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author | Lennart Poettering <lennart@poettering.net> | 2018-03-22 16:53:26 +0100 |
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committer | Lennart Poettering <lennart@poettering.net> | 2018-03-22 20:21:42 +0100 |
commit | ae2a15bc14bc448e625ad93fd044bc077ede4b3f (patch) | |
tree | e503e6cf3b571d0a150dc2cea7d1838f55aaa6ab /src/basic/fs-util.c | |
parent | 1147eef0b6a5937526247ff81ca1e5e45205ed16 (diff) | |
download | systemd-ae2a15bc14bc448e625ad93fd044bc077ede4b3f.tar.gz |
macro: introduce TAKE_PTR() macro
This macro will read a pointer of any type, return it, and set the
pointer to NULL. This is useful as an explicit concept of passing
ownership of a memory area between pointers.
This takes inspiration from Rust:
https://doc.rust-lang.org/std/option/enum.Option.html#method.take
and was suggested by Alan Jenkins (@sourcejedi).
It drops ~160 lines of code from our codebase, which makes me like it.
Also, I think it clarifies passing of ownership, and thus helps
readability a bit (at least for the initiated who know the new macro)
Diffstat (limited to 'src/basic/fs-util.c')
-rw-r--r-- | src/basic/fs-util.c | 19 |
1 files changed, 7 insertions, 12 deletions
diff --git a/src/basic/fs-util.c b/src/basic/fs-util.c index c65ba4bfe5..aec8b00744 100644 --- a/src/basic/fs-util.c +++ b/src/basic/fs-util.c @@ -458,10 +458,8 @@ int get_files_in_directory(const char *path, char ***list) { n++; } - if (list) { - *list = l; - l = NULL; /* avoid freeing */ - } + if (list) + *list = TAKE_PTR(l); return n; } @@ -838,10 +836,9 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags, } /* If this is not a symlink, then let's just add the name we read to what we already verified. */ - if (!done) { - done = first; - first = NULL; - } else { + if (!done) + done = TAKE_PTR(first); + else { /* If done is "/", as first also contains slash at the head, then remove this redundant slash. */ if (streq(done, "/")) *done = '\0'; @@ -863,10 +860,8 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags, return -ENOMEM; } - if (ret) { - *ret = done; - done = NULL; - } + if (ret) + *ret = TAKE_PTR(done); if (flags & CHASE_OPEN) { int q; |