CheckFortranCompilerFlag: Add module to check Fortran flag existence

Copy the CheckCCompilerFlag module and replace 'C' with 'Fortran'.
Also update the common patterns module to match some Fortran compiler
messages.

Help/manual/cmake-modules.7.rst

@@ -22,6 +22,7 @@ All Modules
    /module/CheckCXXSourceCompiles
    /module/CheckCXXSourceRuns
    /module/CheckCXXSymbolExists
+   /module/CheckFortranCompilerFlag
    /module/CheckFortranFunctionExists
    /module/CheckFortranSourceCompiles
    /module/CheckFunctionExists

Help/module/CheckFortranCompilerFlag.rst

@@ -0,0 +1 @@
+.. cmake-module:: ../../Modules/CheckFortranCompilerFlag.cmake

Modules/CMakeCheckCompilerFlagCommonPatterns.cmake

@@ -21,9 +21,9 @@
 
 macro (CHECK_COMPILER_FLAG_COMMON_PATTERNS _VAR)
    set(${_VAR}
-     FAIL_REGEX "unrecognized .*option"                     # GNU
+     FAIL_REGEX "[Uu]nrecogni[sz]ed .*option"               # GNU, NAG
      FAIL_REGEX "unknown .*option"                          # Clang
-     FAIL_REGEX "ignoring unknown option"                   # MSVC
+     FAIL_REGEX "ignoring unknown option"                   # MSVC, Intel
      FAIL_REGEX "warning D9002"                             # MSVC, any lang
      FAIL_REGEX "option.*not supported"                     # Intel
      FAIL_REGEX "invalid argument .*option"                 # Intel
@@ -35,6 +35,7 @@ macro (CHECK_COMPILER_FLAG_COMMON_PATTERNS _VAR)
      FAIL_REGEX "command option .* contains an incorrect subargument" # XL
      FAIL_REGEX "not supported in this configuration. ignored"       # AIX
      FAIL_REGEX "File with unknown suffix passed to linker" # PGI
+     FAIL_REGEX "[Uu]nknown switch"                         # PGI
      FAIL_REGEX "WARNING: unknown flag:"                    # Open64
      FAIL_REGEX "Incorrect command line option:"            # Borland
      FAIL_REGEX "Warning: illegal option"                   # SunStudio 12

Modules/CheckFortranCompilerFlag.cmake

@@ -0,0 +1,66 @@
+#.rst:
+# CheckFortranCompilerFlag
+# ------------------------
+#
+# Check whether the Fortran compiler supports a given flag.
+#
+# CHECK_Fortran_COMPILER_FLAG(<flag> <var>)
+#
+# ::
+#
+#   <flag> - the compiler flag
+#   <var>  - variable to store the result
+#            Will be created as an internal cache variable.
+#
+# This internally calls the check_fortran_source_compiles macro and
+# sets CMAKE_REQUIRED_DEFINITIONS to <flag>.  See help for
+# CheckFortranSourceCompiles for a listing of variables that can
+# otherwise modify the build.  The result only tells that the compiler
+# does not give an error message when it encounters the flag.  If the
+# flag has any effect or even a specific one is beyond the scope of
+# this module.
+
+#=============================================================================
+# Copyright 2015 Nicolas Bock <nicolasbock@gmail.com>
+# Copyright 2006-2011 Kitware, Inc.
+# Copyright 2006 Alexander Neundorf <neundorf@kde.org>
+# Copyright 2011 Matthias Kretz <kretz@kde.org>
+#
+# 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.)
+
+include(CheckFortranSourceCompiles)
+include(CMakeCheckCompilerFlagCommonPatterns)
+
+macro (CHECK_Fortran_COMPILER_FLAG _FLAG _RESULT)
+  set(SAFE_CMAKE_REQUIRED_DEFINITIONS "${CMAKE_REQUIRED_DEFINITIONS}")
+  set(CMAKE_REQUIRED_DEFINITIONS "${_FLAG}")
+
+  # Normalize locale during test compilation.
+  set(_CheckFortranCompilerFlag_LOCALE_VARS LC_ALL LC_MESSAGES LANG)
+  foreach(v ${_CheckFortranCompilerFlag_LOCALE_VARS})
+    set(_CheckFortranCompilerFlag_SAVED_${v} "$ENV{${v}}")
+    set(ENV{${v}} C)
+  endforeach()
+  CHECK_COMPILER_FLAG_COMMON_PATTERNS(_CheckFortranCompilerFlag_COMMON_PATTERNS)
+  CHECK_Fortran_SOURCE_COMPILES("       program test\n       stop\n       end program" ${_RESULT}
+    # Some compilers do not fail with a bad flag
+    FAIL_REGEX "command line option .* is valid for .* but not for Fortran" # GNU
+    ${_CheckFortranCompilerFlag_COMMON_PATTERNS}
+    )
+  foreach(v ${_CheckFortranCompilerFlag_LOCALE_VARS})
+    set(ENV{${v}} ${_CheckFortranCompilerFlag_SAVED_${v}})
+    unset(_CheckFortranCompilerFlag_SAVED_${v})
+  endforeach()
+  unset(_CheckFortranCompilerFlag_LOCALE_VARS)
+  unset(_CheckFortranCompilerFlag_COMMON_PATTERNS)
+
+  set (CMAKE_REQUIRED_DEFINITIONS "${SAFE_CMAKE_REQUIRED_DEFINITIONS}")
+endmacro ()