Compiling DISCON.F90 on Linux

Wind & Water Controls
1

Greetings,

I am in the process of setting up openFAST on a Linux based cluster, and I am facing some problems in trying to compile the DISCON.F90 file using gfortran for Linux. I am using gcc version 4.9.3.

In the terminal, I navigate to the location of the DISCON.F90 source file, and then I type -

gfortran DISCON.F90 -o DISCON.dll , but I get the following error :

DISCON.F90:18:0: warning: \u2018dllexport\u2019 attribute directive ignored [-Wattributes]
SUBROUTINE DISCON ( avrSWAP, aviFAIL, accINFILE, avcOUTNAME, avcMSG ) BIND (C, NAME=‘DISCON’)
^
/lib/…/lib64/crt1.o: In function _start': (.text+0x20): undefined reference to main’
collect2: error: ld returned 1 exit status

Apologies if this has already been asked before, I was not able to find it.

I would be very grateful for help in this matter. Thanks in advance.

Best regards,
Vishal

2

You need to tell it to build a shared library, otherwise it thinks it is a standalone executable that needs a main() routine. Try

gfortran DISCON.F90 -shared -DIMPLICIT_DLLEXPORT -o DISCON.dll

(Or maybe you want a different file extension for linux?)

Alternatively, the DLLs can be built using cmake. See github.com/openfast/r-test#note … line-cases

1 Like
3

Dear Bonnie,

Thank you, that fixed the problem!

Best regards,
Vishal

4

Dear NREL team,

I use OpenFAST in linux environment and compile the DISCON.f90 using the CMakeLists.txt & “cmake” (from the build directory) without any problem.

For a project, we needed to make changes / extentions in DISCON.f90 , therefore we have some additional files containing some new subroutines, which are called from within the DISCON.f90. E.g. read.f90 contains SUBROUTINE Read_input( …) to avoid hard-coding the control parameters, but to read from file.

In order to compile them together and create the DISCON.dll, I assume I need to make changes in the CMakeLists.txt.

Do you have any tips how to fix that ? Thanks in advance.

5

Hi @Salur.Basbug,

You do need to add the new file to the corresponding CMakeLists. Assuming you used the DISCON project from the r-test repository, you should add your new file at line 64 of that CMake Lists. However, I would change that section from:

set(SOURCE_PATH "${CMAKE_CURRENT_LIST_DIR}/DISCON.F90")
file(TO_CMAKE_PATH ${SOURCE_PATH} SOURCE_PATH)

to this more common form:

set(SOURCE_PATH
  "${CMAKE_CURRENT_LIST_DIR}/DISCON.F90"
  "${CMAKE_CURRENT_LIST_DIR}/your_file.F90"
)

Also, you may want to check out ROSCO. They’ve expanded on the DISCON controller in the OpenFAST r-test repo and added functionality to provide parameters through an input file.

1 Like
6

Thanks a lot Rafael,

It worked for me with the way they did in ROSCO. it means that I set the source code path like:

set(SOURCES
src/discon_10.f90
src/Read_DISCON_input.f
…
)

1 Like
7

Perfect - well done and thanks for sharing.

1 Like