Move debug-related stuff from base to the base/debug directory and use the...

base/debug_util_posix.cc

-// Copyright (c) 2010 The Chromium 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 "base/debug_util.h"
-
-#include <errno.h>
-#include <fcntl.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <sys/stat.h>
-#include <sys/sysctl.h>
-#include <sys/types.h>
-#include <unistd.h>
-
-#include <string>
-#include <vector>
-
-#if defined(__GLIBCXX__)
-#include <cxxabi.h>
-#endif
-
-#if defined(OS_MACOSX)
-#include <AvailabilityMacros.h>
-#endif
-
-#include <iostream>
-
-#include "base/basictypes.h"
-#include "base/compat_execinfo.h"
-#include "base/eintr_wrapper.h"
-#include "base/logging.h"
-#include "base/safe_strerror_posix.h"
-#include "base/scoped_ptr.h"
-#include "base/string_piece.h"
-#include "base/stringprintf.h"
-
-#if defined(USE_SYMBOLIZE)
-#include "base/third_party/symbolize/symbolize.h"
-#endif
-
-namespace {
-// The prefix used for mangled symbols, per the Itanium C++ ABI:
-// http://www.codesourcery.com/cxx-abi/abi.html#mangling
-const char kMangledSymbolPrefix[] = "_Z";
-
-// Characters that can be used for symbols, generated by Ruby:
-// (('a'..'z').to_a+('A'..'Z').to_a+('0'..'9').to_a + ['_']).join
-const char kSymbolCharacters[] =
-    "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_";
-
-#if !defined(USE_SYMBOLIZE)
-// Demangles C++ symbols in the given text. Example:
-//
-// "sconsbuild/Debug/base_unittests(_ZN10StackTraceC1Ev+0x20) [0x817778c]"
-// =>
-// "sconsbuild/Debug/base_unittests(StackTrace::StackTrace()+0x20) [0x817778c]"
-void DemangleSymbols(std::string* text) {
-#if defined(__GLIBCXX__)
-
-  std::string::size_type search_from = 0;
-  while (search_from < text->size()) {
-    // Look for the start of a mangled symbol, from search_from.
-    std::string::size_type mangled_start =
-        text->find(kMangledSymbolPrefix, search_from);
-    if (mangled_start == std::string::npos) {
-      break;  // Mangled symbol not found.
-    }
-
-    // Look for the end of the mangled symbol.
-    std::string::size_type mangled_end =
-        text->find_first_not_of(kSymbolCharacters, mangled_start);
-    if (mangled_end == std::string::npos) {
-      mangled_end = text->size();
-    }
-    std::string mangled_symbol =
-        text->substr(mangled_start, mangled_end - mangled_start);
-
-    // Try to demangle the mangled symbol candidate.
-    int status = 0;
-    scoped_ptr_malloc<char> demangled_symbol(
-        abi::__cxa_demangle(mangled_symbol.c_str(), NULL, 0, &status));
-    if (status == 0) {  // Demangling is successful.
-      // Remove the mangled symbol.
-      text->erase(mangled_start, mangled_end - mangled_start);
-      // Insert the demangled symbol.
-      text->insert(mangled_start, demangled_symbol.get());
-      // Next time, we'll start right after the demangled symbol we inserted.
-      search_from = mangled_start + strlen(demangled_symbol.get());
-    } else {
-      // Failed to demangle.  Retry after the "_Z" we just found.
-      search_from = mangled_start + 2;
-    }
-  }
-
-#endif  // defined(__GLIBCXX__)
-}
-#endif  // !defined(USE_SYMBOLIZE)
-
-// Gets the backtrace as a vector of strings. If possible, resolve symbol
-// names and attach these. Otherwise just use raw addresses. Returns true
-// if any symbol name is resolved.  Returns false on error and *may* fill
-// in |error_message| if an error message is available.
-bool GetBacktraceStrings(void **trace, int size,
-                         std::vector<std::string>* trace_strings,
-                         std::string* error_message) {
-  bool symbolized = false;
-
-#if defined(USE_SYMBOLIZE)
-  for (int i = 0; i < size; ++i) {
-    char symbol[1024];
-    // Subtract by one as return address of function may be in the next
-    // function when a function is annotated as noreturn.
-    if (google::Symbolize(static_cast<char *>(trace[i]) - 1,
-                          symbol, sizeof(symbol))) {
-      // Don't call DemangleSymbols() here as the symbol is demangled by
-      // google::Symbolize().
-      trace_strings->push_back(
-          base::StringPrintf("%s [%p]", symbol, trace[i]));
-      symbolized = true;
-    } else {
-      trace_strings->push_back(base::StringPrintf("%p", trace[i]));
-    }
-  }
-#else
-  scoped_ptr_malloc<char*> trace_symbols(backtrace_symbols(trace, size));
-  if (trace_symbols.get()) {
-    for (int i = 0; i < size; ++i) {
-      std::string trace_symbol = trace_symbols.get()[i];
-      DemangleSymbols(&trace_symbol);
-      trace_strings->push_back(trace_symbol);
-    }
-    symbolized = true;
-  } else {
-    if (error_message)
-      *error_message = safe_strerror(errno);
-    for (int i = 0; i < size; ++i) {
-      trace_strings->push_back(base::StringPrintf("%p", trace[i]));
-    }
-  }
-#endif  // defined(USE_SYMBOLIZE)
-
-  return symbolized;
-}
-
-}  // namespace
-
-// static
-bool DebugUtil::SpawnDebuggerOnProcess(unsigned /* process_id */) {
-  NOTIMPLEMENTED();
-  return false;
-}
-
-#if defined(OS_MACOSX)
-
-// Based on Apple's recommended method as described in
-// http://developer.apple.com/qa/qa2004/qa1361.html
-// static
-bool DebugUtil::BeingDebugged() {
-  // If the process is sandboxed then we can't use the sysctl, so cache the
-  // value.
-  static bool is_set = false;
-  static bool being_debugged = false;
-
-  if (is_set) {
-    return being_debugged;
-  }
-
-  // Initialize mib, which tells sysctl what info we want.  In this case,
-  // we're looking for information about a specific process ID.
-  int mib[] = {
-    CTL_KERN,
-    KERN_PROC,
-    KERN_PROC_PID,
-    getpid()
-  };
-
-  // Caution: struct kinfo_proc is marked __APPLE_API_UNSTABLE.  The source and
-  // binary interfaces may change.
-  struct kinfo_proc info;
-  size_t info_size = sizeof(info);
-
-  int sysctl_result = sysctl(mib, arraysize(mib), &info, &info_size, NULL, 0);
-  DCHECK_EQ(sysctl_result, 0);
-  if (sysctl_result != 0) {
-    is_set = true;
-    being_debugged = false;
-    return being_debugged;
-  }
-
-  // This process is being debugged if the P_TRACED flag is set.
-  is_set = true;
-  being_debugged = (info.kp_proc.p_flag & P_TRACED) != 0;
-  return being_debugged;
-}
-
-#elif defined(OS_LINUX)
-
-// We can look in /proc/self/status for TracerPid.  We are likely used in crash
-// handling, so we are careful not to use the heap or have side effects.
-// Another option that is common is to try to ptrace yourself, but then we
-// can't detach without forking(), and that's not so great.
-// static
-bool DebugUtil::BeingDebugged() {
-  int status_fd = open("/proc/self/status", O_RDONLY);
-  if (status_fd == -1)
-    return false;
-
-  // We assume our line will be in the first 1024 characters and that we can
-  // read this much all at once.  In practice this will generally be true.
-  // This simplifies and speeds up things considerably.
-  char buf[1024];
-
-  ssize_t num_read = HANDLE_EINTR(read(status_fd, buf, sizeof(buf)));
-  if (HANDLE_EINTR(close(status_fd)) < 0)
-    return false;
-
-  if (num_read <= 0)
-    return false;
-
-  base::StringPiece status(buf, num_read);
-  base::StringPiece tracer("TracerPid:\t");
-
-  base::StringPiece::size_type pid_index = status.find(tracer);
-  if (pid_index == base::StringPiece::npos)
-    return false;
-
-  // Our pid is 0 without a debugger, assume this for any pid starting with 0.
-  pid_index += tracer.size();
-  return pid_index < status.size() && status[pid_index] != '0';
-}
-
-#elif defined(OS_FREEBSD)
-
-bool DebugUtil::BeingDebugged() {
-  // TODO(benl): can we determine this under FreeBSD?
-  NOTIMPLEMENTED();
-  return false;
-}
-
-#endif  // defined(OS_FREEBSD)
-
-// We want to break into the debugger in Debug mode, and cause a crash dump in
-// Release mode. Breakpad behaves as follows:
-//
-// +-------+-----------------+-----------------+
-// | OS    | Dump on SIGTRAP | Dump on SIGABRT |
-// +-------+-----------------+-----------------+
-// | Linux |       N         |        Y        |
-// | Mac   |       Y         |        N        |
-// +-------+-----------------+-----------------+
-//
-// Thus we do the following:
-// Linux: Debug mode, send SIGTRAP; Release mode, send SIGABRT.
-// Mac: Always send SIGTRAP.
-
-#if defined(NDEBUG) && !defined(OS_MACOSX)
-#define DEBUG_BREAK() abort()
-#elif defined(ARCH_CPU_ARM_FAMILY)
-#define DEBUG_BREAK() asm("bkpt 0")
-#else
-#define DEBUG_BREAK() asm("int3")
-#endif
-
-// static
-void DebugUtil::BreakDebugger() {
-  DEBUG_BREAK();
-}
-
-StackTrace::StackTrace() {
-#if defined(OS_MACOSX) && MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5
-  if (backtrace == NULL) {
-    count_ = 0;
-    return;
-  }
-#endif
-  // Though the backtrace API man page does not list any possible negative
-  // return values, we take no chance.
-  count_ = std::max(backtrace(trace_, arraysize(trace_)), 0);
-}
-
-void StackTrace::PrintBacktrace() {
-#if defined(OS_MACOSX) && MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5
-  if (backtrace_symbols_fd == NULL)
-    return;
-#endif
-  fflush(stderr);
-  std::vector<std::string> trace_strings;
-  GetBacktraceStrings(trace_, count_, &trace_strings, NULL);
-  for (size_t i = 0; i < trace_strings.size(); ++i) {
-    std::cerr << "\t" << trace_strings[i] << "\n";
-  }
-}
-
-void StackTrace::OutputToStream(std::ostream* os) {
-#if defined(OS_MACOSX) && MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5
-  if (backtrace_symbols == NULL)
-    return;
-#endif
-  std::vector<std::string> trace_strings;
-  std::string error_message;
-  if (GetBacktraceStrings(trace_, count_, &trace_strings, &error_message)) {
-    (*os) << "Backtrace:\n";
-  } else {
-    if (!error_message.empty())
-      error_message = " (" + error_message + ")";
-    (*os) << "Unable to get symbols for backtrace" << error_message << ". "
-          << "Dumping raw addresses in trace:\n";
-  }
-
-  for (size_t i = 0; i < trace_strings.size(); ++i) {
-    (*os) << "\t" << trace_strings[i] << "\n";
-  }
-}