[clang] [clang][CodeGen] Make `UnqualPtrTy` truly unqualified (PR #94388)

[Alex Voicu via cfe-commits]

https://github.com/AlexVlx updated https://github.com/llvm/llvm-project/pull/94388

>From cdf95a804614950167d2d4df227d06a86a70d4bb Mon Sep 17 00:00:00 2001
From: Alex Voicu <alexandru.voicu at amd.com>
Date: Tue, 4 Jun 2024 19:52:28 +0100
Subject: [PATCH 1/2] Unqualified `ptr`s should be truly unqualified, and not
 AS0 ptrs.

---
 clang/lib/CodeGen/CodeGenModule.cpp  | 1 +
 clang/lib/CodeGen/CodeGenTypeCache.h | 4 +++-
 clang/lib/CodeGen/ItaniumCXXABI.cpp  | 6 +++---
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index be7bf0b72dc0c..b58ca03ce69da 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -368,6 +368,7 @@ CodeGenModule::CodeGenModule(ASTContext &C,
   IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth());
   IntPtrTy = llvm::IntegerType::get(LLVMContext,
     C.getTargetInfo().getMaxPointerWidth());
+  UnqualPtrTy = llvm::PointerType::getUnqual(LLVMContext);
   Int8PtrTy = llvm::PointerType::get(LLVMContext,
                                      C.getTargetAddressSpace(LangAS::Default));
   const llvm::DataLayout &DL = M.getDataLayout();
diff --git a/clang/lib/CodeGen/CodeGenTypeCache.h b/clang/lib/CodeGen/CodeGenTypeCache.h
index e273ebe3b060f..3b659bc182aa4 100644
--- a/clang/lib/CodeGen/CodeGenTypeCache.h
+++ b/clang/lib/CodeGen/CodeGenTypeCache.h
@@ -51,9 +51,11 @@ struct CodeGenTypeCache {
     llvm::IntegerType *PtrDiffTy;
   };
 
+  /// unqualified void*
+  llvm::PointerType *UnqualPtrTy;
+
   /// void*, void** in the target's default address space (often 0)
   union {
-    llvm::PointerType *UnqualPtrTy;
     llvm::PointerType *VoidPtrTy;
     llvm::PointerType *Int8PtrTy;
     llvm::PointerType *VoidPtrPtrTy;
diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
index 8427286dee887..8952e7ca072da 100644
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -4656,14 +4656,14 @@ static void InitCatchParam(CodeGenFunction &CGF,
   auto catchRD = CatchType->getAsCXXRecordDecl();
   CharUnits caughtExnAlignment = CGF.CGM.getClassPointerAlignment(catchRD);
 
-  llvm::Type *PtrTy = CGF.UnqualPtrTy; // addrspace 0 ok
+  llvm::Type *PtrTy = CGF.UnqualPtrTy; // unqualified is ok
 
   // Check for a copy expression.  If we don't have a copy expression,
   // that means a trivial copy is okay.
   const Expr *copyExpr = CatchParam.getInit();
   if (!copyExpr) {
     llvm::Value *rawAdjustedExn = CallBeginCatch(CGF, Exn, true);
-    Address adjustedExn(CGF.Builder.CreateBitCast(rawAdjustedExn, PtrTy),
+    Address adjustedExn(CGF.Builder.CreatePointerCast(rawAdjustedExn, PtrTy),
                         LLVMCatchTy, caughtExnAlignment);
     LValue Dest = CGF.MakeAddrLValue(ParamAddr, CatchType);
     LValue Src = CGF.MakeAddrLValue(adjustedExn, CatchType);
@@ -4677,7 +4677,7 @@ static void InitCatchParam(CodeGenFunction &CGF,
     CGF.EmitNounwindRuntimeCall(getGetExceptionPtrFn(CGF.CGM), Exn);
 
   // Cast that to the appropriate type.
-  Address adjustedExn(CGF.Builder.CreateBitCast(rawAdjustedExn, PtrTy),
+  Address adjustedExn(CGF.Builder.CreatePointerCast(rawAdjustedExn, PtrTy),
                       LLVMCatchTy, caughtExnAlignment);
 
   // The copy expression is defined in terms of an OpaqueValueExpr.

>From 5eef3a90a2dcfa08aa84bef3f40db17845911039 Mon Sep 17 00:00:00 2001
From: Alex Voicu <alexandru.voicu at amd.com>
Date: Thu, 6 Jun 2024 16:40:24 +0100
Subject: [PATCH 2/2] Pointer to default should work.

---
 clang/lib/CodeGen/ItaniumCXXABI.cpp | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
index 8952e7ca072da..0c4f0c71a41e5 100644
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -4656,15 +4656,12 @@ static void InitCatchParam(CodeGenFunction &CGF,
   auto catchRD = CatchType->getAsCXXRecordDecl();
   CharUnits caughtExnAlignment = CGF.CGM.getClassPointerAlignment(catchRD);
 
-  llvm::Type *PtrTy = CGF.UnqualPtrTy; // unqualified is ok
-
   // Check for a copy expression.  If we don't have a copy expression,
   // that means a trivial copy is okay.
   const Expr *copyExpr = CatchParam.getInit();
   if (!copyExpr) {
     llvm::Value *rawAdjustedExn = CallBeginCatch(CGF, Exn, true);
-    Address adjustedExn(CGF.Builder.CreatePointerCast(rawAdjustedExn, PtrTy),
-                        LLVMCatchTy, caughtExnAlignment);
+    Address adjustedExn(rawAdjustedExn, LLVMCatchTy, caughtExnAlignment);
     LValue Dest = CGF.MakeAddrLValue(ParamAddr, CatchType);
     LValue Src = CGF.MakeAddrLValue(adjustedExn, CatchType);
     CGF.EmitAggregateCopy(Dest, Src, CatchType, AggValueSlot::DoesNotOverlap);
@@ -4676,9 +4673,7 @@ static void InitCatchParam(CodeGenFunction &CGF,
   llvm::CallInst *rawAdjustedExn =
     CGF.EmitNounwindRuntimeCall(getGetExceptionPtrFn(CGF.CGM), Exn);
 
-  // Cast that to the appropriate type.
-  Address adjustedExn(CGF.Builder.CreatePointerCast(rawAdjustedExn, PtrTy),
-                      LLVMCatchTy, caughtExnAlignment);
+  Address adjustedExn(rawAdjustedExn, LLVMCatchTy, caughtExnAlignment);
 
   // The copy expression is defined in terms of an OpaqueValueExpr.
   // Find it and map it to the adjusted expression.