diff options
Diffstat (limited to 'compiler/rustc_codegen_ssa')
| -rw-r--r-- | compiler/rustc_codegen_ssa/messages.ftl | 4 | ||||
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/codegen_attrs.rs | 94 | ||||
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/errors.rs | 11 | ||||
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/target_features.rs | 147 |
4 files changed, 122 insertions, 134 deletions
diff --git a/compiler/rustc_codegen_ssa/messages.ftl b/compiler/rustc_codegen_ssa/messages.ftl index 63f47b9b7de..63e9005da45 100644 --- a/compiler/rustc_codegen_ssa/messages.ftl +++ b/compiler/rustc_codegen_ssa/messages.ftl @@ -62,6 +62,10 @@ codegen_ssa_failed_to_get_layout = failed to get layout for {$ty}: {$err} codegen_ssa_failed_to_write = failed to write {$path}: {$error} +codegen_ssa_feature_not_valid = the feature named `{$feature}` is not valid for this target + .label = `{$feature}` is not valid for this target + .help = consider removing the leading `+` in the feature name + codegen_ssa_field_associated_value_expected = associated value expected for `{$name}` codegen_ssa_forbidden_ctarget_feature = diff --git a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs index 6e2143858de..2713ec07f97 100644 --- a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs +++ b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs @@ -141,6 +141,49 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs { }); } } + AttributeKind::TargetFeature(features, attr_span) => { + let Some(sig) = tcx.hir_node_by_def_id(did).fn_sig() else { + tcx.dcx().span_delayed_bug(*attr_span, "target_feature applied to non-fn"); + continue; + }; + let safe_target_features = + matches!(sig.header.safety, hir::HeaderSafety::SafeTargetFeatures); + codegen_fn_attrs.safe_target_features = safe_target_features; + if safe_target_features { + if tcx.sess.target.is_like_wasm || tcx.sess.opts.actually_rustdoc { + // The `#[target_feature]` attribute is allowed on + // WebAssembly targets on all functions. Prior to stabilizing + // the `target_feature_11` feature, `#[target_feature]` was + // only permitted on unsafe functions because on most targets + // execution of instructions that are not supported is + // considered undefined behavior. For WebAssembly which is a + // 100% safe target at execution time it's not possible to + // execute undefined instructions, and even if a future + // feature was added in some form for this it would be a + // deterministic trap. There is no undefined behavior when + // executing WebAssembly so `#[target_feature]` is allowed + // on safe functions (but again, only for WebAssembly) + // + // Note that this is also allowed if `actually_rustdoc` so + // if a target is documenting some wasm-specific code then + // it's not spuriously denied. + // + // Now that `#[target_feature]` is permitted on safe functions, + // this exception must still exist for allowing the attribute on + // `main`, `start`, and other functions that are not usually + // allowed. + } else { + check_target_feature_trait_unsafe(tcx, did, *attr_span); + } + } + from_target_feature_attr( + tcx, + did, + features, + rust_target_features, + &mut codegen_fn_attrs.target_features, + ); + } AttributeKind::TrackCaller(attr_span) => { let is_closure = tcx.is_closure_like(did.to_def_id()); @@ -190,49 +233,6 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs { codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL } sym::thread_local => codegen_fn_attrs.flags |= CodegenFnAttrFlags::THREAD_LOCAL, - sym::target_feature => { - let Some(sig) = tcx.hir_node_by_def_id(did).fn_sig() else { - tcx.dcx().span_delayed_bug(attr.span(), "target_feature applied to non-fn"); - continue; - }; - let safe_target_features = - matches!(sig.header.safety, hir::HeaderSafety::SafeTargetFeatures); - codegen_fn_attrs.safe_target_features = safe_target_features; - if safe_target_features { - if tcx.sess.target.is_like_wasm || tcx.sess.opts.actually_rustdoc { - // The `#[target_feature]` attribute is allowed on - // WebAssembly targets on all functions. Prior to stabilizing - // the `target_feature_11` feature, `#[target_feature]` was - // only permitted on unsafe functions because on most targets - // execution of instructions that are not supported is - // considered undefined behavior. For WebAssembly which is a - // 100% safe target at execution time it's not possible to - // execute undefined instructions, and even if a future - // feature was added in some form for this it would be a - // deterministic trap. There is no undefined behavior when - // executing WebAssembly so `#[target_feature]` is allowed - // on safe functions (but again, only for WebAssembly) - // - // Note that this is also allowed if `actually_rustdoc` so - // if a target is documenting some wasm-specific code then - // it's not spuriously denied. - // - // Now that `#[target_feature]` is permitted on safe functions, - // this exception must still exist for allowing the attribute on - // `main`, `start`, and other functions that are not usually - // allowed. - } else { - check_target_feature_trait_unsafe(tcx, did, attr.span()); - } - } - from_target_feature_attr( - tcx, - did, - attr, - rust_target_features, - &mut codegen_fn_attrs.target_features, - ); - } sym::linkage => { if let Some(val) = attr.value_str() { let linkage = Some(linkage_by_name(tcx, did, val.as_str())); @@ -536,10 +536,10 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs { .map(|features| (features.name.as_str(), true)) .collect(), ) { - let span = tcx - .get_attrs(did, sym::target_feature) - .next() - .map_or_else(|| tcx.def_span(did), |a| a.span()); + let span = + find_attr!(tcx.get_all_attrs(did), AttributeKind::TargetFeature(_, span) => *span) + .unwrap_or_else(|| tcx.def_span(did)); + tcx.dcx() .create_err(errors::TargetFeatureDisableOrEnable { features, diff --git a/compiler/rustc_codegen_ssa/src/errors.rs b/compiler/rustc_codegen_ssa/src/errors.rs index 1950a35b364..086c069745c 100644 --- a/compiler/rustc_codegen_ssa/src/errors.rs +++ b/compiler/rustc_codegen_ssa/src/errors.rs @@ -1292,3 +1292,14 @@ pub(crate) struct NoMangleNameless { pub span: Span, pub definition: String, } + +#[derive(Diagnostic)] +#[diag(codegen_ssa_feature_not_valid)] +pub(crate) struct FeatureNotValid<'a> { + pub feature: &'a str, + #[primary_span] + #[label] + pub span: Span, + #[help] + pub plus_hint: bool, +} diff --git a/compiler/rustc_codegen_ssa/src/target_features.rs b/compiler/rustc_codegen_ssa/src/target_features.rs index faa278cc766..53df99993f0 100644 --- a/compiler/rustc_codegen_ssa/src/target_features.rs +++ b/compiler/rustc_codegen_ssa/src/target_features.rs @@ -1,8 +1,6 @@ use rustc_attr_data_structures::InstructionSetAttr; use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet}; use rustc_data_structures::unord::{UnordMap, UnordSet}; -use rustc_errors::Applicability; -use rustc_hir as hir; use rustc_hir::def::DefKind; use rustc_hir::def_id::{DefId, LOCAL_CRATE, LocalDefId}; use rustc_middle::middle::codegen_fn_attrs::TargetFeature; @@ -12,110 +10,85 @@ use rustc_session::Session; use rustc_session::lint::builtin::AARCH64_SOFTFLOAT_NEON; use rustc_session::parse::feature_err; use rustc_span::{Span, Symbol, sym}; -use rustc_target::target_features::{self, RUSTC_SPECIFIC_FEATURES, Stability}; +use rustc_target::target_features::{RUSTC_SPECIFIC_FEATURES, Stability}; use smallvec::SmallVec; -use crate::errors; +use crate::errors::FeatureNotValid; +use crate::{errors, target_features}; /// Compute the enabled target features from the `#[target_feature]` function attribute. /// Enabled target features are added to `target_features`. pub(crate) fn from_target_feature_attr( tcx: TyCtxt<'_>, did: LocalDefId, - attr: &hir::Attribute, + features: &[(Symbol, Span)], rust_target_features: &UnordMap<String, target_features::Stability>, target_features: &mut Vec<TargetFeature>, ) { - let Some(list) = attr.meta_item_list() else { return }; - let bad_item = |span| { - let msg = "malformed `target_feature` attribute input"; - let code = "enable = \"..\""; - tcx.dcx() - .struct_span_err(span, msg) - .with_span_suggestion(span, "must be of the form", code, Applicability::HasPlaceholders) - .emit(); - }; let rust_features = tcx.features(); let abi_feature_constraints = tcx.sess.target.abi_required_features(); - for item in list { - // Only `enable = ...` is accepted in the meta-item list. - if !item.has_name(sym::enable) { - bad_item(item.span()); - continue; - } - - // Must be of the form `enable = "..."` (a string). - let Some(value) = item.value_str() else { - bad_item(item.span()); + for &(feature, feature_span) in features { + let feature_str = feature.as_str(); + let Some(stability) = rust_target_features.get(feature_str) else { + let plus_hint = feature_str + .strip_prefix('+') + .is_some_and(|stripped| rust_target_features.contains_key(stripped)); + tcx.dcx().emit_err(FeatureNotValid { + feature: feature_str, + span: feature_span, + plus_hint, + }); continue; }; - // We allow comma separation to enable multiple features. - for feature in value.as_str().split(',') { - let Some(stability) = rust_target_features.get(feature) else { - let msg = format!("the feature named `{feature}` is not valid for this target"); - let mut err = tcx.dcx().struct_span_err(item.span(), msg); - err.span_label(item.span(), format!("`{feature}` is not valid for this target")); - if let Some(stripped) = feature.strip_prefix('+') { - let valid = rust_target_features.contains_key(stripped); - if valid { - err.help("consider removing the leading `+` in the feature name"); - } - } - err.emit(); - continue; - }; - - // Only allow target features whose feature gates have been enabled - // and which are permitted to be toggled. - if let Err(reason) = stability.toggle_allowed() { - tcx.dcx().emit_err(errors::ForbiddenTargetFeatureAttr { - span: item.span(), - feature, - reason, - }); - } else if let Some(nightly_feature) = stability.requires_nightly() - && !rust_features.enabled(nightly_feature) - { - feature_err( - &tcx.sess, - nightly_feature, - item.span(), - format!("the target feature `{feature}` is currently unstable"), - ) - .emit(); - } else { - // Add this and the implied features. - let feature_sym = Symbol::intern(feature); - for &name in tcx.implied_target_features(feature_sym) { - // But ensure the ABI does not forbid enabling this. - // Here we do assume that the backend doesn't add even more implied features - // we don't know about, at least no features that would have ABI effects! - // We skip this logic in rustdoc, where we want to allow all target features of - // all targets, so we can't check their ABI compatibility and anyway we are not - // generating code so "it's fine". - if !tcx.sess.opts.actually_rustdoc { - if abi_feature_constraints.incompatible.contains(&name.as_str()) { - // For "neon" specifically, we emit an FCW instead of a hard error. - // See <https://github.com/rust-lang/rust/issues/134375>. - if tcx.sess.target.arch == "aarch64" && name.as_str() == "neon" { - tcx.emit_node_span_lint( - AARCH64_SOFTFLOAT_NEON, - tcx.local_def_id_to_hir_id(did), - item.span(), - errors::Aarch64SoftfloatNeon, - ); - } else { - tcx.dcx().emit_err(errors::ForbiddenTargetFeatureAttr { - span: item.span(), - feature: name.as_str(), - reason: "this feature is incompatible with the target ABI", - }); - } + // Only allow target features whose feature gates have been enabled + // and which are permitted to be toggled. + if let Err(reason) = stability.toggle_allowed() { + tcx.dcx().emit_err(errors::ForbiddenTargetFeatureAttr { + span: feature_span, + feature: feature_str, + reason, + }); + } else if let Some(nightly_feature) = stability.requires_nightly() + && !rust_features.enabled(nightly_feature) + { + feature_err( + &tcx.sess, + nightly_feature, + feature_span, + format!("the target feature `{feature}` is currently unstable"), + ) + .emit(); + } else { + // Add this and the implied features. + for &name in tcx.implied_target_features(feature) { + // But ensure the ABI does not forbid enabling this. + // Here we do assume that the backend doesn't add even more implied features + // we don't know about, at least no features that would have ABI effects! + // We skip this logic in rustdoc, where we want to allow all target features of + // all targets, so we can't check their ABI compatibility and anyway we are not + // generating code so "it's fine". + if !tcx.sess.opts.actually_rustdoc { + if abi_feature_constraints.incompatible.contains(&name.as_str()) { + // For "neon" specifically, we emit an FCW instead of a hard error. + // See <https://github.com/rust-lang/rust/issues/134375>. + if tcx.sess.target.arch == "aarch64" && name.as_str() == "neon" { + tcx.emit_node_span_lint( + AARCH64_SOFTFLOAT_NEON, + tcx.local_def_id_to_hir_id(did), + feature_span, + errors::Aarch64SoftfloatNeon, + ); + } else { + tcx.dcx().emit_err(errors::ForbiddenTargetFeatureAttr { + span: feature_span, + feature: name.as_str(), + reason: "this feature is incompatible with the target ABI", + }); } } - target_features.push(TargetFeature { name, implied: name != feature_sym }) } + target_features.push(TargetFeature { name, implied: name != feature }) } } } |