[clang] [Clang] Generate the GEP instead of adding AST nodes (PR #73730)

[Bill Wendling via cfe-commits]

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@@ -4022,8 +4168,36 @@ LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
       ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
     else
       ArrayLV = EmitLValue(Array);
+
     auto *Idx = EmitIdxAfterBase(/*Promote*/true);
 
+    if (SanOpts.has(SanitizerKind::ArrayBounds)) {
+      const LangOptions::StrictFlexArraysLevelKind StrictFlexArraysLevel =
+          getLangOpts().getStrictFlexArraysLevel();
+
+      if (const auto *ME = dyn_cast<MemberExpr>(Array);
+          ME &&
+          ME->isFlexibleArrayMemberLike(getContext(), StrictFlexArraysLevel) &&
+          ME->getMemberDecl()->hasAttr<CountedByAttr>()) {
+        RecordDecl *RD = ME->getMemberDecl()
+                             ->getDeclContext()
+                             ->getOuterLexicalRecordContext();
+        Expr *StructBase =
+            StructAccessBase(RD).Visit(const_cast<MemberExpr *>(ME));
+
+        if (StructBase && StructBase->getType()->isPointerType()) {
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bwendling wrote:

Done.

https://github.com/llvm/llvm-project/pull/73730