Use universal references in templated analysis passthrough functions.

base/logging.h

Index: base/logging.h
diff --git a/base/logging.h b/base/logging.h
index c0ebaf92bd3da3da67fa467cea0399542790debd..329e113a3436b62d0f2e900d5608f7d9169b8003 100644
--- a/base/logging.h
+++ b/base/logging.h
@@ -298,8 +298,10 @@ BASE_EXPORT LogMessageHandlerFunction GetLogMessageHandler();
 
 inline void AnalyzerNoReturn() __attribute__((analyzer_noreturn)) {}
 
+// An rvalue parameter is used because it allows both lvalue and rvalue forms of

[danakj, 2017/02/14 20:09:16]

This isn't an rvalue parameter actually, because TVal is a templated type. It's
a universal reference and can bind to an lvalue ref or rvalue ref.

[Kevin M, 2017/02/14 21:05:09]

Updated the comments.

+// |arg| to be passed as arguments.
 template <typename TVal>
-inline constexpr TVal AnalysisAssumeTrue(TVal arg) {
+inline constexpr TVal AnalysisAssumeTrue(TVal&& arg) {
   if (!arg) {
     AnalyzerNoReturn();
   }
@@ -310,8 +312,10 @@ inline constexpr TVal AnalysisAssumeTrue(TVal arg) {
 
 #elif defined(_PREFAST_) && defined(OS_WIN)
 
+// An rvalue parameter is used because it allows both lvalue and rvalue forms of
+// |arg| to be passed as arguments.
 template <typename TVal>
-inline constexpr TVal AnalysisAssumeTrue(TVal arg) {
+inline constexpr TVal AnalysisAssumeTrue(TVal&& arg) {
   __analysis_assume(!!arg);
   return arg;
 }
@@ -628,16 +632,20 @@ std::string* MakeCheckOpString<std::string, std::string>(
 // The (int, int) specialization works around the issue that the compiler
 // will not instantiate the template version of the function on values of
 // unnamed enum type - see comment below.
-#define DEFINE_CHECK_OP_IMPL(name, op) \
-  template <class t1, class t2> \
-  inline std::string* Check##name##Impl(const t1& v1, const t2& v2, \
-                                        const char* names) { \
-    if (v1 op v2) return NULL; \
-    else return ::logging::MakeCheckOpString(v1, v2, names);    \
-  } \
+#define DEFINE_CHECK_OP_IMPL(name, op)                                       \
+  template <class t1, class t2>                                              \
+  inline std::string* Check##name##Impl(const t1& v1, const t2& v2,          \
+                                        const char* names) {                 \
+    if (ANALYZER_ASSUME_TRUE(v1 op v2))                                      \

[danakj, 2017/02/14 20:09:16]

I think this is a separate CL. Can you split this?

[Kevin M, 2017/02/14 21:05:09]

Done.

+      return NULL;                                                           \
+    else                                                                     \
+      return ::logging::MakeCheckOpString(v1, v2, names);                    \
+  }                                                                          \
   inline std::string* Check##name##Impl(int v1, int v2, const char* names) { \
-    if (v1 op v2) return NULL; \
-    else return ::logging::MakeCheckOpString(v1, v2, names);    \
+    if (ANALYZER_ASSUME_TRUE(v1 op v2))                                      \
+      return NULL;                                                           \
+    else                                                                     \
+      return ::logging::MakeCheckOpString(v1, v2, names);                    \
   }
 DEFINE_CHECK_OP_IMPL(EQ, ==)
 DEFINE_CHECK_OP_IMPL(NE, !=)