IssueTracker

CCing +tomhughes and +inglorion, as requested by Bob

Updated title to reflect that it's not just bloonchipper, but all fpmcu-unittests packages.

The title says fails to build because std::auto_ptr was removed, but I don't think we're using std::auto_ptr anywhere (at least not intentionally), and I don't see it mentioned in the error message.

For this error,

/usr/bin/../include/c++/v1/__config:821:8: error: "No thread API"
  821 | #      error "No thread API"
      |        ^

We do build libc++ with thread support disabled, since the EC OS does not support threads.

Ah, yes, sorry. Title was from the other bugs that took this same format (there's a lot of them!). Updated.

This is roughly the line in the current llvm

And at the LLVM Next. It doesn't look like much has changed in the config itself, but something could have changed in the libcxx CMake.

So I'm guessing for whatever reason, _LIBCPP_HAS_NO_THREADS is 0 for the ECs.

Setting V=1, I believe I have the commandline invocation that causes this:

make[1]: Entering directory '/build/amd64-generic/tmp/portage/chromeos-base/chromeos-fpmcu-bloonchipper-unittests-0.0.1-r893/work/chromeos-fpmcu-bloonchipper-unittests-0.0.1/platform/ec'
/usr/bin/ccache armv7m-cros-eabi-clang -E -P -DSECTION_IS_RO= -Itest -DTEST_BUILD= -imacros abort.tasklist -Iboard/bloonchipper -DBOARD_BLOONCHIPPER= -Ibaseboard/bloonchipper -DBASEBOARD_BLOONCHIPPER= -D_MAKEFILE= -imacros ec.tasklist include/task_filter.h
/usr/bin/ccache armv7m-cros-eabi-clang -E -P -DSECTION_IS_RW= -Itest -DTEST_BUILD= -imacros abort.tasklist -Iboard/bloonchipper -DBOARD_BLOONCHIPPER= -Ibaseboard/bloonchipper -DBASEBOARD_BLOONCHIPPER= -D_MAKEFILE= -imacros ec.tasklist include/task_filter.h
/usr/bin/ccache armv7m-cros-eabi-clang -E -DOUTDIR=build/bloonchipper/abort/RO -DCHIP=stm32 -DBOARD_TASKFILE=ec.tasklist -DBOARD=bloonchipper -DCORE=cortex-m -DPROJECT=abort -DCHIP_VARIANT=stm32f412 -DCHIP_FAMILY=STM32F4 -DBOARD_BLOONCHIPPER= -DCHIP_STM32= -DCORE_CORTEX_M= -DCHIP_VARIANT_STM32F412= -DCHIP_FAMILY_STM32F4= -DFINAL_OUTDIR=build/bloonchipper/abort -DPROTOBUF_MIN_PROTOC_VERSION=0 -DHAS_BASEBOARD= -DBASEBOARD_BLOONCHIPPER= -Iinclude  -Icore/cortex-m/include  -Iinclude/driver  -Ibuild/bloonchipper/abort  -Ifuzz  -Itest  -Ithird_party  -I. -DTEST_BUILD= -DTEST_LEGACY_BUILD= -DTEST_TASKFILE=abort.tasklist   -DTEST_abort= -DTEST_ABORT=        -Iinclude/driver  -DSECTION_IS_RO= -DSECTION=RO -DHAS_TASK_RWSIG= -DHAS_TASK_FPSENSOR_RW= -fno-PIC -DCHROMIUM_EC= -DHAS_TASK_HOOKS= -DHAS_TASK_HOSTCMD= -DHAS_TASK_CONSOLE= -DHAS_TASK_TEST= -P -dM -Ichip/stm32 -Ibaseboard/bloonchipper -Iboard/bloonchipper  include/config.h | grep -o "#define \(CONFIG\|VARIANT\)_[A-Z0-9_]*" | cut -c9- | sort
/usr/bin/ccache armv7m-cros-eabi-clang -E -DOUTDIR=build/bloonchipper/abort/RW -DCHIP=stm32 -DBOARD_TASKFILE=ec.tasklist -DBOARD=bloonchipper -DCORE=cortex-m -DPROJECT=abort -DCHIP_VARIANT=stm32f412 -DCHIP_FAMILY=STM32F4 -DBOARD_BLOONCHIPPER= -DCHIP_STM32= -DCORE_CORTEX_M= -DCHIP_VARIANT_STM32F412= -DCHIP_FAMILY_STM32F4= -DFINAL_OUTDIR=build/bloonchipper/abort -DPROTOBUF_MIN_PROTOC_VERSION=0 -DHAS_BASEBOARD= -DBASEBOARD_BLOONCHIPPER= -Iinclude  -Icore/cortex-m/include  -Iinclude/driver  -Ibuild/bloonchipper/abort  -Ifuzz  -Itest  -Ithird_party  -I. -DTEST_BUILD= -DTEST_LEGACY_BUILD= -DTEST_TASKFILE=abort.tasklist   -DTEST_abort= -DTEST_ABORT=        -Iinclude/driver  -DSECTION_IS_RW= -DSECTION=RW -DHAS_TASK_FPSENSOR= -DHAS_TASK_RWSIG_RO= -fno-PIC -DCHROMIUM_EC= -DHAS_TASK_HOOKS= -DHAS_TASK_HOSTCMD= -DHAS_TASK_CONSOLE= -DHAS_TASK_TEST= -P -dM -Ichip/stm32 -Ibaseboard/bloonchipper -Iboard/bloonchipper  include/config.h | grep -o "#define \(CONFIG\|VARIANT\)_[A-Z0-9_]*" | cut -c9- | sort
echo "CONFIG_RW_MEM_OFF" | /usr/bin/ccache armv7m-cros-eabi-clang -E -DOUTDIR=build/bloonchipper/abort/ -DCHIP=stm32 -DBOARD_TASKFILE=ec.tasklist -DBOARD=bloonchipper -DCORE=cortex-m -DPROJECT=abort -DCHIP_VARIANT=stm32f412 -DCHIP_FAMILY=STM32F4 -DBOARD_BLOONCHIPPER= -DCHIP_STM32= -DCORE_CORTEX_M= -DCHIP_VARIANT_STM32F412= -DCHIP_FAMILY_STM32F4= -DFINAL_OUTDIR=build/bloonchipper/abort -DPROTOBUF_MIN_PROTOC_VERSION=0 -DHAS_BASEBOARD= -DBASEBOARD_BLOONCHIPPER= -Iinclude  -Icore/cortex-m/include  -Iinclude/driver  -Ibuild/bloonchipper/abort  -Ifuzz  -Itest  -Ithird_party  -I. -DTEST_BUILD= -DTEST_LEGACY_BUILD= -DTEST_TASKFILE=abort.tasklist   -DTEST_abort= -DTEST_ABORT=        -Iinclude/driver  -DSECTION_IS_= -DSECTION=  -fno-PIC -DCHROMIUM_EC= -DHAS_TASK_HOOKS= -DHAS_TASK_HOSTCMD= -DHAS_TASK_CONSOLE= -DHAS_TASK_TEST=  -P -Ichip/stm32 -Ibaseboard/bloonchipper -Iboard/bloonchipper  -imacros include/config.h -
echo "CONFIG_RW_SIZE" | /usr/bin/ccache armv7m-cros-eabi-clang -E -DOUTDIR=build/bloonchipper/abort/ -DCHIP=stm32 -DBOARD_TASKFILE=ec.tasklist -DBOARD=bloonchipper -DCORE=cortex-m -DPROJECT=abort -DCHIP_VARIANT=stm32f412 -DCHIP_FAMILY=STM32F4 -DBOARD_BLOONCHIPPER= -DCHIP_STM32= -DCORE_CORTEX_M= -DCHIP_VARIANT_STM32F412= -DCHIP_FAMILY_STM32F4= -DFINAL_OUTDIR=build/bloonchipper/abort -DPROTOBUF_MIN_PROTOC_VERSION=0 -DHAS_BASEBOARD= -DBASEBOARD_BLOONCHIPPER= -Iinclude  -Icore/cortex-m/include  -Iinclude/driver  -Ibuild/bloonchipper/abort  -Ifuzz  -Itest  -Ithird_party  -I. -DTEST_BUILD= -DTEST_LEGACY_BUILD= -DTEST_TASKFILE=abort.tasklist   -DTEST_abort= -DTEST_ABORT=        -Iinclude/driver  -DSECTION_IS_= -DSECTION=  -fno-PIC -DCHROMIUM_EC= -DHAS_TASK_HOOKS= -DHAS_TASK_HOSTCMD= -DHAS_TASK_CONSOLE= -DHAS_TASK_TEST=  -P -Ichip/stm32 -Ibaseboard/bloonchipper -Iboard/bloonchipper  -imacros include/config.h -
echo "CONFIG_PROGRAM_MEMORY_BASE" | /usr/bin/ccache armv7m-cros-eabi-clang -E -DOUTDIR=build/bloonchipper/abort/ -DCHIP=stm32 -DBOARD_TASKFILE=ec.tasklist -DBOARD=bloonchipper -DCORE=cortex-m -DPROJECT=abort -DCHIP_VARIANT=stm32f412 -DCHIP_FAMILY=STM32F4 -DBOARD_BLOONCHIPPER= -DCHIP_STM32= -DCORE_CORTEX_M= -DCHIP_VARIANT_STM32F412= -DCHIP_FAMILY_STM32F4= -DFINAL_OUTDIR=build/bloonchipper/abort -DPROTOBUF_MIN_PROTOC_VERSION=0 -DHAS_BASEBOARD= -DBASEBOARD_BLOONCHIPPER= -Iinclude  -Icore/cortex-m/include  -Iinclude/driver  -Ibuild/bloonchipper/abort  -Ifuzz  -Itest  -Ithird_party  -I. -DTEST_BUILD= -DTEST_LEGACY_BUILD= -DTEST_TASKFILE=abort.tasklist   -DTEST_abort= -DTEST_ABORT=        -Iinclude/driver  -DSECTION_IS_= -DSECTION=  -fno-PIC -DCHROMIUM_EC= -DHAS_TASK_HOOKS= -DHAS_TASK_HOSTCMD= -DHAS_TASK_CONSOLE= -DHAS_TASK_TEST=  -P -Ichip/stm32 -Ibaseboard/bloonchipper -Iboard/bloonchipper  -imacros include/config.h -
armv7m-cros-eabi-clang++ -std=gnu++2a -DOUTDIR=build/bloonchipper/abort/RW -DCHIP=stm32 -DBOARD_TASKFILE=ec.tasklist -DBOARD=bloonchipper -DCORE=cortex-m -DPROJECT=abort -DCHIP_VARIANT=stm32f412 -DCHIP_FAMILY=STM32F4 -DBOARD_BLOONCHIPPER= -DCHIP_STM32= -DCORE_CORTEX_M= -DCHIP_VARIANT_STM32F412= -DCHIP_FAMILY_STM32F4= -DFINAL_OUTDIR=build/bloonchipper/abort -DPROTOBUF_MIN_PROTOC_VERSION=0 -DHAS_BASEBOARD= -DBASEBOARD_BLOONCHIPPER= -Iinclude  -Icore/cortex-m/include  -Iinclude/driver  -Icore/cortex-m  -Ichip/stm32  -Ibaseboard/bloonchipper  -Iboard/bloonchipper  -Icommon  -Ifuzz  -Ipower  -Itest  -Icts/common  -Icts/  -Ibuild/bloonchipper/abort/gen  -I../ec-private  -Icommon  -Icommon/fpsensor  -Icommon/mock  -Icommon/spi  -Icommon/spi/flash_reg  -Icommon/spi/flash_reg/private  -Icommon/spi/flash_reg/public  -Icommon/spi/flash_reg/src  -Icommon/usbc  -Icommon/vboot  -Idriver  -Idriver/battery  -Idriver/bc12  -Idriver/cec  -Idriver/charger  -Idriver/fingerprint  -Idriver/fingerprint/egis  -Idriver/fingerprint/egis/platform  -Idriver/fingerprint/egis/platform/inc  -Idriver/fingerprint/egis/platform/src  -Idriver/fingerprint/elan  -Idriver/fingerprint/fpc  -Idriver/fingerprint/fpc/bep  -Idriver/fingerprint/fpc/libfp  -Idriver/ioexpander  -Idriver/led  -Idriver/nfc  -Idriver/ppc  -Idriver/retimer  -Idriver/sha256  -Idriver/tcpm  -Idriver/temp_sensor  -Idriver/usb_mux  -Idriver/wpc  -Ilibc  -Ithird_party/boringssl/common  -Icrypto  -Ibuild/bloonchipper/abort  -Ifuzz  -Itest  -Ithird_party  -Ispi/flash_regpublic  -I. -DTEST_BUILD= -DTEST_LEGACY_BUILD= -DTEST_TASKFILE=abort.tasklist   -DTEST_abort= -DTEST_ABORT=        -Iinclude/driver  -DSECTION_IS_RW= -DSECTION=RW -DHAS_TASK_FPSENSOR= -DHAS_TASK_RWSIG_RO= -fno-PIC -DCHROMIUM_EC= -DHAS_TASK_HOOKS= -DHAS_TASK_HOSTCMD= -DHAS_TASK_CONSOLE= -DHAS_TASK_TEST=  -I../../third_party/boringssl -I../../third_party/boringssl/include -I/build/amd64-generic/tmp/portage/chromeos-base/chromeos-fpmcu-bloonchipper-unittests-0.0.1-r893/work/chromeos-fpmcu-bloonchipper-unittests-0.0.1/platform/ec/third_party/boringssl/include -DCROS_EC -mcpu=cortex-m4 -mcpu=cortex-m4 -mthumb -Oz             -Wl,-mllvm -Wl,-inline-threshold=-10 -mno-unaligned-access -mfloat-abi=hard -flto -g  -Wall -Wundef -Wno-trigraphs -Wno-format-security -Wno-address-of-packed-member -fno-common -fno-strict-aliasing -fno-strict-overflow -Wimplicit-fallthrough -fno-exceptions -fno-unwind-tables -fno-asynchronous-unwind-tables -Werror -ftrapv -Werror=uninitialized -Wno-unused-function  -ffunction-sections -fno-delete-null-pointer-checks -fno-PIC -Wvla -Wall -Wundef -Wno-trigraphs -Wno-format-security -Wno-address-of-packed-member -fno-common -fno-strict-aliasing -fno-strict-overflow -Wimplicit-fallthrough -fno-exceptions -fno-unwind-tables -fno-asynchronous-unwind-tables -Werror -ftrapv -Werror=uninitialized -Wno-unused-function -DPROTOBUF_INLINE_NOT_IN_HEADERS=0 -MMD -MP -MF build/bloonchipper/abort/RW/common/fpsensor/fpsensor.o.d -c common/fpsensor/fpsensor.cc -MT build/bloonchipper/abort/RW/common/fpsensor/fpsensor.o -o build/bloonchipper/abort/RW/common/fpsensor/fpsensor.o
In file included from common/fpsensor/fpsensor.cc:7:
In file included from core/cortex-m/atomic.h:12:
In file included from include/common.h:11:
In file included from include/compile_time_macros.h:12:
In file included from /usr/bin/../include/c++/v1/type_traits:420:
/usr/bin/../include/c++/v1/__config:821:8: error: "No thread API"
  821 | #      error "No thread API"
      |        ^

And with -print-cmdline:

ajordanr@chrysalis /build/amd64-generic/tmp/portage/chromeos-base/chromeos-fpmcu-bloonchipper-unittests-0.0.1-r893/work/chromeos-fpmcu-bloonchipper-unittests-0.0.1/platform/ec $ armv7m-cros-eabi-clang++ -std=gnu++2a -DOUTDIR=build/bloonchipper/abort/RW -DCHIP=stm32 -DBOARD_TASKFILE=ec.tasklist -DBOARD=bloonchipper -DCORE=cortex-m -DPROJECT=abort -DCHIP_VARIANT=stm32f412 -DCHIP_FAMILY=STM32F4 -DBOARD_BLOONCHIPPER= -DCHIP_STM32= -DCORE_CORTEX_M= -DCHIP_VARIANT_STM32F412= -DCHIP_FAMILY_STM32F4= -DFINAL_OUTDIR=build/bloonchipper/abort -DPROTOBUF_MIN_PROTOC_VERSION=0 -DHAS_BASEBOARD= -DBASEBOARD_BLOONCHIPPER= -Iinclude  -Icore/cortex-m/include  -Iinclude/driver  -Icore/cortex-m  -Ichip/stm32  -Ibaseboard/bloonchipper  -Iboard/bloonchipper  -Icommon  -Ifuzz  -Ipower  -Itest  -Icts/common  -Icts/  -Ibuild/bloonchipper/abort/gen  -I../ec-private  -Icommon  -Icommon/fpsensor  -Icommon/mock  -Icommon/spi  -Icommon/spi/flash_reg  -Icommon/spi/flash_reg/private  -Icommon/spi/flash_reg/public  -Icommon/spi/flash_reg/src  -Icommon/usbc  -Icommon/vboot  -Idriver  -Idriver/battery  -Idriver/bc12  -Idriver/cec  -Idriver/charger  -Idriver/fingerprint  -Idriver/fingerprint/egis  -Idriver/fingerprint/egis/platform  -Idriver/fingerprint/egis/platform/inc  -Idriver/fingerprint/egis/platform/src  -Idriver/fingerprint/elan  -Idriver/fingerprint/fpc  -Idriver/fingerprint/fpc/bep  -Idriver/fingerprint/fpc/libfp  -Idriver/ioexpander  -Idriver/led  -Idriver/nfc  -Idriver/ppc  -Idriver/retimer  -Idriver/sha256  -Idriver/tcpm  -Idriver/temp_sensor  -Idriver/usb_mux  -Idriver/wpc  -Ilibc  -Ithird_party/boringssl/common  -Icrypto  -Ibuild/bloonchipper/abort  -Ifuzz  -Itest  -Ithird_party  -Ispi/flash_regpublic  -I. -DTEST_BUILD= -DTEST_LEGACY_BUILD= -DTEST_TASKFILE=abort.tasklist   -DTEST_abort= -DTEST_ABORT=        -Iinclude/driver  -DSECTION_IS_RW= -DSECTION=RW -DHAS_TASK_FPSENSOR= -DHAS_TASK_RWSIG_RO= -fno-PIC -DCHROMIUM_EC= -DHAS_TASK_HOOKS= -DHAS_TASK_HOSTCMD= -DHAS_TASK_CONSOLE= -DHAS_TASK_TEST=  -I../../third_party/boringssl -I../../third_party/boringssl/include -I/build/amd64-generic/tmp/portage/chromeos-base/chromeos-fpmcu-bloonchipper-unittests-0.0.1-r893/work/chromeos-fpmcu-bloonchipper-unittests-0.0.1/platform/ec/third_party/boringssl/include -DCROS_EC -mcpu=cortex-m4 -mcpu=cortex-m4 -mthumb -Oz             -Wl,-mllvm -Wl,-inline-threshold=-10 -mno-unaligned-access -mfloat-abi=hard -flto -g  -Wall -Wundef -Wno-trigraphs -Wno-format-security -Wno-address-of-packed-member -fno-common -fno-strict-aliasing -fno-strict-overflow -Wimplicit-fallthrough -fno-exceptions -fno-unwind-tables -fno-asynchronous-unwind-tables -Werror -ftrapv -Werror=uninitialized -Wno-unused-function  -ffunction-sections -fno-delete-null-pointer-checks -fno-PIC -Wvla -Wall -Wundef -Wno-trigraphs -Wno-format-security -Wno-address-of-packed-member -fno-common -fno-strict-aliasing -fno-strict-overflow -Wimplicit-fallthrough -fno-exceptions -fno-unwind-tables -fno-asynchronous-unwind-tables -Werror -ftrapv -Werror=uninitialized -Wno-unused-function -DPROTOBUF_INLINE_NOT_IN_HEADERS=0 -MMD -MP -MF build/bloonchipper/abort/RW/common/fpsensor/fpsensor.o.d -c common/fpsensor/fpsensor.cc -MT build/bloonchipper/abort/RW/common/fpsensor/fpsensor.o -o build/bloonchipper/abort/RW/common/fpsensor/fpsensor.o -print-cmdline
cd '/build/amd64-generic/tmp/portage/chromeos-base/chromeos-fpmcu-bloonchipper-unittests-0.0.1-r893/work/chromeos-fpmcu-bloonchipper-unittests-0.0.1/platform/ec' && env 'CCACHE_DIR=/var/cache/distfiles/ccache' 'CCACHE_UMASK=002' 'CCACHE_CPP2=yes' '/usr/bin/ccache' '/usr/bin/clang++' '--sysroot=/usr/armv7m-cros-eabi' '-Qunused-arguments' '-Werror=poison-system-directories' '-Wno-deprecated-declarations' '-Wno-error=implicit-function-declaration' '-Wno-error=implicit-int' '-Wno-unknown-warning-option' '-fdebug-default-version=5' '-Wno-int-conversion' '-Wno-incompatible-function-pointer-types' '-Wno-error=vla-cxx-extension' '-D_LIBCPP_ENABLE_CXX17_REMOVED_FEATURES' '-Wno-section' '-static-libgcc' '--prefix=../../../../../../../../../../usr/libexec/gcc/armv7m-cros-eabi/armv7m-cros-eabi-' '-std=gnu++2a' '-DOUTDIR=build/bloonchipper/abort/RW' '-DCHIP=stm32' '-DBOARD_TASKFILE=ec.tasklist' '-DBOARD=bloonchipper' '-DCORE=cortex-m' '-DPROJECT=abort' '-DCHIP_VARIANT=stm32f412' '-DCHIP_FAMILY=STM32F4' '-DBOARD_BLOONCHIPPER=' '-DCHIP_STM32=' '-DCORE_CORTEX_M=' '-DCHIP_VARIANT_STM32F412=' '-DCHIP_FAMILY_STM32F4=' '-DFINAL_OUTDIR=build/bloonchipper/abort' '-DPROTOBUF_MIN_PROTOC_VERSION=0' '-DHAS_BASEBOARD=' '-DBASEBOARD_BLOONCHIPPER=' '-Iinclude' '-Icore/cortex-m/include' '-Iinclude/driver' '-Icore/cortex-m' '-Ichip/stm32' '-Ibaseboard/bloonchipper' '-Iboard/bloonchipper' '-Icommon' '-Ifuzz' '-Ipower' '-Itest' '-Icts/common' '-Icts/' '-Ibuild/bloonchipper/abort/gen' '-I../ec-private' '-Icommon' '-Icommon/fpsensor' '-Icommon/mock' '-Icommon/spi' '-Icommon/spi/flash_reg' '-Icommon/spi/flash_reg/private' '-Icommon/spi/flash_reg/public' '-Icommon/spi/flash_reg/src' '-Icommon/usbc' '-Icommon/vboot' '-Idriver' '-Idriver/battery' '-Idriver/bc12' '-Idriver/cec' '-Idriver/charger' '-Idriver/fingerprint' '-Idriver/fingerprint/egis' '-Idriver/fingerprint/egis/platform' '-Idriver/fingerprint/egis/platform/inc' '-Idriver/fingerprint/egis/platform/src' '-Idriver/fingerprint/elan' '-Idriver/fingerprint/fpc' '-Idriver/fingerprint/fpc/bep' '-Idriver/fingerprint/fpc/libfp' '-Idriver/ioexpander' '-Idriver/led' '-Idriver/nfc' '-Idriver/ppc' '-Idriver/retimer' '-Idriver/sha256' '-Idriver/tcpm' '-Idriver/temp_sensor' '-Idriver/usb_mux' '-Idriver/wpc' '-Ilibc' '-Ithird_party/boringssl/common' '-Icrypto' '-Ibuild/bloonchipper/abort' '-Ifuzz' '-Itest' '-Ithird_party' '-Ispi/flash_regpublic' '-I.' '-DTEST_BUILD=' '-DTEST_LEGACY_BUILD=' '-DTEST_TASKFILE=abort.tasklist' '-DTEST_abort=' '-DTEST_ABORT=' '-Iinclude/driver' '-DSECTION_IS_RW=' '-DSECTION=RW' '-DHAS_TASK_FPSENSOR=' '-DHAS_TASK_RWSIG_RO=' '-fno-PIC' '-DCHROMIUM_EC=' '-DHAS_TASK_HOOKS=' '-DHAS_TASK_HOSTCMD=' '-DHAS_TASK_CONSOLE=' '-DHAS_TASK_TEST=' '-I../../third_party/boringssl' '-I../../third_party/boringssl/include' '-I/build/amd64-generic/tmp/portage/chromeos-base/chromeos-fpmcu-bloonchipper-unittests-0.0.1-r893/work/chromeos-fpmcu-bloonchipper-unittests-0.0.1/platform/ec/third_party/boringssl/include' '-DCROS_EC' '-mcpu=cortex-m4' '-mcpu=cortex-m4' '-mthumb' '-Oz' '-Wl,-mllvm' '-Wl,-inline-threshold=-10' '-mno-unaligned-access' '-mfloat-abi=hard' '-flto' '-g' '-Wall' '-Wundef' '-Wno-trigraphs' '-Wno-format-security' '-Wno-address-of-packed-member' '-fno-common' '-fno-strict-aliasing' '-fno-strict-overflow' '-Wimplicit-fallthrough' '-fno-exceptions' '-fno-unwind-tables' '-fno-asynchronous-unwind-tables' '-Werror' '-ftrapv' '-Werror=uninitialized' '-Wno-unused-function' '-ffunction-sections' '-fno-delete-null-pointer-checks' '-fno-PIC' '-Wvla' '-Wall' '-Wundef' '-Wno-trigraphs' '-Wno-format-security' '-Wno-address-of-packed-member' '-fno-common' '-fno-strict-aliasing' '-fno-strict-overflow' '-Wimplicit-fallthrough' '-fno-exceptions' '-fno-unwind-tables' '-fno-asynchronous-unwind-tables' '-Werror' '-ftrapv' '-Werror=uninitialized' '-Wno-unused-function' '-DPROTOBUF_INLINE_NOT_IN_HEADERS=0' '-MMD' '-MP' '-MF' 'build/bloonchipper/abort/RW/common/fpsensor/fpsensor.o.d' '-c' 'common/fpsensor/fpsensor.cc' '-MT' 'build/bloonchipper/abort/RW/common/fpsensor/fpsensor.o' '-o' 'build/bloonchipper/abort/RW/common/fpsensor/fpsensor.o' '-L/usr/armv7m-cros-eabi/usr/lib' '-B../../../../../../../../../../usr/libexec/gcc/armv7m-cros-eabi' '-target' 'armv7m-cros-eabi'

Hold on. Why is this including /usr/include/c++/v1/__config? Actually, scratch that, it probably is using the right sysroot because of --sysroot.

No wait, hmm.

the /usr/armv7m-cros-eabi/usr/include/c++/v1/__config_site sets _LIBCPP_HAS_NO_THREADS:

      1 //===----------------------------------------------------------------------===//
      2 //
      3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
      4 // See https://llvm.org/LICENSE.txt for license information.
      5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
      6 //
      7 //===----------------------------------------------------------------------===//
      8
      9 #ifndef _LIBCPP___CONFIG_SITE
     10 #define _LIBCPP___CONFIG_SITE
     11 #define _LIBCPP_VERBOSE_ABORT(...)
     12
     13 #define _LIBCPP_ABI_VERSION 1
     14 #define _LIBCPP_ABI_NAMESPACE __1
     15 /* #undef _LIBCPP_ABI_FORCE_ITANIUM */
     16 /* #undef _LIBCPP_ABI_FORCE_MICROSOFT */
     17 #define _LIBCPP_HAS_NO_THREADS
     18 #define _LIBCPP_HAS_NO_MONOTONIC_CLOCK
     19 /* #undef _LIBCPP_HAS_NO_TERMINAL */
     20 /* #undef _LIBCPP_HAS_MUSL_LIBC */
     21 /* #undef _LIBCPP_HAS_THREAD_API_PTHREAD */
     22 /* #undef _LIBCPP_HAS_THREAD_API_EXTERNAL */
     23 /* #undef _LIBCPP_HAS_THREAD_API_WIN32 */
     24 /* #undef _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS */
     25 #define _LIBCPP_HAS_NO_VENDOR_AVAILABILITY_ANNOTATIONS
     26 /* #undef _LIBCPP_NO_VCRUNTIME */
     27 /* #undef _LIBCPP_TYPEINFO_COMPARISON_IMPLEMENTATION */
     28 #define _LIBCPP_HAS_NO_FILESYSTEM
     29 #define _LIBCPP_HAS_NO_RANDOM_DEVICE
     30 /* #undef _LIBCPP_HAS_NO_LOCALIZATION */
     31 #define _LIBCPP_HAS_NO_UNICODE
     32 /* #undef _LIBCPP_HAS_NO_WIDE_CHARACTERS */
     33 /* #undef _LIBCPP_HAS_NO_STD_MODULES */
     34 /* #undef _LIBCPP_HAS_NO_TIME_ZONE_DATABASE */
     35 /* #undef _LIBCPP_INSTRUMENTED_WITH_ASAN */
     36
     37 // PSTL backends
     38 #define _LIBCPP_PSTL_BACKEND_SERIAL
     39 /* #undef _LIBCPP_PSTL_BACKEND_STD_THREAD */
     40 /* #undef _LIBCPP_PSTL_BACKEND_LIBDISPATCH */
     41
     42 // Hardening.
     43 #define _LIBCPP_HARDENING_MODE_DEFAULT 2
     44
     45 // __USE_MINGW_ANSI_STDIO gets redefined on MinGW
     46 #ifdef __clang__
     47 #  pragma clang diagnostic push
     48 #  pragma clang diagnostic ignored "-Wmacro-redefined"
     49 #endif
     50
     51
     52
     53
     54 #ifdef __clang__
     55 #  pragma clang diagnostic pop
     56 #endif
     57

Maybe it isn't using the right sysroot?

See in comparison to /usr/include/c++/v1/__config_site:

      1 //===----------------------------------------------------------------------===//
      2 //
      3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
      4 // See https://llvm.org/LICENSE.txt for license information.
      5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
      6 //
      7 //===----------------------------------------------------------------------===//
      8
      9 #ifndef _LIBCPP___CONFIG_SITE
     10 #define _LIBCPP___CONFIG_SITE
     11
     12 #define _LIBCPP_ABI_VERSION 1
     13 #define _LIBCPP_ABI_NAMESPACE __1
     14 /* #undef _LIBCPP_ABI_FORCE_ITANIUM */
     15 /* #undef _LIBCPP_ABI_FORCE_MICROSOFT */
     16 /* #undef _LIBCPP_HAS_NO_THREADS */
     17 /* #undef _LIBCPP_HAS_NO_MONOTONIC_CLOCK */
     18 /* #undef _LIBCPP_HAS_NO_TERMINAL */
     19 /* #undef _LIBCPP_HAS_MUSL_LIBC */
     20 /* #undef _LIBCPP_HAS_THREAD_API_PTHREAD */
     21 /* #undef _LIBCPP_HAS_THREAD_API_EXTERNAL */
     22 /* #undef _LIBCPP_HAS_THREAD_API_WIN32 */
     23 /* #undef _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS */
     24 #define _LIBCPP_HAS_NO_VENDOR_AVAILABILITY_ANNOTATIONS
     25 /* #undef _LIBCPP_NO_VCRUNTIME */
     26 /* #undef _LIBCPP_TYPEINFO_COMPARISON_IMPLEMENTATION */
     27 /* #undef _LIBCPP_HAS_NO_FILESYSTEM */
     28 /* #undef _LIBCPP_HAS_NO_RANDOM_DEVICE */
     29 /* #undef _LIBCPP_HAS_NO_LOCALIZATION */
     30 /* #undef _LIBCPP_HAS_NO_UNICODE */
     31 /* #undef _LIBCPP_HAS_NO_WIDE_CHARACTERS */
     32 /* #undef _LIBCPP_HAS_NO_STD_MODULES */
     33 /* #undef _LIBCPP_HAS_NO_TIME_ZONE_DATABASE */
     34 /* #undef _LIBCPP_INSTRUMENTED_WITH_ASAN */
     35
     36 // PSTL backends
     37 /* #undef _LIBCPP_PSTL_BACKEND_SERIAL */
     38 #define _LIBCPP_PSTL_BACKEND_STD_THREAD
     39 /* #undef _LIBCPP_PSTL_BACKEND_LIBDISPATCH */
     40
     41 // Hardening.
     42 #define _LIBCPP_HARDENING_MODE_DEFAULT 2
     43
     44 // __USE_MINGW_ANSI_STDIO gets redefined on MinGW
     45 #ifdef __clang__
     46 #  pragma clang diagnostic push
     47 #  pragma clang diagnostic ignored "-Wmacro-redefined"
     48 #endif
     49
     50
     51
     52
     53 #ifdef __clang__
     54 #  pragma clang diagnostic pop
     55 #endif
     56
     57 #endif // _LIBCPP___CONFIG_SITE

Okay, indeed that's what's happening. It's using /usr/include/c++/v1/__config_site, and instead it should be using /usr/armv7m-cros-eabi/usr/include/c++/v1/__config_site. I found this out by changing every single __config header in the chroot until I found the one that caused this.

In file included from common/fpsensor/fpsensor.cc:7:
In file included from core/cortex-m/atomic.h:12:
In file included from include/common.h:11:
In file included from include/compile_time_macros.h:12:
In file included from /usr/bin/../include/c++/v1/type_traits:420:
/usr/bin/../include/c++/v1/__config:821:8: error: "ajordanr: chroot's /usr/include/c++/v1/__config No thread API"
  821 | #      error "ajordanr: chroot's /usr/include/c++/v1/__config No thread API"
      |        ^

I have figured out what's wrong. By appending -v to the command line, we can get the include search path for this fpsensor.cc file. So while we do see /usr/armv7m-cros-eabi/usr/include/c++/v1, it's notably after in the search path for /usr/bin/../include/c++/v1. I'm not sure how the ordering of this happens, or why the system includes are there first consistently.

$ cd \
  '/build/amd64-generic/tmp/portage/chromeos-base/chromeos-fpmcu-bloonchipper-unittests-0.0.1-r893/work/chromeos-fpmcu-bloonchipper-unittests-0.0.1/platform/ec' \
  && \
  env \
  'CCACHE_DIR=/var/cache/distfiles/ccache' \
  'CCACHE_UMASK=002' \
  'CCACHE_CPP2=yes' \
  '/usr/bin/ccache' \
  '/usr/bin/clang++' \
  '-Qunused-arguments' \
  '-Werror=poison-system-directories' \
  '-Wno-deprecated-declarations' \
  '-Wno-error=implicit-function-declaration' \
  '-Wno-error=implicit-int' \
  '-Wno-unknown-warning-option' \
  '-fdebug-default-version=5' \
  '-Wno-int-conversion' \
  '-Wno-incompatible-function-pointer-types' \
  '-Wno-error=vla-cxx-extension' \
  '-D_LIBCPP_ENABLE_CXX17_REMOVED_FEATURES' \
  '-Wno-section' \
  '-static-libgcc' \
  '--prefix=../../../../../../../../../../usr/libexec/gcc/armv7m-cros-eabi/armv7m-cros-eabi-' \
  '-std=gnu++2a' \
  '-DOUTDIR=build/bloonchipper/abort/RW' \
  '-DCHIP=stm32' \
  '-DBOARD_TASKFILE=ec.tasklist' \
  '-DBOARD=bloonchipper' \
  '-DCORE=cortex-m' \
  '-DPROJECT=abort' \
  '-DCHIP_VARIANT=stm32f412' \
  '-DCHIP_FAMILY=STM32F4' \
  '-DBOARD_BLOONCHIPPER=' \
  '-DCHIP_STM32=' \
  '-DCORE_CORTEX_M=' \
  '-DCHIP_VARIANT_STM32F412=' \
  '-DCHIP_FAMILY_STM32F4=' \
  '-DFINAL_OUTDIR=build/bloonchipper/abort' \
  '-DPROTOBUF_MIN_PROTOC_VERSION=0' \
  '-DHAS_BASEBOARD=' \
  '-DBASEBOARD_BLOONCHIPPER=' \
  '-Iinclude' \
  '-Icore/cortex-m/include' \
  '-Iinclude/driver' \
  '-Icore/cortex-m' \
  '-Ichip/stm32' \
  '-Ibaseboard/bloonchipper' \
  '-Iboard/bloonchipper' \
  '-Icommon' \
  '-Ifuzz' \
  '-Ipower' \
  '-Itest' \
  '-Icts/common' \
  '-Icts/' \
  '-Ibuild/bloonchipper/abort/gen' \
  '-I../ec-private' \
  '-Icommon' \
  '-Icommon/fpsensor' \
  '-Icommon/mock' \
  '-Icommon/spi' \
  '-Icommon/spi/flash_reg' \
  '-Icommon/spi/flash_reg/private' \
  '-Icommon/spi/flash_reg/public' \
  '-Icommon/spi/flash_reg/src' \
  '-Icommon/usbc' \
  '-Icommon/vboot' \
  '-Idriver' \
  '-Idriver/battery' \
  '-Idriver/bc12' \
  '-Idriver/cec' \
  '-Idriver/charger' \
  '-Idriver/fingerprint' \
  '-Idriver/fingerprint/egis' \
  '-Idriver/fingerprint/egis/platform' \
  '-Idriver/fingerprint/egis/platform/inc' \
  '-Idriver/fingerprint/egis/platform/src' \
  '-Idriver/fingerprint/elan' \
  '-Idriver/fingerprint/fpc' \
  '-Idriver/fingerprint/fpc/bep' \
  '-Idriver/fingerprint/fpc/libfp' \
  '-Idriver/ioexpander' \
  '-Idriver/led' \
  '-Idriver/nfc' \
  '-Idriver/ppc' \
  '-Idriver/retimer' \
  '-Idriver/sha256' \
  '-Idriver/tcpm' \
  '-Idriver/temp_sensor' \
  '-Idriver/usb_mux' \
  '-Idriver/wpc' \
  '-Ilibc' \
  '-Ithird_party/boringssl/common' \
  '-Icrypto' \
  '-Ibuild/bloonchipper/abort' \
  '-Ifuzz' \
  '-Itest' \
  '-Ithird_party' \
  '-Ispi/flash_regpublic' \
  '-I.' \
  '-DTEST_BUILD=' \
  '-DTEST_LEGACY_BUILD=' \
  '-DTEST_TASKFILE=abort.tasklist' \
  '-DTEST_abort=' \
  '-DTEST_ABORT=' \
  '-Iinclude/driver' \
  '-DSECTION_IS_RW=' \
  '-DSECTION=RW' \
  '-DHAS_TASK_FPSENSOR=' \
  '-DHAS_TASK_RWSIG_RO=' \
  '-fno-PIC' \
  '-DCHROMIUM_EC=' \
  '-DHAS_TASK_HOOKS=' \
  '-DHAS_TASK_HOSTCMD=' \
  '-DHAS_TASK_CONSOLE=' \
  '-DHAS_TASK_TEST=' \
  '-I../../third_party/boringssl' \
  '-I../../third_party/boringssl/include' \
  '-I/build/amd64-generic/tmp/portage/chromeos-base/chromeos-fpmcu-bloonchipper-unittests-0.0.1-r893/work/chromeos-fpmcu-bloonchipper-unittests-0.0.1/platform/ec/third_party/boringssl/include' \
  '-DCROS_EC' \
  '-mcpu=cortex-m4' \
  '-mcpu=cortex-m4' \
  '-mthumb' \
  '-Oz' \
  '-Wl,-mllvm' \
  '-Wl,-inline-threshold=-10' \
  '-mno-unaligned-access' \
  '-mfloat-abi=hard' \
  '-flto' \
  '-g' \
  '-Wall' \
  '-Wundef' \
  '-Wno-trigraphs' \
  '-Wno-format-security' \
  '-Wno-address-of-packed-member' \
  '-fno-common' \
  '-fno-strict-aliasing' \
  '-fno-strict-overflow' \
  '-Wimplicit-fallthrough' \
  '-fno-exceptions' \
  '-fno-unwind-tables' \
  '-fno-asynchronous-unwind-tables' \
  '-Werror' \
  '-ftrapv' \
  '-Werror=uninitialized' \
  '-Wno-unused-function' \
  '-ffunction-sections' \
  '-fno-delete-null-pointer-checks' \
  '-fno-PIC' \
  '-Wvla' \
  '-Wall' \
  '-Wundef' \
  '-Wno-trigraphs' \
  '-Wno-format-security' \
  '-Wno-address-of-packed-member' \
  '-fno-common' \
  '-fno-strict-aliasing' \
  '-fno-strict-overflow' \
  '-Wimplicit-fallthrough' \
  '-fno-exceptions' \
  '-fno-unwind-tables' \
  '-fno-asynchronous-unwind-tables' \
  '-Werror' \
  '-ftrapv' \
  '-Werror=uninitialized' \
  '-Wno-unused-function' \
  '-DPROTOBUF_INLINE_NOT_IN_HEADERS=0' \
  '-MMD' \
  '-MP' \
  '-MF' \
  'build/bloonchipper/abort/RW/common/fpsensor/fpsensor.o.d' \
  '-c' \
  'common/fpsensor/fpsensor.cc' \
  '-MT' \
  'build/bloonchipper/abort/RW/common/fpsensor/fpsensor.o' \
  '-o' \
  'build/bloonchipper/abort/RW/common/fpsensor/fpsensor.o' \
  '-L/usr/armv7m-cros-eabi/usr/lib' \
  '-B../../../../../../../../../../usr/libexec/gcc/armv7m-cros-eabi' \
  '-target' \
  'armv7m-cros-eabi' \
  '--sysroot=/usr/armv7m-cros-eabi' \
  '-v'
Chromium OS 9999 clang version 20.0.0git (https://chromium.googlesource.com/external/github.com/llvm/llvm-project 696a2a0a02b23000c2ea96e6501eda120a8d9d29)
Target: armv7m-cros-unknown-eabi
Thread model: posix
InstalledDir: /usr/bin
 (in-process)
 "/usr/bin/clang-20" -cc1 -triple thumbv7em-cros-unknown-eabihf -emit-llvm-bc -flto=full -flto-unit -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name fpsensor.cc -mrelocation-model static -fno-delete-null-pointer-checks -mframe-pointer=all -relaxed-aliasing -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -nostdsysteminc -target-cpu cortex-m4 -target-feature -crc -target-feature -dotprod -target-feature +dsp -target-feature -mve -target-feature -mve.fp -target-feature -ras -target-feature -bf16 -target-feature -sb -target-feature -i8mm -target-feature -lob -target-feature -cdecp0 -target-feature -cdecp1 -target-feature -cdecp2 -target-feature -cdecp3 -target-feature -cdecp4 -target-feature -cdecp5 -target-feature -cdecp6 -target-feature -cdecp7 -target-feature -pacbti -target-feature -hwdiv-arm -target-feature +hwdiv -target-feature -vfp2 -target-feature +vfp2sp -target-feature -vfp3 -target-feature -vfp3d16 -target-feature +vfp3d16sp -target-feature -vfp3sp -target-feature +fp16 -target-feature -vfp4 -target-feature -vfp4d16 -target-feature +vfp4d16sp -target-feature -vfp4sp -target-feature -fp-armv8 -target-feature -fp-armv8d16 -target-feature -fp-armv8d16sp -target-feature -fp-armv8sp -target-feature -fullfp16 -target-feature -fp64 -target-feature -d32 -target-feature -neon -target-feature -fp16fml -target-feature -crypto -target-feature -sha2 -target-feature -aes -target-feature +strict-align -target-abi aapcs -mfloat-abi hard -Wunaligned-access -debug-info-kind=constructor -dwarf-version=5 -debugger-tuning=gdb -fdebug-compilation-dir=/build/amd64-generic/tmp/portage/chromeos-base/chromeos-fpmcu-bloonchipper-unittests-0.0.1-r893/work/chromeos-fpmcu-bloonchipper-unittests-0.0.1/platform/ec -v -ffunction-sections -fcoverage-compilation-dir=/build/amd64-generic/tmp/portage/chromeos-base/chromeos-fpmcu-bloonchipper-unittests-0.0.1-r893/work/chromeos-fpmcu-bloonchipper-unittests-0.0.1/platform/ec -resource-dir /usr/lib64/clang/20 -dependency-file build/bloonchipper/abort/RW/common/fpsensor/fpsensor.o.d -MT build/bloonchipper/abort/RW/common/fpsensor/fpsensor.o -MP -D _LIBCPP_ENABLE_CXX17_REMOVED_FEATURES -D OUTDIR=build/bloonchipper/abort/RW -D CHIP=stm32 -D BOARD_TASKFILE=ec.tasklist -D BOARD=bloonchipper -D CORE=cortex-m -D PROJECT=abort -D CHIP_VARIANT=stm32f412 -D CHIP_FAMILY=STM32F4 -D BOARD_BLOONCHIPPER= -D CHIP_STM32= -D CORE_CORTEX_M= -D CHIP_VARIANT_STM32F412= -D CHIP_FAMILY_STM32F4= -D FINAL_OUTDIR=build/bloonchipper/abort -D PROTOBUF_MIN_PROTOC_VERSION=0 -D HAS_BASEBOARD= -D BASEBOARD_BLOONCHIPPER= -I include -I core/cortex-m/include -I include/driver -I core/cortex-m -I chip/stm32 -I baseboard/bloonchipper -I board/bloonchipper -I common -I fuzz -I power -I test -I cts/common -I cts/ -I build/bloonchipper/abort/gen -I ../ec-private -I common -I common/fpsensor -I common/mock -I common/spi -I common/spi/flash_reg -I common/spi/flash_reg/private -I common/spi/flash_reg/public -I common/spi/flash_reg/src -I common/usbc -I common/vboot -I driver -I driver/battery -I driver/bc12 -I driver/cec -I driver/charger -I driver/fingerprint -I driver/fingerprint/egis -I driver/fingerprint/egis/platform -I driver/fingerprint/egis/platform/inc -I driver/fingerprint/egis/platform/src -I driver/fingerprint/elan -I driver/fingerprint/fpc -I driver/fingerprint/fpc/bep -I driver/fingerprint/fpc/libfp -I driver/ioexpander -I driver/led -I driver/nfc -I driver/ppc -I driver/retimer -I driver/sha256 -I driver/tcpm -I driver/temp_sensor -I driver/usb_mux -I driver/wpc -I libc -I third_party/boringssl/common -I crypto -I build/bloonchipper/abort -I fuzz -I test -I third_party -I spi/flash_regpublic -I . -D TEST_BUILD= -D TEST_LEGACY_BUILD= -D TEST_TASKFILE=abort.tasklist -D TEST_abort= -D TEST_ABORT= -I include/driver -D SECTION_IS_RW= -D SECTION=RW -D HAS_TASK_FPSENSOR= -D HAS_TASK_RWSIG_RO= -D CHROMIUM_EC= -D HAS_TASK_HOOKS= -D HAS_TASK_HOSTCMD= -D HAS_TASK_CONSOLE= -D HAS_TASK_TEST= -I ../../third_party/boringssl -I ../../third_party/boringssl/include -I /build/amd64-generic/tmp/portage/chromeos-base/chromeos-fpmcu-bloonchipper-unittests-0.0.1-r893/work/chromeos-fpmcu-bloonchipper-unittests-0.0.1/platform/ec/third_party/boringssl/include -D CROS_EC -D PROTOBUF_INLINE_NOT_IN_HEADERS=0 -isysroot /usr/armv7m-cros-eabi -internal-isystem /usr/bin/../include/armv7m-cros-unknown-eabi/c++/v1 -internal-isystem /usr/bin/../include/c++/v1 -internal-isystem /usr/armv7m-cros-eabi/usr/include/c++/v1 -internal-isystem /usr/lib64/clang/20/include -internal-isystem /usr/armv7m-cros-eabi/include -Oz -Werror=poison-system-directories -Wno-deprecated-declarations -Wno-error=implicit-function-declaration -Wno-error=implicit-int -Wno-unknown-warning-option -Wno-int-conversion -Wno-incompatible-function-pointer-types -Wno-error=vla-cxx-extension -Wno-section -Wall -Wundef -Wno-trigraphs -Wno-format-security -Wno-address-of-packed-member -Wimplicit-fallthrough -Werror -Werror=uninitialized -Wno-unused-function -Wvla -Wall -Wundef -Wno-trigraphs -Wno-format-security -Wno-address-of-packed-member -Wimplicit-fallthrough -Werror -Werror=uninitialized -Wno-unused-function -std=gnu++2a -fdeprecated-macro -ferror-limit 19 -ftrapv -fwrapv -fno-signed-char -fgnuc-version=4.2.1 -fno-implicit-modules -fskip-odr-check-in-gmf -fcolor-diagnostics -vectorize-slp -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o build/bloonchipper/abort/RW/common/fpsensor/fpsensor.o -x c++ common/fpsensor/fpsensor.cc

-->8--

ignoring nonexistent directory "../ec-private"
ignoring nonexistent directory "spi/flash_regpublic"
ignoring nonexistent directory "/usr/bin/../include/armv7m-cros-unknown-eabi/c++/v1"
ignoring duplicate directory "common"
ignoring duplicate directory "fuzz"
ignoring duplicate directory "test"
ignoring duplicate directory "include/driver"
ignoring duplicate directory "/usr/lib64/clang/20/include"
#include "..." search starts here:
#include <...> search starts here:
 include
 core/cortex-m/include
 include/driver
 core/cortex-m
 chip/stm32
 baseboard/bloonchipper
 board/bloonchipper
 common
 fuzz
 power
 test
 cts/common
 cts
 build/bloonchipper/abort/gen
 common/fpsensor
 common/mock
 common/spi
 common/spi/flash_reg
 common/spi/flash_reg/private
 common/spi/flash_reg/public
 common/spi/flash_reg/src
 common/usbc
 common/vboot
 driver
 driver/battery
 driver/bc12
 driver/cec
 driver/charger
 driver/fingerprint
 driver/fingerprint/egis
 driver/fingerprint/egis/platform
 driver/fingerprint/egis/platform/inc
 driver/fingerprint/egis/platform/src
 driver/fingerprint/elan
 driver/fingerprint/fpc
 driver/fingerprint/fpc/bep
 driver/fingerprint/fpc/libfp
 driver/ioexpander
 driver/led
 driver/nfc
 driver/ppc
 driver/retimer
 driver/sha256
 driver/tcpm
 driver/temp_sensor
 driver/usb_mux
 driver/wpc
 libc
 third_party/boringssl/common
 crypto
 build/bloonchipper/abort
 third_party
 .
 ../../third_party/boringssl
 ../../third_party/boringssl/include
 /build/amd64-generic/tmp/portage/chromeos-base/chromeos-fpmcu-bloonchipper-unittests-0.0.1-r893/work/chromeos-fpmcu-bloonchipper-unittests-0.0.1/platform/ec/third_party/boringssl/include
 /usr/bin/../include/c++/v1
 /usr/armv7m-cros-eabi/usr/include/c++/v1
 /usr/lib64/clang/20/include
 /usr/armv7m-cros-eabi/include
End of search list.

-->8--

Notably in comparison to the old toolchain:

ajordanr@chrysalis /build/amd64-generic/tmp/portage/chromeos-base/chromeos-fpmcu-bloonchipper-unittests-0.0.1-r893/work/chromeos-fpmcu-bloonchipper-unittests-0.0.1/platform/ec $ source ~/cmdline
Chromium OS 19.0_pre530567 clang version 19.0.0git (/mnt/host/source/src/third_party/llvm-project 3b5e7c83a6e226d5bd7ed2e9b67449b64812074c)
Target: armv7m-cros-unknown-eabi
Thread model: posix
InstalledDir: /usr/bin
 (in-process)
 "/usr/bin/clang-19" -cc1 -triple thumbv7em-cros-unknown-eabihf -emit-llvm-bc -flto=full -flto-unit -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name fpsensor.cc -mrelocation-model static -fno-delete-null-pointer-checks -mframe-pointer=all -relaxed-aliasing -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -nostdsysteminc -target-cpu cortex-m4 -target-feature -crc -target-feature -dotprod -target-feature +dsp -target-feature -mve -target-feature -mve.fp -target-feature -ras -target-feature -bf16 -target-feature -sb -target-feature -i8mm -target-feature -lob -target-feature -cdecp0 -target-feature -cdecp1 -target-feature -cdecp2 -target-feature -cdecp3 -target-feature -cdecp4 -target-feature -cdecp5 -target-feature -cdecp6 -target-feature -cdecp7 -target-feature -pacbti -target-feature -hwdiv-arm -target-feature +hwdiv -target-feature -vfp2 -target-feature +vfp2sp -target-feature -vfp3 -target-feature -vfp3d16 -target-feature +vfp3d16sp -target-feature -vfp3sp -target-feature +fp16 -target-feature -vfp4 -target-feature -vfp4d16 -target-feature +vfp4d16sp -target-feature -vfp4sp -target-feature -fp-armv8 -target-feature -fp-armv8d16 -target-feature -fp-armv8d16sp -target-feature -fp-armv8sp -target-feature -fullfp16 -target-feature -fp64 -target-feature -d32 -target-feature -neon -target-feature -fp16fml -target-feature -crypto -target-feature -sha2 -target-feature -aes -target-feature +strict-align -target-abi aapcs -mfloat-abi hard -Wunaligned-access -debug-info-kind=constructor -dwarf-version=5 -debugger-tuning=gdb -fdebug-compilation-dir=/build/amd64-generic/tmp/portage/chromeos-base/chromeos-fpmcu-bloonchipper-unittests-0.0.1-r893/work/chromeos-fpmcu-bloonchipper-unittests-0.0.1/platform/ec -v -ffunction-sections -fcoverage-compilation-dir=/build/amd64-generic/tmp/portage/chromeos-base/chromeos-fpmcu-bloonchipper-unittests-0.0.1-r893/work/chromeos-fpmcu-bloonchipper-unittests-0.0.1/platform/ec -resource-dir /usr/lib64/clang/19 -dependency-file build/bloonchipper/abort/RW/common/fpsensor/fpsensor.o.d -MT build/bloonchipper/abort/RW/common/fpsensor/fpsensor.o -MP -D _LIBCPP_ENABLE_CXX17_REMOVED_FEATURES -D OUTDIR=build/bloonchipper/abort/RW -D CHIP=stm32 -D BOARD_TASKFILE=ec.tasklist -D BOARD=bloonchipper -D CORE=cortex-m -D PROJECT=abort -D CHIP_VARIANT=stm32f412 -D CHIP_FAMILY=STM32F4 -D BOARD_BLOONCHIPPER= -D CHIP_STM32= -D CORE_CORTEX_M= -D CHIP_VARIANT_STM32F412= -D CHIP_FAMILY_STM32F4= -D FINAL_OUTDIR=build/bloonchipper/abort -D PROTOBUF_MIN_PROTOC_VERSION=0 -D HAS_BASEBOARD= -D BASEBOARD_BLOONCHIPPER= -I include -I core/cortex-m/include -I include/driver -I core/cortex-m -I chip/stm32 -I baseboard/bloonchipper -I board/bloonchipper -I common -I fuzz -I power -I test -I cts/common -I cts/ -I build/bloonchipper/abort/gen -I ../ec-private -I common -I common/fpsensor -I common/mock -I common/spi -I common/spi/flash_reg -I common/spi/flash_reg/private -I common/spi/flash_reg/public -I common/spi/flash_reg/src -I common/usbc -I common/vboot -I driver -I driver/battery -I driver/bc12 -I driver/cec -I driver/charger -I driver/fingerprint -I driver/fingerprint/egis -I driver/fingerprint/egis/platform -I driver/fingerprint/egis/platform/inc -I driver/fingerprint/egis/platform/src -I driver/fingerprint/elan -I driver/fingerprint/fpc -I driver/fingerprint/fpc/bep -I driver/fingerprint/fpc/libfp -I driver/ioexpander -I driver/led -I driver/nfc -I driver/ppc -I driver/retimer -I driver/sha256 -I driver/tcpm -I driver/temp_sensor -I driver/usb_mux -I driver/wpc -I libc -I third_party/boringssl/common -I crypto -I build/bloonchipper/abort -I fuzz -I test -I third_party -I spi/flash_regpublic -I . -D TEST_BUILD= -D TEST_LEGACY_BUILD= -D TEST_TASKFILE=abort.tasklist -D TEST_abort= -D TEST_ABORT= -I include/driver -D SECTION_IS_RW= -D SECTION=RW -D HAS_TASK_FPSENSOR= -D HAS_TASK_RWSIG_RO= -D CHROMIUM_EC= -D HAS_TASK_HOOKS= -D HAS_TASK_HOSTCMD= -D HAS_TASK_CONSOLE= -D HAS_TASK_TEST= -I ../../third_party/boringssl -I ../../third_party/boringssl/include -I /build/amd64-generic/tmp/portage/chromeos-base/chromeos-fpmcu-bloonchipper-unittests-0.0.1-r893/work/chromeos-fpmcu-bloonchipper-unittests-0.0.1/platform/ec/third_party/boringssl/include -D CROS_EC -D PROTOBUF_INLINE_NOT_IN_HEADERS=0 -isysroot /usr/armv7m-cros-eabi -internal-isystem /usr/armv7m-cros-eabi/usr/include/c++/v1 -internal-isystem /usr/lib64/clang/19/include -internal-isystem /usr/armv7m-cros-eabi/include -Oz -Werror=poison-system-directories -Wno-deprecated-declarations -Wno-error=implicit-function-declaration -Wno-error=implicit-int -Wno-unknown-warning-option -Wno-int-conversion -Wno-incompatible-function-pointer-types -Wno-error=vla-cxx-extension -Wno-section -Wall -Wundef -Wno-trigraphs -Wno-format-security -Wno-address-of-packed-member -Wimplicit-fallthrough -Werror=uninitialized -Wno-unused-function -Wvla -Wall -Wundef -Wno-trigraphs -Wno-format-security -Wno-address-of-packed-member -Wimplicit-fallthrough -Werror=uninitialized -Wno-unused-function -Werror -Werror -std=gnu++2a -fdeprecated-macro -ferror-limit 19 -ftrapv -fwrapv -fno-signed-char -fgnuc-version=4.2.1 -fno-implicit-modules -fskip-odr-check-in-gmf -fcolor-diagnostics -vectorize-slp -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o build/bloonchipper/abort/RW/common/fpsensor/fpsensor.o -x c++ common/fpsensor/fpsensor.cc
clang -cc1 version 19.0.0git based upon LLVM 19.0.0git default target x86_64-pc-linux-gnu
ignoring nonexistent directory "../ec-private"
ignoring nonexistent directory "spi/flash_regpublic"
ignoring duplicate directory "common"
ignoring duplicate directory "fuzz"
ignoring duplicate directory "test"
ignoring duplicate directory "include/driver"
ignoring duplicate directory "/usr/lib64/clang/19/include"
#include "..." search starts here:
#include <...> search starts here:
 include
 core/cortex-m/include
 include/driver
 core/cortex-m
 chip/stm32
 baseboard/bloonchipper
 board/bloonchipper
 common
 fuzz
 power
 test
 cts/common
 cts
 build/bloonchipper/abort/gen
 common/fpsensor
 common/mock
 common/spi
 common/spi/flash_reg
 common/spi/flash_reg/private
 common/spi/flash_reg/public
 common/spi/flash_reg/src
 common/usbc
 common/vboot
 driver
 driver/battery
 driver/bc12
 driver/cec
 driver/charger
 driver/fingerprint
 driver/fingerprint/egis
 driver/fingerprint/egis/platform
 driver/fingerprint/egis/platform/inc
 driver/fingerprint/egis/platform/src
 driver/fingerprint/elan
 driver/fingerprint/fpc
 driver/fingerprint/fpc/bep
 driver/fingerprint/fpc/libfp
 driver/ioexpander
 driver/led
 driver/nfc
 driver/ppc
 driver/retimer
 driver/sha256
 driver/tcpm
 driver/temp_sensor
 driver/usb_mux
 driver/wpc
 libc
 third_party/boringssl/common
 crypto
 build/bloonchipper/abort
 third_party
 .
 ../../third_party/boringssl
 ../../third_party/boringssl/include
 /build/amd64-generic/tmp/portage/chromeos-base/chromeos-fpmcu-bloonchipper-unittests-0.0.1-r893/work/chromeos-fpmcu-bloonchipper-unittests-0.0.1/platform/ec/third_party/boringssl/include
 /usr/armv7m-cros-eabi/usr/include/c++/v1
 /usr/lib64/clang/19/include
 /usr/armv7m-cros-eabi/include
End of search list.

So I think the behaviour of --sysroot has changed?

I find this in the new clang: ignoring nonexistent directory "/usr/bin/../include/armv7m-cros-unknown-eabi/c++/v1"

Probably something to do with tuple normalization?

Does creating a symlink to /usr/include/armv7m-cros-unknown-eabi -> armv7-cros-eabi change the bahavior?

Yeah, I noticed that too. So there is a tuple normalisation change that happened back in January, which we encountered with armv6m in b/373947346. The problem is that /usr/include/armv7m-cros-unknown-eabi/c++/v1 is also just as wrong as /usr/include/armv7m-cros-eabi/c++/v1. What we need is /usr/armv7m-cros(-unknown)?-eabi/usr/include/c++/v1. I suppose we could create a symlink between these points, but I don't understand why it's looking in /usr/include instead of /usr/armv7m-cros-eabi/include or /usr/armv7m-cros-unknown-eabi/include.

I'm going to line these up because I sometimes have difficulty seeing which bits of the path are different here.

/usr/ include/          armv7m-cros-unknown-eabi/ c++/     v1  <- what we're searching first
/usr/ armv7m-cros-eabi/ usr/                      include/ c++/  v1  <- where we need to search (and we do, later on)

To answer the edit:

Does creating a symlink to /usr/include/armv7m-cros-unknown-eabi -> armv7-cros-eabi change the bahavior?

No, because /usr/include/armv7m-cros-eabi is mostly empty except for gdb symbols

There was a thread I had a while back with Fuschia team regarding C++ headers detection in sysroot vs relative to clang path. I don't recall the discussion, it probably died without a conclusion but I believe the status at that time was clang seemed to prefer headers relative to its location over sysroot. It didn't make a difference to us since headers in sysroot were identical to global ones.

Maybe it is time to revive that discussion?

So when passed to the driver, it's adding -internal-isystem /usr/bin/../include/c++/v1

If I add '-nostdinc++' to the above command lines, both /usr/bin/../include/c++/v1 AND /usr/armv7m-cros-eabi/usr/include/c++/v1 go away.

Looking at the lib/Driver/ToolChains.cpp code, I see:

void ToolChain::AddClangCXXStdlibIsystemArgs(
    const llvm::opt::ArgList &DriverArgs,
    llvm::opt::ArgStringList &CC1Args) const {
  DriverArgs.ClaimAllArgs(options::OPT_stdlibxx_isystem);
  // This intentionally only looks at -nostdinc++, and not -nostdinc or
  // -nostdlibinc. The purpose of -stdlib++-isystem is to support toolchain
  // setups with non-standard search logic for the C++ headers, while still
  // allowing users of the toolchain to bring their own C++ headers. Such a
  // toolchain likely also has non-standard search logic for the C headers and
  // uses -nostdinc to suppress the default logic, but -stdlib++-isystem should
  // still work in that case and only be suppressed by an explicit -nostdinc++
  // in a project using the toolchain.
  if (!DriverArgs.hasArg(options::OPT_nostdincxx))
    for (const auto &P :
         DriverArgs.getAllArgValues(options::OPT_stdlibxx_isystem))
      addSystemInclude(DriverArgs, CC1Args, P);
}

So somehow I think it's adding these in between as OPT_stdlibxx_isystem, which is converted to -internal-isystem arguments for CC1.

I successfully forced a crash in the compiler when -internal-isystem /usr/bin/../include/c++/v1 is passed:

ajordanr@chrysalis /build/amd64-generic/tmp/portage/chromeos-base/chromeos-fpmcu-bloonchipper-unittests-0.0.1-r893/work/chromeos-fpmcu-bloonchipper-unittests-0.0.1/platform/ec $ source ~/cmdline
Chromium OS 9999 clang version 20.0.0git (https://chromium.googlesource.com/external/github.com/llvm/llvm-project 696a2a0a02b23000c2ea96e6501eda120a8d9d29)
Target: armv7m-cros-unknown-eabi
Thread model: posix
InstalledDir: /usr/bin
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0.      Program arguments: /usr/bin/clang++ --sysroot=/usr/armv7m-cros-eabi -Qunused-arguments -Werror=poison-system-directories -Wno-deprecated-declarations -Wno-error=implicit-function-declaration -Wno-error=implicit-int -Wno-unknown-warning-option -fdebug-default-version=5 -Wno-int-conversion -Wno-incompatible-function-pointer-types -Wno-error=vla-cxx-extension -D_LIBCPP_ENABLE_CXX17_REMOVED_FEATURES -Wno-section -static-libgcc --prefix=../../../../../../../../../../usr/libexec/gcc/armv7m-cros-eabi/armv7m-cros-eabi- -std=gnu++2a -DOUTDIR=build/bloonchipper/abort/RW -DCHIP=stm32 -DBOARD_TASKFILE=ec.tasklist -DBOARD=bloonchipper -DCORE=cortex-m -DPROJECT=abort -DCHIP_VARIANT=stm32f412 -DCHIP_FAMILY=STM32F4 -DBOARD_BLOONCHIPPER= -DCHIP_STM32= -DCORE_CORTEX_M= -DCHIP_VARIANT_STM32F412= -DCHIP_FAMILY_STM32F4= -DFINAL_OUTDIR=build/bloonchipper/abort -DPROTOBUF_MIN_PROTOC_VERSION=0 -DHAS_BASEBOARD= -DBASEBOARD_BLOONCHIPPER= -Iinclude -Icore/cortex-m/include -Iinclude/driver -Icore/cortex-m -Ichip/stm32 -Ibaseboard/bloonchipper -Iboard/bloonchipper -Icommon -Ifuzz -Ipower -Itest -Icts/common -Icts/ -Ibuild/bloonchipper/abort/gen -I../ec-private -Icommon -Icommon/fpsensor -Icommon/mock -Icommon/spi -Icommon/spi/flash_reg -Icommon/spi/flash_reg/private -Icommon/spi/flash_reg/public -Icommon/spi/flash_reg/src -Icommon/usbc -Icommon/vboot -Idriver -Idriver/battery -Idriver/bc12 -Idriver/cec -Idriver/charger -Idriver/fingerprint -Idriver/fingerprint/egis -Idriver/fingerprint/egis/platform -Idriver/fingerprint/egis/platform/inc -Idriver/fingerprint/egis/platform/src -Idriver/fingerprint/elan -Idriver/fingerprint/fpc -Idriver/fingerprint/fpc/bep -Idriver/fingerprint/fpc/libfp -Idriver/ioexpander -Idriver/led -Idriver/nfc -Idriver/ppc -Idriver/retimer -Idriver/sha256 -Idriver/tcpm -Idriver/temp_sensor -Idriver/usb_mux -Idriver/wpc -Ilibc -Ithird_party/boringssl/common -Icrypto -Ibuild/bloonchipper/abort -Ifuzz -Itest -Ithird_party -Ispi/flash_regpublic -I. -DTEST_BUILD= -DTEST_LEGACY_BUILD= -DTEST_TASKFILE=abort.tasklist -DTEST_abort= -DTEST_ABORT= -Iinclude/driver -DSECTION_IS_RW= -DSECTION=RW -DHAS_TASK_FPSENSOR= -DHAS_TASK_RWSIG_RO= -fno-PIC -DCHROMIUM_EC= -DHAS_TASK_HOOKS= -DHAS_TASK_HOSTCMD= -DHAS_TASK_CONSOLE= -DHAS_TASK_TEST= -I../../third_party/boringssl -I../../third_party/boringssl/include -I/build/amd64-generic/tmp/portage/chromeos-base/chromeos-fpmcu-bloonchipper-unittests-0.0.1-r893/work/chromeos-fpmcu-bloonchipper-unittests-0.0.1/platform/ec/third_party/boringssl/include -DCROS_EC -mcpu=cortex-m4 -mcpu=cortex-m4 -mthumb -Oz -Wl,-mllvm -Wl,-inline-threshold=-10 -mno-unaligned-access -mfloat-abi=hard -flto -g -Wall -Wundef -Wno-trigraphs -Wno-format-security -Wno-address-of-packed-member -fno-common -fno-strict-aliasing -fno-strict-overflow -Wimplicit-fallthrough -fno-exceptions -fno-unwind-tables -fno-asynchronous-unwind-tables -Werror -ftrapv -Werror=uninitialized -Wno-unused-function -ffunction-sections -fno-delete-null-pointer-checks -fno-PIC -Wvla -Wall -Wundef -Wno-trigraphs -Wno-format-security -Wno-address-of-packed-member -fno-common -fno-strict-aliasing -fno-strict-overflow -Wimplicit-fallthrough -fno-exceptions -fno-unwind-tables -fno-asynchronous-unwind-tables -Werror -ftrapv -Werror=uninitialized -Wno-unused-function -DPROTOBUF_INLINE_NOT_IN_HEADERS=0 -MMD -MP -MF build/bloonchipper/abort/RW/common/fpsensor/fpsensor.o.d -c common/fpsensor/fpsensor.cc -MT build/bloonchipper/abort/RW/common/fpsensor/fpsensor.o -o build/bloonchipper/abort/RW/common/fpsensor/fpsensor.o -L/usr/armv7m-cros-eabi/usr/lib -B../../../../../../../../../../usr/libexec/gcc/armv7m-cros-eabi -target armv7m-cros-eabi -v
1.      Compilation construction
2.      Building compilation jobs
3.      Building compilation jobs
 #0 0x000055e5751c7b48 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/usr/bin/clang+++0x3719b48)
 #1 0x000055e5751c56a0 llvm::sys::RunSignalHandlers() (/usr/bin/clang+++0x37176a0)
 #2 0x000055e5751c831a SignalHandler(int) Signals.cpp:0:0
 #3 0x00007f74a02680a0 __restore_rt (/lib64/libc.so.6+0x3e0a0)
 #4 0x000055e575a326a5 clang::driver::ToolChain::addSystemInclude(llvm::opt::ArgList const&, llvm::SmallVector<char const*, 16u>&, llvm::Twine const&) (/usr/bin/clang+++0x3f846a5)
 #5 0x000055e575a6cb5d clang::driver::toolchains::BareMetal::AddClangCXXStdlibIncludeArgs(llvm::opt::ArgList const&, llvm::SmallVector<char const*, 16u>&) const BareMetal.cpp:0:0
 #6 0x000055e575a75c5c forAllAssociatedToolChains(clang::driver::Compilation&, clang::driver::JobAction const&, clang::driver::ToolChain const&, llvm::function_ref<void (clang::driver::ToolChain const&)>) Clang.cpp:0:0
 #7 0x000055e575a746d2 clang::driver::tools::Clang::AddPreprocessingOptions(clang::driver::Compilation&, clang::driver::JobAction const&, clang::driver::Driver const&, llvm::opt::ArgList const&, llvm::SmallVector<char const*, 16u>&, clang::driver::InputInfo const&, llvm::SmallVector<clang::driver::InputInfo, 4u> const&) const Clang.cpp:0:0
 #8 0x000055e575a888ec clang::driver::tools::Clang::ConstructJob(clang::driver::Compilation&, clang::driver::JobAction const&, clang::driver::InputInfo const&, llvm::SmallVector<clang::driver::InputInfo, 4u> const&, llvm::opt::ArgList const&, char const*) const Clang.cpp:0:0
 #9 0x000055e575a0af77 clang::driver::Driver::BuildJobsForActionNoCache(clang::driver::Compilation&, clang::driver::Action const*, clang::driver::ToolChain const*, llvm::StringRef, bool, bool, char const*, std::__1::map<std::__1::pair<clang::driver::Action const*, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>, llvm::SmallVector<clang::driver::InputInfo, 4u>, std::__1::less<std::__1::pair<clang::driver::Action const*, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>>, std::__1::allocator<std::__1::pair<std::__1::pair<clang::driver::Action const*, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>> const, llvm::SmallVector<clang::driver::InputInfo, 4u>>>>&, clang::driver::Action::OffloadKind) const (/usr/bin/clang+++0x3f5cf77)
#10 0x000055e575a08ddc clang::driver::Driver::BuildJobsForAction(clang::driver::Compilation&, clang::driver::Action const*, clang::driver::ToolChain const*, llvm::StringRef, bool, bool, char const*, std::__1::map<std::__1::pair<clang::driver::Action const*, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>, llvm::SmallVector<clang::driver::InputInfo, 4u>, std::__1::less<std::__1::pair<clang::driver::Action const*, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>>, std::__1::allocator<std::__1::pair<std::__1::pair<clang::driver::Action const*, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>> const, llvm::SmallVector<clang::driver::InputInfo, 4u>>>>&, clang::driver::Action::OffloadKind) const (/usr/bin/clang+++0x3f5addc)
#11 0x000055e5759fa909 clang::driver::Driver::BuildJobs(clang::driver::Compilation&) const (/usr/bin/clang+++0x3f4c909)
#12 0x000055e5759f3bf0 clang::driver::Driver::BuildCompilation(llvm::ArrayRef<char const*>) (/usr/bin/clang+++0x3f45bf0)
#13 0x000055e573e6f3cc clang_main(int, char**, llvm::ToolContext const&) (/usr/bin/clang+++0x23c13cc)
#14 0x000055e573e7f043 main (/usr/bin/clang+++0x23d1043)
#15 0x00007f74a02537c6 __libc_start_call_main (/lib64/libc.so.6+0x297c6)
#16 0x00007f74a0253882 __libc_start_main@GLIBC_2.2.5 (/lib64/libc.so.6+0x29882)
#17 0x000055e573e6db61 _start (/usr/bin/clang+++0x23bfb61)
Illegal instruction

so it's from inside AddClangCXXStdlibIncludeArgs.

Commit that breaks us is: 135483bf968bc72a9544a9f2640f73f196ca8cbc:

commit 135483bf968bc72a9544a9f2640f73f196ca8cbc
Author: Petr Hosek <phosek@google.com>
Date:   Mon Jul 1 23:47:24 2024 -0700

    [Driver] Support using toolchain libc and libc++ for baremetal (#96736)
    
    We want to support using a complete Clang/LLVM toolchain that includes
    LLVM libc and libc++ for baremetal targets. To do so, we need the driver
    to add the necessary include paths.

I guess I will go reach out to Petr to ask if there's a way to get it to support --sysroot?

After talking to phosek@, this does appear to be a bug, and there's not any obvious workaround beyond using -nostdinc++ and then listing all the paths manually. That wouldn't be the worst decision in the meantime, but it does seem like other use cases would be broken with this behaviour, based on the documentation for sysroot and isysroot.

Project: external/github.com/llvm/llvm-project
Branch: chromeos/llvm-r547379-1
Author: Jordan R Abrahams-Whitehead <ajordanr@google.com>
Link:      https://chromium-review.googlesource.com/6024185

Partial Revert "[Driver] Support using toolchain libc and libc++ for baremetal (#96736)"

Partial Revert "[Driver] Support using toolchain libc and libc++ for baremetal (#96736)" 
 
This reverts commit 135483bf968bc72a9544a9f2640f73f196ca8cbc. 
 
This is a partial revert, reverting only the portions of 
135483bf968bc72a9544a9f2640f73f196ca8cbc which actually break our 
embedded projects. 
 
The original commit breaks FPMCU targets because it does not respect the 
--sysroot or -isysroot clang flags, which should re-root the system 
paths. This commit introduces a new way (and order) to add system 
includes which ends up violating our sysroot, and thus causing 
mismatched headers. 
 
Upstream Commit: 
https://github.com/llvm/llvm-project/commit/135483bf968bc72a9544a9f2640f73f196ca8cbc 
 
patch.cherry: false 
patch.platforms: chromiumos 
patch.version_range.from: 547379 
patch.version_range.until: null 
 
BUG=b:377375234 
TEST=Built chromeos-base/chromeos-fpmcu-bloonchipper-unittests 
 
Change-Id: Ie9158e7e476ee64f8d7342de94e11ceac0626307

This is no longer blocking the mage roll, but is still a bug.