#################################################################

# Adds a build target called "coverage" for code coverage.

#

# This compiles the code using special GCC flags, run the tests,

# and then generates a nice HTML output. This new "coverage" make

# target will only be available if you build using GCC in Debug

# mode. If any of the required programs (lcov and genhtml) were

# not found, a FATAL_ERROR message is printed.

#

# If not already done, this code will set ENABLE_TEST to ON.

#

# To build the code coverage and open it in your browser do this:

#

#    mkdir debug

#    cd debug

#    cmake -DCMAKE_BUILD_TYPE=Debug -DENABLE_COVERAGE=ON ..

#    make -j4

#    make coverage

#    xdg-open coverage/index.html

#################################################################

# Find programs we need 

FIND_PROGRAM(LCOV_EXECUTABLE lcov DOC "Full path to lcov executable")

FIND_PROGRAM(GENHTML_EXECUTABLE genhtml DOC "Full path to genhtml executable")

MARK_AS_ADVANCED(LCOV_EXECUTABLE GENHTML_EXECUTABLE)

# Check, compiler, build types and programs are available

IF(NOT CMAKE_COMPILER_IS_GNUCC)

MESSAGE(FATAL_ERROR "Coverage can only be built on GCC")

ELSEIF(NOT CMAKE_BUILD_TYPE STREQUAL "Debug")

MESSAGE(FATAL_ERROR "Coverage can only be built in Debug mode")

ELSEIF(NOT LCOV_EXECUTABLE)

MESSAGE(FATAL_ERROR "lcov executable not found")

ELSEIF(NOT GENHTML_EXECUTABLE)

MESSAGE(FATAL_ERROR "genhtml executable not found")

ENDIF(NOT CMAKE_COMPILER_IS_GNUCC)

# Enable testing if not already done

SET(ENABLE_TEST ON)

#################################################################

# Set special compiler and linker flags for test coverage

#################################################################

# 0. Enable debug: -g

SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g")

# 1. Disable optimizations: -O0

SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O0")

# 2. Enable all kind of warnings:

SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -W")

# 3. Enable special coverage flag (HINT: --coverage is a synonym for -fprofile-arcs -ftest-coverage)

SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} --coverage")

SET(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} --coverage")

SET(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} --coverage")

#################################################################

ADD_CUSTOM_TARGET(coverage

COMMAND ${CMAKE_COMMAND} -E echo "Beginning test coverage. Output is written to coverage.log."

COMMAND ${CMAKE_COMMAND} -E echo "COVERAGE-STEP-1/5: Reset all execution counts to zero"

COMMAND ${LCOV_EXECUTABLE} --directory . --zerocounters > coverage.log 2>&1

COMMAND ${CMAKE_COMMAND} -E echo "COVERAGE-STEP-2/5: Run testrunner"

COMMAND ${CMAKE_CTEST_COMMAND} >> coverage.log 2>&1

COMMAND ${CMAKE_COMMAND} -E echo "COVERAGE-STEP-3/5: Collect coverage data"

COMMAND ${LCOV_EXECUTABLE} --capture --directory . --output-file "./coverage.info" >> coverage.log 2>&1

COMMAND ${CMAKE_COMMAND} -E echo "COVERAGE-STEP-4/5: Generate HTML from coverage data"

COMMAND ${GENHTML_EXECUTABLE} "coverage.info" --title="libarchive-${LIBARCHIVE_VERSION_STRING}" --show-details --legend --output-directory "./coverage"  >> coverage.log 2>&1

COMMAND ${CMAKE_COMMAND} -E echo "COVERAGE-STEP-5/5: Open test coverage HTML output in browser: xdg-open ./coverage/index.html"

COMMENT "Runs testrunner and generates coverage output (formats: .info and .html)")