ctest: support variadics in function pointers #4367

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1. tgross35

   added

   ctestIssues relating to the ctest crateIssues relating to the ctest crate

   on Apr 3, 2025
2. tgross35 commented on Aug 4, 2026

   

   tgross35

   on Aug 4, 2026

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   We have the c_variadic feature stabilizing in the next version rust-lang/rust#155697, this should make things more workable.
3. tgross35 commented on Aug 4, 2026

   

   tgross35

   on Aug 4, 2026

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   @mbyx I think that with c_variadic being stabilized this may "just work" now (assuming we test on nightly of course). Would you mind submitting a PR testing it?
4. tgross35 commented on Aug 4, 2026

   

   tgross35

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   Actually some of the syntax bits may have to be updated to emit ...
5. mbyx commented on Aug 7, 2026

   

   mbyx

   on Aug 7, 2026

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   Actually, since the way foreign functions are tested changed in the new ctest, we don't construct the type at all. The variadic part remains in the C source, but is never used in the .C test (because we cast to a void pointer), nor in the Rust test (since we just call the foreign_fn_ptr function that takes no arguments and just returns a function pointer with no type information).

   It would really only affect structs that have a function pointer I think.
6. tgross35

   changed the title [-]ctest: support varidics[/-] [+]ctest: support variadics[/+] on Aug 9, 2026
7. tgross35

   closed this as completedin #5385on Aug 9, 2026
8. tgross35 commented on Aug 9, 2026

   

   tgross35

   on Aug 9, 2026

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   That PR pretty much fixed everything but it would be good to handle function pointers as well, so I'll reopen for that
9. tgross35

   reopened this on Aug 9, 2026
10. tgross35

    changed the title [-]ctest: support variadics[/-] [+]ctest: support variadics in function pointers[/+] on Aug 9, 2026
11. mbyx commented on Aug 9, 2026

    

    mbyx

    on Aug 9, 2026

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    I believe the PR also handles function pointers as well. I just checked locally by adding a variadic function pointer to a struct field in the tests, and the tests seem to pass:

    struct Person
    {
        const char *name;
        uint8_t age;
        void (*job)(uint8_t, const char *, ...);
        enum Color favorite_color;
    };

    Which generates this test (among others):

    typedef void (**ctest_field_ty__Person__job)(uint8_t, const char *, ...);
    CTEST_EXTERN ctest_field_ty__Person__job
    ctest_field_ptr__Person__job(struct Person *b) {
        
        ctest_field_ty__Person__job ptr;
        ptr = &b->job;
        (void)ptr; 
    
        return &b->job;
    }

    If this is enough, then when I eventually make a PR regarding testing improvements, I'll add in this specific test as well.
12. tgross35 commented on Aug 9, 2026

    

    tgross35

    on Aug 9, 2026

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    Oh awesome! Yeah that's all, a test would be great