Add __analysis_assume support to CHECK macros to reduce warnings with /analyze.

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 <cassert>
 #include <string>
 #include <cstring>
@@ skipping 432 matching lines @@
 // into a macro (like __debugbreak() on Windows).
 #define CHECK(condition)                                                \
   !(condition) ? ::base::debug::BreakDebugger() : EAT_STREAM_PARAMETERS
 
 #define PCHECK(condition) CHECK(condition)
 
 #define CHECK_OP(name, op, val1, val2) CHECK((val1) op (val2))
 
 #else
 
+#if defined(_PREFAST_) && defined(OS_WIN)
+// Use __analysis_assume to tell the VC++ static analysis engine that
+// assert conditions are true, to suppress warnings.  The LAZY_STREAM
+// parameter doesn't reference 'condition' in /analyze builds because
+// this evaluation confuses /analyze. The !! before condition is because
+// __analysis_assume gets confused on some conditions:
+// http://randomascii.wordpress.com/2011/09/13/analyze-for-visual-studio-the-ugly-part-5/
+
+#define CHECK(condition)                \
+  __analysis_assume(!!(condition)),     \
+  LAZY_STREAM(LOG_STREAM(FATAL), false) \
+  << "Check failed: " #condition ". "
+
+#define PCHECK(condition)                \
+  __analysis_assume(!!(condition)),      \
+  LAZY_STREAM(PLOG_STREAM(FATAL), false) \
+  << "Check failed: " #condition ". "
+
+#else  // _PREFAST_
+
 #define CHECK(condition)                       \
   LAZY_STREAM(LOG_STREAM(FATAL), !(condition)) \
   << "Check failed: " #condition ". "
 
-#define PCHECK(condition) \
+#define PCHECK(condition)                       \
   LAZY_STREAM(PLOG_STREAM(FATAL), !(condition)) \
   << "Check failed: " #condition ". "
 
+#endif  // _PREFAST_
+
 // Helper macro for binary operators.
 // Don't use this macro directly in your code, use CHECK_EQ et al below.
 //
 // TODO(akalin): Rewrite this so that constructs like if (...)
 // CHECK_EQ(...) else { ... } work properly.
 #define CHECK_OP(name, op, val1, val2)                          \
   if (std::string* _result =                                    \
       logging::Check##name##Impl((val1), (val2),                \
                                  #val1 " " #op " " #val2))      \
     logging::LogMessage(__FILE__, __LINE__, _result).stream()
@@ skipping 138 matching lines @@
 #define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_INFO
 const LogSeverity LOG_DCHECK = LOG_INFO;
 
 #endif  // DCHECK_IS_ON
 
 // DCHECK et al. make sure to reference |condition| regardless of
 // whether DCHECKs are enabled; this is so that we don't get unused
 // variable warnings if the only use of a variable is in a DCHECK.
 // This behavior is different from DLOG_IF et al.
 
+#if defined(_PREFAST_) && defined(OS_WIN)
+// See comments on the previous use of __analysis_assume.
+
+#define DCHECK(condition)                                               \
+  __analysis_assume(!!(condition)),                                     \
+  LAZY_STREAM(LOG_STREAM(DCHECK), false)                                \
+  << "Check failed: " #condition ". "
+
+#define DPCHECK(condition)                                              \
+  __analysis_assume(!!(condition)),                                     \
+  LAZY_STREAM(PLOG_STREAM(DCHECK), false)                               \
+  << "Check failed: " #condition ". "
+
+#else  // _PREFAST_
+
 #define DCHECK(condition)                                               \
   LAZY_STREAM(LOG_STREAM(DCHECK), DCHECK_IS_ON ? !(condition) : false)  \
   << "Check failed: " #condition ". "
 
 #define DPCHECK(condition)                                              \
   LAZY_STREAM(PLOG_STREAM(DCHECK), DCHECK_IS_ON ? !(condition) : false) \
   << "Check failed: " #condition ". "
 
+#endif  // _PREFAST_
+
 // Helper macro for binary operators.
 // Don't use this macro directly in your code, use DCHECK_EQ et al below.
 #define DCHECK_OP(name, op, val1, val2)                         \
   if (DCHECK_IS_ON)                                             \
     if (std::string* _result =                                  \
         logging::Check##name##Impl((val1), (val2),              \
                                    #val1 " " #op " " #val2))    \
       logging::LogMessage(                                      \
           __FILE__, __LINE__, ::logging::LOG_DCHECK,            \
           _result).stream()
@@ skipping 252 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_