Restore shared XML files.

[elogind.git] / CODING_STYLE

diff --git a/CODING_STYLE b/CODING_STYLE
index 0340ff0fa31e0beb53248e5c28f957532114c304..feb1a9dd6715ef3731830e99c4b8bf6019d42773 100644 (file)
--- a/CODING_STYLE
+++ b/CODING_STYLE
@@ -212,3 +212,30 @@
 - 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.