compiler-rt/test/cfi/two-vcalls.cpp

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