From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from localhost (localhost [127.0.0.1]) by olra.theworths.org (Postfix) with ESMTP id B3052431FBD for ; Sat, 25 Jan 2014 14:23:00 -0800 (PST) X-Virus-Scanned: Debian amavisd-new at olra.theworths.org X-Spam-Flag: NO X-Spam-Score: 0 X-Spam-Level: X-Spam-Status: No, score=0 tagged_above=-999 required=5 tests=[none] autolearn=disabled Received: from olra.theworths.org ([127.0.0.1]) by localhost (olra.theworths.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 7I2ZIumpBa2J for ; Sat, 25 Jan 2014 14:22:52 -0800 (PST) Received: from guru.guru-group.fi (guru.guru-group.fi [46.183.73.34]) by olra.theworths.org (Postfix) with ESMTP id 3D483431FBC for ; Sat, 25 Jan 2014 14:22:52 -0800 (PST) Received: from guru.guru-group.fi (localhost [IPv6:::1]) by guru.guru-group.fi (Postfix) with ESMTP id AD40A1000B3 for ; Sun, 26 Jan 2014 00:22:47 +0200 (EET) From: Tomi Ollila To: notmuch@notmuchmail.org Subject: Re: [RFC PATCH] configure: check for POSIX.1-2008 realpath(3) implementation. In-Reply-To: <1390687142-16401-1-git-send-email-tomi.ollila@iki.fi> References: <1390687142-16401-1-git-send-email-tomi.ollila@iki.fi> User-Agent: Notmuch/0.17+41~g8e7fabf (http://notmuchmail.org) Emacs/24.3.1 (x86_64-unknown-linux-gnu) X-Face: HhBM'cA~ MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: notmuch@notmuchmail.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: "Use and development of the notmuch mail system." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 25 Jan 2014 22:23:00 -0000 On Sat, Jan 25 2014, Tomi Ollila wrote: > Check whether realpath(3) supports the resolved_path == NULL feature, > standardized in POSIX.1-2008. > > This is tested by executing the realpath(3) with NULL as second > argument and the program is expected to SIGSEGV in case the > feature is not supported. > > If the feature is not supported the compatibility code calls realpath(3) > with second argument pointing to buffer with MAX_PATH in size. With > this more systems are supported; those that have POSIX.1-2008 -capable > realpath(3) and those that have MAX_PATH defined and realpath(3) does > not exceed that limit. > --- > > I tested running configure and then make test; then make clean, > edited Makefile.config POSIX_2008_REALPATH = 0 and make clean > again. then tested sigsegv'ing with (memcpy(0, 0, 4)... > > > configure | 32 ++++++++++++++++++++++++++++++-- > notmuch-config.c | 21 ++++++++++++++++++++- > 2 files changed, 50 insertions(+), 3 deletions(-) > > diff --git a/configure b/configure > index 13b6062..8174219 100755 > --- a/configure > +++ b/configure > @@ -454,6 +454,29 @@ echo $util_byte_order > > rm -f _byteorder _byteorder.c > > +printf "Checking for posix 2008 realpath()... " > +# resolved_path == NULL is standardized in POSIX.1-2008 > +cat > _posix_2008_realpath.c < +#define _BSD_SOURCE > +#include > +#include > +#include > +void exit1(int sig) { exit(1); } > +int main () { > + signal(SIGSEGV, exit1); > + int main () { realpath (".", (char*)0); return 0; > +} > +EOF > +${CC} ${CFLAGS} _posix_2008_realpath.c -o _posix_2008_realpath > /dev/null 2>&1 > +if ./_posix_2008_realpath; then > + echo Yes. > + posix_2008_realpath=1 > +else > + echo No. > + posix_2008_realpath=0 > +fi > +rm -f _posix_2008_realpath _posix_2008_realpath.c > + > if [ $errors -gt 0 ]; then > cat < > @@ -718,6 +741,9 @@ libdir = ${LIBDIR:=\$(prefix)/lib} > # byte order within a 32 bit word. 1234 = little, 4321 = big, 0 = guess > UTIL_BYTE_ORDER = ${util_byte_order} > > +# Whether realpath(3) supports resolved_path == NULL feature > +POSIX_2008_REALPATH = ${posix_2008_realpath} > + > # Whether libdir is in a path configured into ldconfig > LIBDIR_IN_LDCONFIG = ${libdir_in_ldconfig} > > @@ -824,7 +850,8 @@ CONFIGURE_CFLAGS = -DHAVE_GETLINE=\$(HAVE_GETLINE) \$(GMIME_CFLAGS) \\ > -DSTD_GETPWUID=\$(STD_GETPWUID) \\ > -DSTD_ASCTIME=\$(STD_ASCTIME) \\ > -DHAVE_XAPIAN_COMPACT=\$(HAVE_XAPIAN_COMPACT) \\ > - -DUTIL_BYTE_ORDER=\$(UTIL_BYTE_ORDER) > + -DUTIL_BYTE_ORDER=\$(UTIL_BYTE_ORDER) \\ > + -DPOSIX_2008_REALPATH=\$(POSIX_2008_REALPATH) > > CONFIGURE_CXXFLAGS = -DHAVE_GETLINE=\$(HAVE_GETLINE) \$(GMIME_CFLAGS) \\ > \$(TALLOC_CFLAGS) -DHAVE_VALGRIND=\$(HAVE_VALGRIND) \\ > @@ -834,7 +861,8 @@ CONFIGURE_CXXFLAGS = -DHAVE_GETLINE=\$(HAVE_GETLINE) \$(GMIME_CFLAGS) \\ > -DSTD_GETPWUID=\$(STD_GETPWUID) \\ > -DSTD_ASCTIME=\$(STD_ASCTIME) \\ > -DHAVE_XAPIAN_COMPACT=\$(HAVE_XAPIAN_COMPACT) \\ > - -DUTIL_BYTE_ORDER=\$(UTIL_BYTE_ORDER) > + -DUTIL_BYTE_ORDER=\$(UTIL_BYTE_ORDER) \\ > + -DPOSIX_2008_REALPATH=\$(POSIX_2008_REALPATH) > > CONFIGURE_LDFLAGS = \$(GMIME_LDFLAGS) \$(TALLOC_LDFLAGS) \$(XAPIAN_LDFLAGS) > EOF > diff --git a/notmuch-config.c b/notmuch-config.c > index 8d28653..14d0e5c 100644 > --- a/notmuch-config.c > +++ b/notmuch-config.c > @@ -454,10 +454,26 @@ notmuch_config_save (notmuch_config_t *config) > } > > /* Try not to overwrite symlinks. */ > +#if POSIX_2008_REALPATH > filename = realpath (config->filename, NULL); > +#else > + /* compatibility with minor effort, not elegance, is the ruling factor > + in these (two) else branches... */ > + char resolved_path[PATH_MAX]; > + filename = realpath (config->filename, resolved_path); > +#endif > if (! filename) { > if (errno == ENOENT) { > +#if POSIX_2008_REALPATH > filename = strdup (config->filename); > +#else > + /* ... this is the other else... */ > + resolved_path[sizeof resolved_path - 1] = '\0'; > + strncpy(resolved_path, config->filename, sizeof resolved_path); > + /* "faking" out of memory in case path too long -- close enough? */ > + filename = resolved_path[sizeof resolved_path - 1]? > + resolved_path: NULL; Ok, this above is wrong (should be other way around). Tests pass though meaning this is not within test coverage... Tomi > +#endif > if (! filename) { > fprintf (stderr, "Out of memory.\n"); > g_free (data); > @@ -480,12 +496,15 @@ notmuch_config_save (notmuch_config_t *config) > filename, error->message); > } > g_error_free (error); > +#if POSIX_2008_REALPATH > free (filename); > +#endif > g_free (data); > return 1; > } > - > +#if POSIX_2008_REALPATH > free (filename); > +#endif > g_free (data); > return 0; > } > -- > 1.8.5.3