GCC15(-std=gnu23) adjustments

1. Suppress -Wold-style-definition warnings globally since we prefer
   old-style definitions.
2. Fix hlink.c's cast in qsort() call to properly declare type.
3. Fix pool_alloc.c's function pointer type to match its usage.
4. Fix syscall.c's lseek64 forward declarations.
5. Fix bool typedef conflict in wildtest.c by renaming to rsync_bool.

This cleans up the build with modern compilers (GCC15) while maintaining
compatibility with older versions. The qsort comparison function cast in
particular is now more type-safe.

Signed-off-by: Charalampos Mitrodimas <[email protected]>

configure.ac

@@ -131,7 +131,7 @@ CFLAGS="$CFLAGS -DHAVE_CONFIG_H"
 
 # If GCC, turn on warnings.
 if test x"$GCC" = x"yes"; then
-	CFLAGS="$CFLAGS -Wall -W"
+	CFLAGS="$CFLAGS -Wall -W  -Wno-old-style-definition"
 fi
 
 AC_ARG_WITH(openssl-conf,

hlink.c

@@ -117,7 +117,7 @@ static void match_gnums(int32 *ndx_list, int ndx_count)
 	struct ht_int32_node *node = NULL;
 	int32 gnum, gnum_next;
 
-	qsort(ndx_list, ndx_count, sizeof ndx_list[0], (int (*)()) hlink_compare_gnum);
+	qsort(ndx_list, ndx_count, sizeof ndx_list[0], (int (*)(const void*, const void*))hlink_compare_gnum);
 
 	for (from = 0; from < ndx_count; from++) {
 		file = hlink_flist->sorted[ndx_list[from]];

lib/pool_alloc.c

@@ -9,7 +9,7 @@ struct alloc_pool
 	size_t			size;		/* extent size		*/
 	size_t			quantum;	/* allocation quantum	*/
 	struct pool_extent	*extents;	/* top extent is "live" */
-	void			(*bomb)();	/* called if malloc fails */
+	void			(*bomb)(const char*, const char*, int); /* called if malloc fails */
 	int			flags;
 
 	/* statistical data */

syscall.c

@@ -388,14 +388,10 @@ int do_fstat(int fd, STRUCT_STAT *st)
 OFF_T do_lseek(int fd, OFF_T offset, int whence)
 {
 #ifdef HAVE_LSEEK64
-#if !SIZEOF_OFF64_T
-	OFF_T lseek64();
+    /* No need for forward declaration since it's in unistd.h */
+    return lseek64(fd, offset, whence);
 #else
-	off64_t lseek64();
-#endif
-	return lseek64(fd, offset, whence);
-#else
-	return lseek(fd, offset, whence);
+    return lseek(fd, offset, whence);
 #endif
 }
 

wildtest.c

@@ -32,7 +32,7 @@ int fnmatch_errors = 0;
 
 int wildmatch_errors = 0;
 
-typedef char bool;
+typedef char rsync_bool;
 
 int output_iterations = 0;
 int explode_mod = 0;
@@ -50,13 +50,13 @@ static struct poptOption long_options[] = {
 
 /* match just at the start of string (anchored tests) */
 static void
-run_test(int line, bool matches,
+run_test(int line, rsync_bool matches,
 #ifdef COMPARE_WITH_FNMATCH
-	 bool same_as_fnmatch,
+	 rsync_bool same_as_fnmatch,
 #endif
 	 const char *text, const char *pattern)
 {
-    bool matched;
+    rsync_bool matched;
 #ifdef COMPARE_WITH_FNMATCH
     bool fn_matched;
     int flags = strstr(pattern, "**")? 0 : FNM_PATHNAME;