[PATCH] D132247: [clang] Fix emitVoidPtrVAArg for non-zero default alloca address space

[Jessica Clarke via Phabricator via cfe-commits]

jrtc27 created this revision.
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Indirect arguments are passed on the stack and so va_arg should use the
default alloca address space, not hard-code 0, for pointers to those.
The only in-tree target with a non-zero default alloca address space is
AMDGPU, but that does not support variadic arguments, so we cannot test
this upstream. However, downstream in CHERI LLVM (and Morello LLVM, a
further fork of that) we have targets that do both and so require this
change.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D132247

Files:
  clang/lib/CodeGen/TargetInfo.cpp


Index: clang/lib/CodeGen/TargetInfo.cpp
===================================================================
--- clang/lib/CodeGen/TargetInfo.cpp
+++ clang/lib/CodeGen/TargetInfo.cpp
@@ -392,8 +392,10 @@
 
   // Cast the address we've calculated to the right type.
   llvm::Type *DirectTy = CGF.ConvertTypeForMem(ValueTy), *ElementTy = DirectTy;
-  if (IsIndirect)
-    DirectTy = DirectTy->getPointerTo(0);
+  if (IsIndirect) {
+    unsigned AllocaAS = CGF.CGM.getDataLayout().getAllocaAddrSpace();
+    DirectTy = DirectTy->getPointerTo(AllocaAS);
+  }
 
   Address Addr =
       emitVoidPtrDirectVAArg(CGF, VAListAddr, DirectTy, DirectSize, DirectAlign,


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