Re: [systemd-devel] [PATCH] use static_assert instead of assert_cc
On Sat, 29.12.12 02:10, Thomas H.P. Andersen (pho...@gmail.com) wrote: Another item from the todo Heya! Hmm, so I commited a patch for using assert_static() a few days before you did your patches but unfortunately never commited it. It works a bit differently from your patch, i.e. keeps assert_cc() as special version of assert_static() around which only takes one rather than two parameters and generates the message from the passed expression. I am tempted to just leave this code now as I commited it, since having to pass an explicit string to assert_static() is sometimes a bit redundant i'd say, and doesn't really make things more readable unless the expression that is tested is really complicated. Hence, I'd say that we should use assert_cc() and assert_static() from now on like this: assert_cc() for simple expressions where the expression is readable enough as is. assert_static() for complex expressions where it is worth specifying a human readable string. I hope this makes sense? Lennart -- Lennart Poettering - Red Hat, Inc. ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] [PATCH] use static_assert instead of assert_cc
On Thu, 03.01.13 22:34, Lennart Poettering (lenn...@poettering.net) wrote: On Sat, 29.12.12 02:10, Thomas H.P. Andersen (pho...@gmail.com) wrote: Another item from the todo Heya! Hmm, so I commited a patch for using assert_static() a few days before you did your patches but unfortunately never commited it. ^^^ pushed Lennart -- Lennart Poettering - Red Hat, Inc. ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] [PATCH] use static_assert instead of assert_cc
On Thu, Jan 3, 2013 at 10:34 PM, Lennart Poettering lenn...@poettering.net wrote: On Sat, 29.12.12 02:10, Thomas H.P. Andersen (pho...@gmail.com) wrote: Another item from the todo Heya! Hmm, so I commited a patch for using assert_static() a few days before you did your patches but unfortunately never commited it. It works a bit differently from your patch, i.e. keeps assert_cc() as special version of assert_static() around which only takes one rather than two parameters and generates the message from the passed expression. I am tempted to just leave this code now as I commited it, since having to pass an explicit string to assert_static() is sometimes a bit redundant i'd say, and doesn't really make things more readable unless the expression that is tested is really complicated. Hence, I'd say that we should use assert_cc() and assert_static() from now on like this: assert_cc() for simple expressions where the expression is readable enough as is. assert_static() for complex expressions where it is worth specifying a human readable string. I hope this makes sense? yeah, makes sense. It also does not break the build for older compilers :) Do you see warnings about mixed declarations and code? I had to move some of the asserts to avoid that with my patch. ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] [PATCH] use static_assert instead of assert_cc
On Thu, 03.01.13 22:47, Thomas H.P. Andersen (pho...@gmail.com) wrote:
assert_cc() for simple expressions where the expression is readable
enough as is.
assert_static() for complex expressions where it is worth specifying a
human readable string.
I hope this makes sense?
yeah, makes sense. It also does not break the build for older
compilers :) Do you see warnings about mixed declarations and code? I
had to move some of the asserts to avoid that with my patch.
Yes, I did see those. And my dirty workaround was to simply enclose the
assert_static() in a do { } while(false) block... That way it's always
at the beginning of a {} block but still behaves like an individual
expression.
Lennart
--
Lennart Poettering - Red Hat, Inc.
___
systemd-devel mailing list
systemd-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] [PATCH] use static_assert instead of assert_cc
On Sat, Dec 29, 2012 at 11:14:15PM +0100, Thomas H.P. Andersen wrote: On Sat, Dec 29, 2012 at 5:04 PM, Zbigniew Jędrzejewski-Szmek zbys...@in.waw.pl wrote: On Sat, Dec 29, 2012 at 02:10:27AM +0100, Thomas H.P. Andersen wrote: Another item from the todo Hi, the patch looks great, but it raises compatibility problems. AFAICT, required gcc version to raised to 4.6. Debian/squeeze has 4.4. According to http://gcc.gnu.org/projects/cxx0x.html static_assert should be supported from gcc 4.3 Hm, testing (with 4.4) shows that neither static_assert nor _Static_assert are available. With 4.6 _Static_assert is available. Michael Biebl says that Debian/squeeze doesn't have to be supported. This probably means that it's enough to have gcc-4.6 supported. This means that we don't need to support compilers which don't support _Static_assert. clang has _Static_assert, not static_assert. I think that a compile time check is in order. Support for old gcc versions is less important, so it might be enough to document the requirement in README, and then maybe provide a fallback if people complain. OTOH clang compilation support is useful (and used), so it should be kept. It builds with clang here. That is with clang version 3.1 (branches/release_31) from F18. static_assert is provided by /usr/include/assert.h (from glibc). since http://sourceware.org/git/?p=glibc.git;a=commitdiff;h=839e283ec (Jan 01 2012). This version hasn't been officially released yet, AFAICT. The define is trivial, and could be easily provided in missing.h. Zbyszek ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] [PATCH] use static_assert instead of assert_cc
On Sun, Dec 30, 2012 at 4:32 PM, Zbigniew Jędrzejewski-Szmek zbys...@in.waw.pl wrote: On Sat, Dec 29, 2012 at 11:14:15PM +0100, Thomas H.P. Andersen wrote: On Sat, Dec 29, 2012 at 5:04 PM, Zbigniew Jędrzejewski-Szmek zbys...@in.waw.pl wrote: On Sat, Dec 29, 2012 at 02:10:27AM +0100, Thomas H.P. Andersen wrote: Another item from the todo Hi, the patch looks great, but it raises compatibility problems. AFAICT, required gcc version to raised to 4.6. Debian/squeeze has 4.4. According to http://gcc.gnu.org/projects/cxx0x.html static_assert should be supported from gcc 4.3 Hm, testing (with 4.4) shows that neither static_assert nor _Static_assert are available. With 4.6 _Static_assert is available. Michael Biebl says that Debian/squeeze doesn't have to be supported. This probably means that it's enough to have gcc-4.6 supported. This means that we don't need to support compilers which don't support _Static_assert. clang has _Static_assert, not static_assert. I think that a compile time check is in order. Support for old gcc versions is less important, so it might be enough to document the requirement in README, and then maybe provide a fallback if people complain. OTOH clang compilation support is useful (and used), so it should be kept. It builds with clang here. That is with clang version 3.1 (branches/release_31) from F18. static_assert is provided by /usr/include/assert.h (from glibc). since http://sourceware.org/git/?p=glibc.git;a=commitdiff;h=839e283ec (Jan 01 2012). This version hasn't been officially released yet, AFAICT. The define is trivial, and could be easily provided in missing.h. Something like this? The added part is: --- a/src/shared/missing.h +++ b/src/shared/missing.h @@ -257,3 +257,7 @@ static inline int name_to_handle_at(int fd, const char *name, struct file_handle #ifndef TFD_TIMER_CANCEL_ON_SET #define TFD_TIMER_CANCEL_ON_SET (1 1) #endif + +#ifndef static_assert +#define static_assert _Static_assert +#endif 0001-use-static_assert-instead-of-assert_cc.patch Description: Binary data ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] [PATCH] use static_assert instead of assert_cc
On Sat, Dec 29, 2012 at 02:10:27AM +0100, Thomas H.P. Andersen wrote: Another item from the todo Hi, the patch looks great, but it raises compatibility problems. AFAICT, required gcc version to raised to 4.6. Debian/squeeze has 4.4. Also, clang has _Static_assert, not static_assert. I think that a compile time check is in order. Support for old gcc versions is less important, so it might be enough to document the requirement in README, and then maybe provide a fallback if people complain. OTOH clang compilation support is useful (and used), so it should be kept. Zbyszek ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
