1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
| // RUN: %clangxx_cfi_diag -o %t %s
// RUN: %run %t 2>&1 | FileCheck %s
// This test checks that we don't generate two type checks,
// if two virtual calls are in the same function.
// UNSUPPORTED: windows-msvc
// REQUIRES: cxxabi
// TODO(krasin): implement the optimization to not emit two type checks.
// XFAIL: *
#include <stdio.h>
class Base {
public:
virtual void Foo() {
fprintf(stderr, "Base::Foo\n");
}
virtual void Bar() {
fprintf(stderr, "Base::Bar\n");
}
};
class Derived : public Base {
public:
void Foo() override {
fprintf(stderr, "Derived::Foo\n");
}
void Bar() override {
printf("Derived::Bar\n");
}
};
__attribute__((noinline)) void print(Base* ptr) {
ptr->Foo();
// Corrupt the vtable pointer. We expect that the optimization will
// check vtable before the first vcall then store it in a local
// variable, and reuse it for the second vcall. With no optimization,
// CFI will complain about the virtual table being corrupted.
*reinterpret_cast<void**>(ptr) = 0;
ptr->Bar();
}
int main() {
Base b;
Derived d;
// CHECK: Base::Foo
// CHECK: Base::Bar
print(&b);
// CHECK: Derived::Foo
// CHECK-NOT: runtime error
// CHECK: Derived::Bar
print(&d);
return 0;
}
|