#=============================================================================
# Copyright 2004-2009 Kitware, Inc.
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file Copyright.txt for details.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
#  License text for the above reference.)

# determine the compiler to use for Fortran programs
# NOTE, a generator may set CMAKE_Fortran_COMPILER before
# loading this file to force a compiler.
# use environment variable FC first if defined by user, next use
# the cmake variable CMAKE_GENERATOR_FC which can be defined by a generator
# as a default compiler

include(${CMAKE_ROOT}/Modules/CMakeDetermineCompiler.cmake)
include(Platform/${CMAKE_SYSTEM_NAME}-Fortran OPTIONAL)
if(NOT CMAKE_Fortran_COMPILER_NAMES)
  set(CMAKE_Fortran_COMPILER_NAMES f95)
endif()

if(${CMAKE_GENERATOR} MATCHES "Visual Studio")
  set(CMAKE_Fortran_COMPILER_ID_RUN 1)
  set(CMAKE_Fortran_PLATFORM_ID "Windows")
  set(CMAKE_Fortran_COMPILER_ID "Intel")
  set(CMAKE_Fortran_COMPILER "${CMAKE_GENERATOR_FC}")
elseif("${CMAKE_GENERATOR}" MATCHES "Xcode")
  set(CMAKE_Fortran_COMPILER_XCODE_TYPE sourcecode.fortran.f90)
else()
  if(NOT CMAKE_Fortran_COMPILER)
    # prefer the environment variable CC
    if($ENV{FC} MATCHES ".+")
      get_filename_component(CMAKE_Fortran_COMPILER_INIT $ENV{FC} PROGRAM PROGRAM_ARGS CMAKE_Fortran_FLAGS_ENV_INIT)
      if(CMAKE_Fortran_FLAGS_ENV_INIT)
        set(CMAKE_Fortran_COMPILER_ARG1 "${CMAKE_Fortran_FLAGS_ENV_INIT}" CACHE STRING "First argument to Fortran compiler")
      endif()
      if(EXISTS ${CMAKE_Fortran_COMPILER_INIT})
      else()
        message(FATAL_ERROR "Could not find compiler set in environment variable FC:\n$ENV{FC}.")
      endif()
    endif()

    # next try prefer the compiler specified by the generator
    if(CMAKE_GENERATOR_FC)
      if(NOT CMAKE_Fortran_COMPILER_INIT)
        set(CMAKE_Fortran_COMPILER_INIT ${CMAKE_GENERATOR_FC})
      endif()
    endif()

    # finally list compilers to try
    if(NOT CMAKE_Fortran_COMPILER_INIT)
      # Known compilers:
      #  f77/f90/f95: generic compiler names
      #  g77: GNU Fortran 77 compiler
      #  gfortran: putative GNU Fortran 95+ compiler (in progress)
      #  fort77: native F77 compiler under HP-UX (and some older Crays)
      #  frt: Fujitsu F77 compiler
      #  pathf90/pathf95/pathf2003: PathScale Fortran compiler
      #  pgf77/pgf90/pgf95/pgfortran: Portland Group F77/F90/F95 compilers
      #  xlf/xlf90/xlf95: IBM (AIX) F77/F90/F95 compilers
      #  lf95: Lahey-Fujitsu F95 compiler
      #  fl32: Microsoft Fortran 77 "PowerStation" compiler
      #  af77: Apogee F77 compiler for Intergraph hardware running CLIX
      #  epcf90: "Edinburgh Portable Compiler" F90
      #  fort: Compaq (now HP) Fortran 90/95 compiler for Tru64 and Linux/Alpha
      #  ifc: Intel Fortran 95 compiler for Linux/x86
      #  efc: Intel Fortran 95 compiler for IA64
      #
      #  The order is 95 or newer compilers first, then 90,
      #  then 77 or older compilers, gnu is always last in the group,
      #  so if you paid for a compiler it is picked by default.
      set(CMAKE_Fortran_COMPILER_LIST
        ifort ifc af95 af90 efc f95 pathf2003 pathf95 pgf95 pgfortran lf95 xlf95
        fort gfortran gfortran-4 g95 f90 pathf90 pgf90 xlf90 epcf90 fort77
        frt pgf77 xlf fl32 af77 g77 f77
        )

      # Vendor-specific compiler names.
      set(_Fortran_COMPILER_NAMES_GNU       gfortran gfortran-4 g95 g77)
      set(_Fortran_COMPILER_NAMES_Intel     ifort ifc efc)
      set(_Fortran_COMPILER_NAMES_Absoft    af95 af90 af77)
      set(_Fortran_COMPILER_NAMES_PGI       pgf95 pgfortran pgf90 pgf77)
      set(_Fortran_COMPILER_NAMES_PathScale pathf2003 pathf95 pathf90)
      set(_Fortran_COMPILER_NAMES_XL        xlf)
      set(_Fortran_COMPILER_NAMES_VisualAge xlf95 xlf90 xlf)
    endif()

    _cmake_find_compiler(Fortran)

  else()
     # we only get here if CMAKE_Fortran_COMPILER was specified using -D or a pre-made CMakeCache.txt
    # (e.g. via ctest) or set in CMAKE_TOOLCHAIN_FILE
    # if CMAKE_Fortran_COMPILER is a list of length 2, use the first item as
    # CMAKE_Fortran_COMPILER and the 2nd one as CMAKE_Fortran_COMPILER_ARG1

    list(LENGTH CMAKE_Fortran_COMPILER _CMAKE_Fortran_COMPILER_LIST_LENGTH)
    if("${_CMAKE_Fortran_COMPILER_LIST_LENGTH}" EQUAL 2)
      list(GET CMAKE_Fortran_COMPILER 1 CMAKE_Fortran_COMPILER_ARG1)
      list(GET CMAKE_Fortran_COMPILER 0 CMAKE_Fortran_COMPILER)
    endif()

    # if a compiler was specified by the user but without path,
    # now try to find it with the full path
    # if it is found, force it into the cache,
    # if not, don't overwrite the setting (which was given by the user) with "NOTFOUND"
    # if the C compiler already had a path, reuse it for searching the CXX compiler
    get_filename_component(_CMAKE_USER_Fortran_COMPILER_PATH "${CMAKE_Fortran_COMPILER}" PATH)
    if(NOT _CMAKE_USER_Fortran_COMPILER_PATH)
      find_program(CMAKE_Fortran_COMPILER_WITH_PATH NAMES ${CMAKE_Fortran_COMPILER})
      mark_as_advanced(CMAKE_Fortran_COMPILER_WITH_PATH)
      if(CMAKE_Fortran_COMPILER_WITH_PATH)
        set(CMAKE_Fortran_COMPILER ${CMAKE_Fortran_COMPILER_WITH_PATH}
          CACHE STRING "Fortran compiler" FORCE)
      endif()
    endif()
  endif()
  mark_as_advanced(CMAKE_Fortran_COMPILER)

  # Each entry in this list is a set of extra flags to try
  # adding to the compile line to see if it helps produce
  # a valid identification executable.
  set(CMAKE_Fortran_COMPILER_ID_TEST_FLAGS
    # Try compiling to an object file only.
    "-c"

    # Intel on windows does not preprocess by default.
    "-fpp"
    )
endif()

# Build a small source file to identify the compiler.
if(NOT CMAKE_Fortran_COMPILER_ID_RUN)
  set(CMAKE_Fortran_COMPILER_ID_RUN 1)

  # Table of per-vendor compiler id flags with expected output.
  list(APPEND CMAKE_Fortran_COMPILER_ID_VENDORS Compaq)
  set(CMAKE_Fortran_COMPILER_ID_VENDOR_FLAGS_Compaq "-what")
  set(CMAKE_Fortran_COMPILER_ID_VENDOR_REGEX_Compaq "Compaq Visual Fortran")
  list(APPEND CMAKE_Fortran_COMPILER_ID_VENDORS NAG) # Numerical Algorithms Group
  set(CMAKE_Fortran_COMPILER_ID_VENDOR_FLAGS_NAG "-V")
  set(CMAKE_Fortran_COMPILER_ID_VENDOR_REGEX_NAG "NAG Fortran Compiler")

  # Try to identify the compiler.
  set(CMAKE_Fortran_COMPILER_ID)
  include(${CMAKE_ROOT}/Modules/CMakeDetermineCompilerId.cmake)
  CMAKE_DETERMINE_COMPILER_ID(Fortran FFLAGS CMakeFortranCompilerId.F)

  # Fall back to old is-GNU test.
  if(NOT CMAKE_Fortran_COMPILER_ID)
    exec_program(${CMAKE_Fortran_COMPILER}
      ARGS ${CMAKE_Fortran_COMPILER_ID_FLAGS_LIST} -E "\"${CMAKE_ROOT}/Modules/CMakeTestGNU.c\""
      OUTPUT_VARIABLE CMAKE_COMPILER_OUTPUT RETURN_VALUE CMAKE_COMPILER_RETURN)
    if(NOT CMAKE_COMPILER_RETURN)
      if("${CMAKE_COMPILER_OUTPUT}" MATCHES ".*THIS_IS_GNU.*" )
        set(CMAKE_Fortran_COMPILER_ID "GNU")
        file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
          "Determining if the Fortran compiler is GNU succeeded with "
          "the following output:\n${CMAKE_COMPILER_OUTPUT}\n\n")
      else()
        file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
          "Determining if the Fortran compiler is GNU failed with "
          "the following output:\n${CMAKE_COMPILER_OUTPUT}\n\n")
      endif()
      if(NOT CMAKE_Fortran_PLATFORM_ID)
        if("${CMAKE_COMPILER_OUTPUT}" MATCHES ".*THIS_IS_MINGW.*" )
          set(CMAKE_Fortran_PLATFORM_ID "MinGW")
        endif()
        if("${CMAKE_COMPILER_OUTPUT}" MATCHES ".*THIS_IS_CYGWIN.*" )
          set(CMAKE_Fortran_PLATFORM_ID "Cygwin")
        endif()
      endif()
    endif()
  endif()

  # Set old compiler and platform id variables.
  if("${CMAKE_Fortran_COMPILER_ID}" MATCHES "GNU")
    set(CMAKE_COMPILER_IS_GNUG77 1)
  endif()
  if("${CMAKE_Fortran_PLATFORM_ID}" MATCHES "MinGW")
    set(CMAKE_COMPILER_IS_MINGW 1)
  elseif("${CMAKE_Fortran_PLATFORM_ID}" MATCHES "Cygwin")
    set(CMAKE_COMPILER_IS_CYGWIN 1)
  endif()
endif()

if (NOT _CMAKE_TOOLCHAIN_LOCATION)
  get_filename_component(_CMAKE_TOOLCHAIN_LOCATION "${CMAKE_Fortran_COMPILER}" PATH)
endif ()

# if we have a fortran cross compiler, they have usually some prefix, like
# e.g. powerpc-linux-gfortran, arm-elf-gfortran or i586-mingw32msvc-gfortran , optionally
# with a 3-component version number at the end (e.g. arm-eabi-gcc-4.5.2).
# The other tools of the toolchain usually have the same prefix
# NAME_WE cannot be used since then this test will fail for names lile
# "arm-unknown-nto-qnx6.3.0-gcc.exe", where BASENAME would be
# "arm-unknown-nto-qnx6" instead of the correct "arm-unknown-nto-qnx6.3.0-"
if (CMAKE_CROSSCOMPILING  AND NOT _CMAKE_TOOLCHAIN_PREFIX)

  if("${CMAKE_Fortran_COMPILER_ID}" MATCHES "GNU")
    get_filename_component(COMPILER_BASENAME "${CMAKE_Fortran_COMPILER}" NAME)
    if (COMPILER_BASENAME MATCHES "^(.+-)g?fortran(-[0-9]+\\.[0-9]+\\.[0-9]+)?(\\.exe)?$")
      set(_CMAKE_TOOLCHAIN_PREFIX ${CMAKE_MATCH_1})
    endif ()

    # if "llvm-" is part of the prefix, remove it, since llvm doesn't have its own binutils
    # but uses the regular ar, objcopy, etc. (instead of llvm-objcopy etc.)
    if ("${_CMAKE_TOOLCHAIN_PREFIX}" MATCHES "(.+-)?llvm-$")
      set(_CMAKE_TOOLCHAIN_PREFIX ${CMAKE_MATCH_1})
    endif ()
  endif()

endif ()

include(CMakeFindBinUtils)

if(MSVC_Fortran_ARCHITECTURE_ID)
  set(SET_MSVC_Fortran_ARCHITECTURE_ID
    "set(MSVC_Fortran_ARCHITECTURE_ID ${MSVC_Fortran_ARCHITECTURE_ID})")
endif()
# configure variables set in this file for fast reload later on
configure_file(${CMAKE_ROOT}/Modules/CMakeFortranCompiler.cmake.in
  ${CMAKE_PLATFORM_INFO_DIR}/CMakeFortranCompiler.cmake
  @ONLY IMMEDIATE # IMMEDIATE must be here for compatibility mode <= 2.0
  )
set(CMAKE_Fortran_COMPILER_ENV_VAR "FC")