[CMake] Fortan and C++

Dominik Szczerba dominik at itis.ethz.ch
Sun Aug 23 07:02:39 EDT 2009


Hmmm I dont understand. SET(FUNCTIONS...) does not influence anything. 
The messages I get are identical as before, with the only difference 
that the myfconfig.h now has something meaningful inside:

#define myfFUNCTIONS functions_

However, the errors:

-- Failed to find C binding to Fortran module functions.
-- Failed to find Fortran module linkage
-- created /home/domel/build/solve/myconfig.h

are still there. Any valuable ideas?

- Dominik


Michael Wild wrote:
> I think you called the CREATE_FORTRAN_C_INTERFACE function  
> incorrectly. The second argument needs to be the name of a variable  
> containing a list of function names:
> 
> SET( FUNCTIONS cross )
> CREATE_FORTRAN_C_INTERFACE( myf FUNCTIONS ${CMAKE_CURRENT_BINARY_DIR}/ 
> myconfig.h )
> 
> Michael
> 
> 
> 
> On 22. Aug, 2009, at 20:24, Dominik Szczerba wrote:
> 
>> Of course, you are right - not about ifcore that is resolved by ldd,  
>> but about the multibyte magic. I applied your patch. Now I get:
>>
>> -- checking Fortran function linkage: sub_
>> -- found Fortran function linkage
>> -- checking Fortran function with _  linkage: my_sub_
>> -- checking Fortran module linkage: test_interface$sub
>> -- checking Fortran module linkage: TEST_INTERFACE_mp_sub
>> -- checking Fortran module linkage: _test_interface__sub
>> -- checking Fortran module linkage: __test_interface__sub
>> -- checking Fortran module linkage: __test_interface_NMOD_sub
>> -- checking Fortran module linkage: __test_interface_MOD_sub
>> -- Failed to find C binding to Fortran module functions.
>> -- Failed to find Fortran module linkage
>> -- created myfconfig.h
>>
>> The content of myfconfig.h file:
>>
>> /* This file is automatically generated by CMake, DO NOT EDIT.
>>   It contains a mapping from Fortran functions so they can
>>   be called from C or C++.   */
>>
>> Where do I go from here?
>>
>> Many thanks,
>> Dominik
>>
>> Michael Wild wrote:
>>> As I said, FortranCInterface.cmake is buggy as it doesn't pass the   
>>> CMAKE_Fortran_FLAGS and CMAKE_EXE_LINKER_FLAGS variables to the   
>>> TRY_COMPILE project. If you have to set these in order to compile/ 
>>> link  a mixed-language program, it fails. Come to think of it, in  
>>> your case  the ifcore library will also be missing, so probably  
>>> something like a  CMAKE_REQUIRED_LIBRARIES variable will also be  
>>> necessary.
>>> Michael
>>> On 22. Aug, 2009, at 15:40, Dominik Szczerba wrote:
>>>> I naively tried:
>>>>
>>>> INCLUDE(FortranCInterface)
>>>> CREATE_FORTRAN_C_INTERFACE(myf cross myfconfig.h)
>>>>
>>>> to get:
>>>>
>>>> -- checking Fortran function linkage: sub_
>>>> -- checking Fortran function linkage: _sub_
>>>> -- checking Fortran function linkage: __sub_
>>>> -- checking Fortran function linkage: SUB_
>>>> -- checking Fortran function linkage: _SUB_
>>>> -- checking Fortran function linkage: __SUB_
>>>> -- checking Fortran function linkage: sub
>>>> -- checking Fortran function linkage: _sub
>>>> -- checking Fortran function linkage: __sub
>>>> -- checking Fortran function linkage: SUB
>>>> -- checking Fortran function linkage: _SUB
>>>> -- checking Fortran function linkage: __SUB
>>>> CMake Error at /usr/local/share/cmake-2.6/Modules/  
>>>> FortranCInterface.cmake:169 (message):
>>>> Could not find fortran c name mangling.
>>>> Call Stack (most recent call first):
>>>> CMakeLists.txt:34 (create_fortran_c_interface)
>>>>
>>>> I have C CXX and Fortran enabled in the 'project' call. Using  
>>>> icpc/ ifort 11.x
>>>>
>>>> - Dominik
>>>>
>>>> Dominik Szczerba wrote:
>>>>> Hi Michael,
>>>>> Michael Wild wrote:
>>>>>> Hi Dominik
>>>>>>
>>>>>> Concerning the flags: you should add the -no-multibyte-chars to   
>>>>>> the  CMAKE_CXX_FLAGS variable. This will get prepended to all    
>>>>>> CMAKE_CXX_FLAGS_{RELEASE,DEBUG,...} flags, since you don't want   
>>>>>> this  flag to be used for the Release configuration  
>>>>>> exclusively,  but for all  configurations.
>>>>> Thanks for the clarifications.
>>>>>> Linking against ifcore using the C++ compiler only works if it  
>>>>>> is  on  the search path (probably by sourcing ifortvars.sh),  
>>>>>> otherwise  you'll  have to specify it's full path. I think,  
>>>>>> Intel recommends  using the  the Fortran compiler for linking  
>>>>>> instead, and passing  it the -cxxlib  and -nofor_main flags  
>>>>>> (those are the correct names  now, I looked them  up ;-)).
>>>>> I see, will maybe try some day. However, I have no problem  
>>>>> linking  for the moment.
>>>>>> On Mac platforms there is another problem: By default the g++   
>>>>>> compiler  generates 32-bit code, while the Intel Fortran  
>>>>>> compiler  generates 64- bit code (very annoying).
>>>>>>
>>>>>> If you try to use FortranCInterface.cmake, be aware that it is   
>>>>>> quite  buggy, as it doesn't pass the CMAKE_*_FLAGS to the   
>>>>>> try_compile calls.  Further it doesn't ensure that the C  
>>>>>> language  is enabled, altough it  is calling try_compile on C  
>>>>>> code! I'll  file a bug report with an  attached patch for that.
>>>>>>
>>>>> This is new to me. Sounds like automatic handling of calling   
>>>>> decorations. Would be great! Are there any examples how to use  
>>>>> it?  Do I still need it when I know the mangling scheme myself?  
>>>>> Can I  set the pre/suffixes myself in some elegant manner?  
>>>>> Currently I am  just hacking on my own, so indications how to  
>>>>> position myself for  the future are very welcome.
>>>>> Thanks,
>>>>> Dominik
>>>>>> All the best
>>>>>>
>>>>>> Michael
>>>>>>
>>>>>> On 22. Aug, 2009, at 13:35, Dominik Szczerba wrote:
>>>>>>
>>>>>>> Here the report of my tests:
>>>>>>>
>>>>>>> Just ignorant approach (don't google):
>>>>>>>
>>>>>>> It works out of the box on linux with intel compilers 10.x.  
>>>>>>> Just  add  Fortran to the languages in the project signature  
>>>>>>> and add  STUFF.F90  to the source files. You need to link to  
>>>>>>> ifcore  library though.
>>>>>>>
>>>>>>> It does not work out of the box with the compilers 11.x. Here   
>>>>>>> the  ignorant approach failed. The errors were like:
>>>>>>>
>>>>>>> -- Check for working CXX compiler: /usr/local/bin/icpc-11.0.083
>>>>>>> -- Check for working CXX compiler: /usr/local/bin/ 
>>>>>>> icpc-11.0.083  --  broken
>>>>>>> CMake Error at /usr/local/share/cmake-2.6/Modules/   
>>>>>>> CMakeTestCXXCompiler.cmake:25 (MESSAGE):
>>>>>>> The C++ compiler "/usr/local/bin/icpc-11.0.083" is not able  
>>>>>>> to   compile a
>>>>>>> simple test program.
>>>>>>>
>>>>>>> It fails with the following output:
>>>>>>>
>>>>>>> Change Dir: /home/domel/build/solve/CMakeFiles/CMakeTmp
>>>>>>>
>>>>>>> Checking by foot what the compilers at all say during   
>>>>>>> compilations I  found:
>>>>>>>
>>>>>>>> icpc-11.0.083 -c test.cxx
>>>>>>> Catastrophic error: could not set locale "" to allow  
>>>>>>> processing  of  multibyte characters
>>>>>>>
>>>>>>> Googling reveals a bug in the compiler to be circumvented  
>>>>>>> with   adding '-no-multibyte-chars' to the compiler switches.  
>>>>>>> However,   adding this to my CMAKE_XXX_FLAGS_RELEASE (my  
>>>>>>> CMAKE_BUILD_TYPE  is  RELEASE) does not help. I must now either  
>>>>>>> specify  CMAKE_XXX_FLAGS  explicitly on the commandline or in  
>>>>>>> the cache.  Probably because  cmake uses default flags  
>>>>>>> (CMAKE_XXX_FLAGS) for  compiler checks, even  if  
>>>>>>> CMAKE_BUILD_TYPE is explicitly set  release/debug (as well as   
>>>>>>> corresponding release/debug flags).
>>>>>>>
>>>>>>> Maybe cmake should use compiler flags as defined by   
>>>>>>> CMAKE_BUILD_TYPE  to check for compilers?
>>>>>>>
>>>>>>> - Dominik
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Dominik Szczerba wrote:
>>>>>>>> Michael,
>>>>>>>> Many thanks for the feedback.
>>>>>>>> What I am doing with a GNU makefile so far is compile just  
>>>>>>>> one  file  with the fortran compiler use C++ linker to link  
>>>>>>>> all  object files  as usual.
>>>>>>>> A comprehensive solution I would expect in cmake would be 1)    
>>>>>>>> nothing (.f90 file is understood) or something along the  
>>>>>>>> lines  of  setting the file properties (sort of 'to be  
>>>>>>>> compiler with'  flag)...
>>>>>>>> - Dominik
>>>>>>>> Michael Wild wrote:
>>>>>>>>> On 21.08.2009, at 17:57, Dominik Szczerba  <dominik at itis.ethz.ch 
>>>>>>>>>>  wrote:
>>>>>>>>>> I want to compile one file with fortran compiler (intel)  
>>>>>>>>>> and   link  with the rest of my project. Will the latest  
>>>>>>>>>> cmake allow  to  fully  cmakify such scenario?
>>>>>>>>> Hi Dominik
>>>>>>>>>
>>>>>>>>> If I remember correctly, you'll have to set the  
>>>>>>>>> LINK_LANGUAGE   property  of your target to Fortran and then  
>>>>>>>>> ensure that the   Fortran linker also  links against the C++  
>>>>>>>>> standard library.  For  Intel this would be -stdc+ + (or some  
>>>>>>>>> such). If you are  creating  an executable, depending on   
>>>>>>>>> where your main-function  is defined,  you might also need to  
>>>>>>>>> tell the  linker to not add  a Fortran main- function, the  
>>>>>>>>> flag is called - nofor_main if I  remember correctly.   
>>>>>>>>> Otherwise the ifort man-page will  tell  you :)
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> HTH
>>>>>>>>>
>>>>>>>>> Michael
>>>>>>> -- 
>>>>>>> d o m i n i k   s z c z e r b a ,   p h d . . . . . . . . . . .
>>>>>>> c o m p u t a t i o n a l   l i f e   s c i e n c e   g r o u p
>>>>>>> . . . . . . . i t ' i s   r e s e a r c h   f o u n d a t i o n
>>>>>>> . . . . . . . . . . . . . . . . . . . . http://www.itis.ethz.ch
>>>>>>>
>>>> -- 
>>>> d o m i n i k   s z c z e r b a ,   p h d . . . . . . . . . . .
>>>> c o m p u t a t i o n a l   l i f e   s c i e n c e   g r o u p
>>>> . . . . . . . i t ' i s   r e s e a r c h   f o u n d a t i o n
>>>> . . . . . . . . . . . . . . . . . . . . http://www.itis.ethz.ch
>>>>
>>
>> -- 
>> d o m i n i k   s z c z e r b a ,   p h d . . . . . . . . . . .
>> c o m p u t a t i o n a l   l i f e   s c i e n c e   g r o u p
>> . . . . . . . i t ' i s   r e s e a r c h   f o u n d a t i o n
>> . . . . . . . . . . . . . . . . . . . . http://www.itis.ethz.ch
>>
> 


-- 
d o m i n i k   s z c z e r b a ,   p h d . . . . . . . . . . .
c o m p u t a t i o n a l   l i f e   s c i e n c e   g r o u p
. . . . . . . i t ' i s   r e s e a r c h   f o u n d a t i o n
. . . . . . . . . . . . . . . . . . . . http://www.itis.ethz.ch



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