diff --git a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs new file mode 100644 index 0000000000000..c7f2e1966c1ed --- /dev/null +++ b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs @@ -0,0 +1,688 @@ +use rustc_ast::{ast, MetaItemKind, NestedMetaItem}; +use rustc_attr::{list_contains_name, InlineAttr, InstructionSetAttr, OptimizeAttr}; +use rustc_errors::struct_span_err; +use rustc_hir as hir; +use rustc_hir::def_id::{DefId, LocalDefId, LOCAL_CRATE}; +use rustc_hir::{lang_items, weak_lang_items::WEAK_LANG_ITEMS, LangItem}; +use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, CodegenFnAttrs}; +use rustc_middle::mir::mono::Linkage; +use rustc_middle::ty::query::Providers; +use rustc_middle::ty::{self as ty, DefIdTree, TyCtxt}; +use rustc_session::{lint, parse::feature_err}; +use rustc_span::{sym, Span}; +use rustc_target::spec::{abi, SanitizerSet}; + +use crate::target_features::from_target_feature; +use crate::{errors::ExpectedUsedSymbol, target_features::check_target_feature_trait_unsafe}; + +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 { + "appending" => Appending, + "available_externally" => AvailableExternally, + "common" => Common, + "extern_weak" => ExternalWeak, + "external" => External, + "internal" => Internal, + "linkonce" => LinkOnceAny, + "linkonce_odr" => LinkOnceODR, + "private" => Private, + "weak" => WeakAny, + "weak_odr" => WeakODR, + _ => tcx.sess.span_fatal(tcx.def_span(def_id), "invalid linkage specified"), + } +} + +fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: DefId) -> CodegenFnAttrs { + if cfg!(debug_assertions) { + let def_kind = tcx.def_kind(did); + assert!( + def_kind.has_codegen_attrs(), + "unexpected `def_kind` in `codegen_fn_attrs`: {def_kind:?}", + ); + } + + let did = did.expect_local(); + let attrs = tcx.hir().attrs(tcx.hir().local_def_id_to_hir_id(did)); + let mut codegen_fn_attrs = CodegenFnAttrs::new(); + if tcx.should_inherit_track_caller(did) { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::TRACK_CALLER; + } + + let supported_target_features = tcx.supported_target_features(LOCAL_CRATE); + + let mut inline_span = None; + let mut link_ordinal_span = None; + let mut no_sanitize_span = None; + for attr in attrs.iter() { + 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) { + if tcx.is_foreign_item(did) { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::FFI_RETURNS_TWICE; + } else { + // `#[ffi_returns_twice]` is only allowed `extern fn`s. + struct_span_err!( + tcx.sess, + attr.span, + E0724, + "`#[ffi_returns_twice]` may only be used on foreign functions" + ) + .emit(); + } + } else if attr.has_name(sym::ffi_pure) { + if tcx.is_foreign_item(did) { + if attrs.iter().any(|a| a.has_name(sym::ffi_const)) { + // `#[ffi_const]` functions cannot be `#[ffi_pure]` + struct_span_err!( + tcx.sess, + attr.span, + E0757, + "`#[ffi_const]` function cannot be `#[ffi_pure]`" + ) + .emit(); + } else { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::FFI_PURE; + } + } else { + // `#[ffi_pure]` is only allowed on foreign functions + struct_span_err!( + tcx.sess, + attr.span, + E0755, + "`#[ffi_pure]` may only be used on foreign functions" + ) + .emit(); + } + } else if attr.has_name(sym::ffi_const) { + if tcx.is_foreign_item(did) { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::FFI_CONST; + } else { + // `#[ffi_const]` is only allowed on foreign functions + struct_span_err!( + tcx.sess, + attr.span, + E0756, + "`#[ffi_const]` may only be used on foreign functions" + ) + .emit(); + } + } 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 + }; + } + } + } else if attr.has_name(sym::cmse_nonsecure_entry) { + if !matches!(tcx.fn_sig(did).abi(), abi::Abi::C { .. }) { + struct_span_err!( + tcx.sess, + attr.span, + E0776, + "`#[cmse_nonsecure_entry]` requires C ABI" + ) + .emit(); + } + 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; + } 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()) && tcx.fn_sig(did).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::closure_track_caller, + attr.span, + "`#[track_caller]` on closures is currently unstable", + ) + .emit(); + } + 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. + 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::target_feature) { + if !tcx.is_closure(did.to_def_id()) + && tcx.fn_sig(did).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. + } 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, + ); + } 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; + } + } + } 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); + } + } + } 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; + } 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; + } 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(); + } + } + } + } else if attr.has_name(sym::instruction_set) { + codegen_fn_attrs.instruction_set = match attr.meta_kind() { + Some(MetaItemKind::List(ref items)) => match items.as_slice() { + [NestedMetaItem::MetaItem(set)] => { + let segments = + set.path.segments.iter().map(|x| x.ident.name).collect::>(); + 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, + 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 + } + }, + _ => { + struct_span_err!( + tcx.sess.diagnostic(), + attr.span, + E0778, + "must specify an 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) => { + struct_span_err!( + tcx.sess.diagnostic(), + attr.span, + E0589, + "invalid `repr(align)` attribute: {}", + msg + ) + .emit(); + + None + } + } + } + _ => None, + }, + [] => None, + _ => None, + }, + None => None, + }; + } + } + + codegen_fn_attrs.inline = attrs.iter().fold(InlineAttr::None, |ia, attr| { + if !attr.has_name(sym::inline) { + return ia; + } + match attr.meta_kind() { + Some(MetaItemKind::Word) => InlineAttr::Hint, + Some(MetaItemKind::List(ref items)) => { + inline_span = Some(attr.span); + if items.len() != 1 { + struct_span_err!( + tcx.sess.diagnostic(), + attr.span, + E0534, + "expected one argument" + ) + .emit(); + InlineAttr::None + } else if list_contains_name(&items, sym::always) { + InlineAttr::Always + } else if list_contains_name(&items, sym::never) { + InlineAttr::Never + } else { + struct_span_err!( + tcx.sess.diagnostic(), + items[0].span(), + E0535, + "invalid argument" + ) + .help("valid inline arguments are `always` and `never`") + .emit(); + + InlineAttr::None + } + } + Some(MetaItemKind::NameValue(_)) => ia, + None => ia, + } + }); + + codegen_fn_attrs.optimize = attrs.iter().fold(OptimizeAttr::None, |ia, attr| { + if !attr.has_name(sym::optimize) { + return ia; + } + let err = |sp, s| struct_span_err!(tcx.sess.diagnostic(), sp, E0722, "{}", s).emit(); + match attr.meta_kind() { + Some(MetaItemKind::Word) => { + err(attr.span, "expected one argument"); + ia + } + Some(MetaItemKind::List(ref items)) => { + inline_span = Some(attr.span); + if items.len() != 1 { + err(attr.span, "expected one argument"); + OptimizeAttr::None + } else if list_contains_name(&items, sym::size) { + OptimizeAttr::Size + } else if list_contains_name(&items, sym::speed) { + OptimizeAttr::Speed + } else { + err(items[0].span(), "invalid argument"); + OptimizeAttr::None + } + } + Some(MetaItemKind::NameValue(_)) => ia, + None => ia, + } + }); + + // #73631: closures inherit `#[target_feature]` annotations + if tcx.features().target_feature_11 && tcx.is_closure(did.to_def_id()) { + let owner_id = tcx.parent(did.to_def_id()); + if tcx.def_kind(owner_id).has_codegen_attrs() { + codegen_fn_attrs + .target_features + .extend(tcx.codegen_fn_attrs(owner_id).target_features.iter().copied()); + } + } + + // If a function uses #[target_feature] it can't be inlined into general + // purpose functions as they wouldn't have the right target features + // enabled. For that reason we also forbid #[inline(always)] as it can't be + // respected. + if !codegen_fn_attrs.target_features.is_empty() { + if codegen_fn_attrs.inline == InlineAttr::Always { + if let Some(span) = inline_span { + tcx.sess.span_err( + span, + "cannot use `#[inline(always)]` with \ + `#[target_feature]`", + ); + } + } + } + + if !codegen_fn_attrs.no_sanitize.is_empty() { + if codegen_fn_attrs.inline == InlineAttr::Always { + if let (Some(no_sanitize_span), Some(inline_span)) = (no_sanitize_span, inline_span) { + let hir_id = tcx.hir().local_def_id_to_hir_id(did); + tcx.struct_span_lint_hir( + lint::builtin::INLINE_NO_SANITIZE, + hir_id, + no_sanitize_span, + "`no_sanitize` will have no effect after inlining", + |lint| lint.span_note(inline_span, "inlining requested here"), + ) + } + } + } + + if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::NAKED) { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_COVERAGE; + codegen_fn_attrs.inline = InlineAttr::Never; + } + + // Weak lang items have the same semantics as "std internal" symbols in the + // sense that they're preserved through all our LTO passes and only + // strippable by the linker. + // + // Additionally weak lang items have predetermined symbol names. + if WEAK_LANG_ITEMS.iter().any(|&l| tcx.lang_items().get(l) == Some(did.to_def_id())) { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL; + } + if let Some((name, _)) = lang_items::extract(attrs) + && let Some(lang_item) = LangItem::from_name(name) + && let Some(link_name) = lang_item.link_name() + { + codegen_fn_attrs.export_name = Some(link_name); + codegen_fn_attrs.link_name = Some(link_name); + } + check_link_name_xor_ordinal(tcx, &codegen_fn_attrs, link_ordinal_span); + + // Internal symbols to the standard library all have no_mangle semantics in + // that they have defined symbol names present in the function name. This + // also applies to weak symbols where they all have known symbol names. + if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL) { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_MANGLE; + } + + // Any linkage to LLVM intrinsics for now forcibly marks them all as never + // unwinds since LLVM sometimes can't handle codegen which `invoke`s + // intrinsic functions. + if let Some(name) = &codegen_fn_attrs.link_name { + if name.as_str().starts_with("llvm.") { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::NEVER_UNWIND; + } + } + + codegen_fn_attrs +} + +/// 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 { + if let Some(impl_item) = tcx.opt_associated_item(def_id) + && let ty::AssocItemContainer::ImplContainer = impl_item.container + && let Some(trait_item) = impl_item.trait_item_def_id + { + return tcx + .codegen_fn_attrs(trait_item) + .flags + .intersects(CodegenFnAttrFlags::TRACK_CALLER); + } + + false +} + +fn check_link_ordinal(tcx: TyCtxt<'_>, attr: &ast::Attribute) -> Option { + use rustc_ast::{LitIntType, LitKind, MetaItemLit}; + if !tcx.features().raw_dylib && tcx.sess.target.arch == "x86" { + feature_err( + &tcx.sess.parse_sess, + sym::raw_dylib, + attr.span, + "`#[link_ordinal]` is unstable on x86", + ) + .emit(); + } + let meta_item_list = attr.meta_item_list(); + let meta_item_list = meta_item_list.as_deref(); + let sole_meta_list = match meta_item_list { + Some([item]) => item.lit(), + Some(_) => { + tcx.sess + .struct_span_err(attr.span, "incorrect number of arguments to `#[link_ordinal]`") + .note("the attribute requires exactly one argument") + .emit(); + return None; + } + _ => None, + }; + if let Some(MetaItemLit { kind: LitKind::Int(ordinal, LitIntType::Unsuffixed), .. }) = + sole_meta_list + { + // According to the table at https://docs.microsoft.com/en-us/windows/win32/debug/pe-format#import-header, + // the ordinal must fit into 16 bits. Similarly, the Ordinal field in COFFShortExport (defined + // in llvm/include/llvm/Object/COFFImportFile.h), which we use to communicate import information + // to LLVM for `#[link(kind = "raw-dylib"_])`, is also defined to be uint16_t. + // + // FIXME: should we allow an ordinal of 0? The MSVC toolchain has inconsistent support for this: + // both LINK.EXE and LIB.EXE signal errors and abort when given a .DEF file that specifies + // a zero ordinal. However, llvm-dlltool is perfectly happy to generate an import library + // for such a .DEF file, and MSVC's LINK.EXE is also perfectly happy to consume an import + // library produced by LLVM with an ordinal of 0, and it generates an .EXE. (I don't know yet + // if the resulting EXE runs, as I haven't yet built the necessary DLL -- see earlier comment + // about LINK.EXE failing.) + if *ordinal <= u16::MAX as u128 { + Some(*ordinal as u16) + } else { + let msg = format!("ordinal value in `link_ordinal` is too large: `{}`", &ordinal); + tcx.sess + .struct_span_err(attr.span, &msg) + .note("the value may not exceed `u16::MAX`") + .emit(); + None + } + } else { + tcx.sess + .struct_span_err(attr.span, "illegal ordinal format in `link_ordinal`") + .note("an unsuffixed integer value, e.g., `1`, is expected") + .emit(); + None + } +} + +fn check_link_name_xor_ordinal( + tcx: TyCtxt<'_>, + codegen_fn_attrs: &CodegenFnAttrs, + inline_span: Option, +) { + if codegen_fn_attrs.link_name.is_none() || codegen_fn_attrs.link_ordinal.is_none() { + return; + } + let msg = "cannot use `#[link_name]` with `#[link_ordinal]`"; + if let Some(span) = inline_span { + tcx.sess.span_err(span, msg); + } else { + tcx.sess.err(msg); + } +} + +pub fn provide(providers: &mut Providers) { + *providers = Providers { codegen_fn_attrs, should_inherit_track_caller, ..*providers }; +} diff --git a/compiler/rustc_codegen_ssa/src/errors.rs b/compiler/rustc_codegen_ssa/src/errors.rs index e3b6fbf1bc7f0..0620000201f02 100644 --- a/compiler/rustc_codegen_ssa/src/errors.rs +++ b/compiler/rustc_codegen_ssa/src/errors.rs @@ -548,3 +548,10 @@ pub struct ArchiveBuildFailure { pub struct UnknownArchiveKind<'a> { pub kind: &'a str, } + +#[derive(Diagnostic)] +#[diag(codegen_ssa_expected_used_symbol)] +pub struct ExpectedUsedSymbol { + #[primary_span] + pub span: Span, +} diff --git a/compiler/rustc_codegen_ssa/src/lib.rs b/compiler/rustc_codegen_ssa/src/lib.rs index def6390f6a36b..0e6596d4ba781 100644 --- a/compiler/rustc_codegen_ssa/src/lib.rs +++ b/compiler/rustc_codegen_ssa/src/lib.rs @@ -42,6 +42,7 @@ use std::path::{Path, PathBuf}; pub mod back; pub mod base; +pub mod codegen_attrs; pub mod common; pub mod coverageinfo; pub mod debuginfo; @@ -180,6 +181,7 @@ pub fn provide(providers: &mut Providers) { crate::back::symbol_export::provide(providers); crate::base::provide(providers); crate::target_features::provide(providers); + crate::codegen_attrs::provide(providers); } pub fn provide_extern(providers: &mut ExternProviders) { diff --git a/compiler/rustc_codegen_ssa/src/target_features.rs b/compiler/rustc_codegen_ssa/src/target_features.rs index 301683e8e8544..0dabe96b60277 100644 --- a/compiler/rustc_codegen_ssa/src/target_features.rs +++ b/compiler/rustc_codegen_ssa/src/target_features.rs @@ -1,8 +1,19 @@ +use rustc_ast::ast; +use rustc_attr::InstructionSetAttr; +use rustc_data_structures::fx::FxHashMap; +use rustc_data_structures::fx::FxHashSet; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_hir::def_id::DefId; +use rustc_hir::def_id::LocalDefId; use rustc_hir::def_id::LOCAL_CRATE; use rustc_middle::ty::query::Providers; +use rustc_middle::ty::TyCtxt; +use rustc_session::parse::feature_err; use rustc_session::Session; use rustc_span::symbol::sym; use rustc_span::symbol::Symbol; +use rustc_span::Span; /// Features that control behaviour of rustc, rather than the codegen. pub const RUSTC_SPECIFIC_FEATURES: &[&str] = &["crt-static"]; @@ -322,15 +333,148 @@ pub fn tied_target_features(sess: &Session) -> &'static [&'static [&'static str] } } -pub(crate) fn provide(providers: &mut Providers) { - providers.supported_target_features = |tcx, cnum| { - assert_eq!(cnum, LOCAL_CRATE); - if tcx.sess.opts.actually_rustdoc { - // rustdoc needs to be able to document functions that use all the features, so - // whitelist them all - all_known_features().map(|(a, b)| (a.to_string(), b)).collect() - } else { - supported_target_features(tcx.sess).iter().map(|&(a, b)| (a.to_string(), b)).collect() - } +pub fn from_target_feature( + tcx: TyCtxt<'_>, + attr: &ast::Attribute, + supported_target_features: &FxHashMap>, + target_features: &mut Vec, +) { + let Some(list) = attr.meta_item_list() else { return }; + let bad_item = |span| { + let msg = "malformed `target_feature` attribute input"; + let code = "enable = \"..\""; + tcx.sess + .struct_span_err(span, msg) + .span_suggestion(span, "must be of the form", code, Applicability::HasPlaceholders) + .emit(); }; + let rust_features = tcx.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()); + continue; + }; + + // We allow comma separation to enable multiple features. + target_features.extend(value.as_str().split(',').filter_map(|feature| { + let Some(feature_gate) = supported_target_features.get(feature) else { + let msg = + format!("the feature named `{}` is not valid for this target", feature); + let mut err = tcx.sess.struct_span_err(item.span(), &msg); + err.span_label( + item.span(), + format!("`{}` is not valid for this target", feature), + ); + if let Some(stripped) = feature.strip_prefix('+') { + let valid = supported_target_features.contains_key(stripped); + if valid { + err.help("consider removing the leading `+` in the feature name"); + } + } + err.emit(); + return None; + }; + + // Only allow features whose feature gates have been enabled. + let allowed = match feature_gate.as_ref().copied() { + Some(sym::arm_target_feature) => rust_features.arm_target_feature, + Some(sym::hexagon_target_feature) => rust_features.hexagon_target_feature, + Some(sym::powerpc_target_feature) => rust_features.powerpc_target_feature, + Some(sym::mips_target_feature) => rust_features.mips_target_feature, + Some(sym::riscv_target_feature) => rust_features.riscv_target_feature, + Some(sym::avx512_target_feature) => rust_features.avx512_target_feature, + Some(sym::sse4a_target_feature) => rust_features.sse4a_target_feature, + Some(sym::tbm_target_feature) => rust_features.tbm_target_feature, + Some(sym::wasm_target_feature) => rust_features.wasm_target_feature, + Some(sym::cmpxchg16b_target_feature) => rust_features.cmpxchg16b_target_feature, + Some(sym::movbe_target_feature) => rust_features.movbe_target_feature, + Some(sym::rtm_target_feature) => rust_features.rtm_target_feature, + Some(sym::f16c_target_feature) => rust_features.f16c_target_feature, + Some(sym::ermsb_target_feature) => rust_features.ermsb_target_feature, + Some(sym::bpf_target_feature) => rust_features.bpf_target_feature, + Some(sym::aarch64_ver_target_feature) => rust_features.aarch64_ver_target_feature, + Some(name) => bug!("unknown target feature gate {}", name), + None => true, + }; + if !allowed { + feature_err( + &tcx.sess.parse_sess, + feature_gate.unwrap(), + item.span(), + &format!("the target feature `{}` is currently unstable", feature), + ) + .emit(); + } + Some(Symbol::intern(feature)) + })); + } +} + +/// Computes the set of target features used in a function for the purposes of +/// inline assembly. +fn asm_target_features<'tcx>(tcx: TyCtxt<'tcx>, did: DefId) -> &'tcx FxHashSet { + let mut target_features = tcx.sess.unstable_target_features.clone(); + if tcx.def_kind(did).has_codegen_attrs() { + let attrs = tcx.codegen_fn_attrs(did); + target_features.extend(&attrs.target_features); + match attrs.instruction_set { + None => {} + Some(InstructionSetAttr::ArmA32) => { + target_features.remove(&sym::thumb_mode); + } + Some(InstructionSetAttr::ArmT32) => { + target_features.insert(sym::thumb_mode); + } + } + } + + tcx.arena.alloc(target_features) +} + +/// Checks the function annotated with `#[target_feature]` is not a safe +/// trait method implementation, reporting an error if it is. +pub fn check_target_feature_trait_unsafe(tcx: TyCtxt<'_>, id: LocalDefId, attr_span: Span) { + let hir_id = tcx.hir().local_def_id_to_hir_id(id); + let node = tcx.hir().get(hir_id); + if let hir::Node::ImplItem(hir::ImplItem { kind: hir::ImplItemKind::Fn(..), .. }) = node { + let parent_id = tcx.hir().get_parent_item(hir_id); + let parent_item = tcx.hir().expect_item(parent_id.def_id); + if let hir::ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }) = parent_item.kind { + tcx.sess + .struct_span_err( + attr_span, + "`#[target_feature(..)]` cannot be applied to safe trait method", + ) + .span_label(attr_span, "cannot be applied to safe trait method") + .span_label(tcx.def_span(id), "not an `unsafe` function") + .emit(); + } + } +} + +pub(crate) fn provide(providers: &mut Providers) { + *providers = Providers { + supported_target_features: |tcx, cnum| { + assert_eq!(cnum, LOCAL_CRATE); + if tcx.sess.opts.actually_rustdoc { + // rustdoc needs to be able to document functions that use all the features, so + // whitelist them all + all_known_features().map(|(a, b)| (a.to_string(), b)).collect() + } else { + supported_target_features(tcx.sess) + .iter() + .map(|&(a, b)| (a.to_string(), b)) + .collect() + } + }, + asm_target_features, + ..*providers + } } diff --git a/compiler/rustc_error_messages/locales/en-US/codegen_ssa.ftl b/compiler/rustc_error_messages/locales/en-US/codegen_ssa.ftl index 4d1f9c1c901fc..db4c82b35c778 100644 --- a/compiler/rustc_error_messages/locales/en-US/codegen_ssa.ftl +++ b/compiler/rustc_error_messages/locales/en-US/codegen_ssa.ftl @@ -192,3 +192,5 @@ codegen_ssa_archive_build_failure = codegen_ssa_unknown_archive_kind = Don't know how to build archive of type: {$kind} + +codegen_ssa_expected_used_symbol = expected `used`, `used(compiler)` or `used(linker)` diff --git a/compiler/rustc_error_messages/locales/en-US/hir_analysis.ftl b/compiler/rustc_error_messages/locales/en-US/hir_analysis.ftl index a9ea161b93eda..e33323a779536 100644 --- a/compiler/rustc_error_messages/locales/en-US/hir_analysis.ftl +++ b/compiler/rustc_error_messages/locales/en-US/hir_analysis.ftl @@ -101,8 +101,6 @@ hir_analysis_extern_crate_not_idiomatic = `extern crate` is not idiomatic in the new edition .suggestion = convert it to a `{$msg_code}` -hir_analysis_expected_used_symbol = expected `used`, `used(compiler)` or `used(linker)` - hir_analysis_const_impl_for_non_const_trait = const `impl` for trait `{$trait_name}` which is not marked with `#[const_trait]` .suggestion = mark `{$trait_name}` as const diff --git a/compiler/rustc_hir_analysis/src/collect.rs b/compiler/rustc_hir_analysis/src/collect.rs index 72288e5bc761f..1eeaaf55e63af 100644 --- a/compiler/rustc_hir_analysis/src/collect.rs +++ b/compiler/rustc_hir_analysis/src/collect.rs @@ -17,28 +17,20 @@ use crate::astconv::AstConv; use crate::check::intrinsic::intrinsic_operation_unsafety; use crate::errors; -use rustc_ast as ast; -use rustc_ast::{MetaItemKind, NestedMetaItem}; -use rustc_attr::{list_contains_name, InlineAttr, InstructionSetAttr, OptimizeAttr}; use rustc_data_structures::captures::Captures; use rustc_data_structures::fx::{FxHashMap, FxHashSet}; use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder, ErrorGuaranteed, StashKey}; use rustc_hir as hir; -use rustc_hir::def_id::{DefId, LocalDefId, LOCAL_CRATE}; +use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_hir::intravisit::{self, Visitor}; -use rustc_hir::weak_lang_items::WEAK_LANG_ITEMS; -use rustc_hir::{lang_items, GenericParamKind, LangItem, Node}; +use rustc_hir::{GenericParamKind, Node}; use rustc_middle::hir::nested_filter; -use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, CodegenFnAttrs}; -use rustc_middle::mir::mono::Linkage; use rustc_middle::ty::query::Providers; use rustc_middle::ty::util::{Discr, IntTypeExt}; -use rustc_middle::ty::{self, AdtKind, Const, DefIdTree, IsSuggestable, ToPredicate, Ty, TyCtxt}; -use rustc_session::lint; -use rustc_session::parse::feature_err; +use rustc_middle::ty::{self, AdtKind, Const, IsSuggestable, ToPredicate, Ty, TyCtxt}; use rustc_span::symbol::{kw, sym, Ident, Symbol}; use rustc_span::Span; -use rustc_target::spec::{abi, SanitizerSet}; +use rustc_target::spec::abi; use rustc_trait_selection::traits::error_reporting::suggestions::NextTypeParamName; use std::iter; @@ -78,10 +70,7 @@ pub fn provide(providers: &mut Providers) { impl_polarity, is_foreign_item, generator_kind, - codegen_fn_attrs, - asm_target_features, collect_mod_item_types, - should_inherit_track_caller, ..*providers }; } @@ -1455,797 +1444,3 @@ fn generator_kind(tcx: TyCtxt<'_>, def_id: DefId) -> Option _ => bug!("generator_kind applied to non-local def-id {:?}", def_id), } } - -fn from_target_feature( - tcx: TyCtxt<'_>, - attr: &ast::Attribute, - supported_target_features: &FxHashMap>, - target_features: &mut Vec, -) { - let Some(list) = attr.meta_item_list() else { return }; - let bad_item = |span| { - let msg = "malformed `target_feature` attribute input"; - let code = "enable = \"..\""; - tcx.sess - .struct_span_err(span, msg) - .span_suggestion(span, "must be of the form", code, Applicability::HasPlaceholders) - .emit(); - }; - let rust_features = tcx.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()); - continue; - }; - - // We allow comma separation to enable multiple features. - target_features.extend(value.as_str().split(',').filter_map(|feature| { - let Some(feature_gate) = supported_target_features.get(feature) else { - let msg = - format!("the feature named `{}` is not valid for this target", feature); - let mut err = tcx.sess.struct_span_err(item.span(), &msg); - err.span_label( - item.span(), - format!("`{}` is not valid for this target", feature), - ); - if let Some(stripped) = feature.strip_prefix('+') { - let valid = supported_target_features.contains_key(stripped); - if valid { - err.help("consider removing the leading `+` in the feature name"); - } - } - err.emit(); - return None; - }; - - // Only allow features whose feature gates have been enabled. - let allowed = match feature_gate.as_ref().copied() { - Some(sym::arm_target_feature) => rust_features.arm_target_feature, - Some(sym::hexagon_target_feature) => rust_features.hexagon_target_feature, - Some(sym::powerpc_target_feature) => rust_features.powerpc_target_feature, - Some(sym::mips_target_feature) => rust_features.mips_target_feature, - Some(sym::riscv_target_feature) => rust_features.riscv_target_feature, - Some(sym::avx512_target_feature) => rust_features.avx512_target_feature, - Some(sym::sse4a_target_feature) => rust_features.sse4a_target_feature, - Some(sym::tbm_target_feature) => rust_features.tbm_target_feature, - Some(sym::wasm_target_feature) => rust_features.wasm_target_feature, - Some(sym::cmpxchg16b_target_feature) => rust_features.cmpxchg16b_target_feature, - Some(sym::movbe_target_feature) => rust_features.movbe_target_feature, - Some(sym::rtm_target_feature) => rust_features.rtm_target_feature, - Some(sym::f16c_target_feature) => rust_features.f16c_target_feature, - Some(sym::ermsb_target_feature) => rust_features.ermsb_target_feature, - Some(sym::bpf_target_feature) => rust_features.bpf_target_feature, - Some(sym::aarch64_ver_target_feature) => rust_features.aarch64_ver_target_feature, - Some(name) => bug!("unknown target feature gate {}", name), - None => true, - }; - if !allowed { - feature_err( - &tcx.sess.parse_sess, - feature_gate.unwrap(), - item.span(), - &format!("the target feature `{}` is currently unstable", feature), - ) - .emit(); - } - Some(Symbol::intern(feature)) - })); - } -} - -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 { - "appending" => Appending, - "available_externally" => AvailableExternally, - "common" => Common, - "extern_weak" => ExternalWeak, - "external" => External, - "internal" => Internal, - "linkonce" => LinkOnceAny, - "linkonce_odr" => LinkOnceODR, - "private" => Private, - "weak" => WeakAny, - "weak_odr" => WeakODR, - _ => tcx.sess.span_fatal(tcx.def_span(def_id), "invalid linkage specified"), - } -} - -fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: DefId) -> CodegenFnAttrs { - if cfg!(debug_assertions) { - let def_kind = tcx.def_kind(did); - assert!( - def_kind.has_codegen_attrs(), - "unexpected `def_kind` in `codegen_fn_attrs`: {def_kind:?}", - ); - } - - let did = did.expect_local(); - let attrs = tcx.hir().attrs(tcx.hir().local_def_id_to_hir_id(did)); - let mut codegen_fn_attrs = CodegenFnAttrs::new(); - if tcx.should_inherit_track_caller(did) { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::TRACK_CALLER; - } - - let supported_target_features = tcx.supported_target_features(LOCAL_CRATE); - - let mut inline_span = None; - let mut link_ordinal_span = None; - let mut no_sanitize_span = None; - for attr in attrs.iter() { - 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) { - if tcx.is_foreign_item(did) { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::FFI_RETURNS_TWICE; - } else { - // `#[ffi_returns_twice]` is only allowed `extern fn`s. - struct_span_err!( - tcx.sess, - attr.span, - E0724, - "`#[ffi_returns_twice]` may only be used on foreign functions" - ) - .emit(); - } - } else if attr.has_name(sym::ffi_pure) { - if tcx.is_foreign_item(did) { - if attrs.iter().any(|a| a.has_name(sym::ffi_const)) { - // `#[ffi_const]` functions cannot be `#[ffi_pure]` - struct_span_err!( - tcx.sess, - attr.span, - E0757, - "`#[ffi_const]` function cannot be `#[ffi_pure]`" - ) - .emit(); - } else { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::FFI_PURE; - } - } else { - // `#[ffi_pure]` is only allowed on foreign functions - struct_span_err!( - tcx.sess, - attr.span, - E0755, - "`#[ffi_pure]` may only be used on foreign functions" - ) - .emit(); - } - } else if attr.has_name(sym::ffi_const) { - if tcx.is_foreign_item(did) { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::FFI_CONST; - } else { - // `#[ffi_const]` is only allowed on foreign functions - struct_span_err!( - tcx.sess, - attr.span, - E0756, - "`#[ffi_const]` may only be used on foreign functions" - ) - .emit(); - } - } 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(errors::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 - }; - } - } - } else if attr.has_name(sym::cmse_nonsecure_entry) { - if !matches!(tcx.fn_sig(did).abi(), abi::Abi::C { .. }) { - struct_span_err!( - tcx.sess, - attr.span, - E0776, - "`#[cmse_nonsecure_entry]` requires C ABI" - ) - .emit(); - } - 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; - } 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()) && tcx.fn_sig(did).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::closure_track_caller, - attr.span, - "`#[track_caller]` on closures is currently unstable", - ) - .emit(); - } - 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. - 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::target_feature) { - if !tcx.is_closure(did.to_def_id()) - && tcx.fn_sig(did).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. - } 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, - ); - } 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; - } - } - } 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); - } - } - } 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; - } 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; - } 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(); - } - } - } - } else if attr.has_name(sym::instruction_set) { - codegen_fn_attrs.instruction_set = match attr.meta_kind() { - Some(MetaItemKind::List(ref items)) => match items.as_slice() { - [NestedMetaItem::MetaItem(set)] => { - let segments = - set.path.segments.iter().map(|x| x.ident.name).collect::>(); - 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, - 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 - } - }, - _ => { - struct_span_err!( - tcx.sess.diagnostic(), - attr.span, - E0778, - "must specify an 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) => { - struct_span_err!( - tcx.sess.diagnostic(), - attr.span, - E0589, - "invalid `repr(align)` attribute: {}", - msg - ) - .emit(); - - None - } - } - } - _ => None, - }, - [] => None, - _ => None, - }, - None => None, - }; - } - } - - codegen_fn_attrs.inline = attrs.iter().fold(InlineAttr::None, |ia, attr| { - if !attr.has_name(sym::inline) { - return ia; - } - match attr.meta_kind() { - Some(MetaItemKind::Word) => InlineAttr::Hint, - Some(MetaItemKind::List(ref items)) => { - inline_span = Some(attr.span); - if items.len() != 1 { - struct_span_err!( - tcx.sess.diagnostic(), - attr.span, - E0534, - "expected one argument" - ) - .emit(); - InlineAttr::None - } else if list_contains_name(&items, sym::always) { - InlineAttr::Always - } else if list_contains_name(&items, sym::never) { - InlineAttr::Never - } else { - struct_span_err!( - tcx.sess.diagnostic(), - items[0].span(), - E0535, - "invalid argument" - ) - .help("valid inline arguments are `always` and `never`") - .emit(); - - InlineAttr::None - } - } - Some(MetaItemKind::NameValue(_)) => ia, - None => ia, - } - }); - - codegen_fn_attrs.optimize = attrs.iter().fold(OptimizeAttr::None, |ia, attr| { - if !attr.has_name(sym::optimize) { - return ia; - } - let err = |sp, s| struct_span_err!(tcx.sess.diagnostic(), sp, E0722, "{}", s).emit(); - match attr.meta_kind() { - Some(MetaItemKind::Word) => { - err(attr.span, "expected one argument"); - ia - } - Some(MetaItemKind::List(ref items)) => { - inline_span = Some(attr.span); - if items.len() != 1 { - err(attr.span, "expected one argument"); - OptimizeAttr::None - } else if list_contains_name(&items, sym::size) { - OptimizeAttr::Size - } else if list_contains_name(&items, sym::speed) { - OptimizeAttr::Speed - } else { - err(items[0].span(), "invalid argument"); - OptimizeAttr::None - } - } - Some(MetaItemKind::NameValue(_)) => ia, - None => ia, - } - }); - - // #73631: closures inherit `#[target_feature]` annotations - if tcx.features().target_feature_11 && tcx.is_closure(did.to_def_id()) { - let owner_id = tcx.parent(did.to_def_id()); - if tcx.def_kind(owner_id).has_codegen_attrs() { - codegen_fn_attrs - .target_features - .extend(tcx.codegen_fn_attrs(owner_id).target_features.iter().copied()); - } - } - - // If a function uses #[target_feature] it can't be inlined into general - // purpose functions as they wouldn't have the right target features - // enabled. For that reason we also forbid #[inline(always)] as it can't be - // respected. - if !codegen_fn_attrs.target_features.is_empty() { - if codegen_fn_attrs.inline == InlineAttr::Always { - if let Some(span) = inline_span { - tcx.sess.span_err( - span, - "cannot use `#[inline(always)]` with \ - `#[target_feature]`", - ); - } - } - } - - if !codegen_fn_attrs.no_sanitize.is_empty() { - if codegen_fn_attrs.inline == InlineAttr::Always { - if let (Some(no_sanitize_span), Some(inline_span)) = (no_sanitize_span, inline_span) { - let hir_id = tcx.hir().local_def_id_to_hir_id(did); - tcx.struct_span_lint_hir( - lint::builtin::INLINE_NO_SANITIZE, - hir_id, - no_sanitize_span, - "`no_sanitize` will have no effect after inlining", - |lint| lint.span_note(inline_span, "inlining requested here"), - ) - } - } - } - - if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::NAKED) { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_COVERAGE; - codegen_fn_attrs.inline = InlineAttr::Never; - } - - // Weak lang items have the same semantics as "std internal" symbols in the - // sense that they're preserved through all our LTO passes and only - // strippable by the linker. - // - // Additionally weak lang items have predetermined symbol names. - if WEAK_LANG_ITEMS.iter().any(|&l| tcx.lang_items().get(l) == Some(did.to_def_id())) { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL; - } - if let Some((name, _)) = lang_items::extract(attrs) - && let Some(lang_item) = LangItem::from_name(name) - && let Some(link_name) = lang_item.link_name() - { - codegen_fn_attrs.export_name = Some(link_name); - codegen_fn_attrs.link_name = Some(link_name); - } - check_link_name_xor_ordinal(tcx, &codegen_fn_attrs, link_ordinal_span); - - // Internal symbols to the standard library all have no_mangle semantics in - // that they have defined symbol names present in the function name. This - // also applies to weak symbols where they all have known symbol names. - if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL) { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_MANGLE; - } - - // Any linkage to LLVM intrinsics for now forcibly marks them all as never - // unwinds since LLVM sometimes can't handle codegen which `invoke`s - // intrinsic functions. - if let Some(name) = &codegen_fn_attrs.link_name { - if name.as_str().starts_with("llvm.") { - codegen_fn_attrs.flags |= CodegenFnAttrFlags::NEVER_UNWIND; - } - } - - codegen_fn_attrs -} - -/// Computes the set of target features used in a function for the purposes of -/// inline assembly. -fn asm_target_features<'tcx>(tcx: TyCtxt<'tcx>, did: DefId) -> &'tcx FxHashSet { - let mut target_features = tcx.sess.unstable_target_features.clone(); - if tcx.def_kind(did).has_codegen_attrs() { - let attrs = tcx.codegen_fn_attrs(did); - target_features.extend(&attrs.target_features); - match attrs.instruction_set { - None => {} - Some(InstructionSetAttr::ArmA32) => { - target_features.remove(&sym::thumb_mode); - } - Some(InstructionSetAttr::ArmT32) => { - target_features.insert(sym::thumb_mode); - } - } - } - - tcx.arena.alloc(target_features) -} - -/// 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 { - if let Some(impl_item) = tcx.opt_associated_item(def_id) - && let ty::AssocItemContainer::ImplContainer = impl_item.container - && let Some(trait_item) = impl_item.trait_item_def_id - { - return tcx - .codegen_fn_attrs(trait_item) - .flags - .intersects(CodegenFnAttrFlags::TRACK_CALLER); - } - - false -} - -fn check_link_ordinal(tcx: TyCtxt<'_>, attr: &ast::Attribute) -> Option { - use rustc_ast::{LitIntType, LitKind, MetaItemLit}; - if !tcx.features().raw_dylib && tcx.sess.target.arch == "x86" { - feature_err( - &tcx.sess.parse_sess, - sym::raw_dylib, - attr.span, - "`#[link_ordinal]` is unstable on x86", - ) - .emit(); - } - let meta_item_list = attr.meta_item_list(); - let meta_item_list = meta_item_list.as_deref(); - let sole_meta_list = match meta_item_list { - Some([item]) => item.lit(), - Some(_) => { - tcx.sess - .struct_span_err(attr.span, "incorrect number of arguments to `#[link_ordinal]`") - .note("the attribute requires exactly one argument") - .emit(); - return None; - } - _ => None, - }; - if let Some(MetaItemLit { kind: LitKind::Int(ordinal, LitIntType::Unsuffixed), .. }) = - sole_meta_list - { - // According to the table at https://docs.microsoft.com/en-us/windows/win32/debug/pe-format#import-header, - // the ordinal must fit into 16 bits. Similarly, the Ordinal field in COFFShortExport (defined - // in llvm/include/llvm/Object/COFFImportFile.h), which we use to communicate import information - // to LLVM for `#[link(kind = "raw-dylib"_])`, is also defined to be uint16_t. - // - // FIXME: should we allow an ordinal of 0? The MSVC toolchain has inconsistent support for this: - // both LINK.EXE and LIB.EXE signal errors and abort when given a .DEF file that specifies - // a zero ordinal. However, llvm-dlltool is perfectly happy to generate an import library - // for such a .DEF file, and MSVC's LINK.EXE is also perfectly happy to consume an import - // library produced by LLVM with an ordinal of 0, and it generates an .EXE. (I don't know yet - // if the resulting EXE runs, as I haven't yet built the necessary DLL -- see earlier comment - // about LINK.EXE failing.) - if *ordinal <= u16::MAX as u128 { - Some(*ordinal as u16) - } else { - let msg = format!("ordinal value in `link_ordinal` is too large: `{}`", &ordinal); - tcx.sess - .struct_span_err(attr.span, &msg) - .note("the value may not exceed `u16::MAX`") - .emit(); - None - } - } else { - tcx.sess - .struct_span_err(attr.span, "illegal ordinal format in `link_ordinal`") - .note("an unsuffixed integer value, e.g., `1`, is expected") - .emit(); - None - } -} - -fn check_link_name_xor_ordinal( - tcx: TyCtxt<'_>, - codegen_fn_attrs: &CodegenFnAttrs, - inline_span: Option, -) { - if codegen_fn_attrs.link_name.is_none() || codegen_fn_attrs.link_ordinal.is_none() { - return; - } - let msg = "cannot use `#[link_name]` with `#[link_ordinal]`"; - if let Some(span) = inline_span { - tcx.sess.span_err(span, msg); - } else { - tcx.sess.err(msg); - } -} - -/// Checks the function annotated with `#[target_feature]` is not a safe -/// trait method implementation, reporting an error if it is. -fn check_target_feature_trait_unsafe(tcx: TyCtxt<'_>, id: LocalDefId, attr_span: Span) { - let hir_id = tcx.hir().local_def_id_to_hir_id(id); - let node = tcx.hir().get(hir_id); - if let Node::ImplItem(hir::ImplItem { kind: hir::ImplItemKind::Fn(..), .. }) = node { - let parent_id = tcx.hir().get_parent_item(hir_id); - let parent_item = tcx.hir().expect_item(parent_id.def_id); - if let hir::ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }) = parent_item.kind { - tcx.sess - .struct_span_err( - attr_span, - "`#[target_feature(..)]` cannot be applied to safe trait method", - ) - .span_label(attr_span, "cannot be applied to safe trait method") - .span_label(tcx.def_span(id), "not an `unsafe` function") - .emit(); - } - } -} diff --git a/compiler/rustc_hir_analysis/src/errors.rs b/compiler/rustc_hir_analysis/src/errors.rs index c92ab749bc1f7..d9697c63c56e1 100644 --- a/compiler/rustc_hir_analysis/src/errors.rs +++ b/compiler/rustc_hir_analysis/src/errors.rs @@ -253,13 +253,6 @@ pub struct ExternCrateNotIdiomatic { pub suggestion_code: String, } -#[derive(Diagnostic)] -#[diag(hir_analysis_expected_used_symbol)] -pub struct ExpectedUsedSymbol { - #[primary_span] - pub span: Span, -} - #[derive(Diagnostic)] #[diag(hir_analysis_const_impl_for_non_const_trait)] pub struct ConstImplForNonConstTrait {