ladybird/Libraries/LibC/cxxabi.cpp
Andrew Kaster 96a86463dd LibC: Move __cxa_finalize and __cxa_atexit code to their own file
These guys aren't really related to initializing the C runtime,
so move them to a new fancy file named C++ abi. Or rather, cxxabi :)
2020-01-01 17:48:41 +01:00

61 lines
1.8 KiB
C++

#include <AK/Types.h>
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
//#define GLOBAL_DTORS_DEBUG
extern "C" {
typedef void (*AtExitFunction)(void*);
struct __exit_entry {
AtExitFunction method;
void* parameter;
void* dso_handle;
bool has_been_called;
};
static __exit_entry __exit_entries[1024] {};
static int __exit_entry_count = 0;
int __cxa_atexit(AtExitFunction exit_function, void* parameter, void* dso_handle)
{
if (__exit_entry_count >= 1024)
return -1;
__exit_entries[__exit_entry_count++] = { exit_function, parameter, dso_handle, false };
return 0;
}
void __cxa_finalize(void* dso_handle)
{
// From the itanium abi, https://itanium-cxx-abi.github.io/cxx-abi/abi.html#dso-dtor-runtime-api
//
// When __cxa_finalize(d) is called, it should walk the termination function list, calling each in turn
// if d matches __dso_handle for the termination function entry. If d == NULL, it should call all of them.
// Multiple calls to __cxa_finalize shall not result in calling termination function entries multiple times;
// the implementation may either remove entries or mark them finished.
int entry_index = __exit_entry_count;
#ifdef GLOBAL_DTORS_DEBUG
dbgprintf("__cxa_finalize: %d entries in the finalizer list\n", entry_index);
#endif
while (--entry_index >= 0) {
auto& exit_entry = __exit_entries[entry_index];
bool needs_calling = !exit_entry.has_been_called && (!dso_handle || dso_handle == exit_entry.dso_handle);
if (needs_calling) {
#ifdef GLOBAL_DTORS_DEBUG
dbgprintf("__cxa_finalize: calling entry[%d] %p(%p) dso: %p\n", entry_index, exit_entry.method, exit_entry.parameter, exit_entry.dso_handle);
#endif
exit_entry.method(exit_entry.parameter);
exit_entry.has_been_called = true;
}
}
}
} // extern "C"