Fixes GCC 4.6 warnings (patch by Jeffrey Yasskin).

include/gtest/gtest-typed-test.h

@@ -175,7 +175,7 @@ INSTANTIATE_TYPED_TEST_CASE_P(My, FooTest, MyTypes);
     typedef gtest_TypeParam_ TypeParam; \
     virtual void TestBody(); \
   }; \
-  bool gtest_##CaseName##_##TestName##_registered_ = \
+  bool gtest_##CaseName##_##TestName##_registered_ GTEST_ATTRIBUTE_UNUSED_ = \
       ::testing::internal::TypeParameterizedTest< \
           CaseName, \
           ::testing::internal::TemplateSel< \
@@ -229,7 +229,7 @@ INSTANTIATE_TYPED_TEST_CASE_P(My, FooTest, MyTypes);
     typedef gtest_TypeParam_ TypeParam; \
     virtual void TestBody(); \
   }; \
-  static bool gtest_##TestName##_defined_ = \
+  static bool gtest_##TestName##_defined_ GTEST_ATTRIBUTE_UNUSED_ = \
       GTEST_TYPED_TEST_CASE_P_STATE_(CaseName).AddTestName(\
           __FILE__, __LINE__, #CaseName, #TestName); \
   } \
@@ -248,7 +248,7 @@ INSTANTIATE_TYPED_TEST_CASE_P(My, FooTest, MyTypes);
 // since some compilers may choke on '>>' when passing a template
 // instance (e.g. Types<int>)
 #define INSTANTIATE_TYPED_TEST_CASE_P(Prefix, CaseName, Types) \
-  bool gtest_##Prefix##_##CaseName = \
+  bool gtest_##Prefix##_##CaseName GTEST_ATTRIBUTE_UNUSED_ = \
       ::testing::internal::TypeParameterizedTestCase<CaseName, \
           GTEST_CASE_NAMESPACE_(CaseName)::gtest_AllTests_, \
           ::testing::internal::TypeList< Types >::type>::Register(\

include/gtest/gtest.h

@@ -1342,7 +1342,7 @@ class EqHelper {
 };
 
 // This specialization is used when the first argument to ASSERT_EQ()
-// is a null pointer literal.
+// is a null pointer literal, like NULL, false, or 0.
 template <>
 class EqHelper<true> {
  public:
@@ -1351,24 +1351,38 @@ class EqHelper<true> {
   // NOT a pointer, e.g. ASSERT_EQ(0, AnIntFunction()) or
   // EXPECT_EQ(false, a_bool).
   template <typename T1, typename T2>
-  static AssertionResult Compare(const char* expected_expression,
-                                 const char* actual_expression,
-                                 const T1& expected,
-                                 const T2& actual) {
+  static AssertionResult Compare(
+      const char* expected_expression,
+      const char* actual_expression,
+      const T1& expected,
+      const T2& actual,
+      // The following line prevents this overload from being considered if T2
+      // is not a pointer type.  We need this because ASSERT_EQ(NULL, my_ptr)
+      // expands to Compare("", "", NULL, my_ptr), which requires a conversion
+      // to match the Secret* in the other overload, which would otherwise make
+      // this template match better.
+      typename EnableIf<!is_pointer<T2>::value>::type* = 0) {
     return CmpHelperEQ(expected_expression, actual_expression, expected,
                        actual);
   }
 
-  // This version will be picked when the second argument to
-  // ASSERT_EQ() is a pointer, e.g. ASSERT_EQ(NULL, a_pointer).
-  template <typename T1, typename T2>
-  static AssertionResult Compare(const char* expected_expression,
-                                 const char* actual_expression,
-                                 const T1& /* expected */,
-                                 T2* actual) {
+  // This version will be picked when the second argument to ASSERT_EQ() is a
+  // pointer, e.g. ASSERT_EQ(NULL, a_pointer).
+  template <typename T>
+  static AssertionResult Compare(
+      const char* expected_expression,
+      const char* actual_expression,
+      // We used to have a second template parameter instead of Secret*.  That
+      // template parameter would deduce to 'long', making this a better match
+      // than the first overload even without the first overload's EnableIf.
+      // Unfortunately, gcc with -Wconversion-null warns when "passing NULL to
+      // non-pointer argument" (even a deduced integral argument), so the old
+      // implementation caused warnings in user code.
+      Secret* /* expected (NULL) */,
+      T* actual) {
     // We already know that 'expected' is a null pointer.
     return CmpHelperEQ(expected_expression, actual_expression,
-                       static_cast<T2*>(NULL), actual);
+                       static_cast<T*>(NULL), actual);
   }
 };
 

include/gtest/internal/gtest-internal.h

@@ -919,6 +919,13 @@ typedef char IsNotContainer;
 template <class C>
 IsNotContainer IsContainerTest(...) { return '\0'; }
 
+// EnableIf<condition>::type is void when 'Cond' is true, and
+// undefined when 'Cond' is false.  To use SFINAE to make a function
+// overload only apply when a particular expression is true, add
+// "typename EnableIf<expression>::type* = 0" as the last parameter.
+template<bool> struct EnableIf;
+template<> struct EnableIf<true> { typedef void type; };  // NOLINT
+
 // Utilities for native arrays.
 
 // ArrayEq() compares two k-dimensional native arrays using the
@@ -1182,7 +1189,7 @@ class GTEST_TEST_CLASS_NAME_(test_case_name, test_name) : public parent_class {\
   GTEST_TEST_CLASS_NAME_(test_case_name, test_name)() {}\
  private:\
   virtual void TestBody();\
-  static ::testing::TestInfo* const test_info_;\
+  static ::testing::TestInfo* const test_info_ GTEST_ATTRIBUTE_UNUSED_;\
   GTEST_DISALLOW_COPY_AND_ASSIGN_(\
       GTEST_TEST_CLASS_NAME_(test_case_name, test_name));\
 };\