Coverage support with LCOV and GCOV

.gitignore

@@ -10,6 +10,10 @@
 *.pyc
 __pycache__
 
+# lcov
+*.lcov
+/lcov
+
 # cmake files.
 /Testing
 CMakeCache.txt

CMakeLists.txt

@@ -64,6 +64,27 @@ if (BENCHMARK_ENABLE_LTO)
   endif()
 endif()
 
+# Coverage build type
+set(CMAKE_CXX_FLAGS_COVERAGE "${CMAKE_CXX_FLAGS_DEBUG}" CACHE STRING
+  "Flags used by the C++ compiler during coverage builds."
+  FORCE)
+set(CMAKE_EXE_LINKER_FLAGS_COVERAGE
+  "${CMAKE_EXE_LINKER_FLAGS_DEBUG}" CACHE STRING
+  "Flags used for linking binaries during coverage builds."
+  FORCE)
+set(CMAKE_SHARED_LINKER_FLAGS_COVERAGE
+  "${CMAKE_SHARED_LINKER_FLAGS_DEBUG}" CACHE STRING
+  "Flags used by the shared libraries linker during coverage builds."
+  FORCE)
+mark_as_advanced(
+  CMAKE_CXX_FLAGS_COVERAGE
+  CMAKE_EXE_LINKER_FLAGS_COVERAGE
+  CMAKE_SHARED_LINKER_FLAGS_COVERAGE)
+set(CMAKE_BUILD_TYPE "${CMAKE_BUILD_TYPE}" CACHE STRING
+  "Choose the type of build, options are: None Debug Release RelWithDebInfo MinSizeRel Coverage."
+  FORCE)
+add_cxx_compiler_flag(--coverage COVERAGE)
+
 # C++ feature checks
 cxx_feature_check(STD_REGEX)
 cxx_feature_check(GNU_POSIX_REGEX)

test/CMakeLists.txt

@@ -43,3 +43,45 @@ compile_benchmark_test(cxx03_test)
 set_target_properties(cxx03_test
     PROPERTIES COMPILE_FLAGS "${CXX03_FLAGS}")
 add_test(cxx03 cxx03_test --benchmark_min_time=0.01)
+
+# Add the coverage command(s)
+string(TOLOWER ${CMAKE_BUILD_TYPE} CMAKE_BUILD_TYPE_LOWER)
+if (${CMAKE_BUILD_TYPE_LOWER} MATCHES "coverage")
+  find_program(GCOV gcov)
+  find_program(LCOV lcov)
+  find_program(GENHTML genhtml)
+  find_program(CTEST ctest)
+  if (GCOV AND LCOV AND GENHTML AND CTEST AND HAVE_CXX_FLAG_COVERAGE)
+    add_custom_command(
+      OUTPUT ${CMAKE_BINARY_DIR}/lcov/index.html
+      COMMAND ${LCOV} -q -z -d .
+      COMMAND ${LCOV} -q --no-external -c -b "${CMAKE_SOURCE_DIR}" -d . -o before.lcov -i
+      COMMAND ${CTEST} --force-new-ctest-process
+      COMMAND ${LCOV} -q --no-external -c -b "${CMAKE_SOURCE_DIR}" -d . -o after.lcov
+      COMMAND ${LCOV} -q -a before.lcov -a after.lcov --output-file final.lcov
+      COMMAND ${LCOV} -q -r final.lcov "'${CMAKE_SOURCE_DIR}/test/*'" -o final.lcov
+      COMMAND ${GENHTML} final.lcov -o lcov --demangle-cpp --sort -p "${CMAKE_BINARY_DIR}" -t benchmark
+      DEPENDS filter_test benchmark_test options_test basic_test fixture_test cxx03_test
+      WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
+      COMMENT "Running LCOV"
+    )
+    add_custom_target(coverage
+      DEPENDS ${CMAKE_BINARY_DIR}/lcov/index.html
+      COMMENT "LCOV report at lcov/index.html"
+    )
+    message(STATUS "Coverage command added")
+  else()
+    if (HAVE_CXX_FLAG_COVERAGE)
+      set(CXX_FLAG_COVERAGE_MESSAGE supported)
+    else()
+      set(CXX_FLAG_COVERAGE_MESSAGE unavailable)
+    endif()
+    message(WARNING
+      "Coverage not available:\n"
+      "  gcov: ${GCOV}\n"
+      "  lcov: ${LCOV}\n"
+      "  genhtml: ${GENHTML}\n"
+      "  ctest: ${CTEST}\n"
+      "  --coverage flag: ${CXX_FLAG_COVERAGE_MESSAGE}")
+  endif()
+endif()