You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
68 lines
1.8 KiB
68 lines
1.8 KiB
#ifndef UTILS_H
|
|
#define UTILS_H
|
|
|
|
inline void break_optimization(void *arg) {
|
|
__asm__ __volatile__("" : : "r" (arg) : "memory");
|
|
}
|
|
|
|
// Tests will instantiate this class to pad out bit sets to test out the
|
|
// various ways we can represent the bit set (32-bit inline, 64-bit inline,
|
|
// memory). Instantiating this class will trigger the instantiation of I
|
|
// templates with I virtual tables for classes deriving from T, I-2 of which
|
|
// will be of size sizeof(void*) * 5, 1 of which will be of size sizeof(void*)
|
|
// * 3, and 1 of which will be of size sizeof(void*) * 9. (Under the MS ABI
|
|
// each virtual table will be sizeof(void*) bytes smaller). Each category
|
|
// of virtual tables is aligned to a different power of 2, precluding the
|
|
// all-ones optimization. As a result, the bit vector for the base class will
|
|
// need to contain at least I*2 entries to accommodate all the derived virtual
|
|
// tables.
|
|
template <typename T, unsigned I>
|
|
struct Deriver : T {
|
|
Deriver() {
|
|
break_optimization(new Deriver<T, I-1>);
|
|
}
|
|
virtual void f() {}
|
|
virtual void g() {}
|
|
virtual void h() {}
|
|
};
|
|
|
|
template <typename T>
|
|
struct Deriver<T, 0> : T {
|
|
virtual void f() {}
|
|
void g() {}
|
|
};
|
|
|
|
template <typename T>
|
|
struct Deriver<T, 1> : T {
|
|
Deriver() {
|
|
break_optimization(new Deriver<T, 0>);
|
|
}
|
|
virtual void f() {}
|
|
virtual void g() {}
|
|
virtual void h() {}
|
|
virtual void i() {}
|
|
virtual void j() {}
|
|
virtual void k() {}
|
|
virtual void l() {}
|
|
};
|
|
|
|
// Instantiate enough classes to force CFI checks for type T to use bit
|
|
// vectors of size 32 (if B32 defined), 64 (if B64 defined) or >64 (if BM
|
|
// defined).
|
|
template <typename T>
|
|
void create_derivers() {
|
|
#ifdef B32
|
|
break_optimization(new Deriver<T, 10>);
|
|
#endif
|
|
|
|
#ifdef B64
|
|
break_optimization(new Deriver<T, 25>);
|
|
#endif
|
|
|
|
#ifdef BM
|
|
break_optimization(new Deriver<T, 40>);
|
|
#endif
|
|
}
|
|
|
|
#endif
|