X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=CODING_STYLE;h=feb1a9dd6715ef3731830e99c4b8bf6019d42773;hp=0b1f809e79717812c0fdd007e1ef5786a5f4e916;hb=6e27b4609e949a4fb72c409d50440a6ff63598d5;hpb=dd4540da0e1f983540d862cc657df7161a3bdd06

diff --git a/CODING_STYLE b/CODING_STYLE
index 0b1f809e7..feb1a9dd6 100644
--- a/CODING_STYLE
+++ b/CODING_STYLE
@@ -1,4 +1,5 @@
-- 8ch indent, no tabs
+- 8ch indent, no tabs, except for files in man/ which are 2ch indent,
+  and still no tabs
 
 - Don't break code lines too eagerly. We do *not* force line breaks at
   80ch, all of today's screens should be much larger than that. But
@@ -194,4 +195,47 @@
 - When you allocate a file descriptor, it should be made O_CLOEXEC
   right from the beginning, as none of our files should leak to forked
   binaries by default. Hence, whenever you open a file, O_CLOEXEC must
-  be specified, right from the beginning.
+  be specified, right from the beginning. This also applies to
+  sockets. Effectively this means that all invocations to:
+
+  a) open() must get O_CLOEXEC passed
+  b) socket() and socketpair() must get SOCK_CLOEXEC passed
+  c) recvmsg() must get MSG_CMSG_CLOEXEC set
+  d) F_DUPFD_CLOEXEC should be used instead of F_DUPFD, and so on
+
+- We never use the XDG version of basename(). glibc defines it in
+  libgen.h. The only reason to include that file is because dirname()
+  is needed. Everytime you need that please immediately undefine
+  basename(), and add a comment about it, so that no code ever ends up
+  using the XDG version!
+
+- Use the bool type for booleans, not integers. One exception: in public
+  headers (i.e those in src/systemd/sd-*.h) use integers after all, as "bool"
+  is C99 and in our public APIs we try to stick to C89 (with a few extension).
+
+- When you invoke certain calls like unlink(), or mkdir_p() and you
+  know it is safe to ignore the error it might return (because a later
+  call would detect the failure anyway, or because the error is in an
+  error path and you thus couldn't do anything about it anyway), then
+  make this clear by casting the invocation explicitly to (void). Code
+  checks like Coverity understand that, and will not complain about
+  ignored error codes. Hence, please use this:
+
+      (void) unlink("/foo/bar/baz");
+
+  instead of just this:
+
+      unlink("/foo/bar/baz");
+
+- Don't invoke exit(), ever. It is not replacement for proper error
+  handling. Please escalate errors up your call chain, and use normal
+  "return" to exit from the main function of a process. If you
+  fork()ed off a child process, please use _exit() instead of exit(),
+  so that the exit handlers are not run.
+
+- Please never use dup(). Use fcntl(fd, F_DUPFD_CLOEXEC, 3)
+  instead. For two reason: first, you want O_CLOEXEC set on the new fd
+  (see above). Second, dup() will happily duplicate your fd as 0, 1,
+  2, i.e. stdin, stdout, stderr, should those fds be closed. Given the
+  special semantics of those fds, it's probably a good idea to avoid
+  them. F_DUPFD_CLOEXEC with "3" as parameter avoids them.