Hi On Tue, Feb 24, 2015 at 4:15 PM, Zbigniew Jędrzejewski-Szmek <[email protected]> wrote: > On Tue, Feb 24, 2015 at 04:08:17PM +0100, David Herrmann wrote: >> Hi >> >> On Tue, Feb 24, 2015 at 4:07 PM, Zbigniew Jędrzejewski-Szmek >> <[email protected]> wrote: >> > On Tue, Feb 24, 2015 at 07:02:49AM -0800, David Herrmann wrote: >> >> configure.ac | 1 + >> >> 1 file changed, 1 insertion(+) >> >> >> >> New commits: >> >> commit 0a98d66159e474915afd6597d3aa444a698fdd2d >> >> Author: David Herrmann <[email protected]> >> >> Date: Tue Feb 24 15:59:06 2015 +0100 >> >> >> >> build: add -Wno-format-signedness >> >> >> >> gcc5 introduced this option (gcc4 silently ignores it, which is fine). >> >> Given that gcc5 thinks 'unsigned char'/'unsigned short' is promoted to >> >> 'int' for var-args, stuff like this spits out warnings: >> >> uint8_t x; >> >> printf("%" PRIu8", x); >> >> >> >> gcc5 promots 'x' to 'int', instead of 'unsigned int' and thus gets a >> >> signedness-warnings as it expects an 'unsigned int'. >> >> >> >> glibc states otherwise: unsigneds are always promoted to 'unsigned >> >> int'. >> >> Until gcc and glibc figure this out, lets just ignore that warning >> >> (which >> >> is totally useless in its current form). >> >> >> >> diff --git a/configure.ac b/configure.ac >> >> index 9a2235b..22a6f17 100644 >> >> --- a/configure.ac >> >> +++ b/configure.ac >> >> @@ -186,6 +186,7 @@ CC_CHECK_FLAGS_APPEND([with_cflags], [CFLAGS], [\ >> >> -Wno-unused-parameter \ >> >> -Wno-missing-field-initializers \ >> >> -Wno-unused-result \ >> >> + -Wno-format-signedness \ >> > This doesn't really work, as discussed previously on the list. >> >> Why? Works fine with gcc4 and gcc5 here. What's the problem exactly? > Positive version of the option must be used to detect reliably. > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63499
Do we care? I mean I prefer a warning about unknown command-line options over thousands of warnings regarding totally useless (and imo wrong) signedness-mismatches. Furthermore, the warning is only printed if there's another warning. I can have a look at adding a CC_CHECK_NO_WARNING_APPEND() or something like that, which properly tests for the non-negated version. Thanks David _______________________________________________ systemd-devel mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/systemd-devel
