@matheusbsbs / matheus-bagliano / commits / ac95f5d36a

built-ins: use free() not UNLEAK() if trivial, rm dead code

For a lot of uses of UNLEAK() it would be quite tricky to release the memory involved, or we're missing the relevant *_(release|clear)() functions. But in these cases we have them already, and can just invoke them on the variable(s) involved, instead of UNLEAK(). For "builtin/worktree.c" the UNLEAK() was also added in [1], but the struct member it's unleaking was removed in [2]. The only non-"int" member of that structure is "const char *keep_locked", which comes to us via "argv" or a string literal[3]. We have good visibility via the compiler and tooling (e.g. SANITIZE=address) on bad free()-ing, but none on UNLEAK() we don't need anymore. So let's prefer releasing the memory when it's easy. For "bugreport", "worktree" and "config" we need to start using a "ret = ..." return pattern. For "builtin/bugreport.c" these UNLEAK() were added in [4], and for "builtin/config.c" in [1]. For "config" the code seen here was the only user of the "value" variable. For "ACTION_{RENAME,REMOVE}_SECTION" we need to be sure to return the right exit code in the cases where we were relying on falling through to the top-level. I think there's still a use-case for UNLEAK(), but hat it's changed since then. Using it so that "we can see the real leaks" is counter-productive in these cases. It's more useful to have UNLEAK() be a marker of the remaining odd cases where it's hard to free() the memory for whatever reason. With this change less than 20 of them remain in-tree. 1. 0e5bba53af7 (add UNLEAK annotation for reducing leak false positives, 2017-09-08) 2. d861d34a6ed (worktree: remove extra members from struct add_opts, 2018-04-24) 3. 0db4961c49b (worktree: teach `add` to accept --reason <string> with --lock, 2021-07-15) 4. 0e5bba53af7 and 00d8c311050 (commit: fix "author_ident" leak, 2022-05-12). Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Taylor Blau <me@ttaylorr.com>

Ævar Arnfjörð Bjarmason committed Nov 8, 2022 at 19:17 UTC ac95f5d36adb42980064587fd7910fa275ff853e

6 files changed +35 -33

builtin/add.c

+1 -1

@@ -695,6 +695,6 @@ finish:

695 die(_("Unable to write new index file"));

696

697 dir_clear(&dir);

698 - UNLEAK(pathspec);

698 + clear_pathspec(&pathspec);

699 return exit_status;

700 }

builtin/bugreport.c

+6 -3

@@ -106,6 +106,7 @@ int cmd_bugreport(int argc, const char **argv, const char *prefix)

106 const char *user_relative_path = NULL;

107 char *prefixed_filename;

108 size_t output_path_len;

109 + int ret;

110

111 const struct option bugreport_options[] = {

112 OPT_CALLBACK_F(0, "diagnose", &diagnose, N_("mode"),

@@ -182,7 +183,9 @@ int cmd_bugreport(int argc, const char **argv, const char *prefix)

183 user_relative_path);

184

185 free(prefixed_filename);

185 - UNLEAK(buffer);

186 - UNLEAK(report_path);

187 - return !!launch_editor(report_path.buf, NULL, NULL);

186 + strbuf_release(&buffer);

187 +

188 + ret = !!launch_editor(report_path.buf, NULL, NULL);

189 + strbuf_release(&report_path);

190 + return ret;

191 }

builtin/commit.c

+3 -3

@@ -1874,8 +1874,8 @@ int cmd_commit(int argc, const char **argv, const char *prefix)

1874 apply_autostash(git_path_merge_autostash(the_repository));

1875

1876 cleanup:

1877 - UNLEAK(author_ident);

1878 - UNLEAK(err);

1879 - UNLEAK(sb);

1877 + strbuf_release(&author_ident);

1878 + strbuf_release(&err);

1879 + strbuf_release(&sb);

1880 return ret;

1881 }

builtin/config.c

+20 -22

@@ -639,8 +639,9 @@ static char *default_user_config(void)

639 int cmd_config(int argc, const char **argv, const char *prefix)

640 {

641 int nongit = !startup_info->have_repository;

642 - char *value;

642 + char *value = NULL;

643 int flags = 0;

644 + int ret = 0;

645

646 given_config_source.file = xstrdup_or_null(getenv(CONFIG_ENVIRONMENT));

647

@@ -856,44 +857,38 @@ int cmd_config(int argc, const char **argv, const char *prefix)

857 free(config_file);

858 }

859 else if (actions == ACTION_SET) {

859 - int ret;

860 check_write();

861 check_argc(argc, 2, 2);

862 value = normalize_value(argv[0], argv[1]);

863 - UNLEAK(value);

863 ret = git_config_set_in_file_gently(given_config_source.file, argv[0], value);

864 if (ret == CONFIG_NOTHING_SET)

865 error(_("cannot overwrite multiple values with a single value\n"

866 " Use a regexp, --add or --replace-all to change %s."), argv[0]);

868 - return ret;

867 }

868 else if (actions == ACTION_SET_ALL) {

869 check_write();

870 check_argc(argc, 2, 3);

871 value = normalize_value(argv[0], argv[1]);

874 - UNLEAK(value);

875 - return git_config_set_multivar_in_file_gently(given_config_source.file,

876 - argv[0], value, argv[2],

877 - flags);

872 + ret = git_config_set_multivar_in_file_gently(given_config_source.file,

873 + argv[0], value, argv[2],

874 + flags);

875 }

876 else if (actions == ACTION_ADD) {

877 check_write();

878 check_argc(argc, 2, 2);

879 value = normalize_value(argv[0], argv[1]);

883 - UNLEAK(value);

884 - return git_config_set_multivar_in_file_gently(given_config_source.file,

885 - argv[0], value,

886 - CONFIG_REGEX_NONE,

887 - flags);

880 + ret = git_config_set_multivar_in_file_gently(given_config_source.file,

881 + argv[0], value,

882 + CONFIG_REGEX_NONE,

883 + flags);

884 }

885 else if (actions == ACTION_REPLACE_ALL) {

886 check_write();

887 check_argc(argc, 2, 3);

888 value = normalize_value(argv[0], argv[1]);

893 - UNLEAK(value);

894 - return git_config_set_multivar_in_file_gently(given_config_source.file,

895 - argv[0], value, argv[2],

896 - flags | CONFIG_FLAGS_MULTI_REPLACE);

889 + ret = git_config_set_multivar_in_file_gently(given_config_source.file,

890 + argv[0], value, argv[2],

891 + flags | CONFIG_FLAGS_MULTI_REPLACE);

892 }

893 else if (actions == ACTION_GET) {

894 check_argc(argc, 1, 2);

@@ -934,26 +929,28 @@ int cmd_config(int argc, const char **argv, const char *prefix)

929 flags | CONFIG_FLAGS_MULTI_REPLACE);

930 }

931 else if (actions == ACTION_RENAME_SECTION) {

937 - int ret;

932 check_write();

933 check_argc(argc, 2, 2);

934 ret = git_config_rename_section_in_file(given_config_source.file,

935 argv[0], argv[1]);

936 if (ret < 0)

937 return ret;

944 - if (ret == 0)

938 + else if (!ret)

939 die(_("no such section: %s"), argv[0]);

940 + else

941 + ret = 0;

942 }

943 else if (actions == ACTION_REMOVE_SECTION) {

948 - int ret;

944 check_write();

945 check_argc(argc, 1, 1);

946 ret = git_config_rename_section_in_file(given_config_source.file,

947 argv[0], NULL);

948 if (ret < 0)

949 return ret;

955 - if (ret == 0)

950 + else if (!ret)

951 die(_("no such section: %s"), argv[0]);

952 + else

953 + ret = 0;

954 }

955 else if (actions == ACTION_GET_COLOR) {

956 check_argc(argc, 1, 2);

@@ -966,5 +963,6 @@ int cmd_config(int argc, const char **argv, const char *prefix)

963 return get_colorbool(argv[0], argc == 2);

964 }

965

969 - return 0;

966 + free(value);

967 + return ret;

968 }

builtin/diff.c

+1 -1

@@ -609,7 +609,7 @@ int cmd_diff(int argc, const char **argv, const char *prefix)

609 if (1 < rev.diffopt.skip_stat_unmatch)

610 refresh_index_quietly();

611 release_revisions(&rev);

612 - UNLEAK(ent);

612 + object_array_clear(&ent);

613 UNLEAK(blob);

614 return result;

615 }

builtin/worktree.c

+4 -3

@@ -629,6 +629,7 @@ static int add(int ac, const char **av, const char *prefix)

629 N_("try to match the new branch name with a remote-tracking branch")),

630 OPT_END()

631 };

632 + int ret;

633

634 memset(&opts, 0, sizeof(opts));

635 opts.checkout = 1;

@@ -705,9 +706,9 @@ static int add(int ac, const char **av, const char *prefix)

706 die(_("--[no-]track can only be used if a new branch is created"));

707 }

708

708 - UNLEAK(path);

709 - UNLEAK(opts);

710 - return add_worktree(path, branch, &opts);

709 + ret = add_worktree(path, branch, &opts);

710 + free(path);

711 + return ret;

712 }

713

714 static void show_worktree_porcelain(struct worktree *wt, int line_terminator)