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JonathanBrouwerJonathanBrouwer
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Port #[no_mangle] to new attribute parsing infrastructure
Signed-off-by: Jonathan Brouwer <[email protected]>
1 parent a30f178 commit d7a5d0a

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17 files changed

+120
-78
lines changed

17 files changed

+120
-78
lines changed

‎compiler/rustc_attr_data_structures/src/attributes.rs

Lines changed: 3 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -237,6 +237,9 @@ pub enum AttributeKind {
237237
/// Represents [`#[may_dangle]`](https://std-dev-guide.rust-lang.org/tricky/may-dangle.html).
238238
MayDangle(Span),
239239

240+
/// Represents `#[no_mangle]`
241+
NoMangle(Span),
242+
240243
/// Represents `#[optimize(size|speed)]`
241244
Optimize(OptimizeAttr, Span),
242245

‎compiler/rustc_attr_parsing/src/attributes/codegen_attrs.rs

Lines changed: 18 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -56,3 +56,21 @@ impl<S: Stage> SingleAttributeParser<S> for ColdParser {
5656
Some(AttributeKind::Cold(cx.attr_span))
5757
}
5858
}
59+
60+
pub(crate) struct NoMangleParser;
61+
62+
impl<S: Stage> SingleAttributeParser<S> for NoMangleParser {
63+
const PATH: &[rustc_span::Symbol] = &[sym::no_mangle];
64+
const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepLast;
65+
const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Warn;
66+
const TEMPLATE: AttributeTemplate = template!(Word);
67+
68+
fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
69+
if !args.no_args() {
70+
cx.expected_no_args(args.span().unwrap_or(cx.attr_span));
71+
return None;
72+
};
73+
74+
Some(AttributeKind::NoMangle(cx.attr_span))
75+
}
76+
}

‎compiler/rustc_attr_parsing/src/context.rs

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -15,7 +15,7 @@ use rustc_session::Session;
1515
use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span, Symbol, sym};
1616

1717
use crate::attributes::allow_unstable::{AllowConstFnUnstableParser, AllowInternalUnstableParser};
18-
use crate::attributes::codegen_attrs::{ColdParser, OptimizeParser};
18+
use crate::attributes::codegen_attrs::{ColdParser, NoMangleParser, OptimizeParser};
1919
use crate::attributes::confusables::ConfusablesParser;
2020
use crate::attributes::deprecation::DeprecationParser;
2121
use crate::attributes::inline::{InlineParser, RustcForceInlineParser};
@@ -112,6 +112,7 @@ attribute_parsers!(
112112
Single<DeprecationParser>,
113113
Single<InlineParser>,
114114
Single<MayDangleParser>,
115+
Single<NoMangleParser>,
115116
Single<OptimizeParser>,
116117
Single<PubTransparentParser>,
117118
Single<RustcForceInlineParser>,

‎compiler/rustc_codegen_ssa/messages.ftl

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -221,6 +221,8 @@ codegen_ssa_multiple_main_functions = entry symbol `main` declared multiple time
221221
222222
codegen_ssa_no_field = no field `{$name}`
223223
224+
codegen_ssa_no_mangle_nameless = `#[no_mangle]` cannot be used on {$definition} as it has no name
225+
224226
codegen_ssa_no_module_named =
225227
no module named `{$user_path}` (mangled: {$cgu_name}). available modules: {$cgu_names}
226228

‎compiler/rustc_codegen_ssa/src/codegen_attrs.rs

Lines changed: 24 additions & 24 deletions
Original file line numberDiff line numberDiff line change
@@ -23,6 +23,7 @@ use rustc_span::{Ident, Span, sym};
2323
use rustc_target::spec::SanitizerSet;
2424

2525
use crate::errors;
26+
use crate::errors::NoMangleNameless;
2627
use crate::target_features::{
2728
check_target_feature_trait_unsafe, check_tied_features, from_target_feature_attr,
2829
};
@@ -87,7 +88,6 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs {
8788
let mut link_ordinal_span = None;
8889
let mut no_sanitize_span = None;
8990
let mut mixed_export_name_no_mangle_lint_state = MixedExportNameAndNoMangleState::default();
90-
let mut no_mangle_span = None;
9191

9292
for attr in attrs.iter() {
9393
// In some cases, attribute are only valid on functions, but it's the `check_attr`
@@ -122,6 +122,25 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs {
122122
}
123123
AttributeKind::Cold(_) => codegen_fn_attrs.flags |= CodegenFnAttrFlags::COLD,
124124
AttributeKind::Align { align, .. } => codegen_fn_attrs.alignment = Some(*align),
125+
AttributeKind::NoMangle(attr_span) => {
126+
if tcx.opt_item_name(did.to_def_id()).is_some() {
127+
codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_MANGLE;
128+
mixed_export_name_no_mangle_lint_state.track_no_mangle(
129+
*attr_span,
130+
tcx.local_def_id_to_hir_id(did),
131+
attr,
132+
);
133+
} else {
134+
tcx.dcx().emit_err(NoMangleNameless {
135+
span: *attr_span,
136+
definition: format!(
137+
"{} {}",
138+
tcx.def_descr_article(did.to_def_id()),
139+
tcx.def_descr(did.to_def_id())
140+
),
141+
});
142+
}
143+
}
125144
_ => {}
126145
}
127146
}
@@ -141,28 +160,6 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs {
141160
codegen_fn_attrs.flags |= CodegenFnAttrFlags::ALLOCATOR_ZEROED
142161
}
143162
sym::naked => codegen_fn_attrs.flags |= CodegenFnAttrFlags::NAKED,
144-
sym::no_mangle => {
145-
no_mangle_span = Some(attr.span());
146-
if tcx.opt_item_name(did.to_def_id()).is_some() {
147-
codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_MANGLE;
148-
mixed_export_name_no_mangle_lint_state.track_no_mangle(
149-
attr.span(),
150-
tcx.local_def_id_to_hir_id(did),
151-
attr,
152-
);
153-
} else {
154-
tcx.dcx()
155-
.struct_span_err(
156-
attr.span(),
157-
format!(
158-
"`#[no_mangle]` cannot be used on {} {} as it has no name",
159-
tcx.def_descr_article(did.to_def_id()),
160-
tcx.def_descr(did.to_def_id()),
161-
),
162-
)
163-
.emit();
164-
}
165-
}
166163
sym::rustc_std_internal_symbol => {
167164
codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL
168165
}
@@ -544,12 +541,15 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs {
544541
if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL)
545542
&& codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::NO_MANGLE)
546543
{
544+
let no_mangle_span =
545+
find_attr!(attrs, AttributeKind::NoMangle(no_mangle_span) => *no_mangle_span)
546+
.unwrap_or_default();
547547
let lang_item =
548548
lang_items::extract(attrs).map_or(None, |(name, _span)| LangItem::from_name(name));
549549
let mut err = tcx
550550
.dcx()
551551
.struct_span_err(
552-
no_mangle_span.unwrap_or_default(),
552+
no_mangle_span,
553553
"`#[no_mangle]` cannot be used on internal language items",
554554
)
555555
.with_note("Rustc requires this item to have a specific mangled name.")

‎compiler/rustc_codegen_ssa/src/errors.rs

Lines changed: 8 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1310,3 +1310,11 @@ impl<G: EmissionGuarantee> Diagnostic<'_, G> for TargetFeatureDisableOrEnable<'_
13101310
diag
13111311
}
13121312
}
1313+
1314+
#[derive(Diagnostic)]
1315+
#[diag(codegen_ssa_no_mangle_nameless)]
1316+
pub(crate) struct NoMangleNameless {
1317+
#[primary_span]
1318+
pub span: Span,
1319+
pub definition: String,
1320+
}

‎compiler/rustc_lint/src/builtin.rs

Lines changed: 12 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -21,6 +21,7 @@ use rustc_ast::tokenstream::{TokenStream, TokenTree};
2121
use rustc_ast::visit::{FnCtxt, FnKind};
2222
use rustc_ast::{self as ast, *};
2323
use rustc_ast_pretty::pprust::expr_to_string;
24+
use rustc_attr_data_structures::{AttributeKind, find_attr};
2425
use rustc_errors::{Applicability, LintDiagnostic};
2526
use rustc_feature::GateIssue;
2627
use rustc_hir as hir;
@@ -954,7 +955,7 @@ declare_lint_pass!(InvalidNoMangleItems => [NO_MANGLE_CONST_ITEMS, NO_MANGLE_GEN
954955
impl<'tcx> LateLintPass<'tcx> for InvalidNoMangleItems {
955956
fn check_item(&mut self, cx: &LateContext<'_>, it: &hir::Item<'_>) {
956957
let attrs = cx.tcx.hir_attrs(it.hir_id());
957-
let check_no_mangle_on_generic_fn = |attr: &hir::Attribute,
958+
let check_no_mangle_on_generic_fn = |attr_span: Span,
958959
impl_generics: Option<&hir::Generics<'_>>,
959960
generics: &hir::Generics<'_>,
960961
span| {
@@ -967,7 +968,7 @@ impl<'tcx> LateLintPass<'tcx> for InvalidNoMangleItems {
967968
cx.emit_span_lint(
968969
NO_MANGLE_GENERIC_ITEMS,
969970
span,
970-
BuiltinNoMangleGeneric { suggestion: attr.span() },
971+
BuiltinNoMangleGeneric { suggestion: attr_span },
971972
);
972973
break;
973974
}
@@ -976,14 +977,15 @@ impl<'tcx> LateLintPass<'tcx> for InvalidNoMangleItems {
976977
};
977978
match it.kind {
978979
hir::ItemKind::Fn { generics, .. } => {
979-
if let Some(attr) = attr::find_by_name(attrs, sym::export_name)
980-
.or_else(|| attr::find_by_name(attrs, sym::no_mangle))
980+
if let Some(attr_span) = attr::find_by_name(attrs, sym::export_name)
981+
.map(|at| at.span())
982+
.or_else(|| find_attr!(attrs, AttributeKind::NoMangle(span) => *span))
981983
{
982-
check_no_mangle_on_generic_fn(attr, None, generics, it.span);
984+
check_no_mangle_on_generic_fn(attr_span, None, generics, it.span);
983985
}
984986
}
985987
hir::ItemKind::Const(..) => {
986-
if attr::contains_name(attrs, sym::no_mangle) {
988+
if find_attr!(attrs, AttributeKind::NoMangle(..)) {
987989
// account for "pub const" (#45562)
988990
let start = cx
989991
.tcx
@@ -1008,11 +1010,12 @@ impl<'tcx> LateLintPass<'tcx> for InvalidNoMangleItems {
10081010
for it in *items {
10091011
if let hir::AssocItemKind::Fn { .. } = it.kind {
10101012
let attrs = cx.tcx.hir_attrs(it.id.hir_id());
1011-
if let Some(attr) = attr::find_by_name(attrs, sym::export_name)
1012-
.or_else(|| attr::find_by_name(attrs, sym::no_mangle))
1013+
if let Some(attr_span) = attr::find_by_name(attrs, sym::export_name)
1014+
.map(|at| at.span())
1015+
.or_else(|| find_attr!(attrs, AttributeKind::NoMangle(span) => *span))
10131016
{
10141017
check_no_mangle_on_generic_fn(
1015-
attr,
1018+
attr_span,
10161019
Some(generics),
10171020
cx.tcx.hir_get_generics(it.id.owner_id.def_id).unwrap(),
10181021
it.span,

‎compiler/rustc_lint/src/nonstandard_style.rs

Lines changed: 8 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,5 @@
11
use rustc_abi::ExternAbi;
2-
use rustc_attr_data_structures::{AttributeKind, ReprAttr};
2+
use rustc_attr_data_structures::{AttributeKind, ReprAttr, find_attr};
33
use rustc_attr_parsing::AttributeParser;
44
use rustc_hir::def::{DefKind, Res};
55
use rustc_hir::intravisit::FnKind;
@@ -396,7 +396,9 @@ impl<'tcx> LateLintPass<'tcx> for NonSnakeCase {
396396
match &fk {
397397
FnKind::Method(ident, sig, ..) => match method_context(cx, id) {
398398
MethodLateContext::PlainImpl => {
399-
if sig.header.abi != ExternAbi::Rust && cx.tcx.has_attr(id, sym::no_mangle) {
399+
if sig.header.abi != ExternAbi::Rust
400+
&& find_attr!(cx.tcx.get_all_attrs(id), AttributeKind::NoMangle(..))
401+
{
400402
return;
401403
}
402404
self.check_snake_case(cx, "method", ident);
@@ -408,7 +410,9 @@ impl<'tcx> LateLintPass<'tcx> for NonSnakeCase {
408410
},
409411
FnKind::ItemFn(ident, _, header) => {
410412
// Skip foreign-ABI #[no_mangle] functions (Issue #31924)
411-
if header.abi != ExternAbi::Rust && cx.tcx.has_attr(id, sym::no_mangle) {
413+
if header.abi != ExternAbi::Rust
414+
&& find_attr!(cx.tcx.get_all_attrs(id), AttributeKind::NoMangle(..))
415+
{
412416
return;
413417
}
414418
self.check_snake_case(cx, "function", ident);
@@ -514,7 +518,7 @@ impl<'tcx> LateLintPass<'tcx> for NonUpperCaseGlobals {
514518
let attrs = cx.tcx.hir_attrs(it.hir_id());
515519
match it.kind {
516520
hir::ItemKind::Static(_, ident, ..)
517-
if !ast::attr::contains_name(attrs, sym::no_mangle) =>
521+
if !find_attr!(attrs, AttributeKind::NoMangle(..)) =>
518522
{
519523
NonUpperCaseGlobals::check_upper_case(cx, "static variable", &ident);
520524
}

‎compiler/rustc_passes/src/check_attr.rs

Lines changed: 9 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -171,6 +171,9 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
171171
Attribute::Parsed(AttributeKind::MayDangle(attr_span)) => {
172172
self.check_may_dangle(hir_id, *attr_span)
173173
}
174+
Attribute::Parsed(AttributeKind::NoMangle(attr_span)) => {
175+
self.check_no_mangle(hir_id, *attr_span, span, target)
176+
}
174177
Attribute::Unparsed(attr_item) => {
175178
style = Some(attr_item.style);
176179
match attr.path().as_slice() {
@@ -259,7 +262,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
259262
[sym::link, ..] => self.check_link(hir_id, attr, span, target),
260263
[sym::link_name, ..] => self.check_link_name(hir_id, attr, span, target),
261264
[sym::link_section, ..] => self.check_link_section(hir_id, attr, span, target),
262-
[sym::no_mangle, ..] => self.check_no_mangle(hir_id, attr, span, target),
263265
[sym::macro_use, ..] | [sym::macro_escape, ..] => {
264266
self.check_macro_use(hir_id, attr, target)
265267
}
@@ -696,6 +698,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
696698
AttributeKind::Deprecation { .. }
697699
| AttributeKind::Repr { .. }
698700
| AttributeKind::Align { .. }
701+
| AttributeKind::NoMangle(..)
699702
| AttributeKind::Cold(..),
700703
) => {
701704
continue;
@@ -1949,7 +1952,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
19491952
}
19501953

19511954
/// Checks if `#[no_mangle]` is applied to a function or static.
1952-
fn check_no_mangle(&self, hir_id: HirId, attr: &Attribute, span: Span, target: Target) {
1955+
fn check_no_mangle(&self, hir_id: HirId, attr_span: Span, span: Span, target: Target) {
19531956
match target {
19541957
Target::Static | Target::Fn => {}
19551958
Target::Method(..) if self.is_impl_item(hir_id) => {}
@@ -1958,7 +1961,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
19581961
// erroneously allowed it and some crates used it accidentally, to be compatible
19591962
// with crates depending on them, we can't throw an error here.
19601963
Target::Field | Target::Arm | Target::MacroDef => {
1961-
self.inline_attr_str_error_with_macro_def(hir_id, attr.span(), "no_mangle");
1964+
self.inline_attr_str_error_with_macro_def(hir_id, attr_span, "no_mangle");
19621965
}
19631966
// FIXME: #[no_mangle] was previously allowed on non-functions/statics, this should be an error
19641967
// The error should specify that the item that is wrong is specifically a *foreign* fn/static
@@ -1972,8 +1975,8 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
19721975
self.tcx.emit_node_span_lint(
19731976
UNUSED_ATTRIBUTES,
19741977
hir_id,
1975-
attr.span(),
1976-
errors::NoMangleForeign { span, attr_span: attr.span(), foreign_item_kind },
1978+
attr_span,
1979+
errors::NoMangleForeign { span, attr_span, foreign_item_kind },
19771980
);
19781981
}
19791982
_ => {
@@ -1982,7 +1985,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
19821985
self.tcx.emit_node_span_lint(
19831986
UNUSED_ATTRIBUTES,
19841987
hir_id,
1985-
attr.span(),
1988+
attr_span,
19861989
errors::NoMangle { span },
19871990
);
19881991
}

‎src/librustdoc/clean/types.rs

Lines changed: 10 additions & 12 deletions
Original file line numberDiff line numberDiff line change
@@ -746,15 +746,17 @@ impl Item {
746746
Some(tcx.visibility(def_id))
747747
}
748748

749-
pub(crate) fn attributes_without_repr(&self, tcx: TyCtxt<'_>, is_json: bool) -> Vec<String> {
749+
fn attributes_without_repr(&self, tcx: TyCtxt<'_>, is_json: bool) -> Vec<String> {
750750
const ALLOWED_ATTRIBUTES: &[Symbol] =
751751
&[sym::export_name, sym::link_section, sym::no_mangle, sym::non_exhaustive];
752-
753752
self.attrs
754753
.other_attrs
755754
.iter()
756755
.filter_map(|attr| {
757-
if is_json {
756+
// NoMangle is special-cased because cargo-semver-checks uses it
757+
if matches!(attr, hir::Attribute::Parsed(AttributeKind::NoMangle(..))) {
758+
Some("#[no_mangle]".to_string())
759+
} else if is_json {
758760
match attr {
759761
// rustdoc-json stores this in `Item::deprecation`, so we
760762
// don't want it it `Item::attrs`.
@@ -767,26 +769,22 @@ impl Item {
767769
s
768770
}),
769771
}
770-
} else if attr.has_any_name(ALLOWED_ATTRIBUTES) {
772+
} else {
773+
if !attr.has_any_name(ALLOWED_ATTRIBUTES) {
774+
return None;
775+
}
771776
Some(
772777
rustc_hir_pretty::attribute_to_string(&tcx, attr)
773778
.replace("\\\n", "")
774779
.replace('\n', "")
775780
.replace(" ", " "),
776781
)
777-
} else {
778-
None
779782
}
780783
})
781784
.collect()
782785
}
783786

784-
pub(crate) fn attributes_and_repr(
785-
&self,
786-
tcx: TyCtxt<'_>,
787-
cache: &Cache,
788-
is_json: bool,
789-
) -> Vec<String> {
787+
pub(crate) fn attributes(&self, tcx: TyCtxt<'_>, cache: &Cache, is_json: bool) -> Vec<String> {
790788
let mut attrs = self.attributes_without_repr(tcx, is_json);
791789

792790
if let Some(repr_attr) = self.repr(tcx, cache, is_json) {

‎src/librustdoc/html/render/mod.rs

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -1194,7 +1194,7 @@ fn render_assoc_item(
11941194
// a whitespace prefix and newline.
11951195
fn render_attributes_in_pre(it: &clean::Item, prefix: &str, cx: &Context<'_>) -> impl fmt::Display {
11961196
fmt::from_fn(move |f| {
1197-
for a in it.attributes_and_repr(cx.tcx(), cx.cache(), false) {
1197+
for a in it.attributes(cx.tcx(), cx.cache(), false) {
11981198
writeln!(f, "{prefix}{a}")?;
11991199
}
12001200
Ok(())
@@ -1210,7 +1210,7 @@ fn render_code_attribute(code_attr: CodeAttribute, w: &mut impl fmt::Write) {
12101210
// When an attribute is rendered inside a <code> tag, it is formatted using
12111211
// a div to produce a newline after it.
12121212
fn render_attributes_in_code(w: &mut impl fmt::Write, it: &clean::Item, cx: &Context<'_>) {
1213-
for attr in it.attributes_and_repr(cx.tcx(), cx.cache(), false) {
1213+
for attr in it.attributes(cx.tcx(), cx.cache(), false) {
12141214
render_code_attribute(CodeAttribute(attr), w);
12151215
}
12161216
}

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