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Diffstat (limited to 'third_party/abseil-cpp/absl/debugging/failure_signal_handler.h')
| -rw-r--r-- | third_party/abseil-cpp/absl/debugging/failure_signal_handler.h | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/third_party/abseil-cpp/absl/debugging/failure_signal_handler.h b/third_party/abseil-cpp/absl/debugging/failure_signal_handler.h new file mode 100644 index 0000000000..f5a83962f1 --- /dev/null +++ b/third_party/abseil-cpp/absl/debugging/failure_signal_handler.h @@ -0,0 +1,121 @@ +// Copyright 2018 The Abseil Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// https://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. +// +// ----------------------------------------------------------------------------- +// File: failure_signal_handler.h +// ----------------------------------------------------------------------------- +// +// This file configures the Abseil *failure signal handler* to capture and dump +// useful debugging information (such as a stacktrace) upon program failure. +// +// To use the failure signal handler, call `absl::InstallFailureSignalHandler()` +// very early in your program, usually in the first few lines of main(): +// +// int main(int argc, char** argv) { +// // Initialize the symbolizer to get a human-readable stack trace +// absl::InitializeSymbolizer(argv[0]); +// +// absl::FailureSignalHandlerOptions options; +// absl::InstallFailureSignalHandler(options); +// DoSomethingInteresting(); +// return 0; +// } +// +// Any program that raises a fatal signal (such as `SIGSEGV`, `SIGILL`, +// `SIGFPE`, `SIGABRT`, `SIGTERM`, `SIGBUG`, and `SIGTRAP`) will call the +// installed failure signal handler and provide debugging information to stderr. +// +// Note that you should *not* install the Abseil failure signal handler more +// than once. You may, of course, have another (non-Abseil) failure signal +// handler installed (which would be triggered if Abseil's failure signal +// handler sets `call_previous_handler` to `true`). + +#ifndef ABSL_DEBUGGING_FAILURE_SIGNAL_HANDLER_H_ +#define ABSL_DEBUGGING_FAILURE_SIGNAL_HANDLER_H_ + +#include "absl/base/config.h" + +namespace absl { +ABSL_NAMESPACE_BEGIN + +// FailureSignalHandlerOptions +// +// Struct for holding `absl::InstallFailureSignalHandler()` configuration +// options. +struct FailureSignalHandlerOptions { + // If true, try to symbolize the stacktrace emitted on failure, provided that + // you have initialized a symbolizer for that purpose. (See symbolize.h for + // more information.) + bool symbolize_stacktrace = true; + + // If true, try to run signal handlers on an alternate stack (if supported on + // the given platform). An alternate stack is useful for program crashes due + // to a stack overflow; by running on a alternate stack, the signal handler + // may run even when normal stack space has been exausted. The downside of + // using an alternate stack is that extra memory for the alternate stack needs + // to be pre-allocated. + bool use_alternate_stack = true; + + // If positive, indicates the number of seconds after which the failure signal + // handler is invoked to abort the program. Setting such an alarm is useful in + // cases where the failure signal handler itself may become hung or + // deadlocked. + int alarm_on_failure_secs = 3; + + // If true, call the previously registered signal handler for the signal that + // was received (if one was registered) after the existing signal handler + // runs. This mechanism can be used to chain signal handlers together. + // + // If false, the signal is raised to the default handler for that signal + // (which normally terminates the program). + // + // IMPORTANT: If true, the chained fatal signal handlers must not try to + // recover from the fatal signal. Instead, they should terminate the program + // via some mechanism, like raising the default handler for the signal, or by + // calling `_exit()`. Note that the failure signal handler may put parts of + // the Abseil library into a state from which they cannot recover. + bool call_previous_handler = false; + + // If non-null, indicates a pointer to a callback function that will be called + // upon failure, with a std::string argument containing failure data. This function + // may be used as a hook to write failure data to a secondary location, such + // as a log file. This function may also be called with null data, as a hint + // to flush any buffered data before the program may be terminated. Consider + // flushing any buffered data in all calls to this function. + // + // Since this function runs within a signal handler, it should be + // async-signal-safe if possible. + // See http://man7.org/linux/man-pages/man7/signal-safety.7.html + void (*writerfn)(const char*) = nullptr; +}; + +// InstallFailureSignalHandler() +// +// Installs a signal handler for the common failure signals `SIGSEGV`, `SIGILL`, +// `SIGFPE`, `SIGABRT`, `SIGTERM`, `SIGBUG`, and `SIGTRAP` (provided they exist +// on the given platform). The failure signal handler dumps program failure data +// useful for debugging in an unspecified format to stderr. This data may +// include the program counter, a stacktrace, and register information on some +// systems; do not rely on an exact format for the output, as it is subject to +// change. +void InstallFailureSignalHandler(const FailureSignalHandlerOptions& options); + +namespace debugging_internal { +const char* FailureSignalToString(int signo); +} // namespace debugging_internal + +ABSL_NAMESPACE_END +} // namespace absl + +#endif // ABSL_DEBUGGING_FAILURE_SIGNAL_HANDLER_H_ |