diff --git a/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs b/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs index 311bc60c3cd39..a33b1fe283b82 100644 --- a/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs +++ b/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs @@ -172,6 +172,8 @@ impl CodegenFnAttrs { /// * `#[no_mangle]` is present /// * `#[export_name(...)]` is present /// * `#[linkage]` is present + /// + /// Keep this in sync with the logic for the unused_attributes for `#[inline]` lint. pub fn contains_extern_indicator(&self) -> bool { self.flags.contains(CodegenFnAttrFlags::NO_MANGLE) || self.export_name.is_some() diff --git a/compiler/rustc_middle/src/mir/mono.rs b/compiler/rustc_middle/src/mir/mono.rs index 58d5c94d03326..2aa31761178f4 100644 --- a/compiler/rustc_middle/src/mir/mono.rs +++ b/compiler/rustc_middle/src/mir/mono.rs @@ -117,6 +117,7 @@ impl<'tcx> MonoItem<'tcx> { // If the function is #[naked] or contains any other attribute that requires exactly-once // instantiation: + // We emit an unused_attributes lint for this case, which should be kept in sync if possible. let codegen_fn_attrs = tcx.codegen_fn_attrs(instance.def_id()); if codegen_fn_attrs.contains_extern_indicator() || codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::NAKED) diff --git a/compiler/rustc_passes/messages.ftl b/compiler/rustc_passes/messages.ftl index b65430c348027..22631cc96d289 100644 --- a/compiler/rustc_passes/messages.ftl +++ b/compiler/rustc_passes/messages.ftl @@ -383,6 +383,10 @@ passes_inline_ignored_constants = .warn = {-passes_previously_accepted} .note = {-passes_see_issue(issue: "65833")} +passes_inline_ignored_for_exported = + `#[inline]` is ignored on externally exported functions + .help = externally exported functions are functions with `#[no_mangle]`, `#[export_name]`, or `#[linkage]` + passes_inline_ignored_function_prototype = `#[inline]` is ignored on function prototypes diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs index 5ada289cc2090..5a76f7c586d4b 100644 --- a/compiler/rustc_passes/src/check_attr.rs +++ b/compiler/rustc_passes/src/check_attr.rs @@ -445,6 +445,23 @@ impl<'tcx> CheckAttrVisitor<'tcx> { }); } } + + // `#[inline]` is ignored if the symbol must be codegened upstream because it's exported. + if let Some(did) = hir_id.as_owner() + && self.tcx.def_kind(did).has_codegen_attrs() + && !matches!(attr.meta_item_list().as_deref(), Some([item]) if item.has_name(sym::never)) + { + let attrs = self.tcx.codegen_fn_attrs(did); + // Not checking naked as `#[inline]` is forbidden for naked functions anyways. + if attrs.contains_extern_indicator() { + self.tcx.emit_node_span_lint( + UNUSED_ATTRIBUTES, + hir_id, + attr.span(), + errors::InlineIgnoredForExported {}, + ); + } + } } /// Checks that `#[coverage(..)]` is applied to a function/closure/method, diff --git a/compiler/rustc_passes/src/errors.rs b/compiler/rustc_passes/src/errors.rs index 9bb9b2353dc86..b282828a8ae91 100644 --- a/compiler/rustc_passes/src/errors.rs +++ b/compiler/rustc_passes/src/errors.rs @@ -1435,6 +1435,11 @@ pub(crate) struct OnlyHasEffectOn { pub target_name: String, } +#[derive(LintDiagnostic)] +#[diag(passes_inline_ignored_for_exported)] +#[help] +pub(crate) struct InlineIgnoredForExported {} + #[derive(Diagnostic)] #[diag(passes_object_lifetime_err)] pub(crate) struct ObjectLifetimeErr { diff --git a/tests/ui/lint/inline-exported.rs b/tests/ui/lint/inline-exported.rs new file mode 100644 index 0000000000000..69e322ef513ae --- /dev/null +++ b/tests/ui/lint/inline-exported.rs @@ -0,0 +1,30 @@ +//! Ensure the unused_attributes lint fires for externally exported functions with `#[inline]`, +//! because `#[inline]` is ignored for such functions. + +#![crate_type = "lib"] + +#![feature(linkage)] +#![feature(naked_functions)] +#![deny(unused_attributes)] + +#[inline] +//~^ ERROR: `#[inline]` is ignored on externally exported functions +#[no_mangle] +fn no_mangle() {} + +#[inline] +//~^ ERROR: `#[inline]` is ignored on externally exported functions +#[export_name = "export_name"] +fn export_name() {} + +#[inline] +//~^ ERROR: `#[inline]` is ignored on externally exported functions +#[linkage = "external"] +fn external_linkage() {} + +#[inline] +fn normal() {} + +#[inline] +#[linkage = "internal"] // not exported +fn internal_linkage() {} diff --git a/tests/ui/lint/inline-exported.stderr b/tests/ui/lint/inline-exported.stderr new file mode 100644 index 0000000000000..dcf63cc4090e4 --- /dev/null +++ b/tests/ui/lint/inline-exported.stderr @@ -0,0 +1,31 @@ +error: `#[inline]` is ignored on externally exported functions + --> $DIR/inline-exported.rs:10:1 + | +LL | #[inline] + | ^^^^^^^^^ + | + = help: externally exported functions are functions with `#[no_mangle]`, `#[export_name]`, or `#[linkage]` +note: the lint level is defined here + --> $DIR/inline-exported.rs:8:9 + | +LL | #![deny(unused_attributes)] + | ^^^^^^^^^^^^^^^^^ + +error: `#[inline]` is ignored on externally exported functions + --> $DIR/inline-exported.rs:15:1 + | +LL | #[inline] + | ^^^^^^^^^ + | + = help: externally exported functions are functions with `#[no_mangle]`, `#[export_name]`, or `#[linkage]` + +error: `#[inline]` is ignored on externally exported functions + --> $DIR/inline-exported.rs:20:1 + | +LL | #[inline] + | ^^^^^^^^^ + | + = help: externally exported functions are functions with `#[no_mangle]`, `#[export_name]`, or `#[linkage]` + +error: aborting due to 3 previous errors + diff --git a/tests/ui/target-feature/invalid-attribute.stderr b/tests/ui/target-feature/invalid-attribute.stderr index dc8a53041640e..05ae49d6b0ddb 100644 --- a/tests/ui/target-feature/invalid-attribute.stderr +++ b/tests/ui/target-feature/invalid-attribute.stderr @@ -98,6 +98,12 @@ LL | LL | trait Baz {} | ------------ not a function definition +error: cannot use `#[inline(always)]` with `#[target_feature]` + --> $DIR/invalid-attribute.rs:69:1 + | +LL | #[inline(always)] + | ^^^^^^^^^^^^^^^^^ + error: attribute should be applied to a function definition --> $DIR/invalid-attribute.rs:74:1 | @@ -163,12 +169,6 @@ error: malformed `target_feature` attribute input LL | #[target_feature(disable = "baz")] | ^^^^^^^^^^^^^^^ help: must be of the form: `enable = ".."` -error: cannot use `#[inline(always)]` with `#[target_feature]` - --> $DIR/invalid-attribute.rs:69:1 - | -LL | #[inline(always)] - | ^^^^^^^^^^^^^^^^^ - error[E0046]: not all trait items implemented, missing: `foo` --> $DIR/invalid-attribute.rs:81:1 |