[clang] [clang] Implement __attribute__((format_matches)) (PR #116708)

[Erich Keane via cfe-commits]

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@@ -270,4 +270,9 @@ unsigned AlignedAttr::getAlignment(ASTContext &Ctx) const {
   return Ctx.getTargetDefaultAlignForAttributeAligned();
 }
 
+StringLiteral *FormatMatchesAttr::getFormatString() const {
+  // This cannot go in headers because StringLiteral and Expr may be incomplete.
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erichkeane wrote:

This comment isn't really necessary/useful.  

https://github.com/llvm/llvm-project/pull/116708