add coverage target in cmake

CMakeLists.txt

@@ -16,6 +16,7 @@ STRING (REGEX MATCH "#define MSGPACK_VERSION_REVISION *([0-9a-zA-Z_]*)" NULL_OUT
 SET (VERSION_REVISION ${CMAKE_MATCH_1})
 SET (VERSION ${VERSION_MAJOR}.${VERSION_MINOR}.${VERSION_REVISION})
 
+LIST (APPEND CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake/")
 SET (prefix ${CMAKE_INSTALL_PREFIX})
 SET (exec_prefix "\${prefix}")
 SET (libdir "\${exec_prefix}/lib")
@@ -152,6 +153,7 @@ FIND_PACKAGE (ZLIB)
 FIND_PACKAGE (Threads)
 IF (GTEST_FOUND AND ZLIB_FOUND AND THREADS_FOUND AND NOT "${MSGPACK_FUZZ_REGRESSION}" STREQUAL "ON")
     OPTION (MSGPACK_BUILD_TESTS "Build msgpack tests." ON)
+    OPTION (MSGPACK_GEN_COVERAGE "Enable running gcov to get a test coverage report." OFF)
 ENDIF ()
 
 IF (DEFINED BUILD_SHARED_LIBS)
@@ -277,6 +279,21 @@ IF ("${MSGPACK_FUZZ_REGRESSION}" STREQUAL "ON" AND "${CMAKE_CXX_COMPILER_ID}" ST
    SET (MSGPACK_BUILD_EXAMPLES OFF)
 ENDIF ()
 
+IF (MSGPACK_GEN_COVERAGE)
+    IF (NOT MSGPACK_BUILD_TESTS)
+        MESSAGE(FATAL_ERROR "Coverage requires -DMSGPACK_BUILD_TESTS=ON")
+    ENDIF ()
+    STRING(TOUPPER "${CMAKE_BUILD_TYPE}" UPPER_CMAKE_BUILD_TYPE)
+    IF (NOT "${UPPER_CMAKE_BUILD_TYPE}" STREQUAL "DEBUG")
+        MESSAGE(FATAL_ERROR "Coverage requires -DCMAKE_BUILD_TYPE=Debug")
+    ENDIF ()
+
+    INCLUDE(CodeCoverage)
+    SET (CMAKE_C_FLAGS   "${CMAKE_C_FLAGS} ${COVERAGE_FLAGS}")
+    SET (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${COVERAGE_FLAGS}")
+
+    SETUP_TARGET_FOR_COVERAGE(coverage make coverage test)
+ENDIF ()
 
 IF (MSGPACK_BUILD_TESTS)
     ENABLE_TESTING ()

cmake/CodeCoverage.cmake

@@ -0,0 +1,55 @@
+# Check prereqs
+FIND_PROGRAM(GCOV_PATH gcov)
+FIND_PROGRAM(LCOV_PATH lcov)
+FIND_PROGRAM(GENHTML_PATH genhtml)
+
+IF(NOT GCOV_PATH)
+	MESSAGE(FATAL_ERROR "gcov not found! Aborting...")
+ENDIF()
+
+IF(NOT CMAKE_COMPILER_IS_GNUCC)
+	# Clang version 3.0.0 and greater now supports gcov as well.
+	MESSAGE(STATUS "Compiler is not GNU gcc! Clang Version 3.0.0 and greater supports gcov as well, but older versions don't.")
+	IF(NOT "${CMAKE_C_COMPILER_ID}" STREQUAL "Clang" AND NOT "${CMAKE_C_COMPILER_ID}" STREQUAL "AppleClang")
+		MESSAGE(FATAL_ERROR "Compiler is not GNU gcc! Aborting...")
+	ENDIF()
+ENDIF()
+
+SET(COVERAGE_FLAGS "-g -O0 --coverage")
+
+FUNCTION(SETUP_TARGET_FOR_COVERAGE _targetname _testrunner _outputname)
+
+	IF(NOT LCOV_PATH)
+		MESSAGE(FATAL_ERROR "lcov not found! Aborting...")
+	ENDIF()
+
+	IF(NOT GENHTML_PATH)
+		MESSAGE(FATAL_ERROR "genhtml not found! Aborting...")
+	ENDIF()
+
+	# Setup target
+	ADD_CUSTOM_TARGET(${_targetname}
+
+		# Cleanup lcov
+		${LCOV_PATH} --directory . --zerocounters
+
+		# Run tests
+		COMMAND ${_testrunner} ${ARGV3}
+
+		# Capturing lcov counters and generating report
+		COMMAND ${LCOV_PATH} --directory . --capture --output-file ${_outputname}.info --base-directory ${CMAKE_SOURCE_DIR} --no-external --quiet
+		COMMAND ${LCOV_PATH} --remove ${_outputname}.info '*/test/*' '*/fuzz/*' --output-file ${_outputname}.info.cleaned --quiet
+		COMMAND ${GENHTML_PATH} -o ${_outputname} ${_outputname}.info.cleaned --prefix ${CMAKE_SOURCE_DIR}
+		# COMMAND ${CMAKE_COMMAND} -E remove ${_outputname}.info ${_outputname}.info.cleaned
+
+		WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
+		COMMENT "Resetting code coverage counters to zero.\nProcessing code coverage counters and generating report."
+	)
+
+	# Show info where to find the report
+	ADD_CUSTOM_COMMAND(TARGET ${_targetname} POST_BUILD
+		COMMAND ;
+		COMMENT "Open ./${_outputname}/index.html in your browser to view the coverage report."
+	)
+
+ENDFUNCTION()