[clang] 74f2078 - [clang] Fix emitVoidPtrVAArg for non-zero default alloca address space

[Jessica Clarke via cfe-commits]

Author: Jessica Clarke
Date: 2023-05-15T20:26:49+01:00
New Revision: 74f207883bc5fe2a7300c4b4f1ff080a107ab148

URL: https://github.com/llvm/llvm-project/commit/74f207883bc5fe2a7300c4b4f1ff080a107ab148
DIFF: https://github.com/llvm/llvm-project/commit/74f207883bc5fe2a7300c4b4f1ff080a107ab148.diff

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

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.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D132247

Added: 
    

Modified: 
    clang/lib/CodeGen/TargetInfo.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index ff4d516090ea4..9fb5d9ae75f0a 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -401,8 +401,10 @@ static Address emitVoidPtrVAArg(CodeGenFunction &CGF, Address VAListAddr,
 
   // 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, SlotSizeAndAlign,