Cannot link C main

[awvwgk]

I'm currently trying to (ab)use fpm to compile a C project. It is not a C package manager, but it certainly could become one.

Using a project with the following layout:

fpm.toml
app/main.c

fpm.toml:

name = "test"
[[executable]]
name = "test"
main = "main.c"

app/main.c:

int
main (void) {
  return 0;
}

Will fail to link the C executable with

❯ fpm build
 + mkdir -p build/gfortran_2A42023B310FA28D/test
 + gcc -c app/main.c  -I./include -o build/gfortran_2A42023B310FA28D/test/app_main.c.o
❯ fpm run
<INFO> No executables to run
STOP 0

I think the source scanning must find a program statement in the source-file declared as main in the manifest. Instead, it would be preferable if fpm just trust the user input and assumes that the provided main is providing the necessary entry point.

---

Tested with fpm 0.5.0

[arjenmarkus]

How about faking that with: /* program my_c_program */ in the main.c source file? Horrible hack, but it might work for now :). Op ma 3 jan. 2022 om 16:03 schreef Sebastian Ehlert < ***@***.***>:

…

I'm currently trying to (ab)use fpm to compile a C project. It is not a C package manager, but it certainly could become one. Using a project with the following layout: fpm.toml app/main.c fpm.toml: name = "test" [[executable]] name = "test" main = "main.c" app/main.c: int main (void) { return 0; } Will fail to link the C executable with ❯ fpm build + mkdir -p build/gfortran_2A42023B310FA28D/test + gcc -c app/main.c -I./include -o build/gfortran_2A42023B310FA28D/test/app_main.c.o ❯ fpm run <INFO> No executables to run STOP 0 I think the source scanning must find a program statement in the source-file declared as main in the manifest. Instead, it would be preferable if fpm just trust the user input and assumes that the provided main is providing the necessary entry point. ------------------------------ Tested with fpm 0.5.0 — Reply to this email directly, view it on GitHub <#643>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAN6YR42SDJMIPHEAJMW6JDUUG3EHANCNFSM5LFM45JA> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>. You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[awvwgk]

Fpm won't scan C source code for Fortran keywords, therefore it is not able to detect the program statement in the block comment.

[arjenmarkus]

It is being too smart ;). Or I am too wrapped up in today's debugging session to think of such an obvious obstacle. Op ma 3 jan. 2022 om 16:29 schreef Sebastian Ehlert < ***@***.***>:

…

Fpm won't scan C source code for Fortran keywords, therefore it is not able to detect the program statement in the block comment. — Reply to this email directly, view it on GitHub <#643 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAN6YR7DG4WVRQHC56MO6BTUUG6D5ANCNFSM5LFM45JA> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>. You are receiving this because you commented.Message ID: ***@***.***>

[awvwgk]

The issue originates in fpm_sources.f90 the branch for Fortran source code

fpm/src/fpm_sources.f90

Line 30 in d99ad59

if (str_ends_with(lower(source_file_path), fortran_suffixes)) then

can add an executable by setting the exe_name if a program unit was found

fpm/src/fpm_sources.f90

Lines 34 to 36 in d99ad59

	if (source%unit_type == FPM_UNIT_PROGRAM) then
	source%exe_name = basename(source_file_path,suffix=.false.)
	end if

the else branch for C source and headers is missing this capability.