From fcfa9b0ba00cfeb17f050f26428aebe770cb4417 Mon Sep 17 00:00:00 2001 From: Mara Bos Date: Wed, 4 Jun 2025 15:02:31 +0200 Subject: [PATCH] Don't refer to 'local binding' in extern macro. The user has no clue what 'local binding' the compiler is talking about, if they don't know the expansion of the macro. --- .../rustc_borrowck/src/diagnostics/conflict_errors.rs | 8 +++++++- tests/ui/macros/return_from_external_macro.rs | 2 +- tests/ui/macros/return_from_external_macro.stderr | 4 ++-- 3 files changed, 10 insertions(+), 4 deletions(-) diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs index 3b7d31b1b13bd..b7b6a2da5491e 100644 --- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs +++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs @@ -3314,7 +3314,13 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> { "function parameter".to_string(), "function parameter borrowed here".to_string(), ), - LocalKind::Temp if self.body.local_decls[local].is_user_variable() => { + LocalKind::Temp + if self.body.local_decls[local].is_user_variable() + && !self.body.local_decls[local] + .source_info + .span + .in_external_macro(self.infcx.tcx.sess.source_map()) => + { ("local binding".to_string(), "local binding introduced here".to_string()) } LocalKind::ReturnPointer | LocalKind::Temp => { diff --git a/tests/ui/macros/return_from_external_macro.rs b/tests/ui/macros/return_from_external_macro.rs index 43fe99e63add4..91d0c4c64fdfc 100644 --- a/tests/ui/macros/return_from_external_macro.rs +++ b/tests/ui/macros/return_from_external_macro.rs @@ -5,7 +5,7 @@ extern crate ret_from_ext; fn foo() -> impl Sized { drop(|| ret_from_ext::foo!()); - //~^ ERROR cannot return reference to local binding + //~^ ERROR cannot return reference to temporary value ret_from_ext::foo!() //~^ ERROR temporary value dropped while borrowed diff --git a/tests/ui/macros/return_from_external_macro.stderr b/tests/ui/macros/return_from_external_macro.stderr index b6010b8ec793a..6f707b9f52b1e 100644 --- a/tests/ui/macros/return_from_external_macro.stderr +++ b/tests/ui/macros/return_from_external_macro.stderr @@ -1,11 +1,11 @@ -error[E0515]: cannot return reference to local binding +error[E0515]: cannot return reference to temporary value --> $DIR/return_from_external_macro.rs:7:13 | LL | drop(|| ret_from_ext::foo!()); | ^^^^^^^^^^^^^^^^^^^^ | | | returns a reference to data owned by the current function - | local binding introduced here + | temporary value created here | = note: this error originates in the macro `ret_from_ext::foo` (in Nightly builds, run with -Z macro-backtrace for more info)