FindGTest: Teach GTEST_ADD_TESTS about TEST_P

Previously the GTEST_ADD_TESTS function would miss parameterized tests
because it only considered TEST and TEST_F.  Add TEST_P to the list of
considered tests and will run all instantiations of this parameterized
test together.

This is perhaps not as correct as searching for all instantiations of
this parameterized test and separating those into separate runs, but
this will at least run tests that were previously missing.

For reference: https://code.google.com/p/googletest/wiki/Documentation

Modules/FindGTest.cmake

@@ -115,11 +115,19 @@ function(GTEST_ADD_TESTS executable extra_args)
         # obtain sources used for building that executable
         get_property(ARGN TARGET ${executable} PROPERTY SOURCES)
     endif()
+    set(gtest_case_name_regex ".*\\( *([A-Za-z_0-9]+), *([A-Za-z_0-9]+) *\\).*")
     foreach(source ${ARGN})
         file(READ "${source}" contents)
-        string(REGEX MATCHALL "TEST_?F?\\(([A-Za-z_0-9 ,]+)\\)" found_tests ${contents})
+        string(REGEX MATCHALL "TEST_?[FP]?\\(([A-Za-z_0-9 ,]+)\\)" found_tests ${contents})
         foreach(hit ${found_tests})
-            string(REGEX REPLACE ".*\\( *([A-Za-z_0-9]+), *([A-Za-z_0-9]+) *\\).*" "\\1.\\2" test_name ${hit})
+            string(REGEX MATCH "TEST_?[FP]?" test_type ${hit})
+
+            # Parameterized tests have a different signature for the filter
+            if(${test_type} STREQUAL "TEST_P")
+                string(REGEX REPLACE ${gtest_case_name_regex}  "*/\\1.\\2/*" test_name ${hit})
+            else()
+                string(REGEX REPLACE ${gtest_case_name_regex} "\\1.\\2" test_name ${hit})
+            endif()
             add_test(${test_name} ${executable} --gtest_filter=${test_name} ${extra_args})
         endforeach()
     endforeach()