commit f1fe9671e was supposed to make sure we use files.h
macros to avoid double close, but it didn't work.
Meanwhile, virCommand is vastly superior to system(), fork(),
and popen() (also to virExec, but we haven't completed that
conversion), so enforce that, too.
* cfg.mk (sc_prohibit_close): Fix typo that excluded close, and
add pclose.
(sc_prohibit_fork_wrappers): New rule, for fork, system, and popen.
* .x-sc_prohibit_close: More exemptions.
* .x-sc_prohibit_fork_wrappers: New file.
* Makefile.am (syntax_check_exceptions): Ship new file.
* src/datatypes.c (virReleaseConnect): Tweak comment to avoid
false positive.
* src/util/files.h (VIR_CLOSE): Likewise.
Similarly to deprecating close(), I am now deprecating fclose() and
introduce VIR_FORCE_FCLOSE() and VIR_FCLOSE(). Also, fdopen() is replaced with
VIR_FDOPEN().
Most of the files are opened in read-only mode, so usage of
VIR_FORCE_CLOSE() seemed appropriate. Others that are opened in write
mode already had the fclose()< 0 check and I converted those to
VIR_FCLOSE()< 0.
I did not find occurrences of possible double-closed files on the way.
Since bugs due to double-closed file descriptors are difficult to track down in a multi-threaded system, I am introducing the VIR_CLOSE(fd) macro to help avoid mistakes here.
There are lots of places where close() is being used. In this patch I am only cleaning up usage of close() in src/conf where the problems were.
I also dare to declare close() as being deprecated in libvirt code base (HACKING).
