cpptrace/include/cpptrace/from_current.hpp
2024-10-05 18:01:12 -05:00

132 lines
4.7 KiB
C++

#ifndef CPPTRACE_FROM_CURRENT_HPP
#define CPPTRACE_FROM_CURRENT_HPP
#include <cpptrace/basic.hpp>
namespace cpptrace {
CPPTRACE_EXPORT const raw_trace& raw_trace_from_current_exception();
CPPTRACE_EXPORT const stacktrace& from_current_exception();
namespace detail {
// Trace switch is to prevent multiple tracing of stacks on call stacks with multiple catches that don't
// immediately match
inline bool& get_trace_switch() {
static thread_local bool trace_switch = true;
return trace_switch;
}
class CPPTRACE_EXPORT try_canary {
public:
~try_canary() {
// Fires when we exit a try block, either via normal means or during unwinding.
// Either way: Flip the switch.
get_trace_switch() = true;
}
};
CPPTRACE_EXPORT CPPTRACE_FORCE_NO_INLINE void collect_current_trace(std::size_t skip);
// this function can be void, however, a char return is used to prevent TCO of the collect_current_trace
CPPTRACE_FORCE_NO_INLINE inline char exception_unwind_interceptor(std::size_t skip) {
if(get_trace_switch()) {
// Done during a search phase. Flip the switch off, no more traces until an unwind happens
get_trace_switch() = false;
collect_current_trace(skip + 1);
}
return 42;
}
#ifdef _MSC_VER
CPPTRACE_FORCE_NO_INLINE inline int exception_filter() {
exception_unwind_interceptor(1);
return 0; // EXCEPTION_CONTINUE_SEARCH
}
CPPTRACE_FORCE_NO_INLINE inline int unconditional_exception_filter() {
collect_current_trace(1);
return 0; // EXCEPTION_CONTINUE_SEARCH
}
#else
class CPPTRACE_EXPORT unwind_interceptor {
public:
virtual ~unwind_interceptor();
};
class CPPTRACE_EXPORT unconditional_unwind_interceptor {
public:
virtual ~unconditional_unwind_interceptor();
};
CPPTRACE_EXPORT void do_prepare_unwind_interceptor(char(*)(std::size_t));
#ifndef CPPTRACE_DONT_PREPARE_UNWIND_INTERCEPTOR_ON
__attribute__((constructor)) inline void prepare_unwind_interceptor() {
// __attribute__((constructor)) inline functions can be called for every source file they're #included in
// there is still only one copy of the inline function in the final executable, though
// LTO can make the redundant constructs fire only once
// do_prepare_unwind_interceptor prevents against multiple preparations however it makes sense to guard
// against it here too as a fast path, not that this should matter for performance
static bool did_prepare = false;
if(!did_prepare) {
do_prepare_unwind_interceptor(exception_unwind_interceptor);
did_prepare = true;
}
}
#endif
#endif
}
}
#ifdef _MSC_VER
// this awful double-IILE is due to C2713 "You can't use structured exception handling (__try/__except) and C++
// exception handling (try/catch) in the same function."
#define CPPTRACE_TRY \
try { \
::cpptrace::detail::try_canary cpptrace_try_canary; \
[&]() { \
__try { \
[&]() {
#define CPPTRACE_CATCH(param) \
}(); \
} __except(::cpptrace::detail::exception_filter()) {} \
}(); \
} catch(param)
#define CPPTRACE_TRYZ \
try { \
[&]() { \
__try { \
[&]() {
#define CPPTRACE_CATCHZ(param) \
}(); \
} __except(::cpptrace::detail::unconditional_exception_filter()) {} \
}(); \
} catch(param)
#else
#define CPPTRACE_TRY \
try { \
_Pragma("GCC diagnostic push") \
_Pragma("GCC diagnostic ignored \"-Wshadow\"") \
::cpptrace::detail::try_canary cpptrace_try_canary; \
_Pragma("GCC diagnostic pop") \
try {
#define CPPTRACE_CATCH(param) \
} catch(::cpptrace::detail::unwind_interceptor&) {} \
} catch(param)
#define CPPTRACE_TRYZ \
try { \
try {
#define CPPTRACE_CATCHZ(param) \
} catch(::cpptrace::detail::unconditional_unwind_interceptor&) {} \
} catch(param)
#endif
#define CPPTRACE_CATCH_ALT(param) catch(param)
#ifdef CPPTRACE_UNPREFIXED_TRY_CATCH
#define TRY CPPTRACE_TRY
#define CATCH(param) CPPTRACE_CATCH(param)
#define TRYZ CPPTRACE_TRYZ
#define CATCHZ(param) CPPTRACE_CATCHZ(param)
#define CATCH_ALT(param) CPPTRACE_CATCH_ALT(param)
#endif
#endif