Make sure DCHECK compiles out completely if DCHECKS aren't enabled.

base/logging.h

Index: base/logging.h
diff --git a/base/logging.h b/base/logging.h
index 7854e3934e974b4670930d6855f3ab8699a8376f..e75a195e177855c37ab0871209d2454a2312f79b 100644
--- a/base/logging.h
+++ b/base/logging.h
@@ -728,13 +728,21 @@ const LogSeverity LOG_DCHECK = LOG_INFO;
 
 #else  // _PREFAST_
 
-#define DCHECK(condition)                                                \
-  LAZY_STREAM(LOG_STREAM(DCHECK), DCHECK_IS_ON() ? !(condition) : false) \
-      << "Check failed: " #condition ". "
+#if DCHECK_IS_ON()
 
-#define DPCHECK(condition)                                                \
-  LAZY_STREAM(PLOG_STREAM(DCHECK), DCHECK_IS_ON() ? !(condition) : false) \
+#define DCHECK(condition)                       \
+  LAZY_STREAM(LOG_STREAM(DCHECK), !(condition)) \
       << "Check failed: " #condition ". "
+#define DPCHECK(condition)                       \
+  LAZY_STREAM(PLOG_STREAM(DCHECK), !(condition)) \
+      << "Check failed: " #condition ". "
+
+#else  // DCHECK_IS_ON()
+
+#define DCHECK(condition) EAT_STREAM_PARAMETERS << !(condition)

[scottmg, 2017/01/24 21:25:58]

!'ing condition seems a bit odd here.

+#define DPCHECK(condition) EAT_STREAM_PARAMETERS << !(condition)
+
+#endif  // DCHECK_IS_ON()
 
 #endif  // _PREFAST_
 
@@ -744,6 +752,8 @@ const LogSeverity LOG_DCHECK = LOG_INFO;
 // macro is used in an 'if' clause such as:
 // if (a == 1)
 //   DCHECK_EQ(2, a);
+#if DCHECK_IS_ON()
+
 #define DCHECK_OP(name, op, val1, val2)                                \
   switch (0) case 0: default:                                          \
   if (::logging::CheckOpResult true_if_passed =                        \
@@ -755,6 +765,13 @@ const LogSeverity LOG_DCHECK = LOG_INFO;
     ::logging::LogMessage(__FILE__, __LINE__, ::logging::LOG_DCHECK,   \
                           true_if_passed.message()).stream()
 
+#else
+
+#define DCHECK_OP(name, op, val1, val2) \
+  EAT_STREAM_PARAMETERS << ((val1)op(val2))
+
+#endif
+
 // Equality/Inequality checks - compare two values, and log a
 // LOG_DCHECK message including the two values when the result is not
 // as expected.  The values must have operator<<(ostream, ...)