[llvm] [clang] [Clang][IR] add TBAA metadata on pointer, union and array types. (PR #75177)

[John McCall via cfe-commits]

================
@@ -4598,8 +4602,7 @@ LValue CodeGenFunction::EmitLValueForField(LValue base,
   if (base.getTBAAInfo().isMayAlias() ||
           rec->hasAttr<MayAliasAttr>() || FieldType->isVectorType()) {
     FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
-  } else if (rec->isUnion()) {
-    // TODO: Support TBAA for unions.
+  } else if (rec->isUnion() && !CGM.getCodeGenOpts().UnionTBAA) {
----------------
rjmccall wrote:
You've checked that this is the right rule for unions?  We can just record the 
union as a containing aggregate that happens to have all the different union 
members at offset 0?

https://github.com/llvm/llvm-project/pull/75177
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits