Linker: Qt 5 + Intel Visual Fortran 2019

fem_dev

I wrote 2 simple fortran static libraries which have a proper "C ISO Binding" to mix these two with QT 5.13 C/C++ applications.

a) The first one only sends a single number from Fortran lib to my C++ application: Works perfect
b) The second one only try to send a simple Fortran string from Fortran lib to my C++ application: linker error!

unresolved external symbol for_cpystr referenced in function my_long_calc

I don't understand why the first library works well but the second one not link with the QT / C++ application.

Trying to solve the second library issue, I added to my *.pro file all IVF include/library folders that Microsoft Visual Studio 2019 describes inside your IVF 2019 configuration, but I got the same linker error.

Maybe should I need to include the IVF library files inside my *.pro file? I don't know...And, if yes, how can I know which library?

Could you help me?

SGaist

Hi,

@fem_dev said in Linker: QT5 + Intel Visual Fortran 2019:

for_cpystr

From what I could gather this symbol comes from a runtime library related to FORTRAN. You need to also link to that library.

On a side note, it's Qt. QT stands for Apple QuickTime which is not what you are currently looking for :-)

fem_dev

@sgaist thanks,

Now I include the path to the Intel Visual Fortran Libs and this error is gone.
The path is:

C:\Program Files (x86)\IntelSWTools\compilers_and_libraries_2019.4.245\windows\compiler\lib\ia32_win

Now QT Creator is asking me about a *.obj file. What I have to do?

error: LNK1104: cannot open file 'C:\Program Files (x86)\IntelSWTools\compilers_and_libraries_2019.4.245\windows\compiler\lib\ia32_win.obj'

SGaist

How are you including it ?

fem_dev

Sorry, I was incluing the 32 bit folder....but now I change it to x64 bit lib folder and this error is gone.

LIBS += -L"C:/Program Files (x86)/IntelSWTools/compilers_and_libraries_2019.4.245/windows/compiler/lib/intel64_win"
LIBS += ifconsol.lib

The last problem is that my Fortran string is wrong in the output terminal.
It should be "nyck" and "sara" but it is "nnnnnn" and "sssss"....the first letter repeating 5 times (the allocation size that I set in Fortran string variable).

My C++ code:

#include <QCoreApplication>
#include <iostream>

extern "C" {
  void my_long_calc(void);
  void fortran_message(int* value, char* msg1, size_t* len1, char* msg2, size_t* len2);
}

void fortran_message(int* value, char* msg1, size_t* len1, char* msg2, size_t* len2)
{
  std::cout << "value: " << *value << std::endl;
  std::cout << "msg1: " << msg1 << std::endl;
  std::cout << "len1: " << *len1 << std::endl;
  std::cout << "msg2: " << msg2 << std::endl;
  std::cout << "len2: " << *len2 << std::endl;
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    my_long_calc();

    return a.exec();
}

My Fortran code:

module my_interfaces
interface
  subroutine fortran_message (value, msg1, len1, msg2, len2) bind(C)
    use, intrinsic :: ISO_C_BINDING
    integer(C_INT), intent(in) :: value
    character(kind=C_CHAR), intent(in) :: msg1(*)
    integer(C_SIZE_T), intent(in) :: len1
    character(kind=C_CHAR), intent(in) :: msg2(*)
    integer(C_SIZE_T), intent(in) :: len2
  end subroutine fortran_message
end interface
end module my_interfaces

! My long calc subroutine
subroutine my_long_calc() BIND(C, name = 'my_long_calc')
    use, intrinsic :: ISO_C_BINDING
    use my_interfaces
    implicit none
    
    integer(C_INT) :: value
    character(kind=C_CHAR) :: msg1(5)
    integer(C_SIZE_T) :: len1
    character(kind=C_CHAR) :: msg2(5)
    integer(C_SIZE_T) :: len2
    
    value = 10
    msg1 = "nyck"//C_NULL_CHAR
    len1 = 13
    msg2 = "sara"//C_NULL_CHAR
    len2 = 15
    
    ! Send a message to the C++ application:
    call fortran_message(value, msg1, len1, msg2, len2)
end subroutine my_long_calc

The len1 and len2 variables are not important in this example.

How can I get the correct C++ terminal output "nyck" and "sara"?

fem_dev

The complete answer and some details about Qt + IVF can be found here:
https://software.intel.com/en-us/forums/intel-visual-fortran-compiler-for-windows/topic/815889#comment-1943689

[Edit aha_1980: Fixed link]

SGaist

Thank for the feedback !