cpptrace/src/unwind/unwind_with_unwind.cpp
2023-09-18 20:33:46 -04:00

65 lines
1.8 KiB
C++

#ifdef CPPTRACE_UNWIND_WITH_UNWIND
#include "unwind.hpp"
#include "../platform/common.hpp"
#include "../platform/error.hpp"
#include "../platform/utils.hpp"
#include <algorithm>
#include <cassert>
#include <cstddef>
#include <vector>
#include <unwind.h>
namespace cpptrace {
namespace detail {
struct unwind_state {
std::size_t skip;
std::size_t count;
std::vector<uintptr_t>& vec;
};
_Unwind_Reason_Code unwind_callback(_Unwind_Context* context, void* arg) {
unwind_state& state = *static_cast<unwind_state*>(arg);
if(state.skip) {
state.skip--;
if(_Unwind_GetIP(context) == uintptr_t(0)) {
return _URC_END_OF_STACK;
} else {
return _URC_NO_REASON;
}
}
CPPTRACE_VERIFY(
state.count < state.vec.size(),
"Somehow cpptrace::detail::unwind_callback is overflowing a vector"
);
int is_before_instruction = 0;
uintptr_t ip = _Unwind_GetIPInfo(context, &is_before_instruction);
if(!is_before_instruction && ip != uintptr_t(0)) {
ip--;
}
if (ip == uintptr_t(0) || state.count == state.vec.size()) {
return _URC_END_OF_STACK;
} else {
// TODO: push_back?...
state.vec[state.count++] = ip;
return _URC_NO_REASON;
}
}
CPPTRACE_FORCE_NO_INLINE
std::vector<uintptr_t> capture_frames(size_t skip) {
std::vector<uintptr_t> frames(hard_max_frames, 0);
unwind_state state{skip + 1, 0, frames};
_Unwind_Backtrace(unwind_callback, &state); // presumably thread-safe
frames.resize(state.count);
frames.shrink_to_fit();
return frames;
}
}
}
#endif