diff options
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/codegen_attrs.rs | 619 |
1 files changed, 326 insertions, 293 deletions
diff --git a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs index 037b07dec62..57856b4ddb1 100644 --- a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs +++ b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs @@ -10,6 +10,7 @@ use rustc_middle::mir::mono::Linkage; use rustc_middle::ty::query::Providers; use rustc_middle::ty::{self as ty, TyCtxt}; use rustc_session::{lint, parse::feature_err}; +use rustc_span::symbol::Ident; use rustc_span::{sym, Span}; use rustc_target::spec::{abi, SanitizerSet}; @@ -83,336 +84,368 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs { } }; - if attr.has_name(sym::cold) { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::COLD; - } else if attr.has_name(sym::rustc_allocator) { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::ALLOCATOR; - } else if attr.has_name(sym::ffi_returns_twice) { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::FFI_RETURNS_TWICE; - } else if attr.has_name(sym::ffi_pure) { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::FFI_PURE; - } else if attr.has_name(sym::ffi_const) { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::FFI_CONST; - } else if attr.has_name(sym::rustc_nounwind) { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::NEVER_UNWIND; - } else if attr.has_name(sym::rustc_reallocator) { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::REALLOCATOR; - } else if attr.has_name(sym::rustc_deallocator) { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::DEALLOCATOR; - } else if attr.has_name(sym::rustc_allocator_zeroed) { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::ALLOCATOR_ZEROED; - } else if attr.has_name(sym::naked) { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::NAKED; - } else if attr.has_name(sym::no_mangle) { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_MANGLE; - } else if attr.has_name(sym::no_coverage) { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_COVERAGE; - } else if attr.has_name(sym::rustc_std_internal_symbol) { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL; - } else if attr.has_name(sym::used) { - let inner = attr.meta_item_list(); - match inner.as_deref() { - Some([item]) if item.has_name(sym::linker) => { - if !tcx.features().used_with_arg { - feature_err( - &tcx.sess.parse_sess, - sym::used_with_arg, - attr.span, - "`#[used(linker)]` is currently unstable", - ) - .emit(); - } - codegen_fn_attrs.flags |= CodegenFnAttrFlags::USED_LINKER; - } - Some([item]) if item.has_name(sym::compiler) => { - if !tcx.features().used_with_arg { - feature_err( - &tcx.sess.parse_sess, - sym::used_with_arg, - attr.span, - "`#[used(compiler)]` is currently unstable", - ) - .emit(); - } - codegen_fn_attrs.flags |= CodegenFnAttrFlags::USED; - } - Some(_) => { - tcx.sess.emit_err(ExpectedUsedSymbol { span: attr.span }); - } - None => { - // Unfortunately, unconditionally using `llvm.used` causes - // issues in handling `.init_array` with the gold linker, - // but using `llvm.compiler.used` caused a nontrival amount - // of unintentional ecosystem breakage -- particularly on - // Mach-O targets. - // - // As a result, we emit `llvm.compiler.used` only on ELF - // targets. This is somewhat ad-hoc, but actually follows - // our pre-LLVM 13 behavior (prior to the ecosystem - // breakage), and seems to match `clang`'s behavior as well - // (both before and after LLVM 13), possibly because they - // have similar compatibility concerns to us. See - // https://github.com/rust-lang/rust/issues/47384#issuecomment-1019080146 - // and following comments for some discussion of this, as - // well as the comments in `rustc_codegen_llvm` where these - // flags are handled. - // - // Anyway, to be clear: this is still up in the air - // somewhat, and is subject to change in the future (which - // is a good thing, because this would ideally be a bit - // more firmed up). - let is_like_elf = !(tcx.sess.target.is_like_osx - || tcx.sess.target.is_like_windows - || tcx.sess.target.is_like_wasm); - codegen_fn_attrs.flags |= if is_like_elf { - CodegenFnAttrFlags::USED - } else { - CodegenFnAttrFlags::USED_LINKER - }; - } + let Some(Ident { name, .. }) = attr.ident() else { + continue; + }; + + match name { + sym::cold => { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::COLD; } - } else if attr.has_name(sym::cmse_nonsecure_entry) { - if let Some(fn_sig) = fn_sig() - && !matches!(fn_sig.skip_binder().abi(), abi::Abi::C { .. }) - { - struct_span_err!( - tcx.sess, - attr.span, - E0776, - "`#[cmse_nonsecure_entry]` requires C ABI" - ) - .emit(); + sym::rustc_allocator => { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::ALLOCATOR; } - if !tcx.sess.target.llvm_target.contains("thumbv8m") { - struct_span_err!(tcx.sess, attr.span, E0775, "`#[cmse_nonsecure_entry]` is only valid for targets with the TrustZone-M extension") - .emit(); + sym::ffi_returns_twice => { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::FFI_RETURNS_TWICE; } - codegen_fn_attrs.flags |= CodegenFnAttrFlags::CMSE_NONSECURE_ENTRY; - } else if attr.has_name(sym::thread_local) { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::THREAD_LOCAL; - } else if attr.has_name(sym::track_caller) { - if !tcx.is_closure(did.to_def_id()) - && let Some(fn_sig) = fn_sig() - && fn_sig.skip_binder().abi() != abi::Abi::Rust - { - struct_span_err!(tcx.sess, attr.span, E0737, "`#[track_caller]` requires Rust ABI") - .emit(); + sym::ffi_pure => { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::FFI_PURE; } - if tcx.is_closure(did.to_def_id()) && !tcx.features().closure_track_caller { - feature_err( - &tcx.sess.parse_sess, - sym::closure_track_caller, - attr.span, - "`#[track_caller]` on closures is currently unstable", - ) - .emit(); + sym::ffi_const => { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::FFI_CONST; + } + sym::rustc_nounwind => { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::NEVER_UNWIND; + } + sym::rustc_reallocator => { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::REALLOCATOR; + } + sym::rustc_deallocator => { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::DEALLOCATOR; + } + sym::rustc_allocator_zeroed => { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::ALLOCATOR_ZEROED; + } + sym::naked => { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::NAKED; + } + sym::no_mangle => { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_MANGLE; + } + sym::no_coverage => { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_COVERAGE; + } + sym::rustc_std_internal_symbol => { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL; + } + sym::used => { + let inner = attr.meta_item_list(); + match inner.as_deref() { + Some([item]) if item.has_name(sym::linker) => { + if !tcx.features().used_with_arg { + feature_err( + &tcx.sess.parse_sess, + sym::used_with_arg, + attr.span, + "`#[used(linker)]` is currently unstable", + ) + .emit(); + } + codegen_fn_attrs.flags |= CodegenFnAttrFlags::USED_LINKER; + } + Some([item]) if item.has_name(sym::compiler) => { + if !tcx.features().used_with_arg { + feature_err( + &tcx.sess.parse_sess, + sym::used_with_arg, + attr.span, + "`#[used(compiler)]` is currently unstable", + ) + .emit(); + } + codegen_fn_attrs.flags |= CodegenFnAttrFlags::USED; + } + Some(_) => { + tcx.sess.emit_err(ExpectedUsedSymbol { span: attr.span }); + } + None => { + // Unfortunately, unconditionally using `llvm.used` causes + // issues in handling `.init_array` with the gold linker, + // but using `llvm.compiler.used` caused a nontrival amount + // of unintentional ecosystem breakage -- particularly on + // Mach-O targets. + // + // As a result, we emit `llvm.compiler.used` only on ELF + // targets. This is somewhat ad-hoc, but actually follows + // our pre-LLVM 13 behavior (prior to the ecosystem + // breakage), and seems to match `clang`'s behavior as well + // (both before and after LLVM 13), possibly because they + // have similar compatibility concerns to us. See + // https://github.com/rust-lang/rust/issues/47384#issuecomment-1019080146 + // and following comments for some discussion of this, as + // well as the comments in `rustc_codegen_llvm` where these + // flags are handled. + // + // Anyway, to be clear: this is still up in the air + // somewhat, and is subject to change in the future (which + // is a good thing, because this would ideally be a bit + // more firmed up). + let is_like_elf = !(tcx.sess.target.is_like_osx + || tcx.sess.target.is_like_windows + || tcx.sess.target.is_like_wasm); + codegen_fn_attrs.flags |= if is_like_elf { + CodegenFnAttrFlags::USED + } else { + CodegenFnAttrFlags::USED_LINKER + }; + } + } } - codegen_fn_attrs.flags |= CodegenFnAttrFlags::TRACK_CALLER; - } else if attr.has_name(sym::export_name) { - if let Some(s) = attr.value_str() { - if s.as_str().contains('\0') { - // `#[export_name = ...]` will be converted to a null-terminated string, - // so it may not contain any null characters. + sym::cmse_nonsecure_entry => { + if let Some(fn_sig) = fn_sig() + && !matches!(fn_sig.skip_binder().abi(), abi::Abi::C { .. }) + { struct_span_err!( tcx.sess, attr.span, - E0648, - "`export_name` may not contain null characters" + E0776, + "`#[cmse_nonsecure_entry]` requires C ABI" ) .emit(); } - codegen_fn_attrs.export_name = Some(s); - } - } else if attr.has_name(sym::target_feature) { - if !tcx.is_closure(did.to_def_id()) - && let Some(fn_sig) = fn_sig() - && fn_sig.skip_binder().unsafety() == hir::Unsafety::Normal - { - if tcx.sess.target.is_like_wasm || tcx.sess.opts.actually_rustdoc { - // The `#[target_feature]` attribute is allowed on - // WebAssembly targets on all functions, including safe - // ones. Other targets require that `#[target_feature]` is - // only applied to unsafe functions (pending the - // `target_feature_11` feature) 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. - // - // This exception needs to be kept in sync with allowing - // `#[target_feature]` on `main` and `start`. - } else if !tcx.features().target_feature_11 { - let mut err = feature_err( + if !tcx.sess.target.llvm_target.contains("thumbv8m") { + struct_span_err!(tcx.sess, attr.span, E0775, "`#[cmse_nonsecure_entry]` is only valid for targets with the TrustZone-M extension") + .emit(); + } + codegen_fn_attrs.flags |= CodegenFnAttrFlags::CMSE_NONSECURE_ENTRY; + } + sym::thread_local => { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::THREAD_LOCAL; + } + sym::track_caller => { + if !tcx.is_closure(did.to_def_id()) + && let Some(fn_sig) = fn_sig() + && fn_sig.skip_binder().abi() != abi::Abi::Rust + { + struct_span_err!(tcx.sess, attr.span, E0737, "`#[track_caller]` requires Rust ABI") + .emit(); + } + if tcx.is_closure(did.to_def_id()) && !tcx.features().closure_track_caller { + feature_err( &tcx.sess.parse_sess, - sym::target_feature_11, + sym::closure_track_caller, attr.span, - "`#[target_feature(..)]` can only be applied to `unsafe` functions", - ); - err.span_label(tcx.def_span(did), "not an `unsafe` function"); - err.emit(); - } else { - check_target_feature_trait_unsafe(tcx, did, attr.span); + "`#[track_caller]` on closures is currently unstable", + ) + .emit(); } + codegen_fn_attrs.flags |= CodegenFnAttrFlags::TRACK_CALLER; } - from_target_feature( - tcx, - attr, - supported_target_features, - &mut codegen_fn_attrs.target_features, - ); - } else if attr.has_name(sym::linkage) { - if let Some(val) = attr.value_str() { - let linkage = Some(linkage_by_name(tcx, did, val.as_str())); - if tcx.is_foreign_item(did) { - codegen_fn_attrs.import_linkage = linkage; - } else { - codegen_fn_attrs.linkage = linkage; + sym::export_name => { + if let Some(s) = attr.value_str() { + if s.as_str().contains('\0') { + // `#[export_name = ...]` will be converted to a null-terminated string, + // so it may not contain any null characters. + struct_span_err!( + tcx.sess, + attr.span, + E0648, + "`export_name` may not contain null characters" + ) + .emit(); + } + codegen_fn_attrs.export_name = Some(s); } } - } else if attr.has_name(sym::link_section) { - if let Some(val) = attr.value_str() { - if val.as_str().bytes().any(|b| b == 0) { - let msg = format!( - "illegal null byte in link_section \ - value: `{}`", - &val - ); - tcx.sess.span_err(attr.span, &msg); - } else { - codegen_fn_attrs.link_section = Some(val); + sym::target_feature => { + if !tcx.is_closure(did.to_def_id()) + && let Some(fn_sig) = fn_sig() + && fn_sig.skip_binder().unsafety() == hir::Unsafety::Normal + { + if tcx.sess.target.is_like_wasm || tcx.sess.opts.actually_rustdoc { + // The `#[target_feature]` attribute is allowed on + // WebAssembly targets on all functions, including safe + // ones. Other targets require that `#[target_feature]` is + // only applied to unsafe functions (pending the + // `target_feature_11` feature) 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. + // + // This exception needs to be kept in sync with allowing + // `#[target_feature]` on `main` and `start`. + } else if !tcx.features().target_feature_11 { + let mut err = feature_err( + &tcx.sess.parse_sess, + sym::target_feature_11, + attr.span, + "`#[target_feature(..)]` can only be applied to `unsafe` functions", + ); + err.span_label(tcx.def_span(did), "not an `unsafe` function"); + err.emit(); + } else { + check_target_feature_trait_unsafe(tcx, did, attr.span); + } + } + from_target_feature( + tcx, + attr, + supported_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())); + if tcx.is_foreign_item(did) { + codegen_fn_attrs.import_linkage = linkage; + } else { + codegen_fn_attrs.linkage = linkage; + } } } - } else if attr.has_name(sym::link_name) { - codegen_fn_attrs.link_name = attr.value_str(); - } else if attr.has_name(sym::link_ordinal) { - link_ordinal_span = Some(attr.span); - if let ordinal @ Some(_) = check_link_ordinal(tcx, attr) { - codegen_fn_attrs.link_ordinal = ordinal; - } - } else if attr.has_name(sym::no_sanitize) { - no_sanitize_span = Some(attr.span); - if let Some(list) = attr.meta_item_list() { - for item in list.iter() { - if item.has_name(sym::address) { - codegen_fn_attrs.no_sanitize |= - SanitizerSet::ADDRESS | SanitizerSet::KERNELADDRESS; - } else if item.has_name(sym::cfi) { - codegen_fn_attrs.no_sanitize |= SanitizerSet::CFI; - } else if item.has_name(sym::kcfi) { - codegen_fn_attrs.no_sanitize |= SanitizerSet::KCFI; - } else if item.has_name(sym::memory) { - codegen_fn_attrs.no_sanitize |= SanitizerSet::MEMORY; - } else if item.has_name(sym::memtag) { - codegen_fn_attrs.no_sanitize |= SanitizerSet::MEMTAG; - } else if item.has_name(sym::shadow_call_stack) { - codegen_fn_attrs.no_sanitize |= SanitizerSet::SHADOWCALLSTACK; - } else if item.has_name(sym::thread) { - codegen_fn_attrs.no_sanitize |= SanitizerSet::THREAD; - } else if item.has_name(sym::hwaddress) { - codegen_fn_attrs.no_sanitize |= SanitizerSet::HWADDRESS; + sym::link_section => { + if let Some(val) = attr.value_str() { + if val.as_str().bytes().any(|b| b == 0) { + let msg = format!( + "illegal null byte in link_section \ + value: `{}`", + &val + ); + tcx.sess.span_err(attr.span, &msg); } else { - tcx.sess - .struct_span_err(item.span(), "invalid argument for `no_sanitize`") - .note("expected one of: `address`, `cfi`, `hwaddress`, `kcfi`, `memory`, `memtag`, `shadow-call-stack`, or `thread`") - .emit(); + codegen_fn_attrs.link_section = Some(val); } } } - } else if attr.has_name(sym::instruction_set) { - codegen_fn_attrs.instruction_set = attr.meta_item_list().and_then(|l| match &l[..] { - [NestedMetaItem::MetaItem(set)] => { - let segments = - set.path.segments.iter().map(|x| x.ident.name).collect::<Vec<_>>(); - match segments.as_slice() { - [sym::arm, sym::a32] | [sym::arm, sym::t32] => { - if !tcx.sess.target.has_thumb_interworking { - struct_span_err!( - tcx.sess.diagnostic(), - attr.span, - E0779, - "target does not support `#[instruction_set]`" - ) + sym::link_name => { + codegen_fn_attrs.link_name = attr.value_str(); + } + sym::link_ordinal => { + link_ordinal_span = Some(attr.span); + if let ordinal @ Some(_) = check_link_ordinal(tcx, attr) { + codegen_fn_attrs.link_ordinal = ordinal; + } + } + sym::no_sanitize => { + no_sanitize_span = Some(attr.span); + if let Some(list) = attr.meta_item_list() { + for item in list.iter() { + match item.ident().map(|ident| ident.name) { + Some(sym::address) => { + codegen_fn_attrs.no_sanitize |= + SanitizerSet::ADDRESS | SanitizerSet::KERNELADDRESS; + } + Some(sym::cfi) => { + codegen_fn_attrs.no_sanitize |= SanitizerSet::CFI; + } + Some(sym::kcfi) => { + codegen_fn_attrs.no_sanitize |= SanitizerSet::KCFI; + } + Some(sym::memory) => { + codegen_fn_attrs.no_sanitize |= SanitizerSet::MEMORY; + } + Some(sym::memtag) => { + codegen_fn_attrs.no_sanitize |= SanitizerSet::MEMTAG; + } + Some(sym::shadow_call_stack) => { + codegen_fn_attrs.no_sanitize |= SanitizerSet::SHADOWCALLSTACK; + } + Some(sym::thread) => { + codegen_fn_attrs.no_sanitize |= SanitizerSet::THREAD; + } + Some(sym::hwaddress) => { + codegen_fn_attrs.no_sanitize |= SanitizerSet::HWADDRESS; + } + _ => { + tcx.sess + .struct_span_err(item.span(), "invalid argument for `no_sanitize`") + .note("expected one of: `address`, `cfi`, `hwaddress`, `kcfi`, `memory`, `memtag`, `shadow-call-stack`, or `thread`") .emit(); - None - } else if segments[1] == sym::a32 { - Some(InstructionSetAttr::ArmA32) - } else if segments[1] == sym::t32 { - Some(InstructionSetAttr::ArmT32) - } else { - unreachable!() } } - _ => { - struct_span_err!( - tcx.sess.diagnostic(), - attr.span, - E0779, - "invalid instruction set specified", - ) - .emit(); - None - } } } - [] => { - struct_span_err!( - tcx.sess.diagnostic(), - attr.span, - E0778, - "`#[instruction_set]` requires an argument" - ) - .emit(); - None - } - _ => { - struct_span_err!( - tcx.sess.diagnostic(), - attr.span, - E0779, - "cannot specify more than one instruction set" - ) - .emit(); - None - } - }) - } else if attr.has_name(sym::repr) { - codegen_fn_attrs.alignment = match attr.meta_item_list() { - Some(items) => match items.as_slice() { - [item] => match item.name_value_literal() { - Some((sym::align, literal)) => { - let alignment = rustc_attr::parse_alignment(&literal.kind); - - match alignment { - Ok(align) => Some(align), - Err(msg) => { + } + sym::instruction_set => { + codegen_fn_attrs.instruction_set = + attr.meta_item_list().and_then(|l| match &l[..] { + [NestedMetaItem::MetaItem(set)] => { + let segments = + set.path.segments.iter().map(|x| x.ident.name).collect::<Vec<_>>(); + match segments.as_slice() { + [sym::arm, sym::a32] | [sym::arm, sym::t32] => { + if !tcx.sess.target.has_thumb_interworking { + struct_span_err!( + tcx.sess.diagnostic(), + attr.span, + E0779, + "target does not support `#[instruction_set]`" + ) + .emit(); + None + } else if segments[1] == sym::a32 { + Some(InstructionSetAttr::ArmA32) + } else if segments[1] == sym::t32 { + Some(InstructionSetAttr::ArmT32) + } else { + unreachable!() + } + } + _ => { struct_span_err!( tcx.sess.diagnostic(), attr.span, - E0589, - "invalid `repr(align)` attribute: {}", - msg + E0779, + "invalid instruction set specified", ) .emit(); - None } } } - _ => None, - }, - [] => None, - _ => None, - }, - None => None, - }; + [] => { + struct_span_err!( + tcx.sess.diagnostic(), + attr.span, + E0778, + "`#[instruction_set]` requires an argument" + ) + .emit(); + None + } + _ => { + struct_span_err!( + tcx.sess.diagnostic(), + attr.span, + E0779, + "cannot specify more than one instruction set" + ) + .emit(); + None + } + }) + } + sym::repr => { + codegen_fn_attrs.alignment = if let Some(items) = attr.meta_item_list() + && let [item] = items.as_slice() + && let Some((sym::align, literal)) = item.name_value_literal() + { + rustc_attr::parse_alignment(&literal.kind).map_err(|msg| { + struct_span_err!( + tcx.sess.diagnostic(), + attr.span, + E0589, + "invalid `repr(align)` attribute: {}", + msg + ) + .emit(); + }) + .ok() + } else { + None + }; + } + _ => {} } } |