diff options
| -rw-r--r-- | compiler/rustc_passes/src/check_attr.rs | 30 | ||||
| -rw-r--r-- | src/test/ui/extern/extern-no-mangle.rs | 30 | ||||
| -rw-r--r-- | src/test/ui/extern/extern-no-mangle.stderr | 42 |
3 files changed, 102 insertions, 0 deletions
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs index d3dac35d2c9..fd438bdc900 100644 --- a/compiler/rustc_passes/src/check_attr.rs +++ b/compiler/rustc_passes/src/check_attr.rs @@ -1331,6 +1331,36 @@ impl CheckAttrVisitor<'tcx> { Target::Field | Target::Arm | Target::MacroDef => { self.inline_attr_str_error_with_macro_def(hir_id, attr, "no_mangle"); } + // FIXME: #[no_mangle] was previously allowed on non-functions/statics, this should be an error + // The error should specify that the item that is wrong is specifically a *foreign* fn/static + // otherwise the error seems odd + Target::ForeignFn | Target::ForeignStatic => { + let foreign_item_kind = match target { + Target::ForeignFn => "function", + Target::ForeignStatic => "static", + _ => unreachable!(), + }; + self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { + lint.build(&format!( + "`#[no_mangle]` has no effect on a foreign {}", + foreign_item_kind + )) + .warn( + "this was previously accepted by the compiler but is \ + being phased out; it will become a hard error in \ + a future release!", + ) + .span_label(*span, format!("foreign {}", foreign_item_kind)) + .note("symbol names in extern blocks are not mangled") + .span_suggestion( + attr.span, + "remove this attribute", + String::new(), + Applicability::MachineApplicable, + ) + .emit(); + }); + } _ => { // FIXME: #[no_mangle] was previously allowed on non-functions/statics and some // crates used this, so only emit a warning. diff --git a/src/test/ui/extern/extern-no-mangle.rs b/src/test/ui/extern/extern-no-mangle.rs new file mode 100644 index 00000000000..ab7c9824af0 --- /dev/null +++ b/src/test/ui/extern/extern-no-mangle.rs @@ -0,0 +1,30 @@ +#![warn(unused_attributes)] + +// Tests that placing the #[no_mangle] attribute on a foreign fn or static emits +// a specialized warning. +// The previous warning only talks about a "function or static" but foreign fns/statics +// are also not allowed to have #[no_mangle] + +// build-pass + +extern "C" { + #[no_mangle] + //~^ WARNING `#[no_mangle]` has no effect on a foreign static + //~^^ WARNING this was previously accepted by the compiler + pub static FOO: u8; + + #[no_mangle] + //~^ WARNING `#[no_mangle]` has no effect on a foreign function + //~^^ WARNING this was previously accepted by the compiler + pub fn bar(); +} + +fn no_new_warn() { + // Should emit the generic "not a function or static" warning + #[no_mangle] + //~^ WARNING attribute should be applied to a free function, impl method or static + //~^^ WARNING this was previously accepted by the compiler + let x = 0_u8; +} + +fn main() {} diff --git a/src/test/ui/extern/extern-no-mangle.stderr b/src/test/ui/extern/extern-no-mangle.stderr new file mode 100644 index 00000000000..b5642814114 --- /dev/null +++ b/src/test/ui/extern/extern-no-mangle.stderr @@ -0,0 +1,42 @@ +warning: attribute should be applied to a free function, impl method or static + --> $DIR/extern-no-mangle.rs:24:5 + | +LL | #[no_mangle] + | ^^^^^^^^^^^^ +... +LL | let x = 0_u8; + | ------------- not a free function, impl method or static + | +note: the lint level is defined here + --> $DIR/extern-no-mangle.rs:1:9 + | +LL | #![warn(unused_attributes)] + | ^^^^^^^^^^^^^^^^^ + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + +warning: `#[no_mangle]` has no effect on a foreign static + --> $DIR/extern-no-mangle.rs:11:5 + | +LL | #[no_mangle] + | ^^^^^^^^^^^^ help: remove this attribute +... +LL | pub static FOO: u8; + | ------------------- foreign static + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: symbol names in extern blocks are not mangled + +warning: `#[no_mangle]` has no effect on a foreign function + --> $DIR/extern-no-mangle.rs:16:5 + | +LL | #[no_mangle] + | ^^^^^^^^^^^^ help: remove this attribute +... +LL | pub fn bar(); + | ------------- foreign function + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: symbol names in extern blocks are not mangled + +warning: 3 warnings emitted + |