llvm/llvm/lib/Support/Signals.cpp

//===- Signals.cpp - Signal Handling support --------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines some helpful functions for dealing with the possibility of
// Unix signals occurring while your program is running.
//
//===----------------------------------------------------------------------===//

#include "llvm/Support/Signals.h"

#include "DebugOptions.h"

#include "llvm/ADT/StringRef.h"
#include "llvm/Config/llvm-config.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ErrorOr.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/FileUtilities.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/FormatVariadic.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/Program.h"
#include "llvm/Support/StringSaver.h"
#include "llvm/Support/raw_ostream.h"
#include <array>
#include <cmath>
#include <vector>

//===----------------------------------------------------------------------===//
//=== WARNING: Implementation here must contain only TRULY operating system
//===          independent code.
//===----------------------------------------------------------------------===//

usingnamespacellvm;

// Use explicit storage to avoid accessing cl::opt in a signal handler.
static bool DisableSymbolicationFlag = …;
static ManagedStatic<std::string> CrashDiagnosticsDirectory;
namespace {
struct CreateDisableSymbolication { … };
struct CreateCrashDiagnosticsDir { … };
} // namespace
void llvm::initSignalsOptions() { … }

constexpr char DisableSymbolizationEnv[] = …;
constexpr char LLVMSymbolizerPathEnv[] = …;
constexpr char EnableSymbolizerMarkupEnv[] = …;

// Callbacks to run in signal handler must be lock-free because a signal handler
// could be running as we add new callbacks. We don't add unbounded numbers of
// callbacks, an array is therefore sufficient.
struct CallbackAndCookie { … };

static constexpr size_t MaxSignalHandlerCallbacks = …;

// A global array of CallbackAndCookie may not compile with
// -Werror=global-constructors in c++20 and above
static std::array<CallbackAndCookie, MaxSignalHandlerCallbacks> &
CallBacksToRun() { … }

// Signal-safe.
void sys::RunSignalHandlers() { … }

// Signal-safe.
static void insertSignalHandler(sys::SignalHandlerCallback FnPtr,
                                void *Cookie) { … }

static bool findModulesAndOffsets(void **StackTrace, int Depth,
                                  const char **Modules, intptr_t *Offsets,
                                  const char *MainExecutableName,
                                  StringSaver &StrPool);

/// Format a pointer value as hexadecimal. Zero pad it out so its always the
/// same width.
static FormattedNumber format_ptr(void *PC) { … }

/// Helper that launches llvm-symbolizer and symbolizes a backtrace.
LLVM_ATTRIBUTE_USED
static bool printSymbolizedStackTrace(StringRef Argv0, void **StackTrace,
                                      int Depth, llvm::raw_ostream &OS) { … }

static bool printMarkupContext(raw_ostream &OS, const char *MainExecutableName);

LLVM_ATTRIBUTE_USED
static bool printMarkupStackTrace(StringRef Argv0, void **StackTrace, int Depth,
                                  raw_ostream &OS) { … }

// Include the platform-specific parts of this class.
#ifdef LLVM_ON_UNIX
#include "Unix/Signals.inc"
#endif
#ifdef _WIN32
#include "Windows/Signals.inc"
#endif