Compiling sys-devel/gcc-5.* with a cross-compiler using architecture dependent CXXFLAGS such as -mfpu=neon-vfpv4 causes it to fail with "g++: error: unrecognized command line option '-mfpu=neon-vfpv4'" GCC seems to properly set CXXFLAGS_FOR_BUILD in it's Makefile but doesn't properly export it to modules that need it, such as libcpp. It would initially use it to build tools that need to be compiled and run natively. Instead, they pickup the host/target CXXFLAGS which is likely the wrong ARCH.
Created attachment 432356 [details] armv7a-hardfloat-linux-gnueabi-emerge --info
Created attachment 432358 [details] sys-devel:gcc-5.2.0:20160428-015537.log
Created attachment 432360 [details, diff] gcc-5-respect-build-cxxflags.patch This is a patch to gcc-5.* to properly handle CXXFLAGS_FOR_BUILD in its Makefile. It applies cleanly to gcc-5.1.0, gcc-5.2.0, and gcc-5.3.0.
Created attachment 447296 [details] gcc-build-logs.tar.bz2 # armv6j-hardfloat-linux-gnueabi-emerge --info '=sys-devel/gcc-5.4.0::gentoo' Portage 2.3.1 (python 2.7.12-final-0, default/linux/arm/13.0/armv6j, gcc-5.4.0, glibc-2.23-r2, 4.7.4-gentoo x86_64) ================================================================= System Settings ================================================================= System uname: Linux-4.7.4-gentoo-x86_64-Intel-R-_Celeron-R-_2957U_@_1.40GHz-with-gentoo-2.3 KiB Mem: 3967644 total, 470888 free KiB Swap: 2097148 total, 2097124 free Timestamp of repository gentoo: Tue, 20 Sep 2016 08:30:01 +0000 sh bash 4.3_p46 ld GNU ld (Gentoo 2.26.1 p1.0) 2.26.1 distcc 3.2rc1 x86_64-gentoo-linux-gnu [disabled] app-shells/bash: 4.3_p46::gentoo dev-lang/python: 3.4.5::gentoo sys-apps/baselayout: 2.3::gentoo sys-apps/openrc: 0.21.7::gentoo sys-apps/sandbox: 2.10-r2::gentoo sys-devel/binutils: 2.26.1::gentoo sys-devel/gcc-config: 1.8-r1::gentoo sys-devel/make: 4.2.1::gentoo sys-kernel/linux-headers: 4.7::gentoo (virtual/os-headers) sys-libs/glibc: 2.23-r2::gentoo Repositories: gentoo location: /usr/portage sync-type: rsync sync-uri: rsync://rsync.gentoo.org/gentoo-portage priority: -1000 local location: /usr/local/portage/overlay masters: gentoo proaudio gentoo-kodi-overlay priority: 0 gentoo-kodi-overlay location: /usr/local/portage/gentoo-kodi-overlay masters: gentoo priority: 1 proaudio location: /var/lib/layman/proaudio masters: gentoo priority: 50 xmw location: /var/lib/layman/xmw masters: gentoo priority: 50 ACCEPT_KEYWORDS="arm ~arm" ACCEPT_LICENSE="@FREE as-is freedist" CBUILD="x86_64-gentoo-linux-gnu" CFLAGS="-O2 -pipe -march=armv6j -mfpu=vfp -mfloat-abi=hard -fomit-frame-pointer" CHOST="armv6j-hardfloat-linux-gnueabi" CONFIG_PROTECT="/boot/cmdline.txt /boot/config.txt /etc /usr/share/gnupg/qualified.txt" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/dconf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/php/apache2-php7.0/ext-active/ /etc/php/cgi-php7.0/ext-active/ /etc/php/cli-php7.0/ext-active/ /etc/revdep-re" CXXFLAGS="-O2 -pipe -march=armv6j -mfpu=vfp -mfloat-abi=hard -fomit-frame-pointer" DISTDIR="/data/raspi_root/var/portage/distfiles" EMERGE_DEFAULT_OPTS="--with-bdeps y --quiet-build=n --buildpkg" FCFLAGS="-O2 -pipe -march=armv6j" FEATURES="assume-digests binpkg-logs buildpkg candy config-protect-if-modified distlocks ebuild-locks fixlafiles merge-sync news parallel-fetch preserve-libs protect-owned sandbox sfperms strict unknown-features-warn unmerge-logs unmerg" FFLAGS="-O2 -pipe -march=armv6j" GENTOO_MIRRORS="http://distfiles.gentoo.org" LANG="fr_BE.utf8" LDFLAGS="-Wl,-O1 -Wl,--as-needed" MAKEOPTS="-j5 -l2" PKGDIR="/data/raspi_root/var/portage/packages" PORTAGE_CONFIGROOT="/usr/armv6j-hardfloat-linux-gnueabi/" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --omit-dir-times --compress --force --whole-file --delete --stats --human-readable --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages --exclude=/." PORTAGE_TMPDIR="/var/tmp" USE="arm bzip2 cli cracklib crypt cxx dri iconv modules ncurses nls nptl openmp pcre readline seccomp session sqlite ssl tcpd unicode xattr zlib" APACHE2_MODULES="authn_core authz_core socache_shmcb unixd actions alias auth_basic authn_" Unset: CC, CPPFLAGS, CTARGET, CXX, INSTALL_MASK, LC_ALL, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS, USE_PYTHON
With attachment 432360 [details, diff], gcc-5.4.0 can be cross-compiled
Confirming the cross-building failure in my armv7a environment for gcc-5.4.0-r3. Applying attachment 432360 [details, diff] makes it build.
This is still a problem in 6.4.0 (the patch still applies) and I can see that it hasn't even been fixed in gcc master. :(
This is still somehow an issue on =sys-devel/gcc-8.2.0-r2. How has this patch not been either 1) added to the official gentoo patchset or 2) merged upstream?
(In reply to matoro from comment #8) > This is still somehow an issue on =sys-devel/gcc-8.2.0-r2. How has this > patch not been either 1) added to the official gentoo patchset or 2) merged > upstream? No reason. Feel free to send it upstream and post a link here. The patch looks reasonable. I'll test it locally and apply to gentoo's gcc if it works.
The bug has been referenced in the following commit(s): https://gitweb.gentoo.org/proj/gcc-patches.git/commit/?id=52d8f44f45d244184d737cec5a26a1754f877e75 commit 52d8f44f45d244184d737cec5a26a1754f877e75 Author: Sergei Trofimovich <slyfox@gentoo.org> AuthorDate: 2018-09-15 18:40:09 +0000 Commit: Sergei Trofimovich <slyfox@gentoo.org> CommitDate: 2018-09-15 18:40:09 +0000 Pass CXXFLAGS as CXXFLAGS_FOR_BUILD to stage1. Fixes build failure when CXXFLAGS contains TARGET-specific flags. Tested on x86_64-pc-linux-gnu host as: # CFLAGS='-O2 -mfpu=neon-vfpv4' CXXFLAGS='-O2 -mfpu=neon-vfpv4' \ armv7a-unknown-linux-gnueabihf-emerge -v1 sys-devel/gcc --quiet-build=n Fix by Peter Levine. Bug: https://bugs.gentoo.org/581406 Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org> 5.4.0/gentoo/98_all_respect-build-cxxflags.patch | 39 +++++++++++++++++++++++ 5.4.0/gentoo/README.history | 2 ++ 6.4.0/gentoo/102_all_respect-build-cxxflags.patch | 39 +++++++++++++++++++++++ 6.4.0/gentoo/README.history | 1 + 7.3.0/gentoo/100_all_respect-build-cxxflags.patch | 39 +++++++++++++++++++++++ 7.3.0/gentoo/README.history | 1 + 8.2.0/gentoo/102_all_respect-build-cxxflags.patch | 39 +++++++++++++++++++++++ 8.2.0/gentoo/README.history | 1 + 8 files changed, 161 insertions(+)
Patch is included in next patchset for 5.4.0, 6.4.0, 7.3.0, 8.2.0. Meanwhile you can use /etc/portage/patches/ mechanism to workaround the failure.
The bug has been referenced in the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=fb5d77d453273447b9a1d7c63a0f8a09b0840e84 commit fb5d77d453273447b9a1d7c63a0f8a09b0840e84 Author: Sergei Trofimovich <slyfox@gentoo.org> AuthorDate: 2018-09-23 21:04:12 +0000 Commit: Sergei Trofimovich <slyfox@gentoo.org> CommitDate: 2018-09-23 22:35:59 +0000 sys-devel/gcc: cut 1.10 patchset for 5.4.0 One new patch: + 98_all_respect-build-cxxflags.patch fix cross-build for arch-specific CXXFLAGS Bug: https://bugs.gentoo.org/581406 Package-Manager: Portage-2.3.49, Repoman-2.3.11 sys-devel/gcc/Manifest | 1 + sys-devel/gcc/gcc-5.4.0-r5.ebuild | 44 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 45 insertions(+) https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=a8ff963554a3e28f8cd5905180b5c5428d1df7b8 commit a8ff963554a3e28f8cd5905180b5c5428d1df7b8 Author: Sergei Trofimovich <slyfox@gentoo.org> AuthorDate: 2018-09-23 20:54:48 +0000 Commit: Sergei Trofimovich <slyfox@gentoo.org> CommitDate: 2018-09-23 22:35:58 +0000 sys-devel/gcc: cut 1.7 patchset for 6.4.0 Two new patches: + 101_all_x32-fix-eh-return-address.patch fix exception handler ABI on x32 + 102_all_respect-build-cxxflags.patch fix cross-build for arch-specific CXXFLAGS Bug: https://bugs.gentoo.org/664016 Bug: https://bugs.gentoo.org/581406 Package-Manager: Portage-2.3.49, Repoman-2.3.11 sys-devel/gcc/Manifest | 1 + sys-devel/gcc/gcc-6.4.0-r4.ebuild | 24 ++++++++++++++++++++++++ 2 files changed, 25 insertions(+) https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=fd1aa67de92c05d6a066e84ba5cd4236e637629e commit fd1aa67de92c05d6a066e84ba5cd4236e637629e Author: Sergei Trofimovich <slyfox@gentoo.org> AuthorDate: 2018-09-23 20:48:40 +0000 Commit: Sergei Trofimovich <slyfox@gentoo.org> CommitDate: 2018-09-23 22:35:58 +0000 sys-devel/gcc: cut 1.7 patchset for 7.3.0 Three new patches: + 98_all_msp430-partial-int.patch: fix msp430 code generator on complex types + 99_all_x32-fix-eh-return-address.patch fix exception handler ABI on x32 + 100_all_respect-build-cxxflags.patch fix cross-build for arch-specific CXXFLAGS Bug: https://bugs.gentoo.org/664014 Bug: https://bugs.gentoo.org/664016 Bug: https://bugs.gentoo.org/581406 Package-Manager: Portage-2.3.49, Repoman-2.3.11 sys-devel/gcc/Manifest | 1 + sys-devel/gcc/gcc-7.3.0-r5.ebuild | 24 ++++++++++++++++++++++++ 2 files changed, 25 insertions(+) https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=c7ec432dc64cefa8de88292efcc134cc8e9306c9 commit c7ec432dc64cefa8de88292efcc134cc8e9306c9 Author: Sergei Trofimovich <slyfox@gentoo.org> AuthorDate: 2018-09-23 20:36:46 +0000 Commit: Sergei Trofimovich <slyfox@gentoo.org> CommitDate: 2018-09-23 22:35:58 +0000 sys-devel/gcc: cut 1.3 patchset for 8.2.0 Four new patches: + 101_all_x32-fix-eh-return-address.patch: fix exception handler ABI on x32 + 102_all_respect-build-cxxflags.patch: fix cross-build for arch-specific CXXFLAGS + 103_all_mmix-fix-85666-p1.patch + 104_all_mmix-fix-85666-p2.patch backport mmix support Bug: https://bugs.gentoo.org/664016 Bug: https://bugs.gentoo.org/581406 Package-Manager: Portage-2.3.49, Repoman-2.3.11 sys-devel/gcc/Manifest | 1 + sys-devel/gcc/gcc-8.2.0-r3.ebuild | 20 ++++++++++++++++++++ 2 files changed, 21 insertions(+)
*** Bug 653898 has been marked as a duplicate of this bug. ***
*** Bug 645920 has been marked as a duplicate of this bug. ***
