# This file is part of CMake-codecov.
#
# https://github.com/RWTH-ELP/CMake-codecov
#
# Copyright (c)
#   2015-2016 RWTH Aachen University, Federal Republic of Germany
#
# LICENSE : BSD 3-Clause License
#
# Written by Alexander Haase, alexander.haase@rwth-aachen.de
# Updated by Guillaume Jacquenot, guillaume.jacquenot@gmail.com

# include required Modules
include(FindPackageHandleStandardArgs)


# Search for gcov binary.
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 ${ENABLED_LANGUAGES})
  # Gcov evaluation is dependent on the used compiler. Check gcov support for
  # each compiler that is used. If gcov binary was already found for this
  # compiler, do not try to find it again.
  if(NOT GCOV_${CMAKE_${LANG}_COMPILER_ID}_BIN)
    get_filename_component(COMPILER_PATH "${CMAKE_${LANG}_COMPILER}" PATH)

    if("${CMAKE_${LANG}_COMPILER_ID}" STREQUAL "GNU")
      # Some distributions like OSX (homebrew) ship gcov with the compiler
      # version appended as gcov-x. To find this binary we'll build the
      # suggested binary name with the compiler version.
      string(REGEX MATCH "^[0-9]+" GCC_VERSION
        "${CMAKE_${LANG}_COMPILER_VERSION}")

      find_program(GCOV_BIN NAMES gcov-${GCC_VERSION} gcov
        HINTS ${COMPILER_PATH})

    elseif("${CMAKE_${LANG}_COMPILER_ID}" STREQUAL "Clang")
      # Some distributions like Debian ship llvm-cov with the compiler
      # version appended as llvm-cov-x.y. To find this binary we'll build
      # the suggested binary name with the compiler version.
      string(REGEX MATCH "^[0-9]+.[0-9]+" LLVM_VERSION
        "${CMAKE_${LANG}_COMPILER_VERSION}")

      # llvm-cov prior version 3.5 seems to be not working with coverage
      # evaluation tools, but these versions are compatible with the gcc
      # gcov tool.
      if(LLVM_VERSION VERSION_GREATER 3.4)
        find_program(LLVM_COV_BIN NAMES "llvm-cov-${LLVM_VERSION}"
          "llvm-cov" HINTS ${COMPILER_PATH})
        mark_as_advanced(LLVM_COV_BIN)

        if(LLVM_COV_BIN)
          find_program(LLVM_COV_WRAPPER "llvm-cov-wrapper" PATHS
            ${CMAKE_MODULE_PATH})
          if(LLVM_COV_WRAPPER)
            set(GCOV_BIN "${LLVM_COV_WRAPPER}" CACHE FILEPATH "")

            # set additional parameters
            set(GCOV_${CMAKE_${LANG}_COMPILER_ID}_ENV
              "LLVM_COV_BIN=${LLVM_COV_BIN}" CACHE STRING
              "Environment variables for llvm-cov-wrapper.")
            mark_as_advanced(GCOV_${CMAKE_${LANG}_COMPILER_ID}_ENV)
          endif()
        endif()
      endif()

      if(NOT GCOV_BIN)
        # Fall back to gcov binary if llvm-cov was not found or is
        # incompatible. This is the default on OSX, but may crash on
        # recent Linux versions.
        find_program(GCOV_BIN gcov HINTS ${COMPILER_PATH})
      endif()
    endif()


    if(GCOV_BIN)
      set(GCOV_${CMAKE_${LANG}_COMPILER_ID}_BIN "${GCOV_BIN}" CACHE STRING
        "${LANG} gcov binary.")

      if(NOT CMAKE_REQUIRED_QUIET)
        message("-- Found gcov evaluation for "
        "${CMAKE_${LANG}_COMPILER_ID}: ${GCOV_BIN}")
      endif()

      unset(GCOV_BIN CACHE)
    endif()
  endif()
endforeach ()


# Add a new global target for all gcov targets. This target could be used to
# generate the gcov files for the whole project instead of calling <TARGET>-gcov
# for each target.
if(NOT TARGET coverage)
  add_custom_target(coverage)
endif()


# This function will add gcov evaluation for target <TNAME>. Only sources of
# this target will be evaluated and no dependencies will be added. It will call
# Gcov on any source file of <TNAME> once and store the gcov file in the same
# directory.
function (add_gcov_target TNAME)
  set(TDIR ${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/${TNAME}.dir)

  # We don't have to check, if the target has support for coverage, thus this
  # will be checked by add_coverage_target in Findcoverage.cmake. Instead we
  # have to determine which gcov binary to use.
  get_target_property(TSOURCES ${TNAME} SOURCES)
  set(SOURCES "")
  set(TCOMPILER "")
  foreach (FILE ${TSOURCES})
    codecov_path_of_source(${FILE} FILE)
    if(NOT "${FILE}" STREQUAL "")
      codecov_lang_of_source(${FILE} LANG)
      if(NOT "${LANG}" STREQUAL "")
        list(APPEND SOURCES "${FILE}")
        set(TCOMPILER ${CMAKE_${LANG}_COMPILER_ID})
      endif()
    endif()
  endforeach()

  # If no gcov binary was found, coverage data can't be evaluated.
  if(NOT GCOV_${TCOMPILER}_BIN)
    message(WARNING "No coverage evaluation binary found for ${TCOMPILER}.")
    return()
  endif()

  set(GCOV_BIN "${GCOV_${TCOMPILER}_BIN}")
  set(GCOV_ENV "${GCOV_${TCOMPILER}_ENV}")


  set(BUFFER "")
  foreach(FILE ${SOURCES})
    get_filename_component(FILE_PATH "${TDIR}/${FILE}" PATH)

    # call gcov
    add_custom_command(OUTPUT ${TDIR}/${FILE}.gcov
      COMMAND ${GCOV_ENV} ${GCOV_BIN} ${TDIR}/${FILE}.gcno > /dev/null
      DEPENDS ${TNAME} ${TDIR}/${FILE}.gcno
      WORKING_DIRECTORY ${FILE_PATH}
    )

    list(APPEND BUFFER ${TDIR}/${FILE}.gcov)
  endforeach()


  # add target for gcov evaluation of <TNAME>
  add_custom_target(${TNAME}-gcov DEPENDS ${BUFFER})

  # add evaluation target to the global gcov target.
  add_dependencies(coverage ${TNAME}-gcov)
endfunction()
