blob: 66dd0d5e015849c20e109a9cde739a6529ef20bb [file] [log] [blame]
// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "flutter/fml/backtrace.h"
#include <cxxabi.h>
#include <sstream>
#include <dlfcn.h>
#include <execinfo.h>
#include <signal.h>
#include "flutter/fml/logging.h"
namespace fml {
static std::string kKUnknownFrameName = "Unknown";
static std::string DemangleSymbolName(const std::string& mangled) {
if (mangled == kKUnknownFrameName) {
return kKUnknownFrameName;
}
int status = 0;
size_t length = 0;
char* demangled = __cxxabiv1::__cxa_demangle(
mangled.data(), // mangled name
nullptr, // output buffer (malloc-ed if nullptr)
&length, // demangled length
&status);
if (demangled == nullptr || status != 0) {
return mangled;
}
auto demangled_string = std::string{demangled, length};
free(demangled);
return demangled_string;
}
static std::string GetSymbolName(void* symbol) {
Dl_info info = {};
if (::dladdr(symbol, &info) == 0) {
return kKUnknownFrameName;
}
return DemangleSymbolName({info.dli_sname});
}
std::string BacktraceHere(size_t offset) {
constexpr size_t kMaxFrames = 256;
void* symbols[kMaxFrames];
const auto available_frames = ::backtrace(symbols, kMaxFrames);
if (available_frames <= 0) {
return "";
}
std::stringstream stream;
for (int i = 1 + offset; i < available_frames; ++i) {
stream << "Frame " << i - 1 - offset << ": " << symbols[i] << " "
<< GetSymbolName(symbols[i]) << std::endl;
}
return stream.str();
}
static size_t kKnownSignalHandlers[] = {
SIGABRT, // abort program
SIGFPE, // floating-point exception
SIGBUS, // bus error
SIGSEGV, // segmentation violation
SIGSYS, // non-existent system call invoked
SIGPIPE, // write on a pipe with no reader
SIGALRM, // real-time timer expired
SIGTERM, // software termination signal
};
static std::string SignalNameToString(int signal) {
switch (signal) {
case SIGABRT:
return "SIGABRT";
case SIGFPE:
return "SIGFPE";
case SIGBUS:
return "SIGBUS";
case SIGSEGV:
return "SIGSEGV";
case SIGSYS:
return "SIGSYS";
case SIGPIPE:
return "SIGPIPE";
case SIGALRM:
return "SIGALRM";
case SIGTERM:
return "SIGTERM";
};
return std::to_string(signal);
}
static void ToggleSignalHandlers(bool set);
static void SignalHandler(int signal) {
// We are a crash signal handler. This can only happen once. Since we don't
// want to catch crashes while we are generating the crash reports, disable
// all set signal handlers to their default values before reporting the crash
// and re-raising the signal.
ToggleSignalHandlers(false);
FML_LOG(ERROR) << "Caught signal " << SignalNameToString(signal)
<< " during program execution." << std::endl
<< BacktraceHere(3);
::raise(signal);
}
static void ToggleSignalHandlers(bool set) {
for (size_t i = 0; i < sizeof(kKnownSignalHandlers) / sizeof(size_t); ++i) {
auto signal_name = kKnownSignalHandlers[i];
auto handler = set ? &SignalHandler : SIG_DFL;
if (::signal(signal_name, handler) == SIG_ERR) {
FML_LOG(ERROR) << "Could not attach signal handler for " << signal_name;
}
}
}
void InstallCrashHandler() {
ToggleSignalHandlers(true);
}
bool IsCrashHandlingSupported() {
return true;
}
} // namespace fml