Warning "mixture of specific functions and specific subroutines for one generic-spec" with ifx

[vmagnin]

Describe the bug
When using Intel ifx, those warnings appear:

[  7%] Building Fortran object src/CMakeFiles/gtk-fortran_object.dir/gtk-sup.f90.o
/tmp/gtk-fortran/src/gtk-sup.f90(541): warning #6706: There is a mixture of specific functions and specific subroutines for one generic-spec.   [CONVERT_F_STRING_A]
  subroutine convert_f_string_a(f_string, textptr, length)
-------------^

[ 20%] Building Fortran object src/CMakeFiles/gtk-fortran_object.dir/gtk-hl-dialog.f90.o
/tmp/gtk-fortran/src/gtk-hl-dialog.f90(41): warning #6706: There is a mixture of specific functions and specific subroutines for one generic-spec.   [CONVERT_F_STRING_A]
  use gtk_sup
------^

[ 51%] Building Fortran object examples/CMakeFiles/menubar.dir/menubar.f90.o
/tmp/gtk-fortran/examples/menubar.f90(39): warning #6706: There is a mixture of specific functions and specific subroutines for one generic-spec.   [GTK_SUP^CONVERT_F_STRING_A]
  use gtk_sup, only: convert_c_string, f_c_string
------^

[ 58%] Building Fortran object examples/CMakeFiles/bazaar.dir/bazaar.f90.o
/tmp/gtk-fortran/examples/bazaar.f90(363): warning #6706: There is a mixture of specific functions and specific subroutines for one generic-spec.   [GTK_SUP^CONVERT_F_STRING_A]
    use gtk_sup, only: f_c_string
--------^

To Reproduce

$ cmake -D CMAKE_BUILD_TYPE=debug -D EXCLUDE_PLPLOT=true -D CMAKE_Fortran_COMPILER:FILEPATH=$(which ifx) .. && make

Your system:

• OS version: Ubuntu 24.10 64 bits
• Compiler version: ifx (IFX) 2025.1.0 20250317
• GTK branch: gtk4 and gtk3

Additional context
In src/gtk-sup.f90, there are two similar interfaces with two names:

  interface f_c_string
     module procedure convert_f_string_a
     module procedure convert_f_string_aa
     module procedure convert_f_string_s
  end interface f_c_string

  interface convert_f_string
     module procedure convert_f_string_a
     module procedure convert_f_string_aa
     module procedure convert_f_string_s
  end interface convert_f_string

convert_f_string_a, convert_f_string_aa and convert_f_string_s are all subroutines.

[vmagnin]

Maybe related to pull request #295

[vmagnin]

I don't see any valuable reason to have two identical interfaces. Deleting convert_f_string and keeping f_c_string has my preference.

I will tomorrow look in the git history to see if there was some reason at that time (probably ~2012).

@florianober

[florianober]

Hi,
it is your choice, but i would keep the other Interface, as f_c_string is defined in the new fortran 2023 standard. I don't know why there is nothing in the gcc 15 changelog, but as the Compiler gives an Error, they must have implementet it.

[vmagnin]

Ah, that's a good argument.

[vmagnin]

Thanks @florianober
I have merged your PR #295
and will do the same thing in the gtk4 branch.

[vmagnin]

Done in gtk4.