// { dg-do run } // { dg-options "-fno-strict-aliasing" } // Origin: Mark Mitchell <mark@codesourcery.com> #if defined (__GXX_ABI_VERSION) && __GXX_ABI_VERSION >= 100 #include <stddef.h> struct S0 { virtual void s0 (); }; struct S1 : virtual public S0 { virtual void s1 (); }; struct S2 : virtual public S1 { virtual void s1 (); virtual void s0 (); }; struct S3 { virtual void s3 (); }; struct S4 : public S3, virtual public S2 { virtual void s1 (); }; void S0::s0 () { } void S1::s1 () { } void S2::s1 () { } void S2::s0 () { } void S3::s3 () { } void S4::s1 () { } /* The vtables should look like: S0 primary vtable S0 offset to top S0 RTTI S0::s0 ================= S1 primary vtable S0::s0 vcall offset S0 vbase offset S1 offset to top S1 RTTI S0::s0 S1::s1 ================= S2 primary vtable S2::s1 vcall offset S1 vbase offset S2::s0 vcall offset S0 vbase offset S2 offset to top S2 RTTI S2::s0 S2::s1 ================= S3 primary vtable S3 offset to top S3 RTTI S3::s3 ================= S4 primary vtable vbase offset for S0 vbase offset for S1 vbase offset for S2 S4 offset to top S4 RTTI S3::s3 S4::s1 S2-in-S4 secondary vtable S1 vbase offset S4::s1 vcall offset S0 vbase offset S2:s0 vcall offset S2 offset to top S4 RTTI S2::s0 S4::s1 */ // These are tricks to allow us to get raw function pointers for // member functions. extern "C" { /* We can use weakref here without dg-require-weak, because we know the symbols are defined, so we don't actually issue the .weak directives. */ static void S3_s3 () __attribute__((__weakref__ ("_ZN2S32s3Ev"))); static void S4_s1 () __attribute__((__weakref__ ("_ZN2S42s1Ev"))); } // IA-64 uses function descriptors not function pointers in its vtables. #if defined __ia64__ #define CMP_VPTR(A, B) (*(void **)(A) == *(void **)(B)) #ifdef _LP64 #define INC_VPTR(A) ((A) += 2) #define INC_VDATA(A,N) ((A) += (N)) #else #define INC_VPTR(A) ((A) += 4) #define INC_VDATA(A,N) ((A) += 2*(N)) #endif #else #define CMP_VPTR(A, B) (*(A) == (ptrdiff_t)(B)) #define INC_VPTR(A) ((A) += 1) #define INC_VDATA(A,N) ((A) += (N)) #endif int main () { S4 s4; ptrdiff_t **vptr; ptrdiff_t *vtbl; // Set vtbl to point at the beginning of S4's primary vtable. vptr = (ptrdiff_t **) &s4; vtbl = *vptr; INC_VDATA (vtbl, -5); if (*vtbl != ((char*) (S0*) &s4) - (char*) &s4) return 1; INC_VDATA (vtbl, 1); if (*vtbl != ((char*) (S1*) &s4) - (char*) &s4) return 2; INC_VDATA (vtbl, 1); if (*vtbl != ((char*) (S2*) &s4) - (char*) &s4) return 3; INC_VDATA (vtbl, 1); if (*vtbl != 0) return 4; INC_VDATA (vtbl, 1); // Skip the RTTI entry. INC_VDATA (vtbl, 1); if (! CMP_VPTR (vtbl, &S3_s3)) return 5; INC_VPTR (vtbl); if (! CMP_VPTR (vtbl, &S4_s1)) return 6; INC_VPTR (vtbl); // The S1 vbase offset. if (*vtbl != 0) return 7; INC_VDATA (vtbl, 1); // The S4::s1 vcall offset is negative; once you convert to S2, you // have to convert to S4 to find the final overrider. if (*vtbl != ((char*) &s4 - (char*) (S2*) &s4)) return 8; INC_VDATA (vtbl, 1); if (*vtbl != 0) return 9; INC_VDATA (vtbl, 1); if (*vtbl != 0) return 10; INC_VDATA (vtbl, 1); // Now we're at the S2 offset to top entry. if (*vtbl != ((char*) &s4 - (char*) (S2*) &s4)) return 11; INC_VDATA (vtbl, 1); // Skip the RTTI entry. INC_VDATA (vtbl, 1); // Skip the reint maining virtual functions -- they are thunks. INC_VPTR (vtbl); INC_VPTR (vtbl); } #else /* !(defined (__GXX_ABI_VERSION) && __GXX_ABI_VERSION >= 100) */ int main () { } #endif /* !(defined (__GXX_ABI_VERSION) && __GXX_ABI_VERSION >= 100) */