Auto merge of #67246 - JohnTitor:rollup-nfa7skn, r=JohnTitor

Rollup of 8 pull requests

Successful merges:

 - #62514 (Clarify `Box<T>` representation and its use in FFI)
 - #66983 (Fix `unused_parens` triggers on macro by example code)
 - #67215 (Fix `-Z print-type-sizes`'s handling of zero-sized fields.)
 - #67230 (Remove irelevant comment on `register_dtor`)
 - #67236 (resolve: Always resolve visibilities on impl items)
 - #67237 (Some small readability improvements)
 - #67238 (Small std::borrow::Cow improvements)
 - #67239 (Make TinyList::remove iterate instead of recurse)

Failed merges:

r? @ghost

src/test/ui/lint/issue-47775-nested-macro-unnecessary-parens-arg.rs

@@ -17,10 +17,7 @@ macro_rules! the_worship_the_heart_lifts_above {
 
 macro_rules! and_the_heavens_reject_not {
     () => {
-        // ↓ But let's test that we still lint for unused parens around
-        // function args inside of simple, one-deep macros.
         #[allow(dead_code)] fn the_night_for_the_morrow() -> Option<isize> { Some((2)) }
-        //~^ WARN unnecessary parentheses around function argument
     }
 }
 

src/test/ui/lint/issue-47775-nested-macro-unnecessary-parens-arg.stderr

@@ -1,15 +0,0 @@
-warning: unnecessary parentheses around function argument
-  --> $DIR/issue-47775-nested-macro-unnecessary-parens-arg.rs:22:83
-   |
-LL |         #[allow(dead_code)] fn the_night_for_the_morrow() -> Option<isize> { Some((2)) }
-   |                                                                                   ^^^ help: remove these parentheses
-...
-LL | and_the_heavens_reject_not!();
-   | ------------------------------ in this macro invocation
-   |
-note: lint level defined here
-  --> $DIR/issue-47775-nested-macro-unnecessary-parens-arg.rs:3:9
-   |
-LL | #![warn(unused_parens)]
-   |         ^^^^^^^^^^^^^
-

src/test/ui/lint/lint-unnecessary-parens.rs

@@ -25,6 +25,12 @@ fn passes_unused_parens_lint() -> &'static (dyn Trait) {
     panic!()
 }
 
+macro_rules! baz {
+    ($($foo:expr),+) => {
+        ($($foo),*)
+    }
+}
+
 fn main() {
     foo();
     bar((true)); //~ ERROR unnecessary parentheses around function argument
@@ -55,4 +61,7 @@ fn main() {
     let mut _a = (0); //~ ERROR unnecessary parentheses around assigned value
     _a = (0); //~ ERROR unnecessary parentheses around assigned value
     _a += (1); //~ ERROR unnecessary parentheses around assigned value
+
+    let _a = baz!(3, 4);
+    let _b = baz!(3);
 }

src/test/ui/lint/lint-unnecessary-parens.stderr

@@ -23,25 +23,25 @@ LL | fn unused_parens_around_return_type() -> (u32) {
    |                                          ^^^^^ help: remove these parentheses
 
 error: unnecessary parentheses around function argument
-  --> $DIR/lint-unnecessary-parens.rs:30:9
+  --> $DIR/lint-unnecessary-parens.rs:36:9
    |
 LL |     bar((true));
    |         ^^^^^^ help: remove these parentheses
 
 error: unnecessary parentheses around `if` condition
-  --> $DIR/lint-unnecessary-parens.rs:32:8
+  --> $DIR/lint-unnecessary-parens.rs:38:8
    |
 LL |     if (true) {}
    |        ^^^^^^ help: remove these parentheses
 
 error: unnecessary parentheses around `while` condition
-  --> $DIR/lint-unnecessary-parens.rs:33:11
+  --> $DIR/lint-unnecessary-parens.rs:39:11
    |
 LL |     while (true) {}
    |           ^^^^^^ help: remove these parentheses
 
 warning: denote infinite loops with `loop { ... }`
-  --> $DIR/lint-unnecessary-parens.rs:33:5
+  --> $DIR/lint-unnecessary-parens.rs:39:5
    |
 LL |     while (true) {}
    |     ^^^^^^^^^^^^ help: use `loop`
@@ -49,43 +49,43 @@ LL |     while (true) {}
    = note: `#[warn(while_true)]` on by default
 
 error: unnecessary parentheses around `match` head expression
-  --> $DIR/lint-unnecessary-parens.rs:35:11
+  --> $DIR/lint-unnecessary-parens.rs:41:11
    |
 LL |     match (true) {
    |           ^^^^^^ help: remove these parentheses
 
 error: unnecessary parentheses around `let` head expression
-  --> $DIR/lint-unnecessary-parens.rs:38:16
+  --> $DIR/lint-unnecessary-parens.rs:44:16
    |
 LL |     if let 1 = (1) {}
    |                ^^^ help: remove these parentheses
 
 error: unnecessary parentheses around `let` head expression
-  --> $DIR/lint-unnecessary-parens.rs:39:19
+  --> $DIR/lint-unnecessary-parens.rs:45:19
    |
 LL |     while let 1 = (2) {}
    |                   ^^^ help: remove these parentheses
 
 error: unnecessary parentheses around method argument
-  --> $DIR/lint-unnecessary-parens.rs:53:24
+  --> $DIR/lint-unnecessary-parens.rs:59:24
    |
 LL |     X { y: false }.foo((true));
    |                        ^^^^^^ help: remove these parentheses
 
 error: unnecessary parentheses around assigned value
-  --> $DIR/lint-unnecessary-parens.rs:55:18
+  --> $DIR/lint-unnecessary-parens.rs:61:18
    |
 LL |     let mut _a = (0);
    |                  ^^^ help: remove these parentheses
 
 error: unnecessary parentheses around assigned value
-  --> $DIR/lint-unnecessary-parens.rs:56:10
+  --> $DIR/lint-unnecessary-parens.rs:62:10
    |
 LL |     _a = (0);
    |          ^^^ help: remove these parentheses
 
 error: unnecessary parentheses around assigned value
-  --> $DIR/lint-unnecessary-parens.rs:57:11
+  --> $DIR/lint-unnecessary-parens.rs:63:11
    |
 LL |     _a += (1);
    |           ^^^ help: remove these parentheses

src/test/ui/print_type_sizes/zero-sized-fields.rs

@@ -0,0 +1,46 @@
+// compile-flags: -Z print-type-sizes
+// build-pass (FIXME(62277): could be check-pass?)
+
+// At one point, zero-sized fields such as those in this file were causing
+// incorrect output from `-Z print-type-sizes`.
+
+#![feature(start)]
+
+struct S1 {
+    x: u32,
+    y: u32,
+    tag: (),
+}
+
+struct Void();
+struct Empty {}
+
+struct S5<TagW, TagZ> {
+    tagw: TagW,
+    w: u32,
+    unit: (),
+    x: u32,
+    void: Void,
+    y: u32,
+    empty: Empty,
+    z: u32,
+    tagz: TagZ,
+}
+
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    let _s1: S1 = S1 { x: 0, y: 0, tag: () };
+
+    let _s5: S5<(), Empty> = S5 {
+        tagw: (),
+        w: 1,
+        unit: (),
+        x: 2,
+        void: Void(),
+        y: 3,
+        empty: Empty {},
+        z: 4,
+        tagz: Empty {},
+    };
+    0
+}

src/test/ui/print_type_sizes/zero-sized-fields.stdout

@@ -0,0 +1,16 @@
+print-type-size type: `S5<(), Empty>`: 16 bytes, alignment: 4 bytes
+print-type-size     field `.tagw`: 0 bytes
+print-type-size     field `.unit`: 0 bytes
+print-type-size     field `.void`: 0 bytes
+print-type-size     field `.empty`: 0 bytes
+print-type-size     field `.tagz`: 0 bytes
+print-type-size     field `.w`: 4 bytes
+print-type-size     field `.x`: 4 bytes
+print-type-size     field `.y`: 4 bytes
+print-type-size     field `.z`: 4 bytes
+print-type-size type: `S1`: 8 bytes, alignment: 4 bytes
+print-type-size     field `.tag`: 0 bytes
+print-type-size     field `.x`: 4 bytes
+print-type-size     field `.y`: 4 bytes
+print-type-size type: `Empty`: 0 bytes, alignment: 1 bytes
+print-type-size type: `Void`: 0 bytes, alignment: 1 bytes

src/test/ui/resolve/impl-items-vis-unresolved.rs

@@ -0,0 +1,25 @@
+// Visibilities on impl items expanded from macros are resolved (issue #64705).
+
+macro_rules! perftools_inline {
+    ($($item:tt)*) => (
+        $($item)*
+    );
+}
+
+mod state {
+    pub struct RawFloatState;
+    impl RawFloatState {
+        perftools_inline! {
+            pub(super) fn new() {} // OK
+        }
+    }
+}
+
+pub struct RawFloatState;
+impl RawFloatState {
+    perftools_inline! {
+        pub(super) fn new() {} //~ ERROR failed to resolve: there are too many initial `super`s
+    }
+}
+
+fn main() {}

src/test/ui/resolve/impl-items-vis-unresolved.stderr

@@ -0,0 +1,9 @@
+error[E0433]: failed to resolve: there are too many initial `super`s.
+  --> $DIR/impl-items-vis-unresolved.rs:21:13
+   |
+LL |         pub(super) fn new() {}
+   |             ^^^^^ there are too many initial `super`s.
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0433`.