Rework #[cold] attribute parser

compiler/rustc_attr_data_structures/src/attributes.rs

@@ -38,7 +38,8 @@ pub enum InstructionSetAttr {
     ArmT32,
 }
 
-#[derive(Clone, Encodable, Decodable, Debug, PartialEq, Eq, HashStable_Generic, Default)]
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Default, PrintAttribute)]
+#[derive(Encodable, Decodable, HashStable_Generic)]
 pub enum OptimizeAttr {
     /// No `#[optimize(..)]` attribute
     #[default]
@@ -201,6 +202,9 @@ pub enum AttributeKind {
         span: Span,
     },
 
+    /// Represents `#[cold]`.
+    Cold(Span),
+
     /// Represents `#[rustc_confusables]`.
     Confusables {
         symbols: ThinVec<Symbol>,
@@ -229,7 +233,8 @@ pub enum AttributeKind {
 
     /// Represents `#[rustc_macro_transparency]`.
     MacroTransparency(Transparency),
-
+    /// Represents `#[optimize(size|speed)]`
+    Optimize(OptimizeAttr, Span),
     /// Represents [`#[repr]`](https://doc.rust-lang.org/stable/reference/type-layout.html#representations).
     Repr(ThinVec<(ReprAttr, Span)>),
 

compiler/rustc_attr_parsing/src/attributes/codegen_attrs.rs

@@ -0,0 +1,58 @@
+use rustc_attr_data_structures::{AttributeKind, OptimizeAttr};
+use rustc_feature::{AttributeTemplate, template};
+use rustc_span::sym;
+
+use super::{AttributeOrder, OnDuplicate, SingleAttributeParser};
+use crate::context::{AcceptContext, Stage};
+use crate::parser::ArgParser;
+
+pub(crate) struct OptimizeParser;
+
+impl<S: Stage> SingleAttributeParser<S> for OptimizeParser {
+    const PATH: &[rustc_span::Symbol] = &[sym::optimize];
+    const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepLast;
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::WarnButFutureError;
+    const TEMPLATE: AttributeTemplate = template!(List: "size|speed|none");
+
+    fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
+        let Some(list) = args.list() else {
+            cx.expected_list(cx.attr_span);
+            return None;
+        };
+
+        let Some(single) = list.single() else {
+            cx.expected_single_argument(list.span);
+            return None;
+        };
+
+        let res = match single.meta_item().and_then(|i| i.path().word().map(|i| i.name)) {
+            Some(sym::size) => OptimizeAttr::Size,
+            Some(sym::speed) => OptimizeAttr::Speed,
+            Some(sym::none) => OptimizeAttr::DoNotOptimize,
+            _ => {
+                cx.expected_specific_argument(single.span(), vec!["size", "speed", "none"]);
+                OptimizeAttr::Default
+            }
+        };
+
+        Some(AttributeKind::Optimize(res, cx.attr_span))
+    }
+}
+
+pub(crate) struct ColdParser;
+
+impl<S: Stage> SingleAttributeParser<S> for ColdParser {
+    const PATH: &[rustc_span::Symbol] = &[sym::cold];
+    const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepLast;
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Warn;
+    const TEMPLATE: AttributeTemplate = template!(Word);
+
+    fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
+        if !args.no_args() {
+            cx.expected_no_args(args.span().unwrap_or(cx.attr_span));
+            return None;
+        };
+
+        Some(AttributeKind::Cold(cx.attr_span))
+    }
+}

compiler/rustc_attr_parsing/src/attributes/mod.rs

@@ -28,6 +28,7 @@ use crate::session_diagnostics::UnusedMultiple;
 
 pub(crate) mod allow_unstable;
 pub(crate) mod cfg;
+pub(crate) mod codegen_attrs;
 pub(crate) mod confusables;
 pub(crate) mod deprecation;
 pub(crate) mod inline;

compiler/rustc_attr_parsing/src/context.rs

@@ -15,6 +15,7 @@ use rustc_session::Session;
 use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span, Symbol, sym};
 
 use crate::attributes::allow_unstable::{AllowConstFnUnstableParser, AllowInternalUnstableParser};
+use crate::attributes::codegen_attrs::{ColdParser, OptimizeParser};
 use crate::attributes::confusables::ConfusablesParser;
 use crate::attributes::deprecation::DeprecationParser;
 use crate::attributes::inline::{InlineParser, RustcForceInlineParser};
@@ -105,9 +106,11 @@ attribute_parsers!(
 
         // tidy-alphabetical-start
         Single<AsPtrParser>,
+        Single<ColdParser>,
         Single<ConstStabilityIndirectParser>,
         Single<DeprecationParser>,
         Single<InlineParser>,
+        Single<OptimizeParser>,
         Single<RustcForceInlineParser>,
         Single<TransparencyParser>,
         // tidy-alphabetical-end
@@ -232,6 +235,16 @@ impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
         })
     }
 
+    pub(crate) fn expected_no_args(&self, args_span: Span) -> ErrorGuaranteed {
+        self.emit_err(AttributeParseError {
+            span: args_span,
+            attr_span: self.attr_span,
+            template: self.template.clone(),
+            attribute: self.attr_path.clone(),
+            reason: AttributeParseErrorReason::ExpectedNoArgs,
+        })
+    }
+
     /// emit an error that a `name = value` pair was expected at this span. The symbol can be given for
     /// a nicer error message talking about the specific name that was found lacking a value.
     pub(crate) fn expected_name_value(&self, span: Span, name: Option<Symbol>) -> ErrorGuaranteed {

compiler/rustc_attr_parsing/src/session_diagnostics.rs

@@ -474,6 +474,7 @@ pub(crate) struct UnrecognizedReprHint {
 }
 
 pub(crate) enum AttributeParseErrorReason {
+    ExpectedNoArgs,
     ExpectedStringLiteral { byte_string: Option<Span> },
     ExpectedSingleArgument,
     ExpectedList,
@@ -529,6 +530,10 @@ impl<'a, G: EmissionGuarantee> Diagnostic<'a, G> for AttributeParseError {
                 diag.span_label(self.span, format!("didn't expect a literal here"));
                 diag.code(E0565);
             }
+            AttributeParseErrorReason::ExpectedNoArgs => {
+                diag.span_label(self.span, format!("didn't expect any arguments here"));
+                diag.code(E0565);
+            }
             AttributeParseErrorReason::ExpectedNameValue(None) => {
                 diag.span_label(
                     self.span,

compiler/rustc_codegen_ssa/messages.ftl

@@ -48,8 +48,6 @@ codegen_ssa_error_writing_def_file =
 
 codegen_ssa_expected_name_value_pair = expected name value pair
 
-codegen_ssa_expected_one_argument = expected one argument
-
 codegen_ssa_expected_used_symbol = expected `used`, `used(compiler)` or `used(linker)`
 
 codegen_ssa_extern_funcs_not_found = some `extern` functions couldn't be found; some native libraries may need to be installed or have their path specified
@@ -86,9 +84,6 @@ codegen_ssa_incorrect_cgu_reuse_type =
 
 codegen_ssa_insufficient_vs_code_product = VS Code is a different product, and is not sufficient.
 
-codegen_ssa_invalid_argument = invalid argument
-    .help = valid inline arguments are `always` and `never`
-
 codegen_ssa_invalid_instruction_set = invalid instruction set specified
 
 codegen_ssa_invalid_link_ordinal_nargs = incorrect number of arguments to `#[link_ordinal]`

compiler/rustc_codegen_ssa/src/codegen_attrs.rs

@@ -4,7 +4,7 @@ use rustc_abi::ExternAbi;
 use rustc_ast::expand::autodiff_attrs::{AutoDiffAttrs, DiffActivity, DiffMode};
 use rustc_ast::{LitKind, MetaItem, MetaItemInner, attr};
 use rustc_attr_data_structures::{
-    AttributeKind, InlineAttr, InstructionSetAttr, OptimizeAttr, find_attr,
+    AttributeKind, InlineAttr, InstructionSetAttr, OptimizeAttr, ReprAttr, find_attr,
 };
 use rustc_data_structures::fx::FxHashMap;
 use rustc_hir::def::DefKind;
@@ -109,16 +109,27 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs {
             }
         };
 
-        if let hir::Attribute::Parsed(AttributeKind::Align { align, .. }) = attr {
-            codegen_fn_attrs.alignment = Some(*align);
+        if let hir::Attribute::Parsed(p) = attr {
+            match p {
+                AttributeKind::Repr(reprs) => {
+                    codegen_fn_attrs.alignment = reprs
+                        .iter()
+                        .filter_map(
+                            |(r, _)| if let ReprAttr::ReprAlign(x) = r { Some(*x) } else { None },
+                        )
+                        .max();
+                }
+                AttributeKind::Cold(_) => codegen_fn_attrs.flags |= CodegenFnAttrFlags::COLD,
+                AttributeKind::Align { align, .. } => codegen_fn_attrs.alignment = Some(*align),
+                _ => {}
+            }
         }
 
         let Some(Ident { name, .. }) = attr.ident() else {
             continue;
         };
 
         match name {
-            sym::cold => codegen_fn_attrs.flags |= CodegenFnAttrFlags::COLD,
             sym::rustc_allocator => codegen_fn_attrs.flags |= CodegenFnAttrFlags::ALLOCATOR,
             sym::ffi_pure => codegen_fn_attrs.flags |= CodegenFnAttrFlags::FFI_PURE,
             sym::ffi_const => codegen_fn_attrs.flags |= CodegenFnAttrFlags::FFI_CONST,
@@ -455,33 +466,8 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs {
         codegen_fn_attrs.inline = InlineAttr::Never;
     }
 
-    codegen_fn_attrs.optimize = attrs.iter().fold(OptimizeAttr::Default, |ia, attr| {
-        if !attr.has_name(sym::optimize) {
-            return ia;
-        }
-        if attr.is_word() {
-            tcx.dcx().emit_err(errors::ExpectedOneArgumentOptimize { span: attr.span() });
-            return ia;
-        }
-        let Some(ref items) = attr.meta_item_list() else {
-            return OptimizeAttr::Default;
-        };
-
-        let [item] = &items[..] else {
-            tcx.dcx().emit_err(errors::ExpectedOneArgumentOptimize { span: attr.span() });
-            return OptimizeAttr::Default;
-        };
-        if item.has_name(sym::size) {
-            OptimizeAttr::Size
-        } else if item.has_name(sym::speed) {
-            OptimizeAttr::Speed
-        } else if item.has_name(sym::none) {
-            OptimizeAttr::DoNotOptimize
-        } else {
-            tcx.dcx().emit_err(errors::InvalidArgumentOptimize { span: item.span() });
-            OptimizeAttr::Default
-        }
-    });
+    codegen_fn_attrs.optimize =
+        find_attr!(attrs, AttributeKind::Optimize(i, _) => *i).unwrap_or(OptimizeAttr::Default);
 
     // #73631: closures inherit `#[target_feature]` annotations
     //

compiler/rustc_codegen_ssa/src/errors.rs

@@ -208,20 +208,6 @@ pub(crate) struct OutOfRangeInteger {
     pub span: Span,
 }
 
-#[derive(Diagnostic)]
-#[diag(codegen_ssa_expected_one_argument, code = E0722)]
-pub(crate) struct ExpectedOneArgumentOptimize {
-    #[primary_span]
-    pub span: Span,
-}
-
-#[derive(Diagnostic)]
-#[diag(codegen_ssa_invalid_argument, code = E0722)]
-pub(crate) struct InvalidArgumentOptimize {
-    #[primary_span]
-    pub span: Span,
-}
-
 #[derive(Diagnostic)]
 #[diag(codegen_ssa_copy_path_buf)]
 pub(crate) struct CopyPathBuf {

compiler/rustc_error_codes/src/error_codes/E0722.md

@@ -1,8 +1,14 @@
+#### Note: this error code is no longer emitted by the compiler
+
+This is because it was too specific to the `optimize` attribute.
+Similar diagnostics occur for other attributes too.
+The example here will now emit `E0539`
+
 The `optimize` attribute was malformed.
 
 Erroneous code example:
 
-```compile_fail,E0722
+```compile_fail,E0539
 #![feature(optimize_attribute)]
 
 #[optimize(something)] // error: invalid argument

compiler/rustc_error_codes/src/lib.rs

@@ -686,6 +686,7 @@ E0805: 0805,
 //  E0707, // multiple elided lifetimes used in arguments of `async fn`
 //  E0709, // multiple different lifetimes used in arguments of `async fn`
 //  E0721, // `await` keyword
+//  E0722, // replaced with a generic attribute input check
 //  E0723, // unstable feature in `const` context
 //  E0738, // Removed; errored on `#[track_caller] fn`s in `extern "Rust" { ... }`.
 //  E0744, // merged into E0728

compiler/rustc_parse/src/validate_attr.rs

@@ -291,6 +291,8 @@ fn emit_malformed_attribute(
             | sym::repr
             | sym::align
             | sym::deprecated
+            | sym::optimize
+            | sym::cold
     ) {
         return;
     }