string-list.c: avoid conversion from void * to function pointer

ISO C forbids the conversion of void pointers to function pointers. Introduce a context struct that encapsulates the function pointer. Signed-off-by: Beat Bolli <dev+git@drbeat.li> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Beat Bolli committed Jul 9, 2018 at 21:25 UTC b6d3f5a960c2b5dfe3d8d84e7f4c26e03d721d10
1 file changed +14 -4
string-list.c
+14 -4
@@ -224,18 +224,28 @@ struct string_list_item *string_list_append(struct string_list *list,
224 list->strdup_strings ? xstrdup(string) : (char *)string);
225 }
226
227 +/*
228 + * Encapsulate the compare function pointer because ISO C99 forbids
229 + * casting from void * to a function pointer and vice versa.
230 + */
231 +struct string_list_sort_ctx
232 +{
233 + compare_strings_fn cmp;
234 +};
235 +
236 static int cmp_items(const void *a, const void *b, void *ctx)
237 {
229 - compare_strings_fn cmp = ctx;
238 + struct string_list_sort_ctx *sort_ctx = ctx;
239 const struct string_list_item *one = a;
240 const struct string_list_item *two = b;
232 - return cmp(one->string, two->string);
241 + return sort_ctx->cmp(one->string, two->string);
242 }
243
244 void string_list_sort(struct string_list *list)
245 {
237 - QSORT_S(list->items, list->nr, cmp_items,
238 - list->cmp ? list->cmp : strcmp);
246 + struct string_list_sort_ctx sort_ctx = {list->cmp ? list->cmp : strcmp};
247 +
248 + QSORT_S(list->items, list->nr, cmp_items, &sort_ctx);
249 }
250
251 struct string_list_item *unsorted_string_list_lookup(struct string_list *list,