Bug 1224533

Summary: Package alpine does not build with gcc 14 because of a call arguments with an incompatible pointer type
Product: [openSUSE] openSUSE Tumbleweed Reporter: Martin Jambor <mjambor>
Component: OtherAssignee: Reinhard Max <max>
Status: RESOLVED FIXED QA Contact: E-mail List <qa-bugs>
Severity: Normal    
Priority: P5 - None    
Version: Current   
Target Milestone: ---   
Hardware: Other   
OS: Other   
Whiteboard:
Found By: --- Services Priority:
Business Priority: Blocker: ---
Marketing QA Status: --- IT Deployment: ---
Bug Depends on:    
Bug Blocks: 1220571    

Description Martin Jambor 2024-05-20 13:34:19 UTC 
Package alpine fails to build with gcc 14, which newly treats as
errors a number of situations which before were mere warnings.  More
information can be found at https://gcc.gnu.org/gcc-14/porting_to.html
and in bug #1220571.

The failure can be seen online for example at
https://build.opensuse.org/package/live_build_log/home:rguenther:plgrnd/alpine/openSUSE_Factory/x86_64
and be reproduced locally with osc build --clean --alternative-project
home:rguenther:nextgcc

The error which stops the build is:

[   68s] adrbklib.c: In function ‘sort_addr_list’:
[   68s] adrbklib.c:4705:64: error: passing argument 4 of ‘qsort’ from incompatible pointer type [-Wincompatible-pointer-types]
[   68s]  4705 |     qsort((qsort_t *)list, (size_t)(p - list), sizeof(char *), cmp_addr);
[   68s]       |                                                                ^~~~~~~~
[   68s]       |                                                                |
[   68s]       |                                                                int (*)(const char *, const char *)
[   68s] In file included from ../include/system.h:42,
[   68s]                  from ../pith/headers.h:25,
[   68s]                  from adrbklib.c:14:
[   68s] /usr/include/stdlib.h:971:34: note: expected ‘__compar_fn_t’ {aka ‘int (*)(const void *, const void *)’} but argument is of type ‘int (*)(const char *, const char *)’
[   68s]   971 |                    __compar_fn_t __compar) __nonnull ((1, 4));


Interestingly, I while I find see Gentoo and Fedore bugs (see the
links in the meta bug) about alpine not compiling with compilers with
this strict behavior, none of them look like the issue above.
Comment 1 Reinhard Max 2024-05-21 13:06:37 UTC 
Hmm, alpine even has a configure check to see whether qsort() wants the comparison function to take (void *) or (char *) arguments, but something in there seems to go wrong. Investigating ...
Comment 2 Reinhard Max 2024-05-21 13:18:55 UTC 
Ah, the check makes use of implicit int which is now also an error and lets the check for (void *) fail leading to the assumption that (char *) is needed for qsort():

configure:23571: checking argument pointer type of qsort compare function and base
configure:23600: gcc -c [...] conftest.c
conftest.c:141:8: error: type defaults to 'int' in declaration of 'sortf' [-Wimplicit-int]
  141 | extern sortf(const void *, const void *);
      |        ^~~~~
[...]
configure: failed program was:
[...]
| extern void *base;
| extern sortf(const void *, const void *);
| int sortf(a, b)
|   const void *a;
|   const void *b; { return 0; }
[...]
configure:23611: result: char
Comment 3 Reinhard Max 2024-05-21 13:33:18 UTC 
Yep, that prototype should be

 extern int sortf(const void *, const void *);

and after fixing it there are no further errors with gcc 14.
Comment 5 Reinhard Max 2024-06-05 08:29:25 UTC 
Oops, I posted comment 4 to the wrong bug, but anyway, a fixed version of alpine is now in Factory, and so this ticket can remain closed.