Description

Compiling a C executable that makes use of preprocessor directives does not propage the arguments from --c-flag during compilation of the executable.

The preprocessor works as expected for the library target.

This behaviour is NOT present with Fortran preprocessor directives

Expected Behaviour

Propage preprocessor directives used to compile the library to the compilation of executables

Version of fpm

e3fff65

Platform and Architecture

Linux x64

Additional Information

MWE

fpm.toml*

name = "fpm-preproc-bug"
version = "0.1.0"
license = "license"
author = "gnikit"
maintainer = "giannis.nikiteas@gmail.com"
copyright = "Copyright 2022, gnikit"
[build]
auto-executables = true
auto-tests = true
auto-examples = true
[install]
library = false
[library]
include-dir = ["src"]

[[executable]]
name="mwe-c"
main="main.c"

[[executable]]
name="mwe-f90"
main="main.F90"

src/val.h

#ifndef _VAL_H_
#define _VAL_H_

#ifdef VAL
const int variable = 1;
#else
const int variable = 0;
#endif
#endif

src/valf.h

#ifdef VAL
integer, parameter :: variable = 1
#else
integer, parameter :: variable = 0
#endif

app/main.c

#include <stdio.h>
#include "val.h"

int main(){
    printf("%d\n", variable);
}

app/main.F90

program main
#include "valf.h"
    print*, variable
end program main

$ fpm run mwe-c --c-flag="-DVAL"
main.F90                               done.
mwe-f90                                done.
[100%] Project compiled successfully.
0

fpm-preproc-bug.zip