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

base/logging.h

 // 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.
 
 #ifndef BASE_LOGGING_H_
 #define BASE_LOGGING_H_
 
 #include <stddef.h>
 
 #include <cassert>
@@ skipping 279 matching lines @@
 BASE_EXPORT LogMessageHandlerFunction GetLogMessageHandler();
 
 typedef int LogSeverity;
 const LogSeverity LOG_VERBOSE = -1;  // This is level 1 verbosity
 // Note: the log severities are used to index into the array of names,
 // see log_severity_names.
 const LogSeverity LOG_INFO = 0;
 const LogSeverity LOG_WARNING = 1;
 const LogSeverity LOG_ERROR = 2;
 const LogSeverity LOG_FATAL = 3;
-const LogSeverity LOG_NUM_SEVERITIES = 4;
+const LogSeverity LOG_DUMP = 4;

[Wez, 2017/01/15 01:18:42]

gab, danakj: I'm concerned about adding this new LogSeverity, and expect that
there will be a load of sites that don't handle the new value (which should be
treated similarly to LOG_FATAL or LOG_ERROR in most cases).

How would you feel about moving the non-verbose log severities into an enum, so
that most call-sites can continue to use the integer form, but call-sites which
expect a non-verbose severity and switch based on it can be made checked more
easily?

+const LogSeverity LOG_NUM_SEVERITIES = 5;
 
 // LOG_DFATAL is LOG_FATAL in debug mode, ERROR in normal mode
-#ifdef NDEBUG
+#if defined(DCHECK_IS_DUMP_WITHOUT_CRASH)
+const LogSeverity LOG_DFATAL = LOG_DUMP;
+#elif NDEBUG
 const LogSeverity LOG_DFATAL = LOG_ERROR;
 #else
 const LogSeverity LOG_DFATAL = LOG_FATAL;
 #endif
 
 // A few definitions of macros that don't generate much code. These are used
 // by LOG() and LOG_IF, etc. Since these are used all over our code, it's
 // better to have compact code for these operations.
 #define COMPACT_GOOGLE_LOG_EX_INFO(ClassName, ...) \
   ::logging::ClassName(__FILE__, __LINE__, ::logging::LOG_INFO, ##__VA_ARGS__)
@@ skipping 373 matching lines @@
 
 #define DVLOG(verboselevel) DVLOG_IF(verboselevel, VLOG_IS_ON(verboselevel))
 
 #define DVPLOG(verboselevel) DVPLOG_IF(verboselevel, VLOG_IS_ON(verboselevel))
 
 // Definitions for DCHECK et al.
 
 #if DCHECK_IS_ON()
 
 #define COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName, ...) \
-  COMPACT_GOOGLE_LOG_EX_FATAL(ClassName , ##__VA_ARGS__)
-#define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_FATAL
-const LogSeverity LOG_DCHECK = LOG_FATAL;
+  COMPACT_GOOGLE_LOG_EX_DFATAL(ClassName, ##__VA_ARGS__)
+#define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_DFATAL
+const LogSeverity LOG_DCHECK = LOG_DFATAL;
 
 #else  // DCHECK_IS_ON()
 
 // These are just dummy values.
 #define COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName, ...) \
   COMPACT_GOOGLE_LOG_EX_INFO(ClassName , ##__VA_ARGS__)
 #define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_INFO
 const LogSeverity LOG_DCHECK = LOG_INFO;
 
 #endif  // DCHECK_IS_ON()
@@ skipping 308 matching lines @@
 #elif NOTIMPLEMENTED_POLICY == 5
 #define NOTIMPLEMENTED() do {\
   static bool logged_once = false;\
   LOG_IF(ERROR, !logged_once) << NOTIMPLEMENTED_MSG;\
   logged_once = true;\
 } while(0);\
 EAT_STREAM_PARAMETERS
 #endif
 
 #endif  // BASE_LOGGING_H_