Rewrite FortranCInterface module

This is a new FortranCInterface.cmake module to replace the previous
prototype.  All module support files lie in a FortranCInterface
directory next to it.

This module uses a new approach to detect Fortran symbol mangling.  We
build a single test project which defines symbols in a Fortran library
(one per object-file) and calls them from a Fortran executable.  The
executable links to a C library which defines symbols encoding all known
manglings (one per object-file).  The C library falls back to the
Fortran library for symbols it cannot provide.  Therefore the executable
will always link, but prefers the C-implemented symbols when they match.
These symbols store string literals of the form INFO:symbol[<name>] so
we can parse them out of the executable.

This module also provides a simpler interface.  It always detects the
mangling as soon as it is included.  A single macro is provided to
generate mangling macros and optionally pre-mangled symbols.

2 files changed, 38 insertions, 36 deletions

diff --git a/Tests/Fortran/CMakeLists.txt b/Tests/Fortran/CMakeLists.txt
index c435faa..312b4d7 100644
--- a/Tests/Fortran/CMakeLists.txt
+++ b/Tests/Fortran/CMakeLists.txt
@@ -15,47 +15,48 @@ function(test_fortran_c_interface_module)
   # test the C to Fortran interface module
   include(FortranCInterface)
   if(CMAKE_Fortran_COMPILER_SUPPORTS_F90)
-    if(FORTRAN_C_MODULE_MANGLING_FOUND)
+    if(NOT CMAKE_Fortran_COMPILER_ID MATCHES "SunPro|MIPSpro")
+      set(module_expected 1)
+    endif()
+    if(FortranCInterface_MODULE_FOUND OR module_expected)
       set(srcs foo.f)
       set(FORTRAN_FUNCTIONS test_mod:sub)
-    else(FORTRAN_C_MODULE_MANGLING_FOUND)
-      if(CMAKE_Fortran_COMPILER_ID MATCHES "SunPro|MIPSpro")
-        message("${CMAKE_Fortran_COMPILER_ID} compilers do not support"
-          " linking Fortran module procedures from C")
-      else()
-        message("This will fail, but let the user see the error")
-        set(srcs foo.f)
-        set(FORTRAN_FUNCTIONS test_mod:sub)
-      endif()
-    endif(FORTRAN_C_MODULE_MANGLING_FOUND)
+      set(MYC_DEFS TEST_MOD)
+    else()
+      message("${CMAKE_Fortran_COMPILER_ID} compilers do not support"
+        " linking Fortran module procedures from C")
+    endif()
   endif()
-  set(FORTRAN_FUNCTIONS ${FORTRAN_FUNCTIONS} my_sub mysub )
-  create_fortran_c_interface("F_" FORTRAN_FUNCTIONS 
-    "${testf_BINARY_DIR}/foo.h")
+  list(APPEND FORTRAN_FUNCTIONS my_sub mysub)
+  FortranCInterface_HEADER(foo.h
+    MACRO_NAMESPACE "FC_"
+    SYMBOL_NAMESPACE "F_"
+    SYMBOLS ${FORTRAN_FUNCTIONS}
+    )
   include_directories("${testf_BINARY_DIR}")
-  
+
   # if the name mangling is not found for a F90 compiler
   # print out some diagnostic stuff for the dashboard
-  if(CMAKE_Fortran_COMPILER_SUPPORTS_F90)
-    if(NOT FORTRAN_C_MODULE_MANGLING_FOUND)
-      file(GLOB_RECURSE O_OBJFILES
-        "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckFortranLink/*.o"
-        "*.o" )
-      file(GLOB_RECURSE OBJ_OBJFILES 
-        "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckFortranLink/*.obj")
-      find_program(DUMPBIN dumpbin)
-      find_program(NM nm)
-      foreach(ofile ${O_OBJFILES} ${OBJ_OBJFILES})
-        if(DEPENDS)
-          execute_process(COMMAND ${DUMPBIN} /symbols "${ofile}" 
-            OUTPUT_VARIABLE out)
-          message("symbols in ${ofile}:\n${out}")
-        endif()
-        if(NM)
-          execute_process(COMMAND ${NM} "${ofile}" OUTPUT_VARIABLE out)
-          message("symbols in ${ofile}:\n${out}")
-        endif()
-      endforeach()
+  if(NOT FortranCInterface_GLOBAL_FOUND OR
+      (NOT FortranCInterface_MODULE_FOUND AND module_expected) )
+    find_program(FortranCInterface_EXE
+      NAMES FortranCInterface
+      PATHS ${FortranCInterface_BINARY_DIR} ${FortranCInterface_BINARY_DIR}/Debug
+      NO_DEFAULT_PATH
+      )
+    find_program(DUMPBIN dumpbin)
+    find_program(NM nm)
+    if(FortranCInterface_EXE)
+      if(DEPENDS)
+        execute_process(COMMAND ${DUMPBIN} /symbols "${FortranCInterface_EXE}"
+                        OUTPUT_VARIABLE out)
+        message("symbols in ${FortranCInterface_EXE}:\n${out}")
+      endif()
+      if(NM)
+        execute_process(COMMAND ${NM} "${FortranCInterface_EXE}"
+                        OUTPUT_VARIABLE out)
+        message("symbols in ${FortranCInterface_EXE}:\n${out}")
+      endif()
     endif()
   endif()
   message("Fortran = ${CMAKE_Fortran_COMPILER_ID}")
@@ -65,6 +66,7 @@ function(test_fortran_c_interface_module)
 
   add_library(myc myc.c)
   target_link_libraries(myc myfort)
+  set_property(TARGET myc PROPERTY COMPILE_DEFINITIONS ${MYC_DEFS})
 
   add_library(mycxx mycxx.cxx)
   target_link_libraries(mycxx myc)
diff --git a/Tests/Fortran/myc.c b/Tests/Fortran/myc.c
index b817dff..efd9b68 100644
--- a/Tests/Fortran/myc.c
+++ b/Tests/Fortran/myc.c
@@ -5,7 +5,7 @@ int myc(void)
 {
   F_mysub();
   F_my_sub();
-#ifdef F_test_mod_sub
+#ifdef TEST_MOD
   F_test_mod_sub();
 #endif
   return 0;