[CIR] Unblock destructor alias handling

clang/lib/CIR/CodeGen/CIRGenItaniumCXXABI.cpp

@@ -113,8 +113,6 @@ static StructorCIRGen getCIRGenToUse(CIRGenModule &cgm,
 
   GlobalDecl aliasDecl;
   if (const auto *dd = dyn_cast<CXXDestructorDecl>(md)) {
-    // The assignment is correct here, but other support for this is NYI.
-    cgm.errorNYI(md->getSourceRange(), "getCIRGenToUse: dtor");
     aliasDecl = GlobalDecl(dd, Dtor_Complete);
   } else {
     const auto *cd = cast<CXXConstructorDecl>(md);

clang/test/CIR/CodeGen/dtor-alias.cpp

@@ -0,0 +1,75 @@
+// RUN: %clang_cc1 -std=c++17 -triple x86_64-unknown-linux-gnu -mconstructor-aliases -fclangir -emit-cir %s -o %t.cir
+// RUN: FileCheck --input-file=%t.cir %s
+// RUN: %clang_cc1 -std=c++17 -triple x86_64-unknown-linux-gnu -mconstructor-aliases -fclangir -emit-llvm %s -o %t-cir.ll
+// RUN: FileCheck --check-prefix=LLVM --input-file=%t-cir.ll %s
+// RUN: %clang_cc1 -std=c++17 -triple x86_64-unknown-linux-gnu -mconstructor-aliases -emit-llvm %s -o %t.ll
+// RUN: FileCheck --check-prefix=OGCG --input-file=%t.ll %s
+
+struct B {
+  ~B();
+};
+B::~B() {
+}
+
+// OGCG: @_ZN1BD1Ev = unnamed_addr alias void (ptr), ptr @_ZN1BD2Ev
+
+// CHECK: cir.func{{.*}} @_ZN1BD2Ev(%arg0: !cir.ptr<!rec_B>
+// CHECK:   %[[THIS_ADDR:.*]] = cir.alloca !cir.ptr<!rec_B>, !cir.ptr<!cir.ptr<!rec_B>>, ["this", init]
+// CHECK:   cir.store %arg0, %[[THIS_ADDR]]
+// CHECK:   %[[THIS:.*]] = cir.load %[[THIS_ADDR]] : !cir.ptr<!cir.ptr<!rec_B>>, !cir.ptr<!rec_B>
+
+// CHECK: cir.func{{.*}} private dso_local @_ZN1BD1Ev(!cir.ptr<!rec_B>) alias(@_ZN1BD2Ev)
+
+// LLVM: define{{.*}} @_ZN1BD2Ev(ptr %[[THIS_ARG:.*]])
+// LLVM:   %[[THIS_ADDR:.*]] = alloca ptr
+// LLVM:   store ptr %[[THIS_ARG]], ptr %[[THIS_ADDR]]
+// LLVM:   %[[THIS:.*]] = load ptr, ptr %[[THIS_ADDR]]
+
+// This should be an alias, like the similar OGCG alias above, but that's not
+// implemented yet.
+// LLVM: declare dso_local void @_ZN1BD1Ev(ptr)
+
+// OGCG: define{{.*}} @_ZN1BD2Ev(ptr{{.*}} %[[THIS_ARG:.*]])
+// OGCG:   %[[THIS_ADDR:.*]] = alloca ptr
+// OGCG:   store ptr %[[THIS_ARG]], ptr %[[THIS_ADDR]]
+// OGCG:   %[[THIS:.*]] = load ptr, ptr %[[THIS_ADDR]]
+
+// The destructor in this case is handled by RAUW rather than aliasing.
+struct Struk {
+  ~Struk() {}
+};
+
+void baz() {
+  Struk s;
+}
+
+// CHECK:   cir.func{{.*}} @_ZN5StrukD2Ev(%arg0: !cir.ptr<!rec_Struk>
+// CHECK:     %[[THIS_ADDR:.*]] = cir.alloca !cir.ptr<!rec_Struk>, !cir.ptr<!cir.ptr<!rec_Struk>>, ["this", init]
+// CHECK:     cir.store %arg0, %[[THIS_ADDR]] : !cir.ptr<!rec_Struk>, !cir.ptr<!cir.ptr<!rec_Struk>>
+// CHECK:     %[[THIS:.*]] = cir.load %[[THIS_ADDR]] : !cir.ptr<!cir.ptr<!rec_Struk>>, !cir.ptr<!rec_Struk>
+// CHECK:     cir.return
+
+// CHECK-NOT:   cir.func{{.*}} @_ZN5StrukD1Ev
+
+// CHECK:   cir.func{{.*}} @_Z3bazv()
+// CHECK:     %[[S_ADDR:.*]] = cir.alloca !rec_Struk, !cir.ptr<!rec_Struk>, ["s"]
+// CHECK:     cir.call @_ZN5StrukD2Ev(%[[S_ADDR]]) nothrow : (!cir.ptr<!rec_Struk>) -> ()
+
+// LLVM: define linkonce_odr void @_ZN5StrukD2Ev(ptr %[[THIS_ARG]])
+// LLVM:   %[[THIS_ADDR:.*]] = alloca ptr
+// LLVM:   store ptr %[[THIS_ARG]], ptr %[[THIS_ADDR]]
+// LLVM:   %[[THIS:.*]] = load ptr, ptr %[[THIS_ADDR]]
+
+// LLVM: define{{.*}} void @_Z3bazv()
+// LLVM:   %[[S_ADDR:.*]] = alloca %struct.Struk
+// LLVM:   call void @_ZN5StrukD2Ev(ptr{{.*}} %[[S_ADDR]])
+
+// This function gets emitted before the destructor in OGCG.
+// OGCG: define{{.*}} void @_Z3bazv()
+// OGCG:   %[[S_ADDR:.*]] = alloca %struct.Struk
+// OGCG:   call void @_ZN5StrukD2Ev(ptr{{.*}} %[[S_ADDR]])
+
+// OGCG: define linkonce_odr void @_ZN5StrukD2Ev(ptr{{.*}} %[[THIS_ARG]])
+// OGCG:   %[[THIS_ADDR:.*]] = alloca ptr
+// OGCG:   store ptr %[[THIS_ARG]], ptr %[[THIS_ADDR]]
+// OGCG:   %[[THIS:.*]] = load ptr, ptr %[[THIS_ADDR]]