diff options
Diffstat (limited to 'compiler/rustc_codegen_ssa/src/codegen_attrs.rs')
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/codegen_attrs.rs | 220 |
1 files changed, 105 insertions, 115 deletions
diff --git a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs index 7f54a47327a..961bb788149 100644 --- a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs +++ b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs @@ -6,12 +6,10 @@ use rustc_ast::{LitKind, MetaItem, MetaItemInner, attr}; use rustc_hir::attrs::{AttributeKind, InlineAttr, InstructionSetAttr, UsedBy}; use rustc_hir::def::DefKind; use rustc_hir::def_id::{DefId, LOCAL_CRATE, LocalDefId}; -use rustc_hir::weak_lang_items::WEAK_LANG_ITEMS; use rustc_hir::{self as hir, Attribute, LangItem, find_attr, lang_items}; use rustc_middle::middle::codegen_fn_attrs::{ CodegenFnAttrFlags, CodegenFnAttrs, PatchableFunctionEntry, }; -use rustc_middle::mir::mono::Linkage; use rustc_middle::query::Providers; use rustc_middle::span_bug; use rustc_middle::ty::{self as ty, TyCtxt}; @@ -26,31 +24,6 @@ use crate::target_features::{ check_target_feature_trait_unsafe, check_tied_features, from_target_feature_attr, }; -fn linkage_by_name(tcx: TyCtxt<'_>, def_id: LocalDefId, name: &str) -> Linkage { - use rustc_middle::mir::mono::Linkage::*; - - // Use the names from src/llvm/docs/LangRef.rst here. Most types are only - // applicable to variable declarations and may not really make sense for - // Rust code in the first place but allow them anyway and trust that the - // user knows what they're doing. Who knows, unanticipated use cases may pop - // up in the future. - // - // ghost, dllimport, dllexport and linkonce_odr_autohide are not supported - // and don't have to be, LLVM treats them as no-ops. - match name { - "available_externally" => AvailableExternally, - "common" => Common, - "extern_weak" => ExternalWeak, - "external" => External, - "internal" => Internal, - "linkonce" => LinkOnceAny, - "linkonce_odr" => LinkOnceODR, - "weak" => WeakAny, - "weak_odr" => WeakODR, - _ => tcx.dcx().span_fatal(tcx.def_span(def_id), "invalid linkage specified"), - } -} - /// In some cases, attributes are only valid on functions, but it's the `check_attr` /// pass that checks that they aren't used anywhere else, rather than this module. /// In these cases, we bail from performing further checks that are only meaningful for @@ -103,39 +76,6 @@ fn parse_instruction_set_attr(tcx: TyCtxt<'_>, attr: &Attribute) -> Option<Instr } } -// FIXME(jdonszelmann): remove when linkage becomes a parsed attr -fn parse_linkage_attr(tcx: TyCtxt<'_>, did: LocalDefId, attr: &Attribute) -> Option<Linkage> { - let val = attr.value_str()?; - let linkage = linkage_by_name(tcx, did, val.as_str()); - Some(linkage) -} - -// FIXME(jdonszelmann): remove when no_sanitize becomes a parsed attr -fn parse_no_sanitize_attr(tcx: TyCtxt<'_>, attr: &Attribute) -> Option<SanitizerSet> { - let list = attr.meta_item_list()?; - let mut sanitizer_set = SanitizerSet::empty(); - - for item in list.iter() { - match item.name() { - Some(sym::address) => { - sanitizer_set |= SanitizerSet::ADDRESS | SanitizerSet::KERNELADDRESS - } - Some(sym::cfi) => sanitizer_set |= SanitizerSet::CFI, - Some(sym::kcfi) => sanitizer_set |= SanitizerSet::KCFI, - Some(sym::memory) => sanitizer_set |= SanitizerSet::MEMORY, - Some(sym::memtag) => sanitizer_set |= SanitizerSet::MEMTAG, - Some(sym::shadow_call_stack) => sanitizer_set |= SanitizerSet::SHADOWCALLSTACK, - Some(sym::thread) => sanitizer_set |= SanitizerSet::THREAD, - Some(sym::hwaddress) => sanitizer_set |= SanitizerSet::HWADDRESS, - _ => { - tcx.dcx().emit_err(errors::InvalidNoSanitize { span: item.span() }); - } - } - } - - Some(sanitizer_set) -} - // FIXME(jdonszelmann): remove when patchable_function_entry becomes a parsed attr fn parse_patchable_function_entry( tcx: TyCtxt<'_>, @@ -194,7 +134,7 @@ fn parse_patchable_function_entry( #[derive(Default)] struct InterestingAttributeDiagnosticSpans { link_ordinal: Option<Span>, - no_sanitize: Option<Span>, + sanitize: Option<Span>, inline: Option<Span>, no_mangle: Option<Span>, } @@ -210,20 +150,12 @@ fn process_builtin_attrs( let mut interesting_spans = InterestingAttributeDiagnosticSpans::default(); let rust_target_features = tcx.rust_target_features(LOCAL_CRATE); - // If our rustc version supports autodiff/enzyme, then we call our handler - // to check for any `#[rustc_autodiff(...)]` attributes. - // FIXME(jdonszelmann): merge with loop below - if cfg!(llvm_enzyme) { - let ad = autodiff_attrs(tcx, did.into()); - codegen_fn_attrs.autodiff_item = ad; - } - for attr in attrs.iter() { if let hir::Attribute::Parsed(p) = attr { match p { AttributeKind::Cold(_) => codegen_fn_attrs.flags |= CodegenFnAttrFlags::COLD, AttributeKind::ExportName { name, .. } => { - codegen_fn_attrs.export_name = Some(*name) + codegen_fn_attrs.symbol_name = Some(*name) } AttributeKind::Inline(inline, span) => { codegen_fn_attrs.inline = *inline; @@ -231,7 +163,13 @@ fn process_builtin_attrs( } AttributeKind::Naked(_) => codegen_fn_attrs.flags |= CodegenFnAttrFlags::NAKED, AttributeKind::Align { align, .. } => codegen_fn_attrs.alignment = Some(*align), - AttributeKind::LinkName { name, .. } => codegen_fn_attrs.link_name = Some(*name), + AttributeKind::LinkName { name, .. } => { + // FIXME Remove check for foreign functions once #[link_name] on non-foreign + // functions is a hard error + if tcx.is_foreign_item(did) { + codegen_fn_attrs.symbol_name = Some(*name); + } + } AttributeKind::LinkOrdinal { ordinal, span } => { codegen_fn_attrs.link_ordinal = Some(*ordinal); interesting_spans.link_ordinal = Some(*span); @@ -255,7 +193,7 @@ fn process_builtin_attrs( } } AttributeKind::Optimize(optimize, _) => codegen_fn_attrs.optimize = *optimize, - AttributeKind::TargetFeature(features, attr_span) => { + AttributeKind::TargetFeature { features, attr_span, was_forced } => { 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; @@ -263,7 +201,7 @@ fn process_builtin_attrs( 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 safe_target_features && !was_forced { 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 @@ -294,6 +232,7 @@ fn process_builtin_attrs( tcx, did, features, + *was_forced, rust_target_features, &mut codegen_fn_attrs.target_features, ); @@ -332,6 +271,31 @@ fn process_builtin_attrs( AttributeKind::StdInternalSymbol(_) => { codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL } + AttributeKind::Linkage(linkage, _) => { + let linkage = Some(*linkage); + + if tcx.is_foreign_item(did) { + codegen_fn_attrs.import_linkage = linkage; + + if tcx.is_mutable_static(did.into()) { + let mut diag = tcx.dcx().struct_span_err( + attr.span(), + "extern mutable statics are not allowed with `#[linkage]`", + ); + diag.note( + "marking the extern static mutable would allow changing which \ + symbol the static references rather than make the target of the \ + symbol mutable", + ); + diag.emit(); + } + } else { + codegen_fn_attrs.linkage = linkage; + } + } + AttributeKind::Sanitize { span, .. } => { + interesting_spans.sanitize = Some(*span); + } _ => {} } } @@ -349,33 +313,6 @@ fn process_builtin_attrs( codegen_fn_attrs.flags |= CodegenFnAttrFlags::ALLOCATOR_ZEROED } sym::thread_local => codegen_fn_attrs.flags |= CodegenFnAttrFlags::THREAD_LOCAL, - sym::linkage => { - let linkage = parse_linkage_attr(tcx, did, attr); - - if tcx.is_foreign_item(did) { - codegen_fn_attrs.import_linkage = linkage; - - if tcx.is_mutable_static(did.into()) { - let mut diag = tcx.dcx().struct_span_err( - attr.span(), - "extern mutable statics are not allowed with `#[linkage]`", - ); - diag.note( - "marking the extern static mutable would allow changing which \ - symbol the static references rather than make the target of the \ - symbol mutable", - ); - diag.emit(); - } - } else { - codegen_fn_attrs.linkage = linkage; - } - } - sym::no_sanitize => { - interesting_spans.no_sanitize = Some(attr.span()); - codegen_fn_attrs.no_sanitize |= - parse_no_sanitize_attr(tcx, attr).unwrap_or_default(); - } sym::instruction_set => { codegen_fn_attrs.instruction_set = parse_instruction_set_attr(tcx, attr) } @@ -399,6 +336,8 @@ fn apply_overrides(tcx: TyCtxt<'_>, did: LocalDefId, codegen_fn_attrs: &mut Code codegen_fn_attrs.alignment = Ord::max(codegen_fn_attrs.alignment, tcx.sess.opts.unstable_opts.min_function_alignment); + // Compute the disabled sanitizers. + codegen_fn_attrs.no_sanitize |= tcx.disabled_sanitizers_for(did); // On trait methods, inherit the `#[align]` of the trait's method prototype. codegen_fn_attrs.alignment = Ord::max(codegen_fn_attrs.alignment, tcx.inherited_align(did)); @@ -443,6 +382,29 @@ fn apply_overrides(tcx: TyCtxt<'_>, did: LocalDefId, codegen_fn_attrs: &mut Code if tcx.should_inherit_track_caller(did) { codegen_fn_attrs.flags |= CodegenFnAttrFlags::TRACK_CALLER; } + + // Foreign items by default use no mangling for their symbol name. + if tcx.is_foreign_item(did) { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::FOREIGN_ITEM; + + // There's a few exceptions to this rule though: + if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL) { + // * `#[rustc_std_internal_symbol]` mangles the symbol name in a special way + // both for exports and imports through foreign items. This is handled further, + // during symbol mangling logic. + } else if codegen_fn_attrs.symbol_name.is_some() { + // * This can be overridden with the `#[link_name]` attribute + } else { + // NOTE: there's one more exception that we cannot apply here. On wasm, + // some items cannot be `no_mangle`. + // However, we don't have enough information here to determine that. + // As such, no_mangle foreign items on wasm that have the same defid as some + // import will *still* be mangled despite this. + // + // if none of the exceptions apply; apply no_mangle + codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_MANGLE; + } + } } fn check_result( @@ -475,17 +437,17 @@ fn check_result( if !codegen_fn_attrs.no_sanitize.is_empty() && codegen_fn_attrs.inline.always() && let (Some(no_sanitize_span), Some(inline_span)) = - (interesting_spans.no_sanitize, interesting_spans.inline) + (interesting_spans.sanitize, interesting_spans.inline) { let hir_id = tcx.local_def_id_to_hir_id(did); tcx.node_span_lint(lint::builtin::INLINE_NO_SANITIZE, hir_id, no_sanitize_span, |lint| { - lint.primary_message("`no_sanitize` will have no effect after inlining"); + lint.primary_message("setting `sanitize` off will have no effect after inlining"); lint.span_note(inline_span, "inlining requested here"); }) } // error when specifying link_name together with link_ordinal - if let Some(_) = codegen_fn_attrs.link_name + if let Some(_) = codegen_fn_attrs.symbol_name && let Some(_) = codegen_fn_attrs.link_ordinal { let msg = "cannot use `#[link_name]` with `#[link_ordinal]`"; @@ -505,7 +467,7 @@ fn check_result( .collect(), ) { let span = - find_attr!(tcx.get_all_attrs(did), AttributeKind::TargetFeature(_, span) => *span) + find_attr!(tcx.get_all_attrs(did), AttributeKind::TargetFeature{attr_span: span, ..} => *span) .unwrap_or_else(|| tcx.def_span(did)); tcx.dcx() @@ -532,14 +494,11 @@ fn handle_lang_items( // strippable by the linker. // // Additionally weak lang items have predetermined symbol names. - if let Some(lang_item) = lang_item { - if WEAK_LANG_ITEMS.contains(&lang_item) { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL; - } - if let Some(link_name) = lang_item.link_name() { - codegen_fn_attrs.export_name = Some(link_name); - codegen_fn_attrs.link_name = Some(link_name); - } + if let Some(lang_item) = lang_item + && let Some(link_name) = lang_item.link_name() + { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL; + codegen_fn_attrs.symbol_name = Some(link_name); } // error when using no_mangle on a lang item item @@ -605,6 +564,32 @@ fn opt_trait_item(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId> { } } +fn disabled_sanitizers_for(tcx: TyCtxt<'_>, did: LocalDefId) -> SanitizerSet { + // Backtrack to the crate root. + let mut disabled = match tcx.opt_local_parent(did) { + // Check the parent (recursively). + Some(parent) => tcx.disabled_sanitizers_for(parent), + // We reached the crate root without seeing an attribute, so + // there is no sanitizers to exclude. + None => SanitizerSet::empty(), + }; + + // Check for a sanitize annotation directly on this def. + if let Some((on_set, off_set)) = find_attr!(tcx.get_all_attrs(did), AttributeKind::Sanitize {on_set, off_set, ..} => (on_set, off_set)) + { + // the on set is the set of sanitizers explicitly enabled. + // we mask those out since we want the set of disabled sanitizers here + disabled &= !*on_set; + // the off set is the set of sanitizers explicitly disabled. + // we or those in here. + disabled |= *off_set; + // the on set and off set are distjoint since there's a third option: unset. + // a node may not set the sanitizer setting in which case it inherits from parents. + // the code above in this function does this backtracking + } + disabled +} + /// Checks if the provided DefId is a method in a trait impl for a trait which has track_caller /// applied to the method prototype. fn should_inherit_track_caller(tcx: TyCtxt<'_>, def_id: DefId) -> bool { @@ -624,7 +609,7 @@ fn inherited_align<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Option<Align> { /// placeholder functions. We wrote the rustc_autodiff attributes ourself, so this should never /// panic, unless we introduced a bug when parsing the autodiff macro. //FIXME(jdonszelmann): put in the main loop. No need to have two..... :/ Let's do that when we make autodiff parsed. -fn autodiff_attrs(tcx: TyCtxt<'_>, id: DefId) -> Option<AutoDiffAttrs> { +pub fn autodiff_attrs(tcx: TyCtxt<'_>, id: DefId) -> Option<AutoDiffAttrs> { let attrs = tcx.get_attrs(id, sym::rustc_autodiff); let attrs = attrs.filter(|attr| attr.has_name(sym::rustc_autodiff)).collect::<Vec<_>>(); @@ -729,6 +714,11 @@ fn autodiff_attrs(tcx: TyCtxt<'_>, id: DefId) -> Option<AutoDiffAttrs> { } pub(crate) fn provide(providers: &mut Providers) { - *providers = - Providers { codegen_fn_attrs, should_inherit_track_caller, inherited_align, ..*providers }; + *providers = Providers { + codegen_fn_attrs, + should_inherit_track_caller, + inherited_align, + disabled_sanitizers_for, + ..*providers + }; } |