Prints a useful message when GetParam() is called in a non-parameterized test.

include/gtest/gtest.h

@@ -1755,7 +1755,12 @@ class WithParamInterface {
   // references static data, to reduce the opportunity for incorrect uses
   // like writing 'WithParamInterface<bool>::GetParam()' for a test that
   // uses a fixture whose parameter type is int.
-  const ParamType& GetParam() const { return *parameter_; }
+  const ParamType& GetParam() const {
+    GTEST_CHECK_(parameter_ != NULL)
+        << "GetParam() can only be called inside a value-parameterized test "
+        << "-- did you intend to write TEST_P instead of TEST_F?";
+    return *parameter_;
+  }
 
  private:
   // Sets parameter value. The caller is responsible for making sure the value

test/gtest-param-test_test.cc

@@ -865,6 +865,13 @@ TEST_P(ParameterizedDerivedTest, SeesSequence) {
   EXPECT_EQ(GetParam(), global_count_++);
 }
 
+class ParameterizedDeathTest : public ::testing::TestWithParam<int> { };
+
+TEST_F(ParameterizedDeathTest, GetParamDiesFromTestF) {
+  EXPECT_DEATH_IF_SUPPORTED(GetParam(),
+                            ".* value-parameterized test .*");
+}
+
 INSTANTIATE_TEST_CASE_P(RangeZeroToFive, ParameterizedDerivedTest, Range(0, 5));
 
 #endif  // GTEST_HAS_PARAM_TEST