[clang] 7240008 - [Clang][CodeGen] `__dynamic_cast` should care about `type_info`'s address space

[Alex Voicu via cfe-commits]

Author: Alex Voicu
Date: 2023-08-03T23:25:06+01:00
New Revision: 7240008c0afa3e2d12f3f51cfe0235668feb6ef3

URL: https://github.com/llvm/llvm-project/commit/7240008c0afa3e2d12f3f51cfe0235668feb6ef3
DIFF: https://github.com/llvm/llvm-project/commit/7240008c0afa3e2d12f3f51cfe0235668feb6ef3.diff

LOG: [Clang][CodeGen] `__dynamic_cast` should care about `type_info`'s address space

`__dynamic_cast` relies on `type_info`, which its signature assumed to be in the generic / default address space. This patch corrects the oversight (we know that `type_info` resides in the GlobalVar address space)  and adds an associated test.

Reviewed By: yaxunl

Differential Revision: https://reviews.llvm.org/D155870

Added: 
    clang/test/CodeGenCXX/dynamic-cast-address-space.cpp

Modified: 
    clang/lib/CodeGen/ItaniumCXXABI.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
index c8073e248f5c1f..36730875ef0aa4 100644
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -1338,15 +1338,16 @@ void ItaniumCXXABI::emitThrow(CodeGenFunction &CGF, const CXXThrowExpr *E) {
 
 static llvm::FunctionCallee getItaniumDynamicCastFn(CodeGenFunction &CGF) {
   // void *__dynamic_cast(const void *sub,
-  //                      const abi::__class_type_info *src,
-  //                      const abi::__class_type_info *dst,
+  //                      global_as const abi::__class_type_info *src,
+  //                      global_as const abi::__class_type_info *dst,
   //                      std::ptr
diff _t src2dst_offset);
 
   llvm::Type *Int8PtrTy = CGF.Int8PtrTy;
+  llvm::Type *GlobInt8PtrTy = CGF.GlobalsInt8PtrTy;
   llvm::Type *PtrDiffTy =
     CGF.ConvertType(CGF.getContext().getPointerDiffType());
 
-  llvm::Type *Args[4] = { Int8PtrTy, Int8PtrTy, Int8PtrTy, PtrDiffTy };
+  llvm::Type *Args[4] = { Int8PtrTy, GlobInt8PtrTy, GlobInt8PtrTy, PtrDiffTy };
 
   llvm::FunctionType *FTy = llvm::FunctionType::get(Int8PtrTy, Args, false);
 

diff  --git a/clang/test/CodeGenCXX/dynamic-cast-address-space.cpp b/clang/test/CodeGenCXX/dynamic-cast-address-space.cpp
new file mode 100644
index 00000000000000..c278988c9647ba
--- /dev/null
+++ b/clang/test/CodeGenCXX/dynamic-cast-address-space.cpp
@@ -0,0 +1,24 @@
+// RUN: %clang_cc1 -I%S %s -triple amdgcn-amd-amdhsa -emit-llvm -fcxx-exceptions -fexceptions -o - | FileCheck %s
+struct A { virtual void f(); };
+struct B : A { };
+
+// CHECK: {{define.*@_Z1fP1A}}
+// CHECK-SAME:  personality ptr @__gxx_personality_v0
+B fail;
+const B& f(A *a) {
+  try {
+    // CHECK: call ptr @__dynamic_cast
+    // CHECK: br i1
+    // CHECK: invoke void @__cxa_bad_cast() [[NR:#[0-9]+]]
+    dynamic_cast<const B&>(*a);
+  } catch (...) {
+    // CHECK:      landingpad { ptr, i32 }
+    // CHECK-NEXT:   catch ptr null
+  }
+  return fail;
+}
+
+// CHECK: declare ptr @__dynamic_cast(ptr, ptr addrspace(1), ptr addrspace(1), i64) [[NUW_RO:#[0-9]+]]
+
+// CHECK: attributes [[NUW_RO]] = { nounwind memory(read) }
+// CHECK: attributes [[NR]] = { noreturn }