garrettkajmowicz-sophos
commented
2 years ago Looking at the printed environment at the start of a build, it looks like Bazel itself seems to still be performing the correct expansion. However, the environment printed out by wrapper script is different:
Bazel external C/C++ Rules. Building library netmap
Environment:______________
EXT_BUILD_ROOT=/var/tmp/gk/bazel_cache/sandbox/linux-sandbox/4/execroot/__main__
INSTALLDIR=/var/tmp/gk/bazel_cache/sandbox/linux-sandbox/4/execroot/__main__/bazel-out/k8-dbg/bin/netmap/netmap
KERNELDIR=/var/tmp/gk/bazel_cache/sandbox/linux-sandbox/4/execroot/__main__/external/kernel_source_host
PWD=/var/tmp/gk/bazel_cache/sandbox/linux-sandbox/4/execroot/__main__
BUILD_TMPDIR=/var/tmp/gk/bazel_cache/sandbox/linux-sandbox/4/execroot/__main__/bazel-out/k8-dbg/bin/netmap/netmap.build_tmpdir
INSTALL_MOD_PATH=/var/tmp/gk/bazel_cache/sandbox/linux-sandbox/4/execroot/__main__/bazel-out/k8-dbg/bin/netmap/netmap
TMPDIR=/tmp
BUILD_KERNEL=linux-4.14.173-aum-3
EXT_BUILD_DEPS=/var/tmp/gk/bazel_cache/sandbox/linux-sandbox/4/execroot/__main__/bazel-out/k8-dbg/bin/netmap/netmap.ext_build_deps
SHLVL=3
BUILD_LOG=bazel-out/k8-dbg/bin/netmap/netmap_foreign_cc/Make.log
BUILD_SCRIPT=bazel-out/k8-dbg/bin/netmap/netmap_foreign_cc/build_script.sh
BUILD_WRAPPER_SCRIPT=bazel-out/k8-dbg/bin/netmap/netmap_foreign_cc/wrapper_build_script.sh
PATH=/var/tmp/gk/bazel_cache/sandbox/linux-sandbox/4/execroot/__main__:/home/garrettkajmowicz/bin:/opt/sophos/bin:/opt/marvell/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/storage/build_tools:/storage/pit-dev-lab
_=/usr/bin/env
__________________________
+ ARFLAGS=rcsD
+ ASFLAGS='-U_FORTIFY_SOURCE -fstack-protector -Wall -Wunused-but-set-parameter -Wno-free-nonheap-object -fno-omit-frame-pointer -g -fno-canonical-system-headers -Wno-builtin-macro-redefined -D__DATE__=redacted -D__TIMESTAMP__=redacted -D__TIME__=redacted'
+ CFLAGS='-U_FORTIFY_SOURCE -fstack-protector -Wall -Wunused-but-set-parameter -Wno-free-nonheap-object -fno-omit-frame-pointer -g -fno-canonical-system-headers -Wno-builtin-macro-redefined -D__DATE__=redacted -D__TIMESTAMP__=redacted -D__TIME__=redacted'
+ CXXFLAGS='-U_FORTIFY_SOURCE -fstack-protector -Wall -Wunused-but-set-parameter -Wno-free-nonheap-object -fno-omit-frame-pointer -g -std=c++0x -fno-canonical-system-headers -Wno-builtin-macro-redefined -D__DATE__=redacted -D__TIMESTAMP__=redacted -D__TIME__=redacted'
+ LDFLAGS='-fuse-ld=gold -Wl,-no-as-needed -Wl,-z,relro,-z,now -B/usr/bin -pass-exit-codes -lstdc++ -lm'
+ AR=/usr/bin/ar
+ CC=/usr/bin/gcc
+ CXX=/usr/bin/gcc
++ dirname 'EXT_BUILD_ROOT$/external/kernel_source_host/.config'
+ KERNELDIR='EXT_BUILD_ROOT$/external/kernel_source_host'
+ INSTALL_MOD_PATH='{INSTALLDIR}'
+ BUILD_KERNEL=linux-4.14.173-aum-3
+ CPPFLAGS=
+ /var/tmp/gk/bazel_cache/sandbox/linux-sandbox/4/execroot/__main__/bazel-out/k8-opt-exec-2B5CBBC6/bin/external/rules_foreign_cc/toolchains/make/bin/make -C /var/tmp/gk/bazel_cache/sandbox/linux-sandbox/4/execroot/__main__/bazel-out/k8-dbg/bin/netmap/netmap.build_tmpdir netmap_bazel --makefile=Makefile.bazel PREFIX=/var/tmp/gk/bazel_cache/sandbox/linux-sandbox/4/execroot/__main__/bazel-out/k8-dbg/bin/netmap/netmap
fmeum
One of the many tasks that I'm using rules_foreign_cc to perform is to build out-of-tree Linux kernel modules. This requires passing the directory path to the Linux kernel source code as a parameter to the Linux Kbuild process.
I've managed to accomplish all of this by having a make() section in a BUILD file which wraps a call to a local Makefile.bazel which alows me to do genrule() like things, but with appropriate CFLAGS et al. variables set, which ultimately calls the Kbuild system Makefile.
For non-obvious reasons to me, this commit: https://github.com/bazelbuild/rules_foreign_cc/commit/f61ce5d10b221c643ae48063c3484fadf84066d4
seems to have broken certain directory name processing.
In my BUILD file I have:
make ( ... args = [ "--makefile=Makefile.bazel", ], env = { "KERNELDIR": "$$(dirname $(execpath @kernel_source_host//:kernel_config_file))", }, data = [ "@kernel_source_host//:kernel_config_file", "@kernel_source_host//:whole_kernel_tree", ], )This used to run with $(KERNELDIR) being set to the bazel path where the linux kernel source code was available. After this commit, the variable gets set to: EXT_BUILD_ROOTexternal/kernel_source_host
Yes, a literal EXT_BUILD_ROOT without the trailing frontslash.
Is there a way to ensure the previous behavior? Alternatively, is there a way to get the same results as before using a different mechanism?