Port #[patchable_function_entry] to attr parser

Bryntet · Bryntet · commit f36627dbd00a · 2026-01-18T22:22:34.000+01:00
diff --git a/compiler/rustc_attr_parsing/src/attributes/codegen_attrs.rs b/compiler/rustc_attr_parsing/src/attributes/codegen_attrs.rs
@@ -717,3 +717,78 @@ impl<S: Stage> NoArgsAttributeParser<S> for EiiForeignItemParser {
     const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(&[Allow(Target::ForeignFn)]);
     const CREATE: fn(Span) -> AttributeKind = |_| AttributeKind::EiiForeignItem;
 }
+
+pub(crate) struct PatchableFunctionEntryParser;
+
+impl<S: Stage> SingleAttributeParser<S> for PatchableFunctionEntryParser {
+    const PATH: &[Symbol] = &[sym::patchable_function_entry];
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
+    const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepInnermost;
+    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(&[Allow(Target::Fn)]);
+    const TEMPLATE: AttributeTemplate = template!(List: &["prefix_nops = m, entry_nops = n"]);
+
+    fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser) -> Option<AttributeKind> {
+        let Some(meta_item_list) = args.list() else {
+            cx.expected_list(cx.attr_span, args);
+            return None;
+        };
+
+        let mut prefix = None;
+        let mut entry = None;
+
+        let mut errored = false;
+
+        if meta_item_list.len() < 2 {
+            cx.expected_list_with_exact_num_args(2, meta_item_list.span);
+        }
+        for (i, item) in meta_item_list.mixed().enumerate() {
+            if i == 2 {
+                errored = true;
+                continue;
+            }
+            let Some(meta_item) = item.meta_item() else {
+                cx.expected_name_value(item.span(), None);
+                continue;
+            };
+
+            let Some(name_value_lit) = meta_item.args().name_value() else {
+                cx.expected_name_value(item.span(), None);
+                continue;
+            };
+
+            let attrib_to_write = match meta_item.ident().map(|ident| ident.name) {
+                Some(sym::prefix_nops) => &mut prefix,
+                Some(sym::entry_nops) => &mut entry,
+                _ => {
+                    cx.expected_specific_argument(
+                        meta_item.path().span(),
+                        &[sym::prefix_nops, sym::entry_nops],
+                    );
+                    continue;
+                }
+            };
+
+            let rustc_ast::LitKind::Int(val, _) = name_value_lit.value_as_lit().kind else {
+                cx.expected_integer_literal(name_value_lit.value_span);
+                continue;
+            };
+
+            let Ok(val) = val.get().try_into() else {
+                cx.expected_integer_literal_in_range(
+                    name_value_lit.value_span,
+                    u8::MIN as isize,
+                    u8::MAX as isize,
+                );
+                continue;
+            };
+
+            *attrib_to_write = Some(val);
+        }
+
+        if errored {
+            None
+        } else {
+            Some(AttributeKind::PatchableFunctionEntry { prefix: prefix?, entry: entry? })
+        }
+    }
+}
diff --git a/compiler/rustc_attr_parsing/src/context.rs b/compiler/rustc_attr_parsing/src/context.rs
@@ -23,8 +23,8 @@ use crate::attributes::cfi_encoding::CfiEncodingParser;
 use crate::attributes::codegen_attrs::{
     ColdParser, CoverageParser, EiiForeignItemParser, ExportNameParser, ForceTargetFeatureParser,
     NakedParser, NoMangleParser, ObjcClassParser, ObjcSelectorParser, OptimizeParser,
-    RustcPassIndirectlyInNonRusticAbisParser, SanitizeParser, TargetFeatureParser,
-    ThreadLocalParser, TrackCallerParser, UsedParser,
+    PatchableFunctionEntryParser, RustcPassIndirectlyInNonRusticAbisParser, SanitizeParser,
+    TargetFeatureParser, ThreadLocalParser, TrackCallerParser, UsedParser,
 };
 use crate::attributes::confusables::ConfusablesParser;
 use crate::attributes::crate_level::{
@@ -219,6 +219,7 @@ attribute_parsers!(
         Single<ObjcClassParser>,
         Single<ObjcSelectorParser>,
         Single<OptimizeParser>,
+        Single<PatchableFunctionEntryParser>,
         Single<PathAttributeParser>,
         Single<PatternComplexityLimitParser>,
         Single<ProcMacroDeriveParser>,
@@ -492,6 +493,18 @@ impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
         self.emit_parse_error(span, AttributeParseErrorReason::ExpectedIntegerLiteral)
     }
 
+    pub(crate) fn expected_integer_literal_in_range(
+        &self,
+        span: Span,
+        lower_bound: isize,
+        upper_bound: isize,
+    ) -> ErrorGuaranteed {
+        self.emit_parse_error(
+            span,
+            AttributeParseErrorReason::ExpectedIntegerLiteralInRange { lower_bound, upper_bound },
+        )
+    }
+
     pub(crate) fn expected_list(&self, span: Span, args: &ArgParser) -> ErrorGuaranteed {
         let span = match args {
             ArgParser::NoArgs => span,
@@ -512,6 +525,17 @@ impl<'f, 'sess: 'f, S: Stage> AcceptContext<'f, 'sess, S> {
         )
     }
 
+    pub(crate) fn expected_list_with_exact_num_args(
+        &self,
+        args: usize,
+        span: Span,
+    ) -> ErrorGuaranteed {
+        self.emit_parse_error(
+            span,
+            AttributeParseErrorReason::ExpectedListWithExactNumArgs { args },
+        )
+    }
+
     pub(crate) fn expected_list_or_no_args(&self, span: Span) -> ErrorGuaranteed {
         self.emit_parse_error(span, AttributeParseErrorReason::ExpectedListOrNoArgs)
     }
diff --git a/compiler/rustc_attr_parsing/src/lib.rs b/compiler/rustc_attr_parsing/src/lib.rs
@@ -80,6 +80,7 @@
 #![feature(decl_macro)]
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]
+#![feature(new_range_api)]
 #![recursion_limit = "256"]
 // tidy-alphabetical-end
 
diff --git a/compiler/rustc_attr_parsing/src/session_diagnostics.rs b/compiler/rustc_attr_parsing/src/session_diagnostics.rs
@@ -525,13 +525,20 @@ pub(crate) enum AttributeParseErrorReason<'a> {
         byte_string: Option<Span>,
     },
     ExpectedIntegerLiteral,
+    ExpectedIntegerLiteralInRange {
+        lower_bound: isize,
+        upper_bound: isize,
+    },
     ExpectedAtLeastOneArgument,
     ExpectedSingleArgument,
     ExpectedList,
     ExpectedListOrNoArgs,
     ExpectedListWithNumArgsOrMore {
         args: usize,
     },
+    ExpectedListWithExactNumArgs {
+        args: usize,
+    },
     ExpectedNameValueOrNoArgs,
     ExpectedNonEmptyStringLiteral,
     UnexpectedLiteral,
@@ -596,6 +603,17 @@ impl<'a, G: EmissionGuarantee> Diagnostic<'a, G> for AttributeParseError<'_> {
             AttributeParseErrorReason::ExpectedIntegerLiteral => {
                 diag.span_label(self.span, "expected an integer literal here");
             }
+            AttributeParseErrorReason::ExpectedIntegerLiteralInRange {
+                lower_bound,
+                upper_bound,
+            } => {
+                diag.span_label(
+                    self.span,
+                    format!(
+                        "expected an integer literal in the range of {lower_bound}..{upper_bound}"
+                    ),
+                );
+            }
             AttributeParseErrorReason::ExpectedSingleArgument => {
                 diag.span_label(self.span, "expected a single argument here");
                 diag.code(E0805);
@@ -612,6 +630,9 @@ impl<'a, G: EmissionGuarantee> Diagnostic<'a, G> for AttributeParseError<'_> {
             AttributeParseErrorReason::ExpectedListWithNumArgsOrMore { args } => {
                 diag.span_label(self.span, format!("expected {args} or more items"));
             }
+            AttributeParseErrorReason::ExpectedListWithExactNumArgs { args } => {
+                diag.span_label(self.span, format!("expected {args} items"));
+            }
             AttributeParseErrorReason::ExpectedNameValueOrNoArgs => {
                 diag.span_label(self.span, "didn't expect a list here");
             }
diff --git a/compiler/rustc_codegen_ssa/messages.ftl b/compiler/rustc_codegen_ssa/messages.ftl
@@ -48,8 +48,6 @@ codegen_ssa_error_creating_remark_dir = failed to create remark directory: {$err
 codegen_ssa_error_writing_def_file =
     error writing .DEF file: {$error}
 
-codegen_ssa_expected_name_value_pair = expected name value pair
-
 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
 
 codegen_ssa_extract_bundled_libs_archive_member = failed to get data from archive member '{$rlib}': {$error}
@@ -90,9 +88,6 @@ 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_literal_value = invalid literal value
-    .label = value must be an integer between `0` and `255`
-
 codegen_ssa_invalid_monomorphization_basic_float_type = invalid monomorphization of `{$name}` intrinsic: expected basic float type, found `{$ty}`
 
 codegen_ssa_invalid_monomorphization_basic_integer_or_ptr_type = invalid monomorphization of `{$name}` intrinsic: expected basic integer or pointer type, found `{$ty}`
@@ -225,9 +220,6 @@ codegen_ssa_no_natvis_directory = error enumerating natvis directory: {$error}
 
 codegen_ssa_no_saved_object_file = cached cgu {$cgu_name} should have an object file, but doesn't
 
-codegen_ssa_out_of_range_integer = integer value out of range
-    .label = value must be between `0` and `255`
-
 codegen_ssa_processing_dymutil_failed = processing debug info with `dsymutil` failed: {$status}
     .note = {$output}
 
@@ -357,9 +349,6 @@ codegen_ssa_unable_to_run_dsymutil = unable to run `dsymutil`: {$error}
 
 codegen_ssa_unable_to_write_debugger_visualizer = unable to write debugger visualizer file `{$path}`: {$error}
 
-codegen_ssa_unexpected_parameter_name = unexpected parameter name
-    .label = expected `{$prefix_nops}` or `{$entry_nops}`
-
 codegen_ssa_unknown_archive_kind =
     don't know how to build archive of type: {$kind}
 
diff --git a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
@@ -47,59 +47,6 @@ fn try_fn_sig<'tcx>(
     }
 }
 
-// FIXME(jdonszelmann): remove when patchable_function_entry becomes a parsed attr
-fn parse_patchable_function_entry(
-    tcx: TyCtxt<'_>,
-    attr: &Attribute,
-) -> Option<PatchableFunctionEntry> {
-    attr.meta_item_list().and_then(|l| {
-        let mut prefix = None;
-        let mut entry = None;
-        for item in l {
-            let Some(meta_item) = item.meta_item() else {
-                tcx.dcx().emit_err(errors::ExpectedNameValuePair { span: item.span() });
-                continue;
-            };
-
-            let Some(name_value_lit) = meta_item.name_value_literal() else {
-                tcx.dcx().emit_err(errors::ExpectedNameValuePair { span: item.span() });
-                continue;
-            };
-
-            let attrib_to_write = match meta_item.name() {
-                Some(sym::prefix_nops) => &mut prefix,
-                Some(sym::entry_nops) => &mut entry,
-                _ => {
-                    tcx.dcx().emit_err(errors::UnexpectedParameterName {
-                        span: item.span(),
-                        prefix_nops: sym::prefix_nops,
-                        entry_nops: sym::entry_nops,
-                    });
-                    continue;
-                }
-            };
-
-            let rustc_ast::LitKind::Int(val, _) = name_value_lit.kind else {
-                tcx.dcx().emit_err(errors::InvalidLiteralValue { span: name_value_lit.span });
-                continue;
-            };
-
-            let Ok(val) = val.get().try_into() else {
-                tcx.dcx().emit_err(errors::OutOfRangeInteger { span: name_value_lit.span });
-                continue;
-            };
-
-            *attrib_to_write = Some(val);
-        }
-
-        if let (None, None) = (prefix, entry) {
-            tcx.dcx().span_err(attr.span(), "must specify at least one parameter");
-        }
-
-        Some(PatchableFunctionEntry::from_prefix_and_entry(prefix.unwrap_or(0), entry.unwrap_or(0)))
-    })
-}
-
 /// Spans that are collected when processing built-in attributes,
 /// that are useful for emitting diagnostics later.
 #[derive(Default)]
@@ -335,6 +282,10 @@ fn process_builtin_attrs(
                 AttributeKind::InstructionSet(instruction_set) => {
                     codegen_fn_attrs.instruction_set = Some(*instruction_set)
                 }
+                AttributeKind::PatchableFunctionEntry { prefix, entry } => {
+                    codegen_fn_attrs.patchable_function_entry =
+                        Some(PatchableFunctionEntry::from_prefix_and_entry(*prefix, *entry));
+                }
                 _ => {}
             }
         }
@@ -351,10 +302,6 @@ fn process_builtin_attrs(
             sym::rustc_allocator_zeroed => {
                 codegen_fn_attrs.flags |= CodegenFnAttrFlags::ALLOCATOR_ZEROED
             }
-            sym::patchable_function_entry => {
-                codegen_fn_attrs.patchable_function_entry =
-                    parse_patchable_function_entry(tcx, attr);
-            }
             sym::rustc_offload_kernel => {
                 codegen_fn_attrs.flags |= CodegenFnAttrFlags::OFFLOAD_KERNEL
             }
diff --git a/compiler/rustc_codegen_ssa/src/errors.rs b/compiler/rustc_codegen_ssa/src/errors.rs
@@ -136,39 +136,6 @@ pub(crate) struct RequiresRustAbi {
     pub span: Span,
 }
 
-#[derive(Diagnostic)]
-#[diag(codegen_ssa_expected_name_value_pair)]
-pub(crate) struct ExpectedNameValuePair {
-    #[primary_span]
-    pub span: Span,
-}
-
-#[derive(Diagnostic)]
-#[diag(codegen_ssa_unexpected_parameter_name)]
-pub(crate) struct UnexpectedParameterName {
-    #[primary_span]
-    #[label]
-    pub span: Span,
-    pub prefix_nops: Symbol,
-    pub entry_nops: Symbol,
-}
-
-#[derive(Diagnostic)]
-#[diag(codegen_ssa_invalid_literal_value)]
-pub(crate) struct InvalidLiteralValue {
-    #[primary_span]
-    #[label]
-    pub span: Span,
-}
-
-#[derive(Diagnostic)]
-#[diag(codegen_ssa_out_of_range_integer)]
-pub(crate) struct OutOfRangeInteger {
-    #[primary_span]
-    #[label]
-    pub span: Span,
-}
-
 #[derive(Diagnostic)]
 #[diag(codegen_ssa_copy_path_buf)]
 pub(crate) struct CopyPathBuf {
diff --git a/compiler/rustc_hir/src/attrs/data_structures.rs b/compiler/rustc_hir/src/attrs/data_structures.rs
@@ -876,6 +876,9 @@ pub enum AttributeKind {
     /// Represents `#[rustc_pass_by_value]` (used by the `rustc_pass_by_value` lint).
     PassByValue(Span),
 
+    /// Represents `#[patchable_function_entry]`
+    PatchableFunctionEntry { prefix: u8, entry: u8 },
+
     /// Represents `#[path]`
     Path(Symbol, Span),
 
diff --git a/compiler/rustc_hir/src/attrs/encode_cross_crate.rs b/compiler/rustc_hir/src/attrs/encode_cross_crate.rs
@@ -87,6 +87,7 @@ impl AttributeKind {
             Optimize(..) => No,
             ParenSugar(..) => No,
             PassByValue(..) => Yes,
+            PatchableFunctionEntry { .. } => Yes,
             Path(..) => No,
             PatternComplexityLimit { .. } => No,
             PinV2(..) => Yes,
diff --git a/compiler/rustc_hir/src/attrs/pretty_printing.rs b/compiler/rustc_hir/src/attrs/pretty_printing.rs
@@ -171,7 +171,7 @@ macro_rules! print_tup {
 
 print_tup!(A B C D E F G H);
 print_skip!(Span, (), ErrorGuaranteed);
-print_disp!(u16, u128, usize, bool, NonZero<u32>, Limit);
+print_disp!(u8, u16, u128, usize, bool, NonZero<u32>, Limit);
 print_debug!(
     Symbol,
     Ident,
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
@@ -316,6 +316,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                     | AttributeKind::RustcDumpDefParents
                     | AttributeKind::RustcDumpVtable(..)
                     | AttributeKind::NeedsAllocator
+                    | AttributeKind::PatchableFunctionEntry { .. }
                 ) => { /* do nothing  */ }
                 Attribute::Unparsed(attr_item) => {
                     style = Some(attr_item.style);
@@ -341,7 +342,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                             | sym::deny
                             | sym::forbid
                             // need to be fixed
-                            | sym::patchable_function_entry // FIXME(patchable_function_entry)
                             | sym::deprecated_safe // FIXME(deprecated_safe)
                             // internal
                             | sym::prelude_import
diff --git a/tests/ui/attributes/malformed-attrs.stderr b/tests/ui/attributes/malformed-attrs.stderr
diff --git a/tests/ui/patchable-function-entry/patchable-function-entry-attribute.rs b/tests/ui/patchable-function-entry/patchable-function-entry-attribute.rs
diff --git a/tests/ui/patchable-function-entry/patchable-function-entry-attribute.stderr b/tests/ui/patchable-function-entry/patchable-function-entry-attribute.stderr
