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#include "CrashHandler.h"
#include "SkTypes.h"
#include <stdlib.h>
// Disable SetupCrashHandler() unless SK_CRASH_HANDLER is defined.
#ifndef SK_CRASH_HANDLER
void SetupCrashHandler() { }
#else
#if defined(SK_BUILD_FOR_MAC)
// We only use local unwinding, so we can define this to select a faster implementation.
#define UNW_LOCAL_ONLY
#include <libunwind.h>
#include <cxxabi.h>
static void handler(int sig) {
unw_context_t context;
unw_getcontext(&context);
unw_cursor_t cursor;
unw_init_local(&cursor, &context);
SkDebugf("\nSignal %d:\n", sig);
while (unw_step(&cursor) > 0) {
static const size_t kMax = 256;
char mangled[kMax], demangled[kMax];
unw_word_t offset;
unw_get_proc_name(&cursor, mangled, kMax, &offset);
int ok;
size_t len = kMax;
abi::__cxa_demangle(mangled, demangled, &len, &ok);
SkDebugf("%s (+0x%zx)\n", ok == 0 ? demangled : mangled, (size_t)offset);
}
SkDebugf("\n");
// Exit NOW. Don't notify other threads, don't call anything registered with atexit().
_Exit(sig);
}
#elif defined(SK_BUILD_FOR_UNIX) && !defined(SK_BUILD_FOR_NACL) // NACL doesn't have backtrace.
// We'd use libunwind here too, but it's a pain to get installed for
// both 32 and 64 bit on bots. Doesn't matter much: catchsegv is best anyway.
#include <execinfo.h>
static void handler(int sig) {
static const int kMax = 64;
void* stack[kMax];
const int count = backtrace(stack, kMax);
SkDebugf("\nSignal %d [%s]:\n", sig, strsignal(sig));
backtrace_symbols_fd(stack, count, 2/*stderr*/);
// Exit NOW. Don't notify other threads, don't call anything registered with atexit().
_Exit(sig);
}
#endif
#if (defined(SK_BUILD_FOR_MAC) || (defined(SK_BUILD_FOR_UNIX) && !defined(SK_BUILD_FOR_NACL)))
#include <signal.h>
void SetupCrashHandler() {
static const int kSignals[] = {
SIGABRT,
SIGBUS,
SIGFPE,
SIGILL,
SIGSEGV,
};
for (size_t i = 0; i < sizeof(kSignals) / sizeof(kSignals[0]); i++) {
// Register our signal handler unless something's already done so (e.g. catchsegv).
void (*prev)(int) = signal(kSignals[i], handler);
if (prev != SIG_DFL) {
signal(kSignals[i], prev);
}
}
}
#elif defined(SK_CRASH_HANDLER) && defined(SK_BUILD_FOR_WIN)
#include <DbgHelp.h>
static const struct {
const char* name;
int code;
} kExceptions[] = {
#define _(E) {#E, E}
_(EXCEPTION_ACCESS_VIOLATION),
_(EXCEPTION_BREAKPOINT),
_(EXCEPTION_INT_DIVIDE_BY_ZERO),
_(EXCEPTION_STACK_OVERFLOW),
// TODO: more?
#undef _
};
static LONG WINAPI handler(EXCEPTION_POINTERS* e) {
const DWORD code = e->ExceptionRecord->ExceptionCode;
SkDebugf("\nCaught exception %u", code);
for (size_t i = 0; i < SK_ARRAY_COUNT(kExceptions); i++) {
if (kExceptions[i].code == code) {
SkDebugf(" %s", kExceptions[i].name);
}
}
SkDebugf("\n");
// We need to run SymInitialize before doing any of the stack walking below.
HANDLE hProcess = GetCurrentProcess();
SymInitialize(hProcess, 0, true);
STACKFRAME64 frame;
sk_bzero(&frame, sizeof(frame));
// Start frame off from the frame that triggered the exception.
CONTEXT* c = e->ContextRecord;
frame.AddrPC.Mode = AddrModeFlat;
frame.AddrStack.Mode = AddrModeFlat;
frame.AddrFrame.Mode = AddrModeFlat;
#if defined(_X86_)
frame.AddrPC.Offset = c->Eip;
frame.AddrStack.Offset = c->Esp;
frame.AddrFrame.Offset = c->Ebp;
const DWORD machineType = IMAGE_FILE_MACHINE_I386;
#elif defined(_AMD64_)
frame.AddrPC.Offset = c->Rip;
frame.AddrStack.Offset = c->Rsp;
frame.AddrFrame.Offset = c->Rbp;
const DWORD machineType = IMAGE_FILE_MACHINE_AMD64;
#endif
while (StackWalk64(machineType,
GetCurrentProcess(),
GetCurrentThread(),
&frame,
c,
NULL,
SymFunctionTableAccess64,
SymGetModuleBase64,
NULL)) {
// Buffer to store symbol name in.
static const int kMaxNameLength = 1024;
uint8_t buffer[sizeof(IMAGEHLP_SYMBOL64) + kMaxNameLength];
sk_bzero(buffer, sizeof(buffer));
// We have to place IMAGEHLP_SYMBOL64 at the front, and fill in
// how much space it can use.
IMAGEHLP_SYMBOL64* symbol = reinterpret_cast<IMAGEHLP_SYMBOL64*>(&buffer);
symbol->SizeOfStruct = sizeof(IMAGEHLP_SYMBOL64);
symbol->MaxNameLength = kMaxNameLength - 1;
// Translate the current PC into a symbol and byte offset from the symbol.
DWORD64 offset;
SymGetSymFromAddr64(hProcess, frame.AddrPC.Offset, &offset, symbol);
SkDebugf("%s +%x\n", symbol->Name, offset);
}
// Exit NOW. Don't notify other threads, don't call anything registered with atexit().
_exit(1);
// The compiler wants us to return something. This is what we'd do
// if we didn't _exit().
return EXCEPTION_EXECUTE_HANDLER;
}
void SetupCrashHandler() {
SetUnhandledExceptionFilter(handler);
}
#else // We asked for SK_CRASH_HANDLER, but it's not Mac, Linux, or Windows. Sorry!
void SetupCrashHandler() { }
#endif
#endif // SK_CRASH_HANDLER
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