Add NAG Fortran compiler information files

On Linux the NAG Fortran compiler uses gcc under the hood to link.  Use
"-Wl,-v" to pass "-v" to the underlying gcc compiler to get verbose link
output.  Detect the NAG Fortran directory (using -dryrun) and then honor
object files in the directory referenced in the implicit link line.
Pass real linker options with "-Wl,-Xlinker,".  The -Wl, gets through
the NAG front-end and the -Xlinker gets through the gcc front-end.

Modules/Compiler/NAG-Fortran.cmake

@@ -0,0 +1,32 @@
+# Help CMAKE_PARSE_IMPLICIT_LINK_INFO detect NAG Fortran object files.
+if(NOT CMAKE_Fortran_COMPILER_WORKS AND NOT CMAKE_Fortran_COMPILER_FORCED)
+  message(STATUS "Detecting NAG Fortran directory")
+  # Run with -dryrun to see sample "link" line.
+  execute_process(
+    COMMAND ${CMAKE_Fortran_COMPILER} dummy.o -dryrun
+    OUTPUT_VARIABLE _dryrun
+    ERROR_VARIABLE _dryrun
+    )
+  # Match an object file.
+  string(REGEX MATCH "/[^ ]*/[^ /][^ /]*\\.o" _nag_obj "${_dryrun}")
+  if(_nag_obj)
+    # Parse object directory and convert to a regex.
+    string(REGEX REPLACE "/[^/]*$" "" _nag_dir "${_nag_obj}")
+    string(REGEX REPLACE "([][+.*()^])" "\\\\\\1" _nag_regex "${_nag_dir}")
+    set(CMAKE_Fortran_IMPLICIT_OBJECT_REGEX "^${_nag_regex}/")
+    file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
+      "Detecting NAG Fortran directory with -dryrun found\n"
+      "  object: ${_nag_obj}\n"
+      "  directory: ${_nag_dir}\n"
+      "  regex: ${CMAKE_Fortran_IMPLICIT_OBJECT_REGEX}\n"
+      "from output:\n${_dryrun}\n\n")
+    message(STATUS "Detecting NAG Fortran directory - ${_nag_dir}")
+  else()
+    file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
+      "Detecting NAG Fortran directory with -dryrun failed:\n${_dryrun}\n\n")
+    message(STATUS "Detecting NAG Fortran directory - failed")
+  endif()
+endif()
+
+set(CMAKE_Fortran_MODDIR_FLAG "-mdir ")
+set(CMAKE_SHARED_LIBRARY_Fortran_FLAGS "-PIC")

Modules/Platform/Darwin-NAG-Fortran.cmake

@@ -0,0 +1,5 @@
+set(CMAKE_Fortran_VERBOSE_FLAG "-Wl,-v") # Runs gcc under the hood.
+
+# Need -fpp explicitly on case-insensitive filesystem.
+set(CMAKE_Fortran_COMPILE_OBJECT
+  "<CMAKE_Fortran_COMPILER> -fpp -o <OBJECT> <DEFINES> <FLAGS> -c <SOURCE>")

Modules/Platform/Linux-NAG-Fortran.cmake

@@ -0,0 +1,10 @@
+set(CMAKE_Fortran_VERBOSE_FLAG "-Wl,-v") # Runs gcc under the hood.
+
+# Need one "-Wl," level to send flag through to gcc.
+# Use "-Xlinker" to get through gcc to real linker.
+set(CMAKE_SHARED_LIBRARY_CREATE_Fortran_FLAGS "-Wl,-shared")
+set(CMAKE_SHARED_LIBRARY_RUNTIME_Fortran_FLAG "-Wl,-Xlinker,-rpath,-Xlinker,")
+set(CMAKE_SHARED_LIBRARY_RUNTIME_Fortran_FLAG_SEP ":")
+set(CMAKE_SHARED_LIBRARY_RPATH_LINK_Fortran_FLAG "-Wl,-Xlinker,-rpath-link,-Xlinker,")
+set(CMAKE_SHARED_LIBRARY_SONAME_Fortran_FLAG "-Wl,-Xlinker,-soname,-Xlinker,")
+set(CMAKE_SHARED_LIBRARY_LINK_Fortran_FLAGS "-Wl,-rdynamic")