Ensure field-annotations on pointers properly match the AS of the field.

[erichkeane]

Summary

Discovered in SYCL, the field annotations were always cast to an i8*,
which is an invalid bitcast for a pointer type with an address space.
This patch makes sure that we create an intrinsic that takes a pointer
to the correct address-space and properly do our casts.

[aaron.ballman]

LGTM!

clang/lib/CodeGen/CodeGenFunction.cpp

2408

clang/lib/CodeGen/CodeGenFunction.cpp

EmitAnnotationCall(CGM.getIntrinsic(llvm::Intrinsic::var_annotation),
                        I->getAnnotation(), D->getLocation(), I);
 }
 
 Address CodeGenFunction::EmitFieldAnnotations(const FieldDecl *D,
                                               Address Addr) {
   assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
   llvm::Value *V = Addr.getPointer();
   llvm::Type *VTy = V->getType();
-  llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::ptr_annotation,
-                                    CGM.Int8PtrTy);
+  llvm::PointerType *PTy = dyn_cast<llvm::PointerType>(VTy);
+  unsigned AS = PTy ? PTy->getAddressSpace() : 0;
+  llvm::PointerType *IntrinTy =
+      llvm::PointerType::getWithSamePointeeType(CGM.Int8PtrTy, AS);
+  llvm::Function *F =
+      CGM.getIntrinsic(llvm::Intrinsic::ptr_annotation, IntrinTy);
 
   for (const auto *I : D->specific_attrs<AnnotateAttr>()) {
     // FIXME Always emit the cast inst so we can differentiate between
     // annotation on the first field of a struct and annotation on the struct
     // itself.
-    if (VTy != CGM.Int8PtrTy)
-      V = Builder.CreateBitCast(V, CGM.Int8PtrTy);
+    if (VTy != IntrinTy)
+      V = Builder.CreateBitCast(V, IntrinTy);
     V = EmitAnnotationCall(F, V, I->getAnnotation(), D->getLocation(), I);
     V = Builder.CreateBitCast(V, VTy);
   }
 
   return Address(V, Addr.getAlignment());
 }
 
 CodeGenFunction::CGCapturedStmtInfo::~CGCapturedStmtInfo() { }

clang/test/CodeGenSYCL/field-annotate-addr-space.cpp

+// RUN: %clang_cc1 -triple spir64 -fsycl-is-device -disable-llvm-passes -emit-llvm %s -o - | FileCheck %s
+
+// CHECK: [[ANNOT:.+]] = private unnamed_addr constant {{.*}}c"my_annotation\00"
+
+struct HasField {
+  // This caused an assertion on creating a bitcast here,
+  // since the address space didn't match.
+  [[clang::annotate("my_annotation")]]
+  int *a;
+};
+
+void foo(int *b) {
+  struct HasField f;
+  // CHECK: %[[A:.+]] = getelementptr inbounds %struct.HasField, %struct.HasField addrspace(4)* %{{.+}}
+  // CHECK: %[[BITCAST:.+]] = bitcast i32 addrspace(4)* addrspace(4)* %[[A]] to i8 addrspace(4)*
+  // CHECK: %[[CALL:.+]] = call i8 addrspace(4)* @llvm.ptr.annotation.p4i8(i8 addrspace(4)* %[[BITCAST]], i8* getelementptr inbounds ([14 x i8], [14 x i8]* [[ANNOT]]
+  // CHECK: bitcast i8 addrspace(4)* %[[CALL]] to i32 addrspace(4)* addrspace(4)*
+  f.a = b;
+}