From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Petazzoni Date: Fri, 6 Apr 2018 13:37:44 +0200 Subject: [Buildroot] [PATCH 1/2] llvm: add dependency on !BR2_TOOLCHAIN_HAS_GCC_BUG_64735 In-Reply-To: References: <20180406090013.20187-1-thomas.petazzoni@bootlin.com> Message-ID: <20180406133744.43c8f225@windsurf> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net Hello, On Fri, 6 Apr 2018 11:36:26 +0200, Valentin Korenblit wrote: > The three autotests crashed because of std::shared_future, > > I've found the following in: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=820535 > > "This looks like the kind of failure you get when your host toolchain > doesn't support C++11 properly (specifically lock-free atomics in this > case). When I've seen it before GCC was defaulting to a CPU that's > too old to do atomics properly, and that configuration is very > unlikely to be supported by LLVM ever (any more)." > > I was about to send a patch to blacklist ARMv4 and ARMv5 but this should > be a more appropriate solution (I was not aware of BUG_64735). Note: I didn't test building LLVM for ARMv4/ARMv5, with a gcc 7.x compiler. But the build error itself clearly points to this gcc limitation, which has been solved in gcc 7.x. > I'll try to build with the defconfigs from the autobuilder applying the > patch and adding a dependency on !BR2_STATIC_LIBS. So far, there hasn't been any failure to build LLVM in static only configurations, so let's see if any shows up. Thomas -- Thomas Petazzoni, CTO, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com