Created attachment 308769 [details] [review]
[PATCH] Bug 753276 - Fix return value error

Thanks for a bug report and patch. I wish I know how to convince gcc to report such issues. They are pretty simple to detect, still hidden here.

Created commit e6bec28 in eds master (3.17.90+)

After reading gcc/c/c-typeck.c, it seems we should use different gcc options to convert this warning into an error when different standard versions are used:

If we use -std=c89, we can use -Werror=return-type.
If we use -std=c99 or -std=c11, we can use -pedantic-errors.

I do not need to have it as an error, my problem is that I do not see the warning itself at all, gcc doesn't claim anything on stderr (while it claims other warnings, like deprecations, there).

I closely watch the warnings and I try to keep evolution code base compiler-warning-free, though only for those warnings I see.

I found glib/gmessages.h contains this:

/* Suppress warnings when GCC is in -pedantic mode and not -std=c99              
 */                                                                              
#if (__GNUC__ >= 3 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96))                   
#pragma GCC system_header                                                        
#endif


so warnings caused by g_return_if_fail and g_return_val_if_fail are suppressed.

Even if I add the two I do not get those warnings. I filled [1] for a help from the gcc developers:

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1250848