Auto merge of rust-lang#117818 - fmease:properly-reject-defaultness-o…

…n-free-consts, r=cjgillot Properly reject `default` on free const items Fixes rust-lang#117791. Technically speaking, this is a breaking change but I doubt it will lead to any real-world regressions (maybe in some macro-trickery crates?). Doing a crater run probably isn't worth it.
abao168899 · Dec 18, 2023 · 3562c53 · 3562c53
2 parents 37340a1 + df3b981
commit 3562c53
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Showing 3 changed files with 43 additions and 13 deletions.
diff --git a/compiler/rustc_ast_passes/src/ast_validation.rs b/compiler/rustc_ast_passes/src/ast_validation.rs
@@ -1028,12 +1028,14 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
  _ => {}
  }
  }
- ItemKind::Const(box ConstItem { defaultness, expr: None, .. }) => {
+ ItemKind::Const(box ConstItem { defaultness, expr, .. }) => {
  self.check_defaultness(item.span, *defaultness);
- self.session.emit_err(errors::ConstWithoutBody {
- span: item.span,
- replace_span: self.ending_semi_or_hi(item.span),
- });
+ if expr.is_none() {
+ self.session.emit_err(errors::ConstWithoutBody {
+ span: item.span,
+ replace_span: self.ending_semi_or_hi(item.span),
+ });
+ }
  }
  ItemKind::Static(box StaticItem { expr: None, .. }) => {
  self.session.emit_err(errors::StaticWithoutBody {

diff --git a/...it-item-with-defaultness-fail-semantic.rs → ...faultness-invalid-places-fail-semantic.rs b/...it-item-with-defaultness-fail-semantic.rs → ...faultness-invalid-places-fail-semantic.rs
@@ -10,3 +10,7 @@ trait X {
  default fn f1(); //~ ERROR `default` is only allowed on items in trait impls
  default fn f2() {} //~ ERROR `default` is only allowed on items in trait impls
 }
+
+default const E: u8 = 0; //~ ERROR `default` is only allowed on items in trait impls
+default type F = (); //~ ERROR `default` is only allowed on items in trait impls
+default fn h() {} //~ ERROR `default` is only allowed on items in trait impls
diff --git a/...tem-with-defaultness-fail-semantic.stderr → ...tness-invalid-places-fail-semantic.stderr b/...tem-with-defaultness-fail-semantic.stderr → ...tness-invalid-places-fail-semantic.stderr
@@ -1,53 +1,77 @@
 error: `default` is only allowed on items in trait impls
- --> $DIR/trait-item-with-defaultness-fail-semantic.rs:6:5
+ --> $DIR/defaultness-invalid-places-fail-semantic.rs:6:5
  |
 LL | default const A: u8;
  | -------^^^^^^^^^^^^^
  | |
  | `default` because of this
 
 error: `default` is only allowed on items in trait impls
- --> $DIR/trait-item-with-defaultness-fail-semantic.rs:7:5
+ --> $DIR/defaultness-invalid-places-fail-semantic.rs:7:5
  |
 LL | default const B: u8 = 0;
  | -------^^^^^^^^^^^^^^^^^
  | |
  | `default` because of this
 
 error: `default` is only allowed on items in trait impls
- --> $DIR/trait-item-with-defaultness-fail-semantic.rs:8:5
+ --> $DIR/defaultness-invalid-places-fail-semantic.rs:8:5
  |
 LL | default type D;
  | -------^^^^^^^^
  | |
  | `default` because of this
 
 error: `default` is only allowed on items in trait impls
- --> $DIR/trait-item-with-defaultness-fail-semantic.rs:9:5
+ --> $DIR/defaultness-invalid-places-fail-semantic.rs:9:5
  |
 LL | default type C: Ord;
  | -------^^^^^^^^^^^^^
  | |
  | `default` because of this
 
 error: `default` is only allowed on items in trait impls
- --> $DIR/trait-item-with-defaultness-fail-semantic.rs:10:5
+ --> $DIR/defaultness-invalid-places-fail-semantic.rs:10:5
  |
 LL | default fn f1();
  | -------^^^^^^^^^
  | |
  | `default` because of this
 
 error: `default` is only allowed on items in trait impls
- --> $DIR/trait-item-with-defaultness-fail-semantic.rs:11:5
+ --> $DIR/defaultness-invalid-places-fail-semantic.rs:11:5
  |
 LL | default fn f2() {}
  | -------^^^^^^^^
  | |
  | `default` because of this
 
+error: `default` is only allowed on items in trait impls
+ --> $DIR/defaultness-invalid-places-fail-semantic.rs:14:1
+ |
+LL | default const E: u8 = 0;
+ | -------^^^^^^^^^^^^^^^^^
+ | |
+ | `default` because of this
+
+error: `default` is only allowed on items in trait impls
+ --> $DIR/defaultness-invalid-places-fail-semantic.rs:15:1
+ |
+LL | default type F = ();
+ | -------^^^^^^^^^^^^^
+ | |
+ | `default` because of this
+
+error: `default` is only allowed on items in trait impls
+ --> $DIR/defaultness-invalid-places-fail-semantic.rs:16:1
+ |
+LL | default fn h() {}
+ | -------^^^^^^^
+ | |
+ | `default` because of this
+
 warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
- --> $DIR/trait-item-with-defaultness-fail-semantic.rs:1:12
+ --> $DIR/defaultness-invalid-places-fail-semantic.rs:1:12
  |
 LL | #![feature(specialization)]
  | ^^^^^^^^^^^^^^
@@ -56,5 +80,5 @@ LL | #![feature(specialization)]
  = help: consider using `min_specialization` instead, which is more stable and complete
  = note: `#[warn(incomplete_features)]` on by default
 
-error: aborting due to 6 previous errors; 1 warning emitted
+error: aborting due to 9 previous errors; 1 warning emitted