arm64 xenial build fails

[Chris Coulson]

FAILED: /usr/bin/aarch64-linux-gnu-gcc -MMD -MF obj/third_party/libvpx/libvpx/idct32x32_34_add_neon.o.d -DV8_DEPRECATION_WARNINGS -DENABLE_NOTIFICATIONS -DENABLE_PDF=1 -DENABLE_SPELLCHECK=1 -DUSE_UDEV -DUI_COMPOSITOR_IMAGE_TRANSPORT -DUSE_AURA=1 -DUSE_PANGO=1 -DUSE_DEFAULT_RENDER_THEME=1 -DUSE_NSS_CERTS=1 -DUSE_OZONE=1 -DNO_TCMALLOC -DUSE_EXTERNAL_POPUP_MENU=1 -DENABLE_WEBRTC=1 -DDISABLE_NACL -DENABLE_EXTENSIONS=1 -DENABLE_TASK_MANAGER=1 -DENABLE_THEMES=1 -DUSE_PROPRIETARY_CODECS -DFULL_SAFE_BROWSING -DSAFE_BROWSING_CSD -DSAFE_BROWSING_DB_LOCAL -DCHROMIUM_BUILD -DENABLE_MEDIA_ROUTER=1 -DFIELDTRIAL_TESTING_ENABLED -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -DNDEBUG -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -I../.. -Igen -I../../third_party/libvpx/source/config -I../../third_party/libvpx/source/config/linux/arm64 -I../../third_party/libvpx/source/libvpx -Igen/third_party/libvpx -I../../third_party/libvpx/source/libvpx -fno-strict-aliasing --param=ssp-buffer-size=4 -fstack-protector -funwind-tables -fPIC -pipe -pthread -O2 -fno-ident -fdata-sections -ffunction-sections -fno-omit-frame-pointer -g1 -fvisibility=hidden -Wno-unused-local-typedefs -Wno-maybe-uninitialized -Wno-missing-field-initializers -Wno-unused-parameter -Wno-unused-function -Wno-sign-compare -c ../../third_party/libvpx/source/libvpx/vpx_dsp/arm/idct32x32_34_add_neon.c -o obj/third_party/libvpx/libvpx/idct32x32_34_add_neon.o
{standard input}: Assembler messages:
{standard input}: Error: unaligned opcodes detected in executable segment
ninja: build stopped: subcommand failed.
oxide/CMakeFiles/build_all.dir/build.make:60: recipe for target 'oxide/CMakeFiles/build_all' failed
make[4]: *** [oxide/CMakeFiles/build_all] Error 1
make[4]: Leaving directory '/<<PKGBUILDDIR>>/obj-aarch64-linux-gnu'
CMakeFiles/Makefile2:267: recipe for target 'oxide/CMakeFiles/build_all.dir/all' failed
make[3]: *** [oxide/CMakeFiles/build_all.dir/all] Error 2
make[3]: Leaving directory '/<<PKGBUILDDIR>>/obj-aarch64-linux-gnu'
Makefile:141: recipe for target 'all' failed
make[2]: *** [all] Error 2
make[2]: Leaving directory '/<<PKGBUILDDIR>>/obj-aarch64-linux-gnu'
dh_auto_build: make -j4 returned exit code 2
debian/rules:26: recipe for target 'override_dh_auto_build' failed
make[1]: *** [override_dh_auto_build] Error 2
make[1]: Leaving directory '/<<PKGBUILDDIR>>'
debian/rules:20: recipe for target 'build-arch' failed
make: *** [build-arch] Error 2
dpkg-buildpackage: error: debian/rules build-arch gave error exit status 2

[Chris Coulson (chrisccoulson)]

This is the preprocessed source that fails. You can reproduce with (on an amd64 box):

$ aarch64-linux-gnu-gcc-5 -O2 -g2 -c idct32x32_34_add_neon.i
/tmp/cckv0RL4.s: Assembler messages:
/tmp/cckv0RL4.s: Error: unaligned opcodes detected in executable segment

$ apt-cache policy gcc-5-aarch64-linux-gnu
gcc-5-aarch64-linux-gnu:
  Installed: 5.3.1-14ubuntu2cross1
  Candidate: 5.3.1-14ubuntu2cross1
  Version table:
 *** 5.3.1-14ubuntu2cross1 500
        500 http://archive.ubuntu.com/ubuntu xenial/main amd64 Packages
        100 /var/lib/dpkg/status

[Chris Coulson (chrisccoulson)]

And here is a smaller test case, created with c-reduce.

[Chris Coulson (chrisccoulson)]

Note that the problem only occurs on aarch64 with xenial's gcc (both the host compiler and cross compiler). This source compiles fine in yakkety.

[Chris Coulson (chrisccoulson)]

I've worked around this with https://git.launchpad.net/~oxide-developers/oxide/+git/chromium/commit/?id=8c00856e79f147be10873facfacbee56d2695204