ -0,0 +1,3 @@
+fn main() {
+    let _v = || -> _ { [] }; //~ ERROR type annotations needed for the closure
+}

src/test/ui/suggestions/suggest-closure-return-type-1.stderr

@@ -0,0 +1,13 @@
+error[E0282]: type annotations needed for the closure `fn() -> [_; 0]`
+  --> $DIR/suggest-closure-return-type-1.rs:2:24
+   |
+LL |     let _v = || -> _ { [] };
+   |                        ^^ cannot infer type
+help: give this closure an explicit return type without `_` placeholders
+   |
+LL |     let _v = || -> [_; 0] { [] };
+   |                    ^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0282`.

src/test/ui/suggestions/suggest-closure-return-type-2.rs

@@ -0,0 +1,3 @@
+fn main() {
+    let _v = || { [] }; //~ ERROR type annotations needed for the closure
+}

src/test/ui/suggestions/suggest-closure-return-type-2.stderr

@@ -0,0 +1,13 @@
+error[E0282]: type annotations needed for the closure `fn() -> [_; 0]`
+  --> $DIR/suggest-closure-return-type-2.rs:2:19
+   |
+LL |     let _v = || { [] };
+   |                   ^^ cannot infer type
+help: give this closure an explicit return type without `_` placeholders
+   |
+LL |     let _v = || -> [_; 0] { [] };
+   |                 ^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0282`.

src/test/ui/suggestions/suggest-closure-return-type-3.rs

@@ -0,0 +1,3 @@
+fn main() {
+    let _v = || []; //~ ERROR type annotations needed for the closure
+}

src/test/ui/suggestions/suggest-closure-return-type-3.stderr

@@ -0,0 +1,13 @@
+error[E0282]: type annotations needed for the closure `fn() -> [_; 0]`
+  --> $DIR/suggest-closure-return-type-3.rs:2:17
+   |
+LL |     let _v = || [];
+   |                 ^^ cannot infer type
+help: give this closure an explicit return type without `_` placeholders
+   |
+LL |     let _v = || -> [_; 0] { [] };
+   |                 ^^^^^^^^^^^    ^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0282`.