Implement Dump-on-DCHECK (via a new LogSeverity).

base/logging.cc

 // 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.
 
 #include "base/logging.h"
 
 #include <limits.h>
 #include <stdint.h>
 
 #include "base/debug/activity_tracker.h"
@@ skipping 39 matching lines @@
 #include <cstring>
 #include <ctime>
 #include <iomanip>
 #include <ostream>
 #include <string>
 
 #include "base/base_switches.h"
 #include "base/command_line.h"
 #include "base/debug/alias.h"
 #include "base/debug/debugger.h"
+#include "base/debug/dump_without_crashing.h"
 #include "base/debug/stack_trace.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/strings/string_piece.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/synchronization/lock_impl.h"
 #include "base/threading/platform_thread.h"
 #include "base/vlog.h"
@@ skipping 46 matching lines @@
 bool g_log_thread_id = false;
 bool g_log_timestamp = true;
 bool g_log_tickcount = false;
 
 // Should we pop up fatal debug messages in a dialog?
 bool show_error_dialogs = false;
 
 // An assert handler override specified by the client to be called instead of
 // the debug message dialog and process termination.
 LogAssertHandlerFunction log_assert_handler = nullptr;
+
 // A log message handler that gets notified of every log message we process.
 LogMessageHandlerFunction log_message_handler = nullptr;
 
 // Helper functions to wrap platform differences.
 
 int32_t CurrentProcessId() {
 #if defined(OS_WIN)
   return GetCurrentProcessId();
 #elif defined(OS_POSIX)
   return getpid();
@@ skipping 583 matching lines @@
                 &num_written,
                 nullptr);
 #else
       ignore_result(fwrite(
           str_newline.data(), str_newline.size(), 1, g_log_file));
       fflush(g_log_file);
 #endif
     }
   }
 
-  if (severity_ == LOG_FATAL) {
+  if (severity_ == LOG_FATAL || severity_ == LOG_DUMP) {
     // Write the log message to the global activity tracker, if running.
     base::debug::GlobalActivityTracker* tracker =
         base::debug::GlobalActivityTracker::Get();
     if (tracker)
       tracker->RecordLogMessage(str_newline);
 
     // Ensure the first characters of the string are on the stack so they
     // are contained in minidumps for diagnostic purposes.
     char str_stack[1024];
     str_newline.copy(str_stack, arraysize(str_stack));
     base::debug::Alias(str_stack);
 
-    if (log_assert_handler) {
+    if (severity_ == LOG_DUMP) {

[Wez, 2016/12/19 23:57:46]

Q: Is it more or less readable to have LOG_DUMP implemented in the middle of the
LOG_FATAL code like this?

+      // To ensure we don't risk spamming Crash with dump-on-DCHECK reports we
+      // log
+      // only the first[*] DCHECK to fail once DumpWithoutCrashing() is working.
+      // [*] This is racey, but in the pathological case still only results in
+      // one
+      // dump per-racing-thread, rather than our aim of one per-process.

[Wez, 2016/12/19 23:57:46]

Note to self: Fix comment line-wrap.

+      static bool dump_on_dcheck = true;
+      if (dump_on_dcheck)
+        dump_on_dcheck = !base::debug::DumpWithoutCrashing();
+      return;
+    }
+
+
+    else if (log_assert_handler) {
       // Make a copy of the string for the handler out of paranoia.
       log_assert_handler(std::string(stream_.str()));
     } else {
       // Don't use the string with the newline, get a fresh version to send to
       // the debug message process. We also don't display assertions to the
       // user in release mode. The enduser can't do anything with this
       // information, and displaying message boxes when the application is
       // hosed can cause additional problems.
 #ifndef NDEBUG
       if (!base::debug::BeingDebugged()) {
@@ skipping 194 matching lines @@
 BASE_EXPORT void LogErrorNotReached(const char* file, int line) {
   LogMessage(file, line, LOG_ERROR).stream()
       << "NOTREACHED() hit.";
 }
 
 }  // namespace logging
 
 std::ostream& std::operator<<(std::ostream& out, const wchar_t* wstr) {
   return out << (wstr ? base::WideToUTF8(wstr) : std::string());
 }