Auto merge of #142921 - JonathanBrouwer:rustc_attributes_parser, r=oli-obk

Port `#[rustc_layout_scalar_valid_range_start/end]` to the new attrib…

Ports `rustc_layout_scalar_valid_range_start` and `rustc_layout_scalar_valid_range_end` to the new attribute parsing infrastructure for https://github.com/rust-lang/rust/issues/131229#issuecomment-2971353197

r? `@jdonszelmann`

compiler/rustc_passes/messages.ftl

@@ -618,9 +618,6 @@ passes_rustc_force_inline_coro =
     attribute cannot be applied to a `async`, `gen` or `async gen` function
     .label = `async`, `gen` or `async gen` function
 
-passes_rustc_layout_scalar_valid_range_arg =
-    expected exactly one integer literal argument
-
 passes_rustc_layout_scalar_valid_range_not_struct =
     attribute should be applied to a struct
     .label = not a struct

compiler/rustc_passes/src/check_attr.rs

@@ -9,7 +9,7 @@ use std::cell::Cell;
 use std::collections::hash_map::Entry;
 
 use rustc_abi::{Align, ExternAbi, Size};
-use rustc_ast::{AttrStyle, LitKind, MetaItemInner, MetaItemKind, MetaItemLit, ast};
+use rustc_ast::{AttrStyle, LitKind, MetaItemInner, MetaItemKind, ast};
 use rustc_attr_data_structures::{AttributeKind, InlineAttr, ReprAttr, find_attr};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::{Applicability, DiagCtxtHandle, IntoDiagArg, MultiSpan, StashKey};
@@ -186,6 +186,10 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                 Attribute::Parsed(AttributeKind::TrackCaller(attr_span)) => {
                     self.check_track_caller(hir_id, *attr_span, attrs, span, target)
                 }
+                Attribute::Parsed(
+                    AttributeKind::RustcLayoutScalarValidRangeStart(_num, attr_span)
+                    | AttributeKind::RustcLayoutScalarValidRangeEnd(_num, attr_span),
+                ) => self.check_rustc_layout_scalar_valid_range(*attr_span, span, target),
                 Attribute::Parsed(
                     AttributeKind::BodyStability { .. }
                     | AttributeKind::ConstStabilityIndirect
@@ -237,10 +241,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                             &mut doc_aliases,
                         ),
                         [sym::no_link, ..] => self.check_no_link(hir_id, attr, span, target),
-                        [sym::rustc_layout_scalar_valid_range_start, ..]
-                        | [sym::rustc_layout_scalar_valid_range_end, ..] => {
-                            self.check_rustc_layout_scalar_valid_range(attr, span, target)
-                        }
                         [sym::debugger_visualizer, ..] => self.check_debugger_visualizer(attr, target),
                         [sym::rustc_std_internal_symbol, ..] => {
                             self.check_rustc_std_internal_symbol(attr, span, target)
@@ -1678,24 +1678,11 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
         }
     }
 
-    fn check_rustc_layout_scalar_valid_range(&self, attr: &Attribute, span: Span, target: Target) {
+    fn check_rustc_layout_scalar_valid_range(&self, attr_span: Span, span: Span, target: Target) {
         if target != Target::Struct {
-            self.dcx().emit_err(errors::RustcLayoutScalarValidRangeNotStruct {
-                attr_span: attr.span(),
-                span,
-            });
+            self.dcx().emit_err(errors::RustcLayoutScalarValidRangeNotStruct { attr_span, span });
             return;
         }
-
-        let Some(list) = attr.meta_item_list() else {
-            return;
-        };
-
-        if !matches!(&list[..], &[MetaItemInner::Lit(MetaItemLit { kind: LitKind::Int(..), .. })]) {
-            self.tcx
-                .dcx()
-                .emit_err(errors::RustcLayoutScalarValidRangeArg { attr_span: attr.span() });
-        }
     }
 
     /// Checks if `#[rustc_legacy_const_generics]` is applied to a function and has a valid argument.

compiler/rustc_passes/src/errors.rs

@@ -535,13 +535,6 @@ pub(crate) struct RustcLayoutScalarValidRangeNotStruct {
     pub span: Span,
 }
 
-#[derive(Diagnostic)]
-#[diag(passes_rustc_layout_scalar_valid_range_arg)]
-pub(crate) struct RustcLayoutScalarValidRangeArg {
-    #[primary_span]
-    pub attr_span: Span,
-}
-
 #[derive(Diagnostic)]
 #[diag(passes_rustc_legacy_const_generics_only)]
 pub(crate) struct RustcLegacyConstGenericsOnly {