devirtualize-virtual-function-calls-final.cpp
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// RUN: %clang_cc1 -triple i386-unknown-unknown -std=c++11 %s -emit-llvm -o - | FileCheck %s
namespace Test1 {
struct A {
virtual int f() final;
};
// CHECK-LABEL: define i32 @_ZN5Test11fEPNS_1AE
int f(A *a) {
// CHECK: call i32 @_ZN5Test11A1fEv
return a->f();
}
}
namespace Test2 {
struct A final {
virtual int f();
};
// CHECK-LABEL: define i32 @_ZN5Test21fEPNS_1AE
int f(A *a) {
// CHECK: call i32 @_ZN5Test21A1fEv
return a->f();
}
}
namespace Test2a {
struct A {
virtual ~A() final {}
virtual int f();
};
// CHECK-LABEL: define i32 @_ZN6Test2a1fEPNS_1AE
int f(A *a) {
// CHECK: call i32 @_ZN6Test2a1A1fEv
return a->f();
}
}
namespace Test3 {
struct A {
virtual int f(); };
struct B final : A { };
// CHECK-LABEL: define i32 @_ZN5Test31fEPNS_1BE
int f(B *b) {
// CHECK: call i32 @_ZN5Test31A1fEv
return b->f();
}
// CHECK-LABEL: define i32 @_ZN5Test31fERNS_1BE
int f(B &b) {
// CHECK: call i32 @_ZN5Test31A1fEv
return b.f();
}
// CHECK-LABEL: define i32 @_ZN5Test31fEPv
int f(void *v) {
// CHECK: call i32 @_ZN5Test31A1fEv
return static_cast<B*>(v)->f();
}
}
namespace Test4 {
struct A {
virtual void f();
virtual int operator-();
};
struct B final : A {
virtual void f();
virtual int operator-();
};
// CHECK-LABEL: define void @_ZN5Test41fEPNS_1BE
void f(B* d) {
// CHECK: call void @_ZN5Test41B1fEv
static_cast<A*>(d)->f();
// CHECK: call i32 @_ZN5Test41BngEv
-static_cast<A&>(*d);
}
}
namespace Test5 {
struct A {
virtual void f();
virtual int operator-();
};
struct B : A {
virtual void f();
virtual int operator-();
};
struct C final : B {
};
// CHECK-LABEL: define void @_ZN5Test51fEPNS_1CE
void f(C* d) {
// FIXME: It should be possible to devirtualize this case, but that is
// not implemented yet.
// CHECK: getelementptr
// CHECK-NEXT: %[[FUNC:.*]] = load
// CHECK-NEXT: call void %[[FUNC]]
static_cast<A*>(d)->f();
}
// CHECK-LABEL: define void @_ZN5Test53fopEPNS_1CE
void fop(C* d) {
// FIXME: It should be possible to devirtualize this case, but that is
// not implemented yet.
// CHECK: getelementptr
// CHECK-NEXT: %[[FUNC:.*]] = load
// CHECK-NEXT: call i32 %[[FUNC]]
-static_cast<A&>(*d);
}
}
namespace Test6 {
struct A {
virtual ~A();
};
struct B : public A {
virtual ~B();
};
struct C {
virtual ~C();
};
struct D final : public C, public B {
};
// CHECK-LABEL: define void @_ZN5Test61fEPNS_1DE
void f(D* d) {
// CHECK: call void @_ZN5Test61DD1Ev
static_cast<A*>(d)->~A();
}
}
namespace Test7 {
struct foo {
virtual void g() {}
};
struct bar {
virtual int f() { return 0; }
};
struct zed final : public foo, public bar {
int z;
virtual int f() {return z;}
};
// CHECK-LABEL: define i32 @_ZN5Test71fEPNS_3zedE
int f(zed *z) {
// CHECK: alloca
// CHECK-NEXT: store
// CHECK-NEXT: load
// CHECK-NEXT: call i32 @_ZN5Test73zed1fEv
// CHECK-NEXT: ret
return static_cast<bar*>(z)->f();
}
}
namespace Test8 {
struct A { virtual ~A() {} };
struct B {
int b;
virtual int foo() { return b; }
};
struct C final : A, B { };
// CHECK-LABEL: define i32 @_ZN5Test84testEPNS_1CE
int test(C *c) {
// CHECK: %[[THIS:.*]] = phi
// CHECK-NEXT: call i32 @_ZN5Test81B3fooEv(%"struct.Test8::B"* %[[THIS]])
return static_cast<B*>(c)->foo();
}
}
namespace Test9 {
struct A {
int a;
};
struct B {
int b;
};
struct C : public B, public A {
};
struct RA {
virtual A *f() {
return 0;
}
virtual A *operator-() {
return 0;
}
};
struct RC final : public RA {
virtual C *f() {
C *x = new C();
x->a = 1;
x->b = 2;
return x;
}
virtual C *operator-() {
C *x = new C();
x->a = 1;
x->b = 2;
return x;
}
};
// CHECK: define {{.*}} @_ZN5Test91fEPNS_2RCE
A *f(RC *x) {
// FIXME: It should be possible to devirtualize this case, but that is
// not implemented yet.
// CHECK: load
// CHECK: bitcast
// CHECK: [[F_PTR_RA:%.+]] = bitcast
// CHECK: [[VTABLE:%.+]] = load {{.+}} [[F_PTR_RA]]
// CHECK: [[VFN:%.+]] = getelementptr inbounds {{.+}} [[VTABLE]], i{{[0-9]+}} 0
// CHECK-NEXT: %[[FUNC:.*]] = load {{.+}} [[VFN]]
// CHECK-NEXT: = call {{.*}} %[[FUNC]]
return static_cast<RA*>(x)->f();
}
// CHECK: define {{.*}} @_ZN5Test93fopEPNS_2RCE
A *fop(RC *x) {
// FIXME: It should be possible to devirtualize this case, but that is
// not implemented yet.
// CHECK: load
// CHECK: bitcast
// CHECK: [[F_PTR_RA:%.+]] = bitcast
// CHECK: [[VTABLE:%.+]] = load {{.+}} [[F_PTR_RA]]
// CHECK: [[VFN:%.+]] = getelementptr inbounds {{.+}} [[VTABLE]], i{{[0-9]+}} 1
// CHECK-NEXT: %[[FUNC:.*]] = load {{.+}} [[VFN]]
// CHECK-NEXT: = call {{.*}} %[[FUNC]]
return -static_cast<RA&>(*x);
}
}
namespace Test10 {
struct A {
virtual int f();
};
struct B : A {
int f() final;
};
// CHECK-LABEL: define i32 @_ZN6Test101fEPNS_1BE
int f(B *b) {
// CHECK: call i32 @_ZN6Test101B1fEv
return static_cast<A *>(b)->f();
}
}
namespace TestVBase {
struct A { virtual void f(); };
struct B : virtual A {};
struct C : virtual A { void f() override; };
extern struct BC final : B, C {} &bc;
extern struct BCusingA final : B, C { using A::f; } &bc_using_a;
extern struct BCusingB final : B, C { using B::f; } &bc_using_b;
extern struct BCusingC final : B, C { using C::f; } &bc_using_c;
extern struct CB final : C, B {} &cb;
extern struct CBusingA final : C, B { using A::f; } &cb_using_a;
extern struct CBusingB final : C, B { using B::f; } &cb_using_b;
extern struct CBusingC final : C, B { using C::f; } &cb_using_c;
// CHECK-LABEL: @_ZN9TestVBase4testEv(
void test() {
// FIXME: The 'using A' case can be devirtualized to call A's virtual
// adjustment thunk for C::f.
// FIXME: The 'using B' case can be devirtualized, but requires us to emit
// a derived-to-base or base-to-derived conversion as part of
// devirtualization.
// CHECK: call void @_ZN9TestVBase1C1fEv(
bc.f();
// CHECK: call void %
bc_using_a.f();
// CHECK: call void %
bc_using_b.f();
// CHECK: call void @_ZN9TestVBase1C1fEv(
bc_using_c.f();
// CHECK: call void @_ZN9TestVBase1C1fEv(
cb.f();
// CHECK: call void %
cb_using_a.f();
// CHECK: call void %
cb_using_b.f();
// CHECK: call void @_ZN9TestVBase1C1fEv(
cb_using_c.f();
}
}
namespace Test11 {
// Check that the definitions of Derived's operators are emitted.
// CHECK-LABEL: define linkonce_odr void @_ZN6Test111SIiE4foo1Ev(
// CHECK: call void @_ZN6Test111SIiE7DerivedclEv(
// CHECK: call zeroext i1 @_ZN6Test111SIiE7DerivedeqERKNS_4BaseE(
// CHECK: call zeroext i1 @_ZN6Test111SIiE7DerivedntEv(
// CHECK: call nonnull align 4 dereferenceable(4) %"class.Test11::Base"* @_ZN6Test111SIiE7DerivedixEi(
// CHECK: define linkonce_odr void @_ZN6Test111SIiE7DerivedclEv(
// CHECK: define linkonce_odr zeroext i1 @_ZN6Test111SIiE7DerivedeqERKNS_4BaseE(
// CHECK: define linkonce_odr zeroext i1 @_ZN6Test111SIiE7DerivedntEv(
// CHECK: define linkonce_odr nonnull align 4 dereferenceable(4) %"class.Test11::Base"* @_ZN6Test111SIiE7DerivedixEi(
class Base {
public:
virtual void operator()() {}
virtual bool operator==(const Base &other) { return false; }
virtual bool operator!() { return false; }
virtual Base &operator[](int i) { return *this; }
};
template<class T>
struct S {
class Derived final : public Base {
public:
void operator()() override {}
bool operator==(const Base &other) override { return true; }
bool operator!() override { return true; }
Base &operator[](int i) override { return *this; }
};
Derived *ptr = nullptr, *ptr2 = nullptr;
void foo1() {
if (ptr && ptr2) {
// These calls get devirtualized. Linkage fails if the definitions of
// the called functions are not emitted.
(*ptr)();
(void)(*ptr == *ptr2);
(void)(!(*ptr));
(void)((*ptr)[1]);
}
}
};
void foo2() {
S<int> *s = new S<int>;
s->foo1();
}
}