From 3b319885c4febb5f7ea9b5ab31c3395548ed6886 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= Date: Sun, 16 Oct 2016 19:23:35 -0400 Subject: [PATCH] tree-wide: introduce free_and_replace helper It's a common pattern, so add a helper for it. A macro is necessary because a function that takes a pointer to a pointer would be type specific, similarly to cleanup functions. Seems better to use a macro. --- coccinelle/free_and_replace.cocci | 15 +++++++++++++++ src/basic/alloc-util.h | 8 ++++++++ src/basic/fs-util.c | 8 ++------ src/basic/path-util.c | 4 +--- src/core/load-fragment.c | 10 ++-------- src/core/mount.c | 14 +++----------- src/core/service.c | 4 +--- src/journal-remote/journal-upload.c | 4 +--- src/shared/install.c | 10 ++-------- 9 files changed, 35 insertions(+), 42 deletions(-) create mode 100644 coccinelle/free_and_replace.cocci diff --git a/coccinelle/free_and_replace.cocci b/coccinelle/free_and_replace.cocci new file mode 100644 index 0000000000..9dcdbf4d42 --- /dev/null +++ b/coccinelle/free_and_replace.cocci @@ -0,0 +1,15 @@ +@@ +expression p, q; +@@ +- free(p); +- p = q; +- q = NULL; +- return 0; ++ return free_and_replace(p, q); +@@ +expression p, q; +@@ +- free(p); +- p = q; +- q = NULL; ++ free_and_replace(p, q); diff --git a/src/basic/alloc-util.h b/src/basic/alloc-util.h index ceeee519b7..a44dd473c1 100644 --- a/src/basic/alloc-util.h +++ b/src/basic/alloc-util.h @@ -43,6 +43,14 @@ static inline void *mfree(void *memory) { return NULL; } +#define free_and_replace(a, b) \ + ({ \ + free(a); \ + (a) = (b); \ + (b) = NULL; \ + 0; \ + }) + void* memdup(const void *p, size_t l) _alloc_(2); static inline void freep(void *p) { diff --git a/src/basic/fs-util.c b/src/basic/fs-util.c index 86d9ad7e36..48952a1c26 100644 --- a/src/basic/fs-util.c +++ b/src/basic/fs-util.c @@ -678,9 +678,7 @@ int chase_symlinks(const char *path, const char *_root, char **ret) { !path_startswith(parent, root)) return -EINVAL; - free(done); - done = parent; - parent = NULL; + free_and_replace(done, parent); fd_parent = openat(fd, "..", O_CLOEXEC|O_NOFOLLOW|O_PATH); if (fd_parent < 0) @@ -724,9 +722,7 @@ int chase_symlinks(const char *path, const char *_root, char **ret) { if (fd < 0) return -errno; - free(buffer); - buffer = destination; - destination = NULL; + free_and_replace(buffer, destination); todo = buffer; free(done); diff --git a/src/basic/path-util.c b/src/basic/path-util.c index a76963aa9f..0f5b20cf05 100644 --- a/src/basic/path-util.c +++ b/src/basic/path-util.c @@ -288,9 +288,7 @@ char **path_strv_resolve(char **l, const char *prefix) { } else { /* canonicalized path goes outside of * prefix, keep the original path instead */ - free(u); - u = orig; - orig = NULL; + free_and_replace(u, orig); } } else free(t); diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c index 06c156a623..8cc7a8e765 100644 --- a/src/core/load-fragment.c +++ b/src/core/load-fragment.c @@ -1591,11 +1591,7 @@ int config_parse_fdname( return 0; } - free(s->fdname); - s->fdname = p; - p = NULL; - - return 0; + return free_and_replace(s->fdname, p); } int config_parse_service_sockets( @@ -2052,9 +2048,7 @@ int config_parse_working_directory( return 0; } - free(c->working_directory); - c->working_directory = k; - k = NULL; + free_and_replace(c->working_directory, k); c->working_directory_home = false; } diff --git a/src/core/mount.c b/src/core/mount.c index 15619dffe3..da480001e1 100644 --- a/src/core/mount.c +++ b/src/core/mount.c @@ -1484,17 +1484,9 @@ static int mount_setup_unit( MOUNT(u)->from_proc_self_mountinfo = true; - free(p->what); - p->what = w; - w = NULL; - - free(p->options); - p->options = o; - o = NULL; - - free(p->fstype); - p->fstype = f; - f = NULL; + free_and_replace(p->what, w); + free_and_replace(p->options, o); + free_and_replace(p->fstype, f); if (load_extras) { r = mount_add_extras(MOUNT(u)); diff --git a/src/core/service.c b/src/core/service.c index 63045ede55..c949de9cbe 100644 --- a/src/core/service.c +++ b/src/core/service.c @@ -3088,9 +3088,7 @@ static void service_notify_message(Unit *u, pid_t pid, char **tags, FDSet *fds) if (!streq_ptr(s->status_text, t)) { - free(s->status_text); - s->status_text = t; - t = NULL; + free_and_replace(s->status_text, t); notify_dbus = true; } diff --git a/src/journal-remote/journal-upload.c b/src/journal-remote/journal-upload.c index c0f967ab94..61190ff83c 100644 --- a/src/journal-remote/journal-upload.c +++ b/src/journal-remote/journal-upload.c @@ -527,9 +527,7 @@ static int perform_upload(Uploader *u) { log_debug("Upload finished successfully with code %ld: %s", status, strna(u->answer)); - free(u->last_cursor); - u->last_cursor = u->current_cursor; - u->current_cursor = NULL; + free_and_replace(u->last_cursor, u->current_cursor); return update_cursor_state(u); } diff --git a/src/shared/install.c b/src/shared/install.c index c1ef62b337..f70b3e3dd5 100644 --- a/src/shared/install.c +++ b/src/shared/install.c @@ -1107,11 +1107,7 @@ static int config_parse_default_instance( if (!unit_instance_is_valid(printed)) return -EINVAL; - free(i->default_instance); - i->default_instance = printed; - printed = NULL; - - return 0; + return free_and_replace(i->default_instance, printed); } static int unit_file_load( @@ -1357,9 +1353,7 @@ static int install_info_follow( if (!streq(basename(i->symlink_target), i->name)) return -EXDEV; - free(i->path); - i->path = i->symlink_target; - i->symlink_target = NULL; + free_and_replace(i->path, i->symlink_target); i->type = _UNIT_FILE_TYPE_INVALID; return unit_file_load_or_readlink(c, i, i->path, root_dir, flags);