[clang] [C] Allow __attribute__((nonstring)) on multidimensional arrays (PR #138133)

[Aaron Ballman via cfe-commits]

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@@ -261,8 +261,21 @@ static void CheckStringInit(Expr *Str, QualType &DeclT, const ArrayType *AT,
           << Str->getSourceRange();
     else if (StrLength - 1 == ArrayLen) {
       // If the entity being initialized has the nonstring attribute, then
-      // silence the "missing nonstring" diagnostic.
-      if (const ValueDecl *D = Entity.getDecl();
+      // silence the "missing nonstring" diagnostic. If there's no entity,
+      // check whether we're initializing an array of arrays; if so, walk the
+      // parents to find an entity.
+      auto FindCorrectEntity = [](const InitializedEntity &Entity) {
+        const ValueDecl *Ret = nullptr;
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AaronBallman wrote:

I've updated to make it more clear and added additional test coverage.

https://github.com/llvm/llvm-project/pull/138133