Findcodecov.cmake

# This file is part of CMake-codecov.
#
# Copyright (c) 2015-2020 RWTH Aachen University, Federal Republic of Germany
#
# See the LICENSE file in the package base directory for details
#
# Written by Alexander Haase, alexander.haase@rwth-aachen.de
#

# Add an option to choose, if coverage should be enabled or not. If enabled
# marked targets will be build with coverage support and appropriate targets
# will be added. If disabled coverage will be ignored for *ALL* targets.
option(ENABLE_COVERAGE "Enable coverage build." OFF)

set(COVERAGE_FLAG_CANDIDATES
    # gcc and clang
    "-O0 -g -fprofile-arcs -ftest-coverage"
    # gcc and clang fallback
    "-O0 -g --coverage")

# Add coverage support for target ${TNAME} and register target for coverage
# evaluation. If coverage is disabled or not supported, this function will
# simply do nothing.
#
# Note: This function is only a wrapper to define this function always, even if
# coverage is not supported by the compiler or disabled. This function must be
# defined here, because the module will be exited, if there is no coverage
# support by the compiler or it is disabled by the user.
function(add_coverage TNAME)
  # only add coverage for target, if coverage is support and enabled.
  if(ENABLE_COVERAGE)
    foreach(TNAME ${ARGV})
      add_coverage_target(${TNAME})
    endforeach()
  endif()
endfunction(add_coverage)

# Add global target to gather coverage information after all targets have been
# added. Other evaluation functions could be added here, after checks for the
# specific module have been passed.
#
# Note: This function is only a wrapper to define this function always, even if
# coverage is not supported by the compiler or disabled. This function must be
# defined here, because the module will be exited, if there is no coverage
# support by the compiler or it is disabled by the user.
function(coverage_evaluate)
  # add lcov evaluation
  if(LCOV_FOUND)
    lcov_capture_initial()
    lcov_capture()
  endif(LCOV_FOUND)
endfunction()

# Exit this module, if coverage is disabled. add_coverage is defined before this
# return, so this module can be exited now safely without breaking any build-
# scripts.
if(NOT ENABLE_COVERAGE)
  return()
endif()

# Find the required flags foreach language.
set(CMAKE_REQUIRED_QUIET_SAVE ${CMAKE_REQUIRED_QUIET})
set(CMAKE_REQUIRED_QUIET ${codecov_FIND_QUIETLY})

get_property(ENABLED_LANGUAGES GLOBAL PROPERTY ENABLED_LANGUAGES)
foreach(LANG ${ENABLED_LANGUAGES})
  if(NOT ${LANG} MATCHES "^(C|CXX|Fortran)$")
    message(STATUS "Skipping coverage for unsupported language: ${LANG}")
    continue()
  endif()

  # Coverage flags are not dependent on language, but the used compiler. So
  # instead of searching flags foreach language, search flags foreach compiler
  # used.
  set(COMPILER ${CMAKE_${LANG}_COMPILER_ID})
  if(NOT COVERAGE_${COMPILER}_FLAGS)
    foreach(FLAG ${COVERAGE_FLAG_CANDIDATES})
      if(NOT CMAKE_REQUIRED_QUIET)
        message(STATUS "Try ${COMPILER} code coverage flag = [${FLAG}]")
      endif()

      set(CMAKE_REQUIRED_FLAGS "${FLAG}")
      unset(COVERAGE_FLAG_DETECTED CACHE)

      if(${LANG} STREQUAL "C")
        include(CheckCCompilerFlag)
        check_c_compiler_flag("${FLAG}" COVERAGE_FLAG_DETECTED)

      elseif(${LANG} STREQUAL "CXX")
        include(CheckCXXCompilerFlag)
        check_cxx_compiler_flag("${FLAG}" COVERAGE_FLAG_DETECTED)

      elseif(${LANG} STREQUAL "Fortran")
        # CheckFortranCompilerFlag was introduced in CMake 3.x. To be compatible
        # with older Cmake versions, we will check if this module is present
        # before we use it. Otherwise we will define Fortran coverage support as
        # not available.
        include(CheckFortranCompilerFlag OPTIONAL RESULT_VARIABLE INCLUDED)
        if(INCLUDED)
          CHECK_Fortran_COMPILER_FLAG("${FLAG}" COVERAGE_FLAG_DETECTED)
        elseif(NOT CMAKE_REQUIRED_QUIET)
          message("-- Performing Test COVERAGE_FLAG_DETECTED")
          message("-- Performing Test COVERAGE_FLAG_DETECTED - Failed"
                  " (Check not supported)")
        endif()
      endif()

      if(COVERAGE_FLAG_DETECTED)
        set(COVERAGE_${COMPILER}_FLAGS
            "${FLAG}"
            CACHE STRING "${COMPILER} flags for code coverage.")
        mark_as_advanced(COVERAGE_${COMPILER}_FLAGS)
        break()
      else()
        message(WARNING "Code coverage is not available for ${COMPILER}"
                        " compiler. Targets using this compiler will be "
                        "compiled without it.")
      endif()
    endforeach()
  endif()
endforeach()

set(CMAKE_REQUIRED_QUIET ${CMAKE_REQUIRED_QUIET_SAVE})

# Helper function to get the language of a source file.
function(codecov_lang_of_source FILE RETURN_VAR)
  # Usually, only the last extension of the file should be checked, to avoid
  # template files (i.e. *.t.cpp) are checked with the full file extension.
  # However, this feature requires CMake 3.14 or later.
  set(EXT_COMP "LAST_EXT")
  if(${CMAKE_VERSION} VERSION_LESS "3.14.0")
    set(EXT_COMP "EXT")
  endif()

  get_filename_component(FILE_EXT "${FILE}" ${EXT_COMP})
  string(TOLOWER "${FILE_EXT}" FILE_EXT)
  string(SUBSTRING "${FILE_EXT}" 1 -1 FILE_EXT)

  get_property(ENABLED_LANGUAGES GLOBAL PROPERTY ENABLED_LANGUAGES)
  foreach(LANG ${ENABLED_LANGUAGES})
    list(FIND CMAKE_${LANG}_SOURCE_FILE_EXTENSIONS "${FILE_EXT}" TEMP)
    if(NOT ${TEMP} EQUAL -1)
      set(${RETURN_VAR}
          "${LANG}"
          PARENT_SCOPE)
      return()
    endif()
  endforeach()

  set(${RETURN_VAR}
      ""
      PARENT_SCOPE)
endfunction()

# Helper function to get the relative path of the source file destination path.
# This path is needed by FindGcov and FindLcov cmake files to locate the
# captured data.
function(codecov_path_of_source FILE RETURN_VAR)
  string(REGEX MATCH "TARGET_OBJECTS:([^ >]+)" _source ${FILE})

  # If expression was found, SOURCEFILE is a generator-expression for an object
  # library. Currently we found no way to call this function automatic for the
  # referenced target, so it must be called in the directoryso of the object
  # library definition.
  if(NOT "${_source}" STREQUAL "")
    set(${RETURN_VAR}
        ""
        PARENT_SCOPE)
    return()
  endif()

  string(REPLACE "${CMAKE_CURRENT_BINARY_DIR}/" "" FILE "${FILE}")
  if(IS_ABSOLUTE ${FILE})
    file(RELATIVE_PATH FILE ${CMAKE_CURRENT_SOURCE_DIR} ${FILE})
  endif()

  # get the right path for file
  string(REPLACE ".." "__" PATH "${FILE}")

  set(${RETURN_VAR}
      "${PATH}"
      PARENT_SCOPE)
endfunction()

# Add coverage support for target ${TNAME} and register target for coverage
# evaluation.
function(add_coverage_target TNAME)
  # Check if all sources for target use the same compiler. If a target uses e.g.
  # C and Fortran mixed and uses different compilers (e.g. clang and gfortran)
  # this can trigger huge problems, because different compilers may use
  # different implementations for code coverage.
  get_target_property(TSOURCES ${TNAME} SOURCES)
  set(TARGET_COMPILER "")
  set(ADDITIONAL_FILES "")
  foreach(FILE ${TSOURCES})
    # If expression was found, FILE is a generator-expression for an object
    # library. Object libraries will be ignored.
    string(REGEX MATCH "TARGET_OBJECTS:([^ >]+)" _file ${FILE})
    if("${_file}" STREQUAL "")
      codecov_lang_of_source(${FILE} LANG)
      if(LANG)
        list(APPEND TARGET_COMPILER ${CMAKE_${LANG}_COMPILER_ID})

        list(APPEND ADDITIONAL_FILES "${FILE}.gcno")
        list(APPEND ADDITIONAL_FILES "${FILE}.gcda")
      endif()
    endif()
  endforeach()

  list(REMOVE_DUPLICATES TARGET_COMPILER)
  list(LENGTH TARGET_COMPILER NUM_COMPILERS)

  if(NUM_COMPILERS GREATER 1)
    message(
      WARNING "Can't use code coverage for target ${TNAME}, because "
              "it will be compiled by incompatible compilers. Target will be "
              "compiled without code coverage.")
    return()

  elseif(NUM_COMPILERS EQUAL 0)
    message(
      WARNING "Can't use code coverage for target ${TNAME}, because "
              "it uses an unknown compiler. Target will be compiled without "
              "code coverage.")
    return()

  elseif(NOT DEFINED "COVERAGE_${TARGET_COMPILER}_FLAGS")
    # A warning has been printed before, so just return if flags for this
    # compiler aren't available.
    return()
  endif()

  # enable coverage for target
  set_property(
    TARGET ${TNAME}
    APPEND_STRING
    PROPERTY COMPILE_FLAGS " ${COVERAGE_${TARGET_COMPILER}_FLAGS}")
  set_property(
    TARGET ${TNAME}
    APPEND_STRING
    PROPERTY LINK_FLAGS " ${COVERAGE_${TARGET_COMPILER}_FLAGS}")

  # Add gcov files generated by compiler to clean target.
  set(CLEAN_FILES "")
  foreach(FILE ${ADDITIONAL_FILES})
    codecov_path_of_source(${FILE} FILE)
    list(APPEND CLEAN_FILES "CMakeFiles/${TNAME}.dir/${FILE}")
  endforeach()

  if(${CMAKE_VERSION} VERSION_LESS "3.15.0")
    set_directory_properties(PROPERTIES ADDITIONAL_MAKE_CLEAN_FILES
                                        "${CLEAN_FILES}")
  else()
    set_directory_properties(PROPERTIES ADDITIONAL_CLEAN_FILES "${CLEAN_FILES}")
  endif()

  add_gcov_target(${TNAME})
  add_lcov_target(${TNAME})
endfunction(add_coverage_target)

# Include modules for parsing the collected data and output it in a readable
# format (like gcov and lcov).
find_package(Gcov)
find_package(Lcov)