From mboxrd@z Thu Jan 1 00:00:00 1970 From: jbaron@redhat.com (Jason Baron) Date: Tue, 22 Nov 2011 18:39:50 -0500 Subject: [PATCH 4/4] ARM: add jump label support In-Reply-To: <4ECC2A07.8050701@codeaurora.org> References: <1321888429-3519-1-git-send-email-rabin@rab.in> <1321888429-3519-4-git-send-email-rabin@rab.in> <20111122194213.GC9581@n2100.arm.linux.org.uk> <4ECC2A07.8050701@codeaurora.org> Message-ID: <20111122233949.GA24453@redhat.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Nov 22, 2011 at 03:02:31PM -0800, Stephen Boyd wrote: > On 11/22/11 11:42, Russell King - ARM Linux wrote: > > On Mon, Nov 21, 2011 at 08:43:49PM +0530, Rabin Vincent wrote: > >> Add the arch-specific code to support jump labels for ARM and Thumb-2. > >> > >> Note that to build succesfully it requires (what will be) GCC 4.7.0 > >> because of incomplete support for the '%c' specifier in earlier > >> versions: > >> > >> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48637 > >> > >> Cc: Jason Baron > >> Signed-off-by: Rabin Vincent > > This appears to imply that with this patch, we're upping the minimum > > gcc version for successfully building kernels to 4.7.0. That's _way_ > > too early (I'm using 4.3.5 here and don't have plans to update.) > > Is there a way to detect that the compiler doesn't support %c? Perhaps > we can do that in the same spirit of how we detect asm goto support for > jump labels. > Right, for jump labels we have a script at: scripts/gcc-goto.sh, which basically just checks if we can compile 'asm goto' without error, so for %c, you could probably have some simple 'asm()' that uses %c, and see if it compiles. Although, I'm not sure if there's a arch specific dir, for such a thing? thanks, -Jason