[DRE-maint] Bug#1075472: ruby-posix-spawn: ftbfs with GCC-14

[Philipp Kern]

Control: tag -1 + patch

> gcc -fdebug-prefix-map=/<<PKGBUILDDIR>>=. -I. -I/usr/include/x86_64-linux-gnu/ruby-3.1.0 -I/usr/include/ruby-3.1.0/ruby/backward -I/usr/include/ruby-3.1.0 -I. -Wdate-time -D_FORTIFY_SOURCE=2   -fPIC -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=BUILDDIR=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -fcf-protection -fPIC -Wall   -o posix-spawn.o -c posix-spawn.c
> posix-spawn.c: In function ‘posixspawn_file_actions_init’:
> posix-spawn.c:226:34: error: passing argument 2 of ‘rb_hash_foreach’ from incompatible pointer type [-Wincompatible-pointer-types]
>   226 |         rb_hash_foreach(options, posixspawn_file_actions_operations_iter, (VALUE)fops);
>       |                                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>       |                                  |
>       |                                  int (*)(VALUE,  VALUE,  posix_spawn_file_actions_t *) {aka int (*)(long unsigned int,  long unsigned int,  posix_spawn_file_actions_t *)}
> In file included from /usr/include/ruby-3.1.0/ruby/internal/scan_args.h:37,
>                  from /usr/include/ruby-3.1.0/ruby/ruby.h:46,
>                  from /usr/include/ruby-3.1.0/ruby.h:38,
>                  from posix-spawn.c:14:
> /usr/include/ruby-3.1.0/ruby/internal/intern/hash.h:83:40: note: expected ‘int (*)(VALUE,  VALUE,  VALUE)’ {aka ‘int (*)(long unsigned int,  long unsigned int,  long unsigned int)’} but argument is of type ‘int (*)(VALUE,  VALUE,  posix_spawn_file_actions_t *)’ {aka ‘int (*)(long unsigned int,  long unsigned int,  posix_spawn_file_actions_t *)’}
>    83 | void rb_hash_foreach(VALUE hash, int (*func)(VALUE key, VALUE val, VALUE arg), VALUE arg);
>       |                                  ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> make[2]: *** [Makefile:246: posix-spawn.o] Error 1

This patch would fix this issue (curiously rb_foreach_func is not
exported from Ruby's hash.c in a header):

Index: ruby-posix-spawn-0.3.15/ext/posix-spawn.c
===================================================================
--- ruby-posix-spawn-0.3.15.orig/ext/posix-spawn.c
+++ ruby-posix-spawn-0.3.15/ext/posix-spawn.c
@@ -212,6 +212,8 @@ posixspawn_file_actions_operations_iter(
        return ST_CONTINUE;
 }

+typedef int rb_foreach_func(VALUE, VALUE, VALUE);
+
 /*
  * Initialize the posix_spawn_file_actions_t structure and add operations from
  * the options hash. Keys in the options Hash that are processed by handlers are
@@ -223,7 +225,7 @@ static void
 posixspawn_file_actions_init(posix_spawn_file_actions_t *fops, VALUE options)
 {
        posix_spawn_file_actions_init(fops);
-       rb_hash_foreach(options, posixspawn_file_actions_operations_iter, (VALUE)fops);
+       rb_hash_foreach(options, (rb_foreach_func*)posixspawn_file_actions_operations_iter, (VALUE)fops);
 }

 /*

The prototype of posixspawn_file_actions_operations_iter is VALUE,
VALUE, posix_spawn_file_actions_t*. Of course this also expects that
the pointer fits into VALUE. But presumably that's not the first
module with that assumption.

Kind regards
Philipp Kern