Replace DumpBacktrace with Chromium's StackTrace implementation.

src/base/debug/stack_trace_posix.cc

Index: src/base/debug/stack_trace_posix.cc
diff --git a/src/base/debug/stack_trace_posix.cc b/src/base/debug/stack_trace_posix.cc
new file mode 100644
index 0000000000000000000000000000000000000000..f2bbdd09b35954c23a048e6bddd37f813996d2ec
--- /dev/null
+++ b/src/base/debug/stack_trace_posix.cc
@@ -0,0 +1,445 @@
+// Copyright (c) 2012 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.
+
+// Slightly adapted for inclusion in V8.
+// Copyright 2016 the V8 project authors. All rights reserved.
+
+#include "src/base/debug/stack_trace.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <map>
+#include <memory>
+#include <ostream>
+#include <string>
+#include <vector>
+
+#if V8_LIBC_GLIBC || V8_OS_BSD
+#include <cxxabi.h>
+#include <execinfo.h>
+#endif
+#if V8_OS_MACOSX
+#include <AvailabilityMacros.h>
+#endif
+
+#include "src/base/build_config.h"
+#include "src/base/free_deleter.h"
+#include "src/base/logging.h"
+#include "src/base/macros.h"
+
+namespace v8 {
+namespace base {
+namespace debug {
+
+namespace internal {
+
+// POSIX doesn't define any async-signal safe function for converting
+// an integer to ASCII. We'll have to define our own version.
+// itoa_r() converts a (signed) integer to ASCII. It returns "buf", if the
+// conversion was successful or NULL otherwise. It never writes more than "sz"
+// bytes. Output will be truncated as needed, and a NUL character is always
+// appended.
+char* itoa_r(intptr_t i, char* buf, size_t sz, int base, size_t padding);
+
+}  // namespace internal
+
+namespace {
+
+volatile sig_atomic_t in_signal_handler = 0;
+bool dump_stack_in_signal_handler = 1;
+
+// 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_";
+
+// Demangles C++ symbols in the given text. Example:
+//
+// "out/Debug/base_unittests(_ZN10StackTraceC1Ev+0x20) [0x817778c]"
+// =>
+// "out/Debug/base_unittests(StackTrace::StackTrace()+0x20) [0x817778c]"
+void DemangleSymbols(std::string* text) {
+  // Note: code in this function is NOT async-signal safe (std::string uses
+  // malloc internally).
+
+#if V8_LIBC_GLIBC || V8_OS_BSD
+
+  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;
+    std::unique_ptr<char, FreeDeleter> 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  // V8_LIBC_GLIBC || V8_OS_BSD
+}
+
+class BacktraceOutputHandler {
+ public:
+  virtual void HandleOutput(const char* output) = 0;
+
+ protected:
+  virtual ~BacktraceOutputHandler() {}
+};
+
+void OutputPointer(void* pointer, BacktraceOutputHandler* handler) {
+  // This should be more than enough to store a 64-bit number in hex:
+  // 16 hex digits + 1 for null-terminator.
+  char buf[17] = {'\0'};
+  handler->HandleOutput("0x");
+  internal::itoa_r(reinterpret_cast<intptr_t>(pointer), buf, sizeof(buf), 16,
+                   12);
+  handler->HandleOutput(buf);
+}
+
+void ProcessBacktrace(void* const* trace, size_t size,
+                      BacktraceOutputHandler* handler) {
+  // NOTE: This code MUST be async-signal safe (it's used by in-process
+  // stack dumping signal handler). NO malloc or stdio is allowed here.
+  handler->HandleOutput("\n");
+  handler->HandleOutput("==== C stack trace ===============================\n");
+  handler->HandleOutput("\n");
+
+  bool printed = false;
+
+  // Below part is async-signal unsafe (uses malloc), so execute it only
+  // when we are not executing the signal handler.
+  if (in_signal_handler == 0) {
+    std::unique_ptr<char*, FreeDeleter> trace_symbols(
+        backtrace_symbols(trace, static_cast<int>(size)));
+    if (trace_symbols.get()) {
+      for (size_t i = 0; i < size; ++i) {
+        std::string trace_symbol = trace_symbols.get()[i];
+        DemangleSymbols(&trace_symbol);
+        handler->HandleOutput("    ");
+        handler->HandleOutput(trace_symbol.c_str());
+        handler->HandleOutput("\n");
+      }
+
+      printed = true;
+    }
+  }
+
+  if (!printed) {
+    for (size_t i = 0; i < size; ++i) {
+      handler->HandleOutput(" [");
+      OutputPointer(trace[i], handler);
+      handler->HandleOutput("]\n");
+    }
+  }
+}
+
+void PrintToStderr(const char* output) {
+  // NOTE: This code MUST be async-signal safe (it's used by in-process
+  // stack dumping signal handler). NO malloc or stdio is allowed here.
+  write(STDERR_FILENO, output, strlen(output));
+}
+
+void StackDumpSignalHandler(int signal, siginfo_t* info, void* void_context) {
+  // NOTE: This code MUST be async-signal safe.
+  // NO malloc or stdio is allowed here.
+
+  // Record the fact that we are in the signal handler now, so that the rest
+  // of StackTrace can behave in an async-signal-safe manner.
+  in_signal_handler = 1;
+
+  PrintToStderr("Received signal ");
+  char buf[1024] = {0};
+  internal::itoa_r(signal, buf, sizeof(buf), 10, 0);
+  PrintToStderr(buf);
+  if (signal == SIGBUS) {
+    if (info->si_code == BUS_ADRALN)
+      PrintToStderr(" BUS_ADRALN ");
+    else if (info->si_code == BUS_ADRERR)
+      PrintToStderr(" BUS_ADRERR ");
+    else if (info->si_code == BUS_OBJERR)
+      PrintToStderr(" BUS_OBJERR ");
+    else
+      PrintToStderr(" <unknown> ");
+  } else if (signal == SIGFPE) {
+    if (info->si_code == FPE_FLTDIV)
+      PrintToStderr(" FPE_FLTDIV ");
+    else if (info->si_code == FPE_FLTINV)
+      PrintToStderr(" FPE_FLTINV ");
+    else if (info->si_code == FPE_FLTOVF)
+      PrintToStderr(" FPE_FLTOVF ");
+    else if (info->si_code == FPE_FLTRES)
+      PrintToStderr(" FPE_FLTRES ");
+    else if (info->si_code == FPE_FLTSUB)
+      PrintToStderr(" FPE_FLTSUB ");
+    else if (info->si_code == FPE_FLTUND)
+      PrintToStderr(" FPE_FLTUND ");
+    else if (info->si_code == FPE_INTDIV)
+      PrintToStderr(" FPE_INTDIV ");
+    else if (info->si_code == FPE_INTOVF)
+      PrintToStderr(" FPE_INTOVF ");
+    else
+      PrintToStderr(" <unknown> ");
+  } else if (signal == SIGILL) {
+    if (info->si_code == ILL_BADSTK)
+      PrintToStderr(" ILL_BADSTK ");
+    else if (info->si_code == ILL_COPROC)
+      PrintToStderr(" ILL_COPROC ");
+    else if (info->si_code == ILL_ILLOPN)
+      PrintToStderr(" ILL_ILLOPN ");
+    else if (info->si_code == ILL_ILLADR)
+      PrintToStderr(" ILL_ILLADR ");
+    else if (info->si_code == ILL_ILLTRP)
+      PrintToStderr(" ILL_ILLTRP ");
+    else if (info->si_code == ILL_PRVOPC)
+      PrintToStderr(" ILL_PRVOPC ");
+    else if (info->si_code == ILL_PRVREG)
+      PrintToStderr(" ILL_PRVREG ");
+    else
+      PrintToStderr(" <unknown> ");
+  } else if (signal == SIGSEGV) {
+    if (info->si_code == SEGV_MAPERR)
+      PrintToStderr(" SEGV_MAPERR ");
+    else if (info->si_code == SEGV_ACCERR)
+      PrintToStderr(" SEGV_ACCERR ");
+    else
+      PrintToStderr(" <unknown> ");
+  }
+  if (signal == SIGBUS || signal == SIGFPE || signal == SIGILL ||
+      signal == SIGSEGV) {
+    internal::itoa_r(reinterpret_cast<intptr_t>(info->si_addr), buf,
+                     sizeof(buf), 16, 12);
+    PrintToStderr(buf);
+  }
+  PrintToStderr("\n");
+  if (dump_stack_in_signal_handler) {
+    debug::StackTrace().Print();
+    PrintToStderr("[end of stack trace]\n");
+  }
+
+  if (::signal(signal, SIG_DFL) == SIG_ERR) _exit(1);
+}
+
+class PrintBacktraceOutputHandler : public BacktraceOutputHandler {
+ public:
+  PrintBacktraceOutputHandler() {}
+
+  void HandleOutput(const char* output) override {
+    // NOTE: This code MUST be async-signal safe (it's used by in-process
+    // stack dumping signal handler). NO malloc or stdio is allowed here.
+    PrintToStderr(output);
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(PrintBacktraceOutputHandler);
+};
+
+class StreamBacktraceOutputHandler : public BacktraceOutputHandler {
+ public:
+  explicit StreamBacktraceOutputHandler(std::ostream* os) : os_(os) {}
+
+  void HandleOutput(const char* output) override { (*os_) << output; }
+
+ private:
+  std::ostream* os_;
+
+  DISALLOW_COPY_AND_ASSIGN(StreamBacktraceOutputHandler);
+};
+
+void WarmUpBacktrace() {
+  // Warm up stack trace infrastructure. It turns out that on the first
+  // call glibc initializes some internal data structures using pthread_once,
+  // and even backtrace() can call malloc(), leading to hangs.
+  //
+  // Example stack trace snippet (with tcmalloc):
+  //
+  // #8  0x0000000000a173b5 in tc_malloc
+  //             at ./third_party/tcmalloc/chromium/src/debugallocation.cc:1161
+  // #9  0x00007ffff7de7900 in _dl_map_object_deps at dl-deps.c:517
+  // #10 0x00007ffff7ded8a9 in dl_open_worker at dl-open.c:262
+  // #11 0x00007ffff7de9176 in _dl_catch_error at dl-error.c:178
+  // #12 0x00007ffff7ded31a in _dl_open (file=0x7ffff625e298 "libgcc_s.so.1")
+  //             at dl-open.c:639
+  // #13 0x00007ffff6215602 in do_dlopen at dl-libc.c:89
+  // #14 0x00007ffff7de9176 in _dl_catch_error at dl-error.c:178
+  // #15 0x00007ffff62156c4 in dlerror_run at dl-libc.c:48
+  // #16 __GI___libc_dlopen_mode at dl-libc.c:165
+  // #17 0x00007ffff61ef8f5 in init
+  //             at ../sysdeps/x86_64/../ia64/backtrace.c:53
+  // #18 0x00007ffff6aad400 in pthread_once
+  //             at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_once.S:104
+  // #19 0x00007ffff61efa14 in __GI___backtrace
+  //             at ../sysdeps/x86_64/../ia64/backtrace.c:104
+  // #20 0x0000000000752a54 in base::debug::StackTrace::StackTrace
+  //             at base/debug/stack_trace_posix.cc:175
+  // #21 0x00000000007a4ae5 in
+  //             base::(anonymous namespace)::StackDumpSignalHandler
+  //             at base/process_util_posix.cc:172
+  // #22 <signal handler called>
+  StackTrace stack_trace;
+}
+
+}  // namespace
+
+bool EnableInProcessStackDumping() {
+  // When running in an application, our code typically expects SIGPIPE
+  // to be ignored.  Therefore, when testing that same code, it should run
+  // with SIGPIPE ignored as well.
+  struct sigaction sigpipe_action;
+  memset(&sigpipe_action, 0, sizeof(sigpipe_action));
+  sigpipe_action.sa_handler = SIG_IGN;
+  sigemptyset(&sigpipe_action.sa_mask);
+  bool success = (sigaction(SIGPIPE, &sigpipe_action, NULL) == 0);
+
+  // Avoid hangs during backtrace initialization, see above.
+  WarmUpBacktrace();
+
+  struct sigaction action;
+  memset(&action, 0, sizeof(action));
+  action.sa_flags = SA_RESETHAND | SA_SIGINFO;
+  action.sa_sigaction = &StackDumpSignalHandler;
+  sigemptyset(&action.sa_mask);
+
+  success &= (sigaction(SIGILL, &action, NULL) == 0);
+  success &= (sigaction(SIGABRT, &action, NULL) == 0);
+  success &= (sigaction(SIGFPE, &action, NULL) == 0);
+  success &= (sigaction(SIGBUS, &action, NULL) == 0);
+  success &= (sigaction(SIGSEGV, &action, NULL) == 0);
+  success &= (sigaction(SIGSYS, &action, NULL) == 0);
+
+  dump_stack_in_signal_handler = true;
+
+  return success;
+}
+
+void DisableSignalStackDump() {
+  dump_stack_in_signal_handler = false;
+}
+
+StackTrace::StackTrace() {
+  // NOTE: This code MUST be async-signal safe (it's used by in-process
+  // stack dumping signal handler). NO malloc or stdio is allowed here.
+
+  // Though the backtrace API man page does not list any possible negative
+  // return values, we take no chance.
+  count_ = static_cast<size_t>(backtrace(trace_, arraysize(trace_)));
+}
+
+void StackTrace::Print() const {
+  // NOTE: This code MUST be async-signal safe (it's used by in-process
+  // stack dumping signal handler). NO malloc or stdio is allowed here.
+
+  PrintBacktraceOutputHandler handler;
+  ProcessBacktrace(trace_, count_, &handler);
+}
+
+void StackTrace::OutputToStream(std::ostream* os) const {
+  StreamBacktraceOutputHandler handler(os);
+  ProcessBacktrace(trace_, count_, &handler);
+}
+
+namespace internal {
+
+// NOTE: code from sandbox/linux/seccomp-bpf/demo.cc.
+char* itoa_r(intptr_t i, char* buf, size_t sz, int base, size_t padding) {
+  // Make sure we can write at least one NUL byte.
+  size_t n = 1;
+  if (n > sz) return NULL;
+
+  if (base < 2 || base > 16) {
+    buf[0] = '\000';
+    return NULL;
+  }
+
+  char* start = buf;
+
+  uintptr_t j = i;
+
+  // Handle negative numbers (only for base 10).
+  if (i < 0 && base == 10) {
+    // This does "j = -i" while avoiding integer overflow.
+    j = static_cast<uintptr_t>(-(i + 1)) + 1;
+
+    // Make sure we can write the '-' character.
+    if (++n > sz) {
+      buf[0] = '\000';
+      return NULL;
+    }
+    *start++ = '-';
+  }
+
+  // Loop until we have converted the entire number. Output at least one
+  // character (i.e. '0').
+  char* ptr = start;
+  do {
+    // Make sure there is still enough space left in our output buffer.
+    if (++n > sz) {
+      buf[0] = '\000';
+      return NULL;
+    }
+
+    // Output the next digit.
+    *ptr++ = "0123456789abcdef"[j % base];
+    j /= base;
+
+    if (padding > 0) padding--;
+  } while (j > 0 || padding > 0);
+
+  // Terminate the output with a NUL character.
+  *ptr = '\000';
+
+  // Conversion to ASCII actually resulted in the digits being in reverse
+  // order. We can't easily generate them in forward order, as we can't tell
+  // the number of characters needed until we are done converting.
+  // So, now, we reverse the string (except for the possible "-" sign).
+  while (--ptr > start) {
+    char ch = *ptr;
+    *ptr = *start;
+    *start++ = ch;
+  }
+  return buf;
+}
+
+}  // namespace internal
+
+}  // namespace debug
+}  // namespace base
+}  // namespace v8