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

[PATCH 02/34] path.c: make get_pathname() call sites return const char *

From
Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Date
Nov 30, 2014, 08:24 UTC
Message-ID
<1417335899-27307-3-git-send-email-pclouds@gmail.com>
In-Reply-To
<1417335899-27307-1-git-send-email-pclouds@gmail.com>

Before the previous commit, get_pathname returns an array of PATH_MAX length. Even if git_path() and similar functions does not use the whole array, git_path() caller can, in theory.

After the commit, get_pathname() may return a buffer that has just enough room for the returned string and git_path() caller should never write beyond that.

Make git_path(), mkpath() and git_path_submodule() return a const buffer to make sure callers do not write in it at all.

This could have been part of the previous commit, but the "const" conversion is too much distraction from the core changes in path.c.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 builtin/checkout.c     | 2 +-
 builtin/clone.c        | 9 +++++----
 builtin/fetch.c        | 5 +++--
 builtin/fsck.c         | 4 ++--
 builtin/receive-pack.c | 2 +-
 builtin/remote.c       | 2 +-
 builtin/repack.c       | 8 +++++---
 cache.h                | 6 +++---
 fast-import.c          | 2 +-
 notes-merge.c          | 6 +++---
 path.c                 | 6 +++---
 refs.c                 | 8 ++++----
 run-command.c          | 4 ++--
 run-command.h          | 2 +-
 sha1_file.c            | 2 +-
 15 files changed, 36 insertions(+), 32 deletions(-)
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 5410dac..c600ec1 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -589,7 +589,7 @@ static void update_refs_for_switch(const struct checkout_opts *opts,
 			if (opts->new_branch_log && !log_all_ref_updates) {
 				int temp;
 				char log_file[PATH_MAX];
-				char *ref_name = mkpath("refs/heads/%s", opts->new_orphan_branch);
+				const char *ref_name = mkpath("refs/heads/%s", opts->new_orphan_branch);
 
 				temp = log_all_ref_updates;
 				log_all_ref_updates = 1;
diff --git a/builtin/clone.c b/builtin/clone.c
index d5e7532..a9af3f2 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -290,16 +290,17 @@ static void copy_alternates(struct strbuf *src, struct strbuf *dst,
 	struct strbuf line = STRBUF_INIT;
 
 	while (strbuf_getline(&line, in, '\n') != EOF) {
-		char *abs_path, abs_buf[PATH_MAX];
+		char *abs_path;
 		if (!line.len || line.buf[0] == '#')
 			continue;
 		if (is_absolute_path(line.buf)) {
 			add_to_alternates_file(line.buf);
 			continue;
 		}
-		abs_path = mkpath("%s/objects/%s", src_repo, line.buf);
-		normalize_path_copy(abs_buf, abs_path);
-		add_to_alternates_file(abs_buf);
+		abs_path = mkpathdup("%s/objects/%s", src_repo, line.buf);
+		normalize_path_copy(abs_path, abs_path);
+		add_to_alternates_file(abs_path);
+		free(abs_path);
 	}
 	strbuf_release(&line);
 	fclose(in);
diff --git a/builtin/fetch.c b/builtin/fetch.c
index 7b84d35..cb54936 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -587,7 +587,8 @@ static int store_updated_refs(const char *raw_url, const char *remote_name,
 	struct strbuf note = STRBUF_INIT;
 	const char *what, *kind;
 	struct ref *rm;
-	char *url, *filename = dry_run ? "/dev/null" : git_path("FETCH_HEAD");
+	char *url;
+	const char *filename = dry_run ? "/dev/null" : git_path("FETCH_HEAD");
 	int want_status;
 
 	fp = fopen(filename, "a");
@@ -821,7 +822,7 @@ static void check_not_current_branch(struct ref *ref_map)
 
 static int truncate_fetch_head(void)
 {
-	char *filename = git_path("FETCH_HEAD");
+	const char *filename = git_path("FETCH_HEAD");
 	FILE *fp = fopen(filename, "w");
 
 	if (!fp)
diff --git a/builtin/fsck.c b/builtin/fsck.c
index a27515a..b92aeff 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -225,12 +225,12 @@ static void check_unreachable_object(struct object *obj)
 			printf("dangling %s %s\n", typename(obj->type),
 			       sha1_to_hex(obj->sha1));
 		if (write_lost_and_found) {
-			char *filename = git_path("lost-found/%s/%s",
+			const char *filename = git_path("lost-found/%s/%s",
 				obj->type == OBJ_COMMIT ? "commit" : "other",
 				sha1_to_hex(obj->sha1));
 			FILE *f;
 
-			if (safe_create_leading_directories(filename)) {
+			if (safe_create_leading_directories_const(filename)) {
 				error("Could not create lost-found");
 				return;
 			}
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 32fc540..3b8f420 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -869,7 +869,7 @@ static void run_update_post_hook(struct command *commands)
 	int argc;
 	const char **argv;
 	struct child_process proc = CHILD_PROCESS_INIT;
-	char *hook;
+	const char *hook;
 
 	hook = find_hook("post-update");
 	for (argc = 0, cmd = commands; cmd; cmd = cmd->next) {
diff --git a/builtin/remote.c b/builtin/remote.c
index 7f28f92..4ce396f 100644
--- a/builtin/remote.c
+++ b/builtin/remote.c
@@ -582,7 +582,7 @@ static int migrate_file(struct remote *remote)
 {
 	struct strbuf buf = STRBUF_INIT;
 	int i;
-	char *path = NULL;
+	const char *path = NULL;
 
 	strbuf_addf(&buf, "remote.%s.url", remote->name);
 	for (i = 0; i < remote->url_nr; i++)
diff --git a/builtin/repack.c b/builtin/repack.c
index 2845620..9c04e1d 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -284,7 +284,8 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	failed = 0;
 	for_each_string_list_item(item, &names) {
 		for (ext = 0; ext < ARRAY_SIZE(exts); ext++) {
-			char *fname, *fname_old;
+			const char *fname_old;
+			char *fname;
 			fname = mkpathdup("%s/pack-%s%s", packdir,
 						item->string, exts[ext].name);
 			if (!file_exists(fname)) {
@@ -312,7 +313,8 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	if (failed) {
 		struct string_list rollback_failure = STRING_LIST_INIT_DUP;
 		for_each_string_list_item(item, &rollback) {
-			char *fname, *fname_old;
+			const char *fname_old;
+			char *fname;
 			fname = mkpathdup("%s/%s", packdir, item->string);
 			fname_old = mkpath("%s/old-%s", packdir, item->string);
 			if (rename(fname_old, fname))
@@ -365,7 +367,7 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	/* Remove the "old-" files */
 	for_each_string_list_item(item, &names) {
 		for (ext = 0; ext < ARRAY_SIZE(exts); ext++) {
-			char *fname;
+			const char *fname;
 			fname = mkpath("%s/old-%s%s",
 					packdir,
 					item->string,
diff --git a/cache.h b/cache.h
index 99ed096..dbee0a3 100644
--- a/cache.h
+++ b/cache.h
@@ -687,9 +687,9 @@ extern char *mkpathdup(const char *fmt, ...)
 	__attribute__((format (printf, 1, 2)));
 
 /* Return a statically allocated filename matching the sha1 signature */
-extern char *mkpath(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
-extern char *git_path(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
-extern char *git_path_submodule(const char *path, const char *fmt, ...)
+extern const char *mkpath(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
+extern const char *git_path(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
+extern const char *git_path_submodule(const char *path, const char *fmt, ...)
 	__attribute__((format (printf, 2, 3)));
 
 /*
diff --git a/fast-import.c b/fast-import.c
index d0bd285..3018130 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -405,7 +405,7 @@ static void dump_marks_helper(FILE *, uintmax_t, struct mark_set *);
 
 static void write_crash_report(const char *err)
 {
-	char *loc = git_path("fast_import_crash_%"PRIuMAX, (uintmax_t) getpid());
+	const char *loc = git_path("fast_import_crash_%"PRIuMAX, (uintmax_t) getpid());
 	FILE *rpt = fopen(loc, "w");
 	struct branch *b;
 	unsigned long lu;
diff --git a/notes-merge.c b/notes-merge.c
index 7eb9d7a..f39e906 100644
--- a/notes-merge.c
+++ b/notes-merge.c
@@ -280,7 +280,7 @@ static void check_notes_merge_worktree(struct notes_merge_options *o)
 				    "(%s exists).", git_path("NOTES_MERGE_*"));
 		}
 
-		if (safe_create_leading_directories(git_path(
+		if (safe_create_leading_directories_const(git_path(
 				NOTES_MERGE_WORKTREE "/.test")))
 			die_errno("unable to create directory %s",
 				  git_path(NOTES_MERGE_WORKTREE));
@@ -295,8 +295,8 @@ static void write_buf_to_worktree(const unsigned char *obj,
 				  const char *buf, unsigned long size)
 {
 	int fd;
-	char *path = git_path(NOTES_MERGE_WORKTREE "/%s", sha1_to_hex(obj));
-	if (safe_create_leading_directories(path))
+	const char *path = git_path(NOTES_MERGE_WORKTREE "/%s", sha1_to_hex(obj));
+	if (safe_create_leading_directories_const(path))
 		die_errno("unable to create directory for '%s'", path);
 	if (file_exists(path))
 		die("found existing file at '%s'", path);
diff --git a/path.c b/path.c
index 015c0e4..a7ceea2 100644
--- a/path.c
+++ b/path.c
@@ -106,7 +106,7 @@ char *mkpathdup(const char *fmt, ...)
 	return strbuf_detach(&sb, NULL);
 }
 
-char *mkpath(const char *fmt, ...)
+const char *mkpath(const char *fmt, ...)
 {
 	va_list args;
 	struct strbuf *pathname = get_pathname();
@@ -116,7 +116,7 @@ char *mkpath(const char *fmt, ...)
 	return cleanup_path(pathname->buf);
 }
 
-char *git_path(const char *fmt, ...)
+const char *git_path(const char *fmt, ...)
 {
 	struct strbuf *pathname = get_pathname();
 	va_list args;
@@ -154,7 +154,7 @@ void home_config_paths(char **global, char **xdg, char *file)
 	free(to_free);
 }
 
-char *git_path_submodule(const char *path, const char *fmt, ...)
+const char *git_path_submodule(const char *path, const char *fmt, ...)
 {
 	struct strbuf *buf = get_pathname();
 	const char *git_dir;
diff --git a/refs.c b/refs.c
index 5ff457e..23617e0 100644
--- a/refs.c
+++ b/refs.c
@@ -1351,7 +1351,7 @@ static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
 {
 	int fd, len;
 	char buffer[128], *p;
-	char *path;
+	const char *path;
 
 	if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
 		return -1;
@@ -2229,7 +2229,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 					    const struct string_list *skip,
 					    int flags, int *type_p)
 {
-	char *ref_file;
+	const char *ref_file;
 	const char *orig_refname = refname;
 	struct ref_lock *lock;
 	int last_errno = 0;
@@ -2303,7 +2303,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 		lock->force_write = 1;
 
  retry:
-	switch (safe_create_leading_directories(ref_file)) {
+	switch (safe_create_leading_directories_const(ref_file)) {
 	case SCLD_OK:
 		break; /* success */
 	case SCLD_VANISHED:
@@ -2743,7 +2743,7 @@ static int rename_tmp_log(const char *newrefname)
 	int attempts_remaining = 4;
 
  retry:
-	switch (safe_create_leading_directories(git_path("logs/%s", newrefname))) {
+	switch (safe_create_leading_directories_const(git_path("logs/%s", newrefname))) {
 	case SCLD_OK:
 		break; /* success */
 	case SCLD_VANISHED:
diff --git a/run-command.c b/run-command.c
index a476999..c4a62aa 100644
--- a/run-command.c
+++ b/run-command.c
@@ -794,9 +794,9 @@ int finish_async(struct async *async)
 #endif
 }
 
-char *find_hook(const char *name)
+const char *find_hook(const char *name)
 {
-	char *path = git_path("hooks/%s", name);
+	const char *path = git_path("hooks/%s", name);
 	if (access(path, X_OK) < 0)
 		path = NULL;
 
diff --git a/run-command.h b/run-command.h
index 2137315..892892d 100644
--- a/run-command.h
+++ b/run-command.h
@@ -52,7 +52,7 @@ int start_command(struct child_process *);
 int finish_command(struct child_process *);
 int run_command(struct child_process *);
 
-extern char *find_hook(const char *name);
+extern const char *find_hook(const char *name);
 LAST_ARG_MUST_BE_NULL
 extern int run_hook_le(const char *const *env, const char *name, ...);
 extern int run_hook_ve(const char *const *env, const char *name, va_list args);
diff --git a/sha1_file.c b/sha1_file.c
index d7f1838..1ed74f9 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -405,7 +405,7 @@ void add_to_alternates_file(const char *reference)
 {
 	struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
 	int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR);
-	char *alt = mkpath("%s\n", reference);
+	const char *alt = mkpath("%s\n", reference);
 	write_or_die(fd, alt, strlen(alt));
 	if (commit_lock_file(lock))
 		die("could not close alternates file");

-- 
2.1.0.rc0.78.gc0d8480
Previous: Nguyễn Thái Ngọc DuyNext: Nguyễn Thái Ngọc Duy
Message 3 of 45 in “nd/multiple-work-trees reroll”
  1. 00/34 nd/multiple-work-trees rerollNguyễn Thái Ngọc Duy, Nov 30, 2014
  2. 01/34 path.c: make get_pathname() return strbuf instead of static bufferNguyễn Thái Ngọc Duy, Nov 30, 2014
  3. 02/34 path.c: make get_pathname() call sites return const char *Nguyễn Thái Ngọc Duy, Nov 30, 2014
  4. 03/34 git_snpath(): retire and replace with strbuf_git_path()Nguyễn Thái Ngọc Duy, Nov 30, 2014
  5. 04/34 path.c: rename vsnpath() to do_git_path()Nguyễn Thái Ngọc Duy, Nov 30, 2014
  6. 05/34 path.c: group git_path(), git_pathdup() and strbuf_git_path() togetherNguyễn Thái Ngọc Duy, Nov 30, 2014
  7. 06/34 git_path(): be aware of file relocation in $GIT_DIRNguyễn Thái Ngọc Duy, Nov 30, 2014
  8. 07/34 *.sh: respect $GIT_INDEX_FILENguyễn Thái Ngọc Duy, Nov 30, 2014
  9. 08/34 reflog: avoid constructing .lock path with git_pathNguyễn Thái Ngọc Duy, Nov 30, 2014
  10. 09/34 fast-import: use git_path() for accessing .git dir instead of get_git_dir()Nguyễn Thái Ngọc Duy, Nov 30, 2014
  11. 10/34 commit: use SEQ_DIR instead of hardcoding "sequencer"Nguyễn Thái Ngọc Duy, Nov 30, 2014
  12. 11/34 $GIT_COMMON_DIR: a new environment variableNguyễn Thái Ngọc Duy, Nov 30, 2014
  13. 12/34 git-sh-setup.sh: use rev-parse --git-path to get $GIT_DIR/objectsNguyễn Thái Ngọc Duy, Nov 30, 2014
  14. 13/34 *.sh: avoid hardcoding $GIT_DIR/hooks/...Nguyễn Thái Ngọc Duy, Nov 30, 2014
  15. 14/34 git-stash: avoid hardcoding $GIT_DIR/logs/....Nguyễn Thái Ngọc Duy, Nov 30, 2014
  16. 15/34 setup.c: convert is_git_directory() to use strbufNguyễn Thái Ngọc Duy, Nov 30, 2014
  17. 16/34 setup.c: detect $GIT_COMMON_DIR in is_git_directory()Nguyễn Thái Ngọc Duy, Nov 30, 2014
  18. 17/34 setup.c: convert check_repository_format_gently to use strbufNguyễn Thái Ngọc Duy, Nov 30, 2014
  19. 18/34 setup.c: detect $GIT_COMMON_DIR check_repository_format_gently()Nguyễn Thái Ngọc Duy, Nov 30, 2014
  20. 19/34 setup.c: support multi-checkout repo setupNguyễn Thái Ngọc Duy, Nov 30, 2014
  21. 20/34 wrapper.c: wrapper to open a file, fprintf then closeNguyễn Thái Ngọc Duy, Nov 30, 2014
  22. 21/34 use new wrapper write_file() for simple file writingNguyễn Thái Ngọc Duy, Nov 30, 2014
  23. 22/34 checkout: support checking out into a new working directoryNguyễn Thái Ngọc Duy, Nov 30, 2014
  24. 23/34 prune: strategies for linked checkoutsNguyễn Thái Ngọc Duy, Nov 30, 2014
  25. 24/34 checkout: reject if the branch is already checked out elsewhereNguyễn Thái Ngọc Duy, Nov 30, 2014
  26. Mark LevedahlNov 30, 2014
  27. Duy NguyenDec 1, 2014
  28. Junio C HamanoDec 1, 2014
  29. Mark LevedahlDec 2, 2014
  30. Duy NguyenDec 2, 2014
  31. Junio C HamanoDec 2, 2014
  32. Mark LevedahlDec 3, 2014
  33. Duy NguyenDec 3, 2014
  34. Junio C HamanoDec 3, 2014
  35. Duy NguyenDec 2, 2014
  36. 25/34 checkout: clean up half-prepared directories in --to modeNguyễn Thái Ngọc Duy, Nov 30, 2014
  37. 26/34 gc: style change -- no SP before closing parenthesisNguyễn Thái Ngọc Duy, Nov 30, 2014
  38. 27/34 gc: factor out gc.pruneexpire parsing codeNguyễn Thái Ngọc Duy, Nov 30, 2014
  39. 28/34 gc: support prune --worktreesNguyễn Thái Ngọc Duy, Nov 30, 2014
  40. 29/34 count-objects: report unused files in $GIT_DIR/worktrees/...Nguyễn Thái Ngọc Duy, Nov 30, 2014
  41. 30/34 git_path(): keep "info/sparse-checkout" per work-treeNguyễn Thái Ngọc Duy, Nov 30, 2014
  42. 31/34 checkout: don't require a work tree when checking out into a new oneNguyễn Thái Ngọc Duy, Nov 30, 2014
  43. 32/34 t2025: add a test to make sure grafts is working from a linked checkoutNguyễn Thái Ngọc Duy, Nov 30, 2014
  44. 33/34 checkout: do not fail if target is an empty directoryNguyễn Thái Ngọc Duy, Nov 30, 2014
  45. 34/34 git-common-dir: make "modules/" per-working-directory directoryNguyễn Thái Ngọc Duy, Nov 30, 2014

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.