| // dynamic_cast |
| // Ensure that dynamic casting works normally |
| |
| // RUN: %clang_cc1 %s -triple=aarch64-unknown-fuchsia -O3 -S -o - -emit-llvm | FileCheck %s |
| |
| // CHECK: define{{.*}} %class.A* @_Z6upcastP1B(%class.B* readnone %b) local_unnamed_addr |
| // CHECK-NEXT: entry: |
| // CHECK-NEXT: [[a:%[0-9]+]] = getelementptr %class.B, %class.B* %b, i64 0, i32 0 |
| // CHECK-NEXT: ret %class.A* [[a]] |
| // CHECK-NEXT: } |
| |
| // CHECK: define{{.*}} %class.B* @_Z8downcastP1A(%class.A* readonly %a) local_unnamed_addr |
| // CHECK-NEXT: entry: |
| // CHECK-NEXT: [[isnull:%[0-9]+]] = icmp eq %class.A* %a, null |
| // CHECK-NEXT: br i1 [[isnull]], label %[[dynamic_cast_end:[a-z0-9._]+]], label %[[dynamic_cast_notnull:[a-z0-9._]+]] |
| // CHECK: [[dynamic_cast_notnull]]: |
| // CHECK-NEXT: [[a:%[0-9]+]] = bitcast %class.A* %a to i8* |
| // CHECK-NEXT: [[as_b:%[0-9]+]] = tail call i8* @__dynamic_cast(i8* nonnull [[a]], i8* bitcast ({ i8*, i8* }* @_ZTI1A to i8*), i8* bitcast ({ i8*, i8*, i8* }* @_ZTI1B to i8*), i64 0) |
| // CHECK-NEXT: [[b:%[0-9]+]] = bitcast i8* [[as_b]] to %class.B* |
| // CHECK-NEXT: br label %[[dynamic_cast_end]] |
| // CHECK: [[dynamic_cast_end]]: |
| // CHECK-NEXT: [[res:%[0-9]+]] = phi %class.B* [ [[b]], %[[dynamic_cast_notnull]] ], [ null, %entry ] |
| // CHECK-NEXT: ret %class.B* [[res]] |
| // CHECK-NEXT: } |
| |
| // CHECK: declare i8* @__dynamic_cast(i8*, i8*, i8*, i64) local_unnamed_addr |
| |
| // CHECK: define{{.*}} %class.B* @_Z8selfcastP1B(%class.B* readnone returned %b) local_unnamed_addr |
| // CHECK-NEXT: entry |
| // CHECK-NEXT: ret %class.B* %b |
| // CHECK-NEXT: } |
| |
| // CHECK: define{{.*}} i8* @_Z9void_castP1B(%class.B* readonly %b) local_unnamed_addr |
| // CHECK-NEXT: entry: |
| // CHECK-NEXT: [[isnull:%[0-9]+]] = icmp eq %class.B* %b, null |
| // CHECK-NEXT: br i1 [[isnull]], label %[[dynamic_cast_end:[a-z0-9._]+]], label %[[dynamic_cast_notnull:[a-z0-9._]+]] |
| // CHECK: [[dynamic_cast_notnull]]: |
| // CHECK-DAG: [[b2:%[0-9]+]] = bitcast %class.B* %b to i32** |
| // CHECK-DAG: [[vtable:%[a-z0-9]+]] = load i32*, i32** [[b2]], align 8 |
| // CHECK-DAG: [[offset_ptr:%.+]] = getelementptr inbounds i32, i32* [[vtable]], i64 -2 |
| // CHECK-DAG: [[offset_to_top:%.+]] = load i32, i32* [[offset_ptr]], align 4 |
| // CHECK-DAG: [[b:%[0-9]+]] = bitcast %class.B* %b to i8* |
| // CHECK-DAG: [[offset_to_top2:%.+]] = sext i32 [[offset_to_top]] to i64 |
| // CHECK-DAG: [[casted:%.+]] = getelementptr inbounds i8, i8* [[b]], i64 [[offset_to_top2]] |
| // CHECK-NEXT: br label %[[dynamic_cast_end]] |
| // CHECK: [[dynamic_cast_end]]: |
| // CHECK-NEXT: [[res:%[0-9]+]] = phi i8* [ [[casted]], %[[dynamic_cast_notnull]] ], [ null, %entry ] |
| // CHECK-NEXT: ret i8* [[res]] |
| // CHECK-NEXT: } |
| |
| class A { |
| public: |
| virtual void foo(); |
| }; |
| |
| class B : public A { |
| public: |
| void foo() override; |
| }; |
| |
| void A::foo() {} |
| void B::foo() {} |
| |
| A *upcast(B *b) { |
| return dynamic_cast<A *>(b); |
| } |
| |
| B *downcast(A *a) { |
| return dynamic_cast<B *>(a); |
| } |
| |
| B *selfcast(B *b) { |
| return dynamic_cast<B *>(b); |
| } |
| |
| void *void_cast(B *b) { |
| return dynamic_cast<void *>(b); |
| } |