Auto merge of #120279 - fmease:rollup-4nhar13, r=fmease

Rollup of 12 pull requests

Successful merges:

 - #112806 (Small code improvements in `collect_intra_doc_links.rs`)
 - #119460 (coverage: Never emit improperly-ordered coverage regions)
 - #119766 (Split tait and impl trait in assoc items logic)
 - #120062 (llvm: change data layout bug to an error and make it trigger more)
 - #120099 (linker: Refactor library linking methods in `trait Linker`)
 - #120139 (Do not normalize closure signature when building `FnOnce` shim)
 - #120160 (Manually implement derived `NonZero` traits.)
 - #120171 (Fix assume and assert in jump threading)
 - #120183 (Add `#[coverage(off)]` to closures introduced by `#[test]` and `#[bench]`)
 - #120195 (add several resolution test cases)
 - #120259 (Split Diagnostics for Uncommon Codepoints: Add List to Display Characters Involved)
 - #120261 (Provide structured suggestion to use trait objects in some cases of `if` arm type divergence)

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

Author: bors

compiler/rustc_builtin_macros/src/lib.rs

@@ -6,6 +6,7 @@
 #![doc(rust_logo)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![feature(array_windows)]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(decl_macro)]
 #![feature(if_let_guard)]

compiler/rustc_builtin_macros/src/test.rs

@@ -9,6 +9,7 @@ use rustc_errors::{Applicability, DiagnosticBuilder, Level};
 use rustc_expand::base::*;
 use rustc_span::symbol::{sym, Ident, Symbol};
 use rustc_span::{ErrorGuaranteed, FileNameDisplayPreference, Span};
+use std::assert_matches::assert_matches;
 use std::iter;
 use thin_vec::{thin_vec, ThinVec};
 
@@ -182,6 +183,16 @@ pub fn expand_test_or_bench(
     // creates $name: $expr
     let field = |name, expr| cx.field_imm(sp, Ident::from_str_and_span(name, sp), expr);
 
+    // Adds `#[coverage(off)]` to a closure, so it won't be instrumented in
+    // `-Cinstrument-coverage` builds.
+    // This requires `#[allow_internal_unstable(coverage_attribute)]` on the
+    // corresponding macro declaration in `core::macros`.
+    let coverage_off = |mut expr: P<ast::Expr>| {
+        assert_matches!(expr.kind, ast::ExprKind::Closure(_));
+        expr.attrs.push(cx.attr_nested_word(sym::coverage, sym::off, sp));
+        expr
+    };
+
     let test_fn = if is_bench {
         // A simple ident for a lambda
         let b = Ident::from_str_and_span("b", attr_sp);
@@ -190,8 +201,9 @@ pub fn expand_test_or_bench(
             sp,
             cx.expr_path(test_path("StaticBenchFn")),
             thin_vec![
+                // #[coverage(off)]
                 // |b| self::test::assert_test_result(
-                cx.lambda1(
+                coverage_off(cx.lambda1(
                     sp,
                     cx.expr_call(
                         sp,
@@ -206,16 +218,17 @@ pub fn expand_test_or_bench(
                         ],
                     ),
                     b,
-                ), // )
+                )), // )
             ],
         )
     } else {
         cx.expr_call(
             sp,
             cx.expr_path(test_path("StaticTestFn")),
             thin_vec![
+                // #[coverage(off)]
                 // || {
-                cx.lambda0(
+                coverage_off(cx.lambda0(
                     sp,
                     // test::assert_test_result(
                     cx.expr_call(
@@ -230,7 +243,7 @@ pub fn expand_test_or_bench(
                             ), // )
                         ],
                     ), // }
-                ), // )
+                )), // )
             ],
         )
     };