implement VLOG(x)

base/logging.cc

@@ -16,6 +16,8 @@
 
 #include "base/logging.h"
 
+DEFINE_int32(log_level, 0, "Log level (0 is the default).");
+
 namespace operations_research {
 DateLogger::DateLogger() {
 #if defined(_MSC_VER)

base/logging.h

@@ -17,8 +17,11 @@
 #include <assert.h>
 #include <stdlib.h>
 #include <iostream>  // NOLINT
+#include "base/commandlineflags.h"
 #include "base/macros.h"
 
+DECLARE_int32(log_level);
+
 // Debug-only checking.
 #define DCHECK(condition) assert(condition)
 #define DCHECK_EQ(val1, val2) assert((val1) == (val2))
@@ -45,7 +48,7 @@
 #define LOG_FATAL LogMessageFatal(__FILE__, __LINE__)
 #define LOG_QFATAL LOG_FATAL
 
-#define VLOG(x) if ((x) <= 0) LOG_INFO.stream()
+#define VLOG(x) if ((x) <= FLAGS_log_level) LOG_INFO.stream()
 
 #ifdef NDEBUG
 #define DEBUG_MODE 0