[clang] [Clang] [Parser] Fixing all callers of `ParseExternalDeclaration` that didn't parse gnu attributes (PR #117148)

[Mathys Gasnier via cfe-commits]

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@@ -267,9 +267,11 @@ void Parser::ParseInnerNamespace(const InnerNamespaceInfoList &InnerNSs,
     while (!tryParseMisplacedModuleImport() && Tok.isNot(tok::r_brace) &&
            Tok.isNot(tok::eof)) {
       ParsedAttributes DeclAttrs(AttrFactory);
-      MaybeParseCXX11Attributes(DeclAttrs);
-      ParsedAttributes EmptyDeclSpecAttrs(AttrFactory);
-      ParseExternalDeclaration(DeclAttrs, EmptyDeclSpecAttrs);
+      ParsedAttributes DeclSpecAttrs(AttrFactory);
+      while (MaybeParseCXX11Attributes(DeclAttrs) ||
+              MaybeParseGNUAttributes(DeclSpecAttrs))
+        ;
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Mathys-Gasnier wrote:

If we factor out `ParseExternalDeclaration` in a function that also parses the attributes, factoring out attributes parsing is probably not as usefull right ?

Since it's quite a lot of changes, should I do it in two commits ? One fixing the bug and adding missing attribute parsing, and the other factoring everything into a `ParseExternalDeclarationWithAttrs` and replacing all uses that fit the need.

https://github.com/llvm/llvm-project/pull/117148