other c link 添加 “-fsanitize-coverage=func,trace-pc-guard” other swift link 添加 “-sanitize-coverage=trace-pc-guard”
// trace-pc-guard-cb.cc
#include <stdint.h>
#include <stdio.h>
#include <sanitizer/coverage_interface.h>
// This callback is inserted by the compiler as a module constructor
// into every DSO. 'start' and 'stop' correspond to the
// beginning and end of the section with the guards for the entire
// binary (executable or DSO). The callback will be called at least
// once per DSO and may be called multiple times with the same parameters.
extern "C" void __sanitizer_cov_trace_pc_guard_init(uint32_t *start,
uint32_t *stop) {
static uint64_t N; // Counter for the guards.
if (start == stop || *start) return; // Initialize only once.
printf("INIT: %p %p\n", start, stop);
for (uint32_t *x = start; x < stop; x++)
*x = ++N; // Guards should start from 1.
}
// This callback is inserted by the compiler on every edge in the
// control flow (some optimizations apply).
// Typically, the compiler will emit the code like this:
// if(*guard)
// __sanitizer_cov_trace_pc_guard(guard);
// But for large functions it will emit a simple call:
// __sanitizer_cov_trace_pc_guard(guard);
extern "C" void __sanitizer_cov_trace_pc_guard(uint32_t *guard) {
if (!*guard) return; // Duplicate the guard check.
// If you set *guard to 0 this code will not be called again for this edge.
// Now you can get the PC and do whatever you want:
// store it somewhere or symbolize it and print right away.
// The values of `*guard` are as you set them in
// __sanitizer_cov_trace_pc_guard_init and so you can make them consecutive
// and use them to dereference an array or a bit vector.
void *PC = __builtin_return_address(0);
char PcDescr[1024];
// This function is a part of the sanitizer run-time.
// To use it, link with AddressSanitizer or other sanitizer.
__sanitizer_symbolize_pc(PC, "%p %F %L", PcDescr, sizeof(PcDescr));
printf("guard: %p %x PC %s\n", guard, *guard, PcDescr);
}
