[clang] [llvm] [PAC] Fix address discrimination for type info vtable pointers (PR #102199)

[Eli Friedman via cfe-commits]

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@@ -4207,16 +4214,31 @@ llvm::Constant *ItaniumRTTIBuilder::BuildTypeInfo(
     break;
   }
 
-  llvm::Constant *Init = llvm::ConstantStruct::getAnon(Fields);
-
   SmallString<256> Name;
   llvm::raw_svector_ostream Out(Name);
   CGM.getCXXABI().getMangleContext().mangleCXXRTTI(Ty, Out);
   llvm::Module &M = CGM.getModule();
   llvm::GlobalVariable *OldGV = M.getNamedGlobal(Name);
-  llvm::GlobalVariable *GV =
-      new llvm::GlobalVariable(M, Init->getType(),
-                               /*isConstant=*/true, Linkage, Init, Name);
+  llvm::GlobalVariable *GV = new llvm::GlobalVariable(
+      M, llvm::ConstantStruct::getTypeForElements(Fields),
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efriedma-quic wrote:

Since you're going to replace the initializer anyway, you don't need to call ConstantStruct::getTypeForElements here; you can just use an arbitrary type, like i8.  That should allow you to pass the global into BuildVTablePointer(), instead of replacing it later.

https://github.com/llvm/llvm-project/pull/102199