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Move some codegen-y methods from rustc_hir_analysis::collect -> rustc_codegen_ssa

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Michael Goulet 2022-12-08 03:53:35 +00:00
parent b96d9e0e20
commit a8a45100a0
8 changed files with 857 additions and 828 deletions
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688
compiler/rustc_codegen_ssa/src/codegen_attrs.rs Normal file
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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::<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,
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<u16> {
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<Span>,
) {
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 };
}

7
compiler/rustc_codegen_ssa/src/errors.rs
View file

@ -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,
}

2
compiler/rustc_codegen_ssa/src/lib.rs
View file

@ -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) {

164
compiler/rustc_codegen_ssa/src/target_features.rs
View file

@ -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<String, Option<Symbol>>,
target_features: &mut Vec<Symbol>,
) {
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<Symbol> {
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
}
}

2
compiler/rustc_error_messages/locales/en-US/codegen_ssa.ftl
View file

@ -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)`

2
compiler/rustc_error_messages/locales/en-US/hir_analysis.ftl
View file

@ -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

813
compiler/rustc_hir_analysis/src/collect.rs
View file

@ -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<hir::GeneratorKind>
_ => bug!("generator_kind applied to non-local def-id {:?}", def_id),
}
}
fn from_target_feature(
tcx: TyCtxt<'_>,
attr: &ast::Attribute,
supported_target_features: &FxHashMap<String, Option<Symbol>>,
target_features: &mut Vec<Symbol>,
) {
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::<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,
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<Symbol> {
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<u16> {
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<Span>,
) {
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();
}
}
}

7
compiler/rustc_hir_analysis/src/errors.rs
View file

@ -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 {