Subject: [GSoC PATCH v3] pathspec: fix sign comparison warnings

From: Arnav Bhate <[email-masked]>
Date: Sun, 30 Mar 2025 23:15:06 +0530

There are multiple places, especially in loops, where a signed and an
unsigned data type are compared. Git uses a mix of signed and unsigned
types to store lengths of arrays. This sometimes leads to using a signed
index for an array whose length is stored in an unsigned variable or
vice versa. In some cases, where both signed and unsigned data types
have been used to store lengths of arrays in the same function, only
one variable was used to iterate over both types.

Replace signed data types with unsigned data types and vice versa
wherever necessary. Where both types of iterators are required, move
the declaration inside the for loop. In cases where this is not
possible, add appropriate cast.

Remove #define DISABLE_SIGN_COMPARE_WARNINGS.

Signed-off-by: Arnav Bhate <[email-masked]>
---
 pathspec.c | 32 +++++++++++++++++---------------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/pathspec.c b/pathspec.c
index 89663645e1..2b4e434bc0 100644
--- a/pathspec.c
+++ b/pathspec.c
@@ -1,5 +1,4 @@
 #define USE_THE_REPOSITORY_VARIABLE
-#define DISABLE_SIGN_COMPARE_WARNINGS
 
 #include "git-compat-util.h"
 #include "abspath.h"
@@ -35,7 +34,7 @@ void add_pathspec_matches_against_index(const struct pathspec *pathspec,
 					char *seen,
 					enum ps_skip_worktree_action sw_action)
 {
-	int num_unmatched = 0, i;
+	int num_unmatched = 0;
 
 	/*
 	 * Since we are walking the index as if we were walking the directory,
@@ -43,12 +42,12 @@ void add_pathspec_matches_against_index(const struct pathspec *pathspec,
 	 * mistakenly think that the user gave a pathspec that did not match
 	 * anything.
 	 */
-	for (i = 0; i < pathspec->nr; i++)
+	for (int i = 0; i < pathspec->nr; i++)
 		if (!seen[i])
 			num_unmatched++;
 	if (!num_unmatched)
 		return;
-	for (i = 0; i < istate->cache_nr; i++) {
+	for (unsigned int i = 0; i < istate->cache_nr; i++) {
 		const struct cache_entry *ce = istate->cache[i];
 		if (sw_action == PS_IGNORE_SKIP_WORKTREE &&
 		    (ce_skip_worktree(ce) || !path_in_sparse_checkout(ce->name, istate)))
@@ -78,7 +77,7 @@ char *find_pathspecs_matching_skip_worktree(const struct pathspec *pathspec)
 {
 	struct index_state *istate = the_repository->index;
 	char *seen = xcalloc(pathspec->nr, 1);
-	int i;
+	unsigned int i;
 
 	for (i = 0; i < istate->cache_nr; i++) {
 		struct cache_entry *ce = istate->cache[i];
@@ -130,7 +129,7 @@ static void prefix_magic(struct strbuf *sb, int prefixlen,
 	if (element[1] != '(') {
 		/* Process an element in shorthand form (e.g. ":!/<match>") */
 		strbuf_addstr(sb, ":(");
-		for (int i = 0; i < ARRAY_SIZE(pathspec_magic); i++) {
+		for (unsigned int i = 0; i < ARRAY_SIZE(pathspec_magic); i++) {
 			if ((magic & pathspec_magic[i].bit) &&
 			    pathspec_magic[i].mnemonic) {
 				if (sb->buf[sb->len - 1] != '(')
@@ -341,7 +340,7 @@ static const char *parse_long_magic(unsigned *magic, int *prefix_len,
 
 	for (pos = elem + 2; *pos && *pos != ')'; pos = nextat) {
 		size_t len = strcspn_escaped(pos, ",)");
-		int i;
+		unsigned int i;
 
 		if (pos[len] == ',')
 			nextat = pos + len + 1; /* handle ',' */
@@ -354,7 +353,7 @@ static const char *parse_long_magic(unsigned *magic, int *prefix_len,
 		if (starts_with(pos, "prefix:")) {
 			char *endptr;
 			*prefix_len = strtol(pos + 7, &endptr, 10);
-			if (endptr - pos != len)
+			if ((size_t)(endptr - pos) != len)
 				die(_("invalid parameter for pathspec magic 'prefix'"));
 			continue;
 		}
@@ -400,7 +399,7 @@ static const char *parse_short_magic(unsigned *magic, const char *elem)
 
 	for (pos = elem + 1; *pos && *pos != ':'; pos++) {
 		char ch = *pos;
-		int i;
+		unsigned int i;
 
 		/* Special case alias for '!' */
 		if (ch == '^') {
@@ -564,7 +563,7 @@ static int pathspec_item_cmp(const void *a_, const void *b_)
 
 void pathspec_magic_names(unsigned magic, struct strbuf *out)
 {
-	int i;
+	unsigned int i;
 	for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++) {
 		const struct pathspec_magic *m = pathspec_magic + i;
 		if (!(magic & m->bit))
@@ -803,8 +802,8 @@ int match_pathspec_attrs(struct index_state *istate,
 int pathspec_needs_expanded_index(struct index_state *istate,
 				  const struct pathspec *pathspec)
 {
-	unsigned int i, pos;
-	int res = 0;
+	unsigned int pos;
+	int i, res = 0;
 	char *skip_worktree_seen = NULL;
 
 	/*
@@ -845,7 +844,8 @@ int pathspec_needs_expanded_index(struct index_state *istate,
 			 * - not-in-cone/bar*: may need expanded index
 			 * - **.c: may need expanded index
 			 */
-			if (strspn(item.original + item.nowildcard_len, "*") == item.len - item.nowildcard_len &&
+			if (strspn(item.original + item.nowildcard_len, "*") ==
+				    (unsigned int)(item.len - item.nowildcard_len) &&
 			    path_in_cone_mode_sparse_checkout(item.original, istate))
 				continue;
 
@@ -860,8 +860,10 @@ int pathspec_needs_expanded_index(struct index_state *istate,
 				 * directory name and the sparse directory is the first
 				 * component of the pathspec, need to expand the index.
 				 */
-				if (item.nowildcard_len > ce_namelen(ce) &&
-				    !strncmp(item.original, ce->name, ce_namelen(ce))) {
+				if ((unsigned int)item.nowildcard_len >
+					    ce_namelen(ce) &&
+				    !strncmp(item.original, ce->name,
+					     ce_namelen(ce))) {
 					res = 1;
 					break;
 				}
-- 
2.49.0