git/list[1] front-page[2] threads[3] people[4] search[5] about
 

[PATCH v2 4/8] string-list: enable sign compare warnings check

From
shejialuo <shejialuo@gmail.com>
Date
May 18, 2025, 15:57 UTC
Message-ID
<aCoDY4A62uWb-_MV@ArchLinux>
In-Reply-To
<aCoDB9P5XV1lHMil@ArchLinux>

The only sign compare warning in "string-list" is that we compare the `index` of the `int` type with the `list->nr` of unsigned type. We get index by calling "get_entry_index", which would always return unsigned index.

Let's change the return type of "get_entry_index" to be "size_t" by slightly modifying the binary search algorithm. Instead of letting "left" to be "-1" initially, assign 0 to it.

Then, we could delete "#define DISABLE_SIGN_COMPARE_WARNING" to enable sign warnings check for "string-list"

Signed-off-by: shejialuo <shejialuo@gmail.com>
---
 string-list.c | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)
diff --git a/string-list.c b/string-list.c
index 171cef5dbb..53faaa8420 100644
--- a/string-list.c
+++ b/string-list.c
@@ -1,5 +1,3 @@
-#define DISABLE_SIGN_COMPARE_WARNINGS
-
 #include "git-compat-util.h"
 #include "string-list.h"
 
@@ -17,19 +15,19 @@ void string_list_init_dup(struct string_list *list)
 
 /* if there is no exact match, point to the index where the entry could be
  * inserted */
-static int get_entry_index(const struct string_list *list, const char *string,
-		int *exact_match)
+static size_t get_entry_index(const struct string_list *list, const char *string,
+			      int *exact_match)
 {
-	int left = -1, right = list->nr;
+	size_t left = 0, right = list->nr;
 	compare_strings_fn cmp = list->cmp ? list->cmp : strcmp;
 
-	while (left + 1 < right) {
-		int middle = left + (right - left) / 2;
+	while (left < right) {
+		size_t middle = left + (right - left) / 2;
 		int compare = cmp(string, list->items[middle].string);
 		if (compare < 0)
 			right = middle;
 		else if (compare > 0)
-			left = middle;
+			left = middle + 1;
 		else {
 			*exact_match = 1;
 			return middle;
@@ -40,10 +38,10 @@ static int get_entry_index(const struct string_list *list, const char *string,
 	return right;
 }
 
-static int add_entry(struct string_list *list, const char *string)
+static size_t add_entry(struct string_list *list, const char *string)
 {
 	int exact_match = 0;
-	int index = get_entry_index(list, string, &exact_match);
+	size_t index = get_entry_index(list, string, &exact_match);
 
 	if (exact_match)
 		return index;
@@ -62,7 +60,7 @@ static int add_entry(struct string_list *list, const char *string)
 
 struct string_list_item *string_list_insert(struct string_list *list, const char *string)
 {
-	int index = add_entry(list, string);
+	size_t index = add_entry(list, string);
 
 	return list->items + index;
 }
-- 
2.49.0
Previous: shejialuoNext: Patrick Steinhardt
Message 31 of 52 in “enhance "string_list" code and test”
  1. 0/5 enhance "string_list" code and testshejialuo, Apr 22, 2025
  2. 1/5 string-list: fix sign compare warningsshejialuo, Apr 22, 2025
  3. Junio C HamanoApr 22, 2025
  4. shejialuoApr 24, 2025
  5. 2/5 u-string-list: move "test_split" into "u-string-list.c"shejialuo, Apr 22, 2025
  6. Junio C HamanoApr 22, 2025
  7. shejialuoApr 24, 2025
  8. Patrick SteinhardtApr 23, 2025
  9. shejialuoApr 24, 2025
  10. 3/5 u-string-list: move "test_split_in_place" to "u-string-list.c"shejialuo, Apr 22, 2025
  11. Patrick SteinhardtApr 23, 2025
  12. 4/5 u-string-list: move "filter string" test to "u-string-list.c"shejialuo, Apr 22, 2025
  13. 5/5 u-string-list: move "remove duplicates" test to "u-string-list.c"shejialuo, Apr 22, 2025
  14. Patrick SteinhardtApr 23, 2025
  15. shejialuoApr 24, 2025
  16. 0/8 enhance "string_list" code and testshejialuo, May 18, 2025
  17. 1/8 string-list: fix sign compare warnings for loop iteratorshejialuo, May 18, 2025
  18. Patrick SteinhardtMay 19, 2025
  19. shejialuoMay 26, 2025
  20. 2/8 string-list: remove unused "insert_at" parameter from add_entryshejialuo, May 18, 2025
  21. Patrick SteinhardtMay 19, 2025
  22. shejialuoMay 26, 2025
  23. Jeff KingMay 19, 2025
  24. shejialuoMay 26, 2025
  25. Patrick SteinhardtMay 26, 2025
  26. 3/8 string-list: return index directly when inserting an existing elementshejialuo, May 18, 2025
  27. Patrick SteinhardtMay 19, 2025
  28. shejialuoMay 26, 2025
  29. Jeff KingMay 19, 2025
  30. shejialuoMay 26, 2025
  31. 4/8 string-list: enable sign compare warnings checkshejialuo, May 18, 2025
  32. Patrick SteinhardtMay 19, 2025
  33. shejialuoMay 26, 2025
  34. 5/8 u-string-list: move "test_split" into "u-string-list.c"shejialuo, May 18, 2025
  35. Patrick SteinhardtMay 19, 2025
  36. 6/8 u-string-list: move "test_split_in_place" to "u-string-list.c"shejialuo, May 18, 2025
  37. 7/8 u-string-list: move "filter string" test to "u-string-list.c"shejialuo, May 18, 2025
  38. Patrick SteinhardtMay 19, 2025
  39. shejialuoMay 26, 2025
  40. 8/8 u-string-list: move "remove duplicates" test to "u-string-list.c"shejialuo, May 18, 2025
  41. Patrick SteinhardtMay 19, 2025
  42. 0/8 enhance "string_list" code and testshejialuo, Jun 29, 2025
  43. 1/8 string-list: fix sign compare warnings for loop iteratorshejialuo, Jun 29, 2025
  44. 2/8 string-list: remove unused "insert_at" parameter from add_entryshejialuo, Jun 29, 2025
  45. 3/8 string-list: return index directly when inserting an existing elementshejialuo, Jun 29, 2025
  46. 4/8 string-list: enable sign compare warnings checkshejialuo, Jun 29, 2025
  47. 5/8 u-string-list: move "test_split" into "u-string-list.c"shejialuo, Jun 29, 2025
  48. 6/8 u-string-list: move "test_split_in_place" to "u-string-list.c"shejialuo, Jun 29, 2025
  49. 7/8 u-string-list: move "filter string" test to "u-string-list.c"shejialuo, Jun 29, 2025
  50. 8/8 u-string-list: move "remove duplicates" test to "u-string-list.c"shejialuo, Jun 29, 2025
  51. Patrick SteinhardtJul 4, 2025
  52. Junio C HamanoJul 7, 2025

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.