@matheusbsbs / matheus-bagliano / commits / 5e7fe8a7b8

commit-reach: use `size_t` to track indices when computing merge bases

The functions `repo_get_merge_bases_many()` and friends accepts an array of commits as well as a parameter that indicates how large that array is. This parameter is using a signed integer, which leads to a couple of warnings with -Wsign-compare. Refactor the code to use `size_t` to track indices instead and adapt callers accordingly. While most callers are trivial, there are two callers that require a bit more scrutiny: - builtin/merge-base.c:show_merge_base() subtracts `1` from the `rev_nr` before calling `repo_get_merge_bases_many_dirty()`, so if the variable was `0` it would wrap. This code is fine though because its only caller will execute that code only when `argc >= 2`, and it follows that `rev_nr >= 2`, as well. - bisect.ccheck_merge_bases() similarly subtracts `1` from `rev_nr`. Again, there is only a single caller that populates `rev_nr` with `good_revs.nr`. And because a bisection always requires at least one good revision it follws that `rev_nr >= 1`. Mark the file as -Wsign-compare-clean. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Patrick Steinhardt committed Dec 27, 2024 at 11:46 UTC 5e7fe8a7b89a07d8c3ab298ac69bc33f6ba88b47

5 files changed +11 -12

bisect.c

+1 -1

@@ -855,7 +855,7 @@ static void handle_skipped_merge_base(const struct object_id *mb)

855 * for early success, this will be converted back to 0 in

856 * check_good_are_ancestors_of_bad().

857 */

858 -static enum bisect_error check_merge_bases(int rev_nr, struct commit **rev, int no_checkout)

858 +static enum bisect_error check_merge_bases(size_t rev_nr, struct commit **rev, int no_checkout)

859 {

860 enum bisect_error res = BISECT_OK;

861 struct commit_list *result = NULL;

builtin/merge-base.c

+2 -2

@@ -8,7 +8,7 @@

8 #include "parse-options.h"

9 #include "commit-reach.h"

11 -static int show_merge_base(struct commit **rev, int rev_nr, int show_all)

11 +static int show_merge_base(struct commit **rev, size_t rev_nr, int show_all)

12 {

13 struct commit_list *result = NULL, *r;

@@ -149,7 +149,7 @@ int cmd_merge_base(int argc,

149 struct repository *repo UNUSED)

150 {

151 struct commit **rev;

152 - int rev_nr = 0;

152 + size_t rev_nr = 0;

153 int show_all = 0;

154 int cmdmode = 0;

155 int ret;

commit-reach.c

+3 -4

@@ -1,5 +1,4 @@

1 #define USE_THE_REPOSITORY_VARIABLE

2 -#define DISABLE_SIGN_COMPARE_WARNINGS

3 #include "git-compat-util.h"

4 #include "commit.h"

@@ -421,7 +420,7 @@ static int remove_redundant(struct repository *r, struct commit **array,

420

421 static int get_merge_bases_many_0(struct repository *r,

422 struct commit *one,

424 - int n,

423 + size_t n,

424 struct commit **twos,

425 int cleanup,

426 struct commit_list **result)

@@ -469,7 +468,7 @@ static int get_merge_bases_many_0(struct repository *r,

468

469 int repo_get_merge_bases_many(struct repository *r,

470 struct commit *one,

472 - int n,

471 + size_t n,

472 struct commit **twos,

473 struct commit_list **result)

474 {

@@ -478,7 +477,7 @@ int repo_get_merge_bases_many(struct repository *r,

477

478 int repo_get_merge_bases_many_dirty(struct repository *r,

479 struct commit *one,

481 - int n,

480 + size_t n,

481 struct commit **twos,

482 struct commit_list **result)

483 {

commit-reach.h

+2 -2

@@ -14,12 +14,12 @@ int repo_get_merge_bases(struct repository *r,

14 struct commit *rev2,

15 struct commit_list **result);

16 int repo_get_merge_bases_many(struct repository *r,

17 - struct commit *one, int n,

17 + struct commit *one, size_t n,

18 struct commit **twos,

19 struct commit_list **result);

20 /* To be used only when object flags after this call no longer matter */

21 int repo_get_merge_bases_many_dirty(struct repository *r,

22 - struct commit *one, int n,

22 + struct commit *one, size_t n,

23 struct commit **twos,

24 struct commit_list **result);

t/helper/test-reach.c

+3 -3

@@ -35,7 +35,7 @@ int cmd__reach(int ac, const char **av)

35 struct commit_list *X, *Y;

36 struct object_array X_obj = OBJECT_ARRAY_INIT;

37 struct commit **X_array, **Y_array;

38 - int X_nr, X_alloc, Y_nr, Y_alloc;

38 + size_t X_nr, X_alloc, Y_nr, Y_alloc;

39 struct strbuf buf = STRBUF_INIT;

40 struct repository *r = the_repository;

@@ -157,7 +157,7 @@ int cmd__reach(int ac, const char **av)

157 clear_contains_cache(&cache);

158 } else if (!strcmp(av[1], "get_reachable_subset")) {

159 const int reachable_flag = 1;

160 - int i, count = 0;

160 + int count = 0;

161 struct commit_list *current;

162 struct commit_list *list = get_reachable_subset(X_array, X_nr,

163 Y_array, Y_nr,

@@ -169,7 +169,7 @@ int cmd__reach(int ac, const char **av)

169 oid_to_hex(&list->item->object.oid));

170 count++;

171 }

172 - for (i = 0; i < Y_nr; i++) {

172 + for (size_t i = 0; i < Y_nr; i++) {

173 if (Y_array[i]->object.flags & reachable_flag)

174 count--;

175 }