[llvm-dev] Compiling for baremetal ARMv4 on Ubuntu Linux
Peter Smith via llvm-dev
llvm-dev at lists.llvm.org
Thu Mar 21 03:19:14 PDT 2019
Hello Christian,
That's good to know. Some explanation of the warnings:
"lld uses blx, no object with architecture supporting feature
detected" : lld assumes that it can use the BLX instruction to change
state between Arm and Thumb, this instruction isn't available on an
Arm7tdmi (Architecture 4vt), the instruction was introduced on Armv5t.
If you are genuinely running the program on an Arm7tdmi I'd be careful
to only use Arm instructions so that there are no linker generated
transitions to Thumb. If you are running on a more recent CPU that
supports BLX then you can ignore this warning. A clang target of
arm-none-eabi will default to -mcpu=arm7tdmi, if will be worth telling
clang that you are compiling for a more recent architecture.
As I understand it, the clang bare metal driver doesn't include any c
library startup code (crt0 etc.) so I'd expect it to always be
--nostartfiles.
Your clang linker invocation is using clang -v
--target=armv6m-none-eabi I'm guessing because that will select the
v6m compiler-rt. This will be Thumb v6m code. This won't be a problem
if the compiler doesn't call anything from compiler-rt, but due to
LLD's use of BLX to transition from Arm to Thumb then it will cause
you some problems if run on an Arm7tdmi that doesn't support BLX. The
best way to work around that would be to either compile compiler-rt
builtins for Arm7tdmi, or use libgcc.a. To use libgcc.a you'll need
--nostdlib -lc -lgcc and possibly a -L with a path to libgcc.a
The size difference is probably coming from page alignment, LLD
currently assumes page alignment (4k for Arm) even for embedded
systems. On ld.bfd you can use -N (--omagic) or -n (--nmagic) to
disable page alignment. LLD has some support for -N but it doesn't
disable page alignment. You can use -zmax-page-size=1 to disable page
alignment. This may result in a smaller binary.
Peter
On Thu, 21 Mar 2019 at 09:29, Christian Richter
<christian.richter at hsu-hh.de> wrote:
>
> Hello Peter,
>
> so in short: It works now! The compiler call looked like this in the
> final version:
>
> root at virtual-machine:/home/progs/clang# cat BAREhelloCLANG.sh
> clang -v --target=arm-none-eabi -O4 -c start.c -o start.o
> clang -v --target=arm-none-eabi -c barehello.c -o barehello.o
> clang -v --target=arm-none-eabi -c io.c -o io.o
> clang -v --target=armv6m-none-eabi -L/usr/lib/gcc/arm-none-eabi/6.3.1/
> -L/usr/lib/arm-none-eabi/lib/ start.o barehello.o io.o -nostartfiles
> -Wl,--build-id=none -Wl,-init=_start -Ttext 0x8000 -static -o helloCLANG
> arm-none-eabi-objcopy -O binary helloCLANG oc_hello_bare_CLANG
>
> while I get two warnings ( "unused command -nostartfiles" and "lld uses
> blx, no object with architecture supporting feature detected") and the
> resulting files is significantly larger (gcc: 204 bytes, clang: 4000
> bytes, probably because of the inclusion of unused libraries from the
> look of the assembly), the resulting file executed correctly on the
> baremetal arm. The __start()-stuff was not (yet) needed as it seems
> (contrary to the gcc version).
>
> So once more thanks a lot!
>
> Christian
>
>
> On 11.03.2019 19:06, Peter Smith wrote:
> > Hello Christian,
> >
> > I reran my script with a similar cmake command to yours. After the
> > build finished the following command from the build directory gave me:
> > find . -name \*builtins.a
> > ./lib/clang/9.0.0/armv6m-none-eabi/lib/libclang_rt.builtins.a
> > ./lib/clang/9.0.0/armv7m-none-eabi/lib/libclang_rt.builtins.a
> > ./lib/clang/9.0.0/armv7em-none-eabi/lib/libclang_rt.builtins.a
> > I hope you see something like this with your build. You can check that
> > they are correct by disassembling them to see if they contain the
> > instructions that you are looking for.
> >
> > Unfortunately it looks like the runtimes method does not produce the
> > library names that match what the driver is expecting:
> > For example with --target=armv7m-none-eabi I get with -v
> > -L/path/to/my/clang/build/dir/lib/clang/9.0.0/lib/baremetal -lc -lm
> > -lclang_rt.builtins-armv7m.a
> >
> > I suggest renaming the files when copying them to the
> > /path/to/my/clang/build/dir/lib/clang/9.0.0/lib/baremetal dir.
> > libclang_rt.builtins-armv6m.a
> > libclang_rt.builtins-armv7m.a
> > libclang_rt.builtins-armv7em.a
> >
> > When I build the builtins using the standalone build then I get the
> > correct names:
> > find /linaro/compiler-rt/build_rt_arm_v7m/ -name \*.a
> > /path/to/compiler-rt/build/dir/lib/baremetal/libclang_rt.builtins-armv7m.a
> >
> > Hope that gets you a bit further. You may need to write your __start
> > function in assembler, I don't think clang allows function calls in
> > naked functions.
> >
> > Peter
> >
> > On Sat, 9 Mar 2019 at 17:18, Christian Richter
> > <christian.richter at hsu-hh.de> wrote:
> >> Hello Peter,
> >>
> >> the unable to find -lc, -lm was indeed fixed as soon as I got the -L right, thanks! So for the record, the correct way to include the paths was „-L/usr/lib/gcc/arm-none-eabi/6.3.1/ -L/usr/lib/arm-none-eabi/lib/“.
> >>
> >> The -clang_rt.builtins-armv6m.a still puzzles me: I built the compiler-rt according to the mentioned baremetal recipe some time ago with
> >>
> >> cmake –G Ninja –DBAREMETAL_ARMV6M_SYSROOT=${ARMEABI5GCC} -DBAREMETAL_ARMV7M_SYSROOT=${ARMEABI5GCC}- DBAREMETAL_ARMV7EM_SYSROOT=${ARMEABI5GCC} –DCMAKE_BUILD_TYPE=Release –C /home/llvm_4rt/llvm/tools/clang/cmake/caches/BaremetalARM.cmake /home/llvm_4rt/llvm/
> >>
> >> where ARMEABI5GCC=/home/crichter/Downloads/gcc-arm-none-eabi-5_4-2016q3/arm-none-eabi is from the sysroot download site you gave me back then.
> >>
> >> That resulted in a libclang_rt.builtins.a file which I considered to be the right one to use now, but neither copying it into
> >> /usr/local/myclang/lib/clang/8.0.0/lib/baremetal (which did not exist before, only /linux was present already) or adding another .a behind the name helped the linker, nor did adding a -l<path-to-libclang_rt.builtins.a>. Did I
> >> build the wrong one or am I using it incorrectly?
> >>
> >> The part about the int _start () __attribute__ ((naked)) was needed when compiling with gcc because otherwise the program contained an unwanted push{r4, lr}. But this is a problem for a later day that might not even occur with clang. I'll see if it comes back to haunt me when I'm able to compile the program with clang, I guess :-)
> >>
> >> Thanks once more!
> >> Christian
> >>
> >>
> >> Hello Christian,
> >>
> >> I'd expect that adding the library paths (-L) from gcc -v should fix
> >> the unable to find -lc, -lm but it won't fix the
> >> -lclang_rt.builtins-armv6m.a . To get clang_rt.builtins-armv6m.a you
> >> will need to cross compile compiler-rt for v6m and copy it to
> >> /usr/local/myclang/lib/clang/8.0.0/lib/baremetal . Beware that
> >> building compiler-rt for v6m does need quite a bit of fighting cmake
> >> (https://llvm.org/docs/HowToCrossCompileBuiltinsOnArm.html). Your
> >> alternative if you already have a libgcc.a is to use --nostdlib or
> >> --nodefaultlibs to stop the driver adding -lm -lc
> >> -lclang_rt.builtins-armv6m.a , although you'll need to add your c
> >> library (and possibly math library) yourself in that case.
> >>
> >> I don't understand the part about __start. I'd expect __start to be
> >> provided by the c library, probably newlib or newlib nano from
> >> arm-none-eabi.
> >>
> >> Peter
> >>
> >>
> >> On Sat, 2 Mar 2019 at 14:08, Christian Richter
> >> <christian.richter at hsu-hh.de> wrote:
> >>
> >> Hello again,
> >>
> >> so I've tried the following: I created a working gcc version with arm-none-eabi-gcc (this took some time, hence the late answer I'm afraid). The output of the linker stage looks like this:
> >>
> >> root at christian-forschung-virtual-machine:/home/progs# arm-none-eabi-gcc -v start.o barehello.o io.o -nostartfiles -Wl,--build-id=none -Wl,-init=_start -Ttext 0x8000 -static -o hello
> >>
> >> Using built-in specs.
> >> COLLECT_GCC=arm-none-eabi-gcc
> >> COLLECT_LTO_WRAPPER=/usr/lib/gcc/arm-none-eabi/6.3.1/lto-wrapper
> >> Target: arm-none-eabi
> >> Configured with: ../src/configure --build=x86_64-linux-gnu --prefix=/usr --includedir='/usr/lib/include' --mandir='/usr/lib/share/man' --infodir='/usr/lib/share/info' --sysconfdir=/etc --localstatedir=/var --disable-silent-rules --libdir='/usr/lib/lib/x86_64-linux-gnu' --libexecdir='/usr/lib/lib/x86_64-linux-gnu' --disable-maintainer-mode --disable-dependency-tracking --mandir=/usr/share/man --enable-languages=c,c++,lto --enable-multilib --disable-decimal-float --disable-libffi --disable-libgomp --disable-libmudflap --disable-libquadmath --disable-libssp --disable-libstdcxx-pch --disable-nls --disable-shared --disable-threads --disable-tls --build=x86_64-linux-gnu --target=arm-none-eabi --with-system-zlib --with-gnu-as --with-gnu-ld --with-pkgversion=15:6.3.1+svn253039-1build1 --without-included-gettext --prefix=/usr/lib --infodir=/usr/share/doc/gcc-arm-none-eabi/info --htmldir=/usr/share/doc/gcc-arm-none-eabi/html --pdfdir=/usr/share/doc/gcc-arm-none-eabi/pdf --bindir=/usr/bin --libexecdir=/usr/lib --libdir=/usr/lib --disable-libstdc++-v3 --host=x86_64-linux-gnu --with-headers=no --without-newlib --with-multilib-list=rmprofile CFLAGS='-g -O2 -fdebug-prefix-map=/build/gcc-arm-none-eabi-iopiMw/gcc-arm-none-eabi-6.3.1+svn253039=. -fstack-protector-strong' CPPFLAGS='-Wdate-time -D_FORTIFY_SOURCE=2' CXXFLAGS='-g -O2 -fdebug-prefix-map=/build/gcc-arm-none-eabi-iopiMw/gcc-arm-none-eabi-6.3.1+svn253039=. -fstack-protector-strong' FCFLAGS='-g -O2 -fdebug-prefix-map=/build/gcc-arm-none-eabi-iopiMw/gcc-arm-none-eabi-6.3.1+svn253039=. -fstack-protector-strong' FFLAGS='-g -O2 -fdebug-prefix-map=/build/gcc-arm-none-eabi-iopiMw/gcc-arm-none-eabi-6.3.1+svn253039=. -fstack-protector-strong' GCJFLAGS='-g -O2 -fdebug-prefix-map=/build/gcc-arm-none-eabi-iopiMw/gcc-arm-none-eabi-6.3.1+svn253039=. -fstack-protector-strong' LDFLAGS='-Wl,-Bsymbolic-functions -Wl,-z,relro' OBJCFLAGS='-g -O2 -fdebug-prefix-map=/build/gcc-arm-none-eabi-iopiMw/gcc-arm-none-eabi-6.3.1+svn253039=. -fstack-protector-strong' OBJCXXFLAGS='-g -O2 -fdebug-prefix-map=/build/gcc-arm-none-eabi-iopiMw/gcc-arm-none-eabi-6.3.1+svn253039=. -fstack-protector-strong' INHIBIT_LIBC_CFLAGS=-DUSE_TM_CLONE_REGISTRY=0 AR_FOR_TARGET=arm-none-eabi-ar AS_FOR_TARGET=arm-none-eabi-as LD_FOR_TARGET=arm-none-eabi-ld NM_FOR_TARGET=arm-none-eabi-nm OBJDUMP_FOR_TARGET=arm-none-eabi-objdump RANLIB_FOR_TARGET=arm-none-eabi-ranlib READELF_FOR_TARGET=arm-none-eabi-readelf STRIP_FOR_TARGET=arm-none-eabi-strip
> >> Thread model: single
> >> gcc version 6.3.1 20170620 (15:6.3.1+svn253039-1build1)
> >> COMPILER_PATH=/usr/lib/gcc/arm-none-eabi/6.3.1/:/usr/lib/gcc/arm-none-eabi/6.3.1/:/usr/lib/gcc/arm-none-eabi/:/usr/lib/gcc/arm-none-eabi/6.3.1/:/usr/lib/gcc/arm-none-eabi/:/usr/lib/gcc/arm-none-eabi/6.3.1/../../../arm-none-eabi/bin/
> >> LIBRARY_PATH=/usr/lib/gcc/arm-none-eabi/6.3.1/:/usr/lib/gcc/arm-none-eabi/6.3.1/../../../arm-none-eabi/lib/
> >> COLLECT_GCC_OPTIONS='-v' '-nostartfiles' '-Ttext' '0x8000' '-static' '-o' 'hello'
> >> /usr/lib/gcc/arm-none-eabi/6.3.1/collect2 -plugin /usr/lib/gcc/arm-none-eabi/6.3.1/liblto_plugin.so -plugin-opt=/usr/lib/gcc/arm-none-eabi/6.3.1/lto-wrapper -plugin-opt=-fresolution=/tmp/cceNgJBK.res -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lc -Bstatic -X -o hello -L/usr/lib/gcc/arm-none-eabi/6.3.1 -L/usr/lib/gcc/arm-none-eabi/6.3.1/../../../arm-none-eabi/lib start.o barehello.o io.o --build-id=none -init=_start --start-group -lgcc -lc --end-group -Ttext 0x8000
> >> COLLECT_GCC_OPTIONS='-v' '-nostartfiles' '-Ttext' '0x8000' '-static' '-o' 'hello'
> >>
> >>
> >> and the resulting program works on the baremetal ARM (after objcopying it). So far, so good. Using a similar call for clang --target=armv6m-none-eabi fails like this:
> >>
> >> root at christian-forschung-virtual-machine:/home/progs/clang# clang -v start.o barehello.o io.o --target=armv6m-none-eabi -Wl,--build-id=none -Wl,-init=_start -Ttext 0x8000 -static -o hello
> >>
> >> clang version 8.0.0 (https://git.llvm.org/git/clang.git/ a152c7a4b7ba8f4cb9532ead9a38a7121db43d50) (https://git.llvm.org/git/llvm.git/ 1959ce6f3e01241919968ac1911fd45660239d23)
> >> Target: armv6m-none-unknown-eabi
> >> Thread model: posix
> >> InstalledDir: /usr/local/myclang/bin
> >> "/usr/local/myclang/bin/ld.lld" start.o barehello.o io.o --build-id=none -init=_start -Bstatic -L/usr/local/myclang/lib/clang/8.0.0/lib/baremetal -Ttext 0x8000 -lc -lm -lclang_rt.builtins-armv6m.a -o hello
> >> ld.lld: error: unable to find library -lc
> >> ld.lld: error: unable to find library -lm
> >> ld.lld: error: unable to find library -lclang_rt.builtins-armv6m.a
> >> clang-8: error: ld.lld command failed with exit code 1 (use -v to see invocation)
> >>
> >> I downloaded the sysroot (from https://developer.arm.com/open-source/gnu-toolchain/gnu-rm ) and tried to include it via --sysroot (like --sysroot=/home/crichter/Downloads/gcc-arm-none-eabi-5_4-2016q3/arm-none-eabi) or -L or -l and tried the same for the two libraries gcc seems to use according to its -v (LIBRARY_PATH=/usr/lib/gcc/arm-none-eabi/6.3.1/:/usr/lib/gcc/arm-none-eabi/6.3.1/../../../arm-none-eabi/lib/) or combinations of it, but it all resulted in the same error above. I also tried to use the runtime library I built earlier, but to no avail. So basically, I (still) haven't figured out how to tell clang to use the right libraries. On a side note, I actually needed to include int _start () __attribute__ ((naked)); into the .c file to make the program work, but clang does not support this (as it seems to be problematic), is there an alternative?
> >>
> >> Thanks once more!
> >>
> >> Christian
> >>
> >>
> >>
> >> On 04.02.2019 16:26, Peter Smith wrote:
> >>
> >> Hello Christian,
> >>
> >> I've put some comments inline,
> >>
> >> On Sun, 3 Feb 2019 at 13:11, Christian Richter
> >> <christian.richter at hsu-hh.de> wrote:
> >>
> >> Hello again,
> >>
> >> so after I successfully build the compiler-rt for armv6 I tried to
> >> actually use it in compiling a small helloworld for a baremetal arm
> >> (consisting of barehelloCLANG.c and a small io.h + io.c) , but the
> >> linking part of the compilation resulted in this:
> >>
> >> root at christian-forschung-virtual-machine:/home/progs# clang -v
> >> --target=armv6-none-eabi -L
> >> /home/llvm_all/buildrecipe/lib/clang/8.0.0/armv6m-none-eabi
> >> -lclang_rt.builtins.arm barehelloCLANG.o io.o -o helloCLANGstatic
> >> -static -fuse-ld=lld
> >> clang version 8.0.0 (https://git.llvm.org/git/clang.git/
> >> a152c7a4b7ba8f4cb9532ead9a38a7121db43d50)
> >> (https://git.llvm.org/git/llvm.git/
> >> 1959ce6f3e01241919968ac1911fd45660239d23)
> >> Target: armv6-none-unknown-eabi
> >> Thread model: posix
> >> InstalledDir: /usr/local/myclang/bin
> >> "/usr/local/myclang/bin/ld.lld" -lclang_rt.builtins.arm
> >> barehelloCLANG.o io.o -Bstatic
> >> -L/usr/local/myclang/lib/clang/8.0.0/lib/baremetal
> >> -L/home/llvm_all/buildrecipe/lib/clang/8.0.0/armv6m-none-eabi -lc -lm
> >> -lclang_rt.builtins-armv6.a -o helloCLANGstatic
> >> ld.lld: error: unable to find library -lclang_rt.builtins.arm
> >> ld.lld: error: unable to find library -lc
> >> ld.lld: error: unable to find library -lm
> >> ld.lld: error: unable to find library -lclang_rt.builtins-armv6.a
> >> clang-8: error: ld.lld command failed with exit code 1 (use -v to see
> >> invocation)
> >>
> >> Just to be sure; do you really mean --target=armv6-none-eabi ? That is
> >> targeting an old ArmV6 device such as an ARM1176 as used on the
> >> Raspberry Pi; this is very different from --target=armv6m-none-eabi ,
> >> as used on the cortex-m0, despite there being only one letter
> >> difference in the target! Whichever you need you'll need to have the
> >> right compiler-rt.
> >>
> >> When you use a -none-eabi target clang will use the BareMetal driver
> >> that in contrast with the Linux driver adds very few include and
> >> library paths automatically. The driver will automatically add
> >> -lclang_rt.builtins-{arch-name}.a where arch-name will be armv6 if you
> >> are using --target=armv6-none-eabi. Unfortunately when LLD sees
> >> -l{library name} it will search for {library name}.a and {library
> >> name}.so, even if {library name} ends in .a, so LLD will be looking
> >> for clang_rt.builtins-armv6.a.a which it won't find. Personally I
> >> think this could be considered a bug in the BareMetal driver. As a
> >> workaround you can rename, copy or symlink a
> >> clang_rt.builtins-{arch-name}.a.a so that LLD can find it.
> >>
> >> So basically, the compiler does not use/find the given libraries, but
> >> after trying a lot of variations of the above with the same result I
> >> can't figure out why.
> >> /home/llvm_all/buildrecipe/lib/clang/8.0.0/armv6m-none-eabi is what the
> >> recipe from https://llvm.org/docs/HowToCrossCompileBuiltinsOnArm.html
> >> gave me and is empty except for clang_rt.builtins-armv6.a. Do I still
> >> need to use the sysroot for baremetal arm in addition or do the
> >> compiler-rt suffice? Once more thanks in advance for any hint or help!
> >>
> >> Yes you'll still need to use a sysroot for bare metal Arm. The
> >> compiler-rt builtins library provides run-time functions that the
> >> compiler can use in code-generation, a good example is supporting for
> >> software floating point emulation. It isn't a replacement for a C or
> >> Math library. The last time I tried to make a bare-metal Arm program
> >> work with clang I did the following:
> >> - Downloaded the arm-none-eabi GNU toolchain
> >> https://developer.arm.com/open-source/gnu-toolchain/gnu-rm
> >> - Found one of the sample programs in the
> >> share/gcc-arm-none-eabi/samples directory and built that.
> >> - Made sure the program worked.
> >> - Used arm-none-eabi-gcc -v to find the libraries and paths that GCC was using.
> >> - Substituted clang for arm-none-eabi-gcc after after removing the
> >> libraries I had clang equivalents for.
> >>
> >> This is obviously not a great user experience, the BareMetal driver
> >> needs quite a bit of work. Unfortunately due to the needs of multilib
> >> and the dependencies between newlib/newlib-nano and libgloss
> >> components that gcc uses specs files for, this is not simple.
> >>
> >> Peter
> >>
> >> Christian Richter
> >>
> >>
> >>
> >> On 14.12.2018 18:28, Peter Smith wrote:
> >>
> >> Hello again Christian,
> >>
> >> I've posted https://reviews.llvm.org/D55709 to see if we can get the
> >> documentation on how to cross-compile compiler-rt improved. I'll be
> >> out of office until next year so I may be a bit slow to respond to any
> >> follow ups.
> >>
> >> Peter
> >>
> >> On Thu, 13 Dec 2018 at 17:10, Peter Smith <peter.smith at linaro.org> wrote:
> >>
> >> Hello Christian,
> >>
> >> I've just retried the runtimes way of building for v6m, v7m and v7e-m
> >> . My cmake command was
> >> ARMEABIGCC=/path/to/gcceabi/arm-none-eabi
> >> cmake \
> >> -G Ninja\
> >> -DBAREMETAL_ARMV6M_SYSROOT=${ARMEABIGCC}\
> >> -DBAREMETAL_ARMV7M_SYSROOT=${ARMEABIGCC}\
> >> -DBAREMETAL_ARMV7EM_SYSROOT=${ARMEABIGCC}\
> >> -DCMAKE_BUILD_TYPE=Release\
> >> -C/path/to/llvm/tools/clang/cmake/caches/BaremetalARM.cmake \
> >> /path/to/llvm
> >>
> >> The cache file requires clang and lld. From the build directory they
> >> will go into lib/clang. That worked for me (TM). Hopefully if you can
> >> edit the paths it will work for you. My guess is that you'll want to
> >> set ARMEABIGCC=/home/crichter/Downloads/gcc-arm-none-eabi-5_4-2016q3/arm-none-eabi
> >>
> >> Peter
> >>
> >> On Thu, 13 Dec 2018 at 12:08, Christian Richter
> >> <christian.richter at hsu-hh.de> wrote:
> >>
> >> Hello Peter and Lists,
> >>
> >> thanks a lot, that way it worked out! The final cmake was
> >>
> >> cmake -G "Ninja" ../llvm/projects/compiler-rt/ -DCOMPILER_RT_BUILD_BUILTINS=ON -DCOMPILER_RT_BUILD_SANITIZERS=OFF -DCOMPILER_RT_BUILD_XRAY=OFF -DCOMPILER_RT_BUILD_LIBFUZZER=OFF -DCOMPILER_RT_BUILD_PROFILE=OFF -DCMAKE_C_COMPILER=/usr/local/myclang/bin/clang -DCMAKE_AR=/usr/local/myclang/bin/llvm-ar -DCMAKE_NM=/usr/local/myclang/bin/llvm-nm -DCMAKE_RANLIB=/usr/local/myclang/bin/llvm-ranlib -DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY -DCMAKE_C_COMPILER_TARGET="arm-linux-gnueabihf" -DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON -DLLVM_CONFIG_PATH=/usr/local/myclang/bin/llvm-config -DCMAKE_ASM_FLAGS="--target=arm-linux-gnueabihf -march=armv7a --gcc-toolchain=/home/crichter/arm-linux-gnueabihf/gcc-arm --sysroot=/home/crichter/arm-linux-gnueabihf/sysroot-glibc/" -DCMAKE_C_FLAGS="--target=arm-linux-gnueabihf -march=armv7a --gcc-toolchain=/home/crichter/arm-linux-gnueabihf/gcc-arm --sysroot=/home/crichter/arm-linux-gnueabihf/sysroot-glibc/"
> >>
> >> where sysroot-glibc/ contains sysroot-glibc-8.2-x86_64 and /arm-linux-gnueabihf/gcc-arm contains gcc-arm-8.2 for Aarch32 hard float from https://developer.arm.com/open-source/gnu-toolchain/gnu-a/downloads. This resulted in successfully building libclang_rt.builtins-armhf.a
> >>
> >> So next, I tried to use the cmake recipe for BaremetalARM as in the documentation. Therefore, I moved the compiler-rt directory from llvm/projects to llvm/runtimes. I downloaded the latest updates of gcc-arm-none-eabi6/7/8 from https://developer.arm.com/open-source/gnu-toolchain/gnu-rm/downloads and tried to build in a new directory. But whether I gave the -C the path to BaremetalARM.cmake's directory or the file itself, nothing started. I was unsure whether to keep the paths to llvm-ar, llvm-nm and so on as well and whether or not to give the new compiler-rt-directory or the whole llvm-directory as a starting point. Am I using the wrong build directory here? Is this still "Ninja"? The error message (see below) is true: /home/llvm_4rt/llvm/tools/clang/cmake/caches contains no CMakeLists.txt, just the BaremetalARM.cmake among other recipes. Giving -C the file directly just leads to a "this is a file, not a directory" error.
> >>
> >> This is (one of my) cmake commands:
> >>
> >> root at christian-forschung-virtual-machine:/home/llvm_4rt/buildrecipe# cmake -G "Ninja" ../llvm/runtimes/compiler-rt -DCOMPILER_RT_BUILD_BUILTINS=ON -DCOMPILER_RT_BUILD_SANITIZERS=OFF -DCOMPILER_RT_BUILD_XRAY=OFF -DCOMPILER_RT_BUILD_LIBFUZZER=OFF -DCOMPILER_RT_BUILD_PROFILE=OFF -DCMAKE_C_COMPILER=/usr/local/myclang/bin/clang -DCMAKE_AR=/usr/local/myclang/bin/llvm-ar -DCMAKE_NM=/usr/local/myclang/bin/llvm-nm -DCMAKE_RANLIB=/usr/local/myclang/bin/llvm-ranlib -DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY -DCMAKE_C_COMPILER_TARGET="arm-linux-gnueabihf" -DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON -DLLVM_CONFIG_PATH=/usr/local/myclang/bin/llvm-config -DBAREMETAL_ARMV5M_SYSROOT=/home/crichter/Downloads/gcc-arm-none-eabi-5_4-2016q3
> >> -DBAREMETAL_ARMV6M_SYSROOT=/home/crichter/Downloads/gcc-arm-none-eabi-6-2017-q2-update -DBAREMETAL_ARMV7M_SYSROOT=/home/crichter/Downloads/gcc-arm-none-eabi-7-2018-q2-update -C /home/llvm_4rt/llvm/tools/clang/cmake/caches
> >>
> >> loading initial cache file /home/llvm_4rt/llvm/tools/clang/cmake/caches
> >> CMake Error: Error processing file: /home/llvm_4rt/llvm/tools/clang/cmake/caches
> >> CMake Error: The source directory "/home/llvm_4rt/llvm/tools/clang/cmake/caches" does not appear to contain CMakeLists.txt.
> >> Specify --help for usage, or press the help button on the CMake GUI.
> >>
> >> So I'm obviously using it wrong, would appreciate any pointers in the right direction!
> >> Christian
> >>
> >>
> >> On 10.12.2018 17:59, Peter Smith wrote:
> >>
> >> Hello Christian,
> >>
> >> Yes it does look like clang will add /usr/local/include unless
> >> --nostdinc is used, although that will mean skipping a lot of other
> >> include directories that clang will implicitly add based on the
> >> target. I can think of a couple of ways to proceed:
> >> 1.) use -nostdinc and add in the directories you need manually
> >> 2.) use a cross gcc toolchain in a different directory such as one
> >> from (https://developer.arm.com/open-source/gnu-toolchain/gnu-a/downloads)
> >> and use --gcc-toolchain and --sysroot.
> >>
> >> I must admit I've only ever done 2.) myself as I've wanted to make
> >> sure I've not inadvertently depended on something on my machine.
> >>
> >> Apologies for the confusion.
> >>
> >> Peter
> >>
> >> On Mon, 10 Dec 2018 at 16:05, Christian Richter
> >> <christian.richter at hsu-hh.de> wrote:
> >>
> >> Hello again!
> >>
> >> Tried out the small Hello World Setup, worked as intended:
> >>
> >> root at christian-forschung-virtual-machine:/home/progs# clang -v --target=arm-linux-gnueabihf hello.c -o hello -fuse-ld=lld
> >> clang version 8.0.0 (https://git.llvm.org/git/clang.git/ a152c7a4b7ba8f4cb9532ead9a38a7121db43d50) (https://git.llvm.org/git/llvm.git/ 1959ce6f3e01241919968ac1911fd45660239d23)
> >> Target: arm-unknown-linux-gnueabihf
> >> Thread model: posix
> >> InstalledDir: /usr/local/myclang/bin
> >> Found candidate GCC installation: /usr/lib/gcc-cross/arm-linux-gnueabihf/7
> >> Found candidate GCC installation: /usr/lib/gcc-cross/arm-linux-gnueabihf/7.3.0
> >> Selected GCC installation: /usr/lib/gcc-cross/arm-linux-gnueabihf/7.3.0
> >> Candidate multilib: .;@m32
> >> Selected multilib: .;@m32
> >> "/usr/local/myclang/bin/clang-8" -cc1 -triple armv6kz-unknown-linux-gnueabihf -emit-obj -mrelax-all -disable-free -disable-llvm-verifier -discard-value-names -main-file-name hello.c -mrelocation-model static -mthread-model posix -mdisable-fp-elim -fmath-errno -masm-verbose -mconstructor-aliases -fuse-init-array -target-cpu arm1176jzf-s -target-feature +strict-align -target-abi aapcs-linux -mfloat-abi hard -fallow-half-arguments-and-returns -dwarf-column-info -debugger-tuning=gdb -v -resource-dir /usr/local/myclang/lib/clang/8.0.0 -internal-isystem /usr/local/include -internal-isystem /usr/local/myclang/lib/clang/8.0.0/include -internal-externc-isystem /include -internal-externc-isystem /usr/include -fdebug-compilation-dir /home/progs -ferror-limit 19 -fmessage-length 202 -fno-signed-char -fobjc-runtime=gcc -fdiagnostics-show-option -fcolor-diagnostics -o /tmp/hello-98a3a7.o -x c hello.c -faddrsig
> >> clang -cc1 version 8.0.0 based upon LLVM 8.0.0svn default target x86_64-unknown-linux-gnu
> >> ignoring nonexistent directory "/include"
> >> #include "..." search starts here:
> >> #include <...> search starts here:
> >> /usr/local/include
> >> /usr/local/myclang/lib/clang/8.0.0/include
> >> /usr/include
> >> End of search list.
> >> "/usr/local/myclang/bin/ld.lld" -EL -z relro -X --hash-style=gnu --eh-frame-hdr -m armelf_linux_eabi -dynamic-linker /lib/ld-linux-armhf.so.3 -o hello /usr/lib/gcc-cross/arm-linux-gnueabihf/7.3.0/../../../../arm-linux-gnueabihf/lib/../lib/crt1.o /usr/lib/gcc-cross/arm-linux-gnueabihf/7.3.0/../../../../arm-linux-gnueabihf/lib/../lib/crti.o /usr/lib/gcc-cross/arm-linux-gnueabihf/7.3.0/crtbegin.o -L/usr/lib/gcc-cross/arm-linux-gnueabihf/7.3.0 -L/usr/lib/gcc-cross/arm-linux-gnueabihf/7.3.0/../../../../arm-linux-gnueabihf/lib/../lib -L/usr/lib/gcc-cross/arm-linux-gnueabihf/7.3.0/../../../../lib -L/usr/local/myclang/bin/../lib -L/lib/../lib -L/usr/lib/../lib -L/usr/lib/arm-linux-gnueabihf/../../lib -L/usr/lib/gcc-cross/arm-linux-gnueabihf/7.3.0/../../../../arm-linux-gnueabihf/lib -L/usr/lib/gcc-cross/arm-linux-gnueabihf/7.3.0/../../.. -L/usr/local/myclang/bin/../lib -L/lib -L/usr/lib /tmp/hello-98a3a7.o -lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s --no-as-needed /usr/lib/gcc-cross/arm-linux-gnueabihf/7.3.0/crtend.o /usr/lib/gcc-cross/arm-linux-gnueabihf/7.3.0/../../../../arm-linux-gnueabihf/lib/../lib/crtn.o
> >>
> >> root at christian-forschung-virtual-machine:/home/progs# qemu-arm -L /usr/arm-linux-gnueabihf hello
> >>
> >> Hello, World!
> >>
> >> So far, so good. The Paths written more readable seem to be
> >>
> >> /usr/local/myclang/lib, /lib, /usr/lib, /usr/arm-linux-gnueabihf/lib, so no surprised there.
> >>
> >> Then I added the suggested -DCMAKE_ASM_FLAGS to the cmake for the standalone compiler-rt build while leaving out the --sysroot and --gcc-toolchain:
> >>
> >> cmake -G "Ninja" ../llvm/projects/compiler-rt/ -DCOMPILER_RT_BUILD_BUILTINS=ON -DCOMPILER_RT_BUILD_SANITIZERS=OFF -DCOMPILER_RT_BUILD_XRAY=OFF -DCOMPILER_RT_BUILD_LIBFUZZER=OFF -DCOMPILER_RT_BUILD_PROFILE=OFF -DCMAKE_C_COMPILER=/usr/local/myclang/bin/clang -DCMAKE_AR=/usr/local/myclang/bin/llvm-ar -DCMAKE_NM=/usr/local/myclang/bin/llvm-nm -DCMAKE_RANLIB=/usr/local/myclang/bin/llvm-ranlib -DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY -DCMAKE_C_COMPILER_TARGET="arm-linux-gnueabihf" -DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON -DLLVM_CONFIG_PATH=/usr/local/myclang/bin/llvm-config -DCMAKE_ASM_FLAGS="--target=arm-linux-gnueabihf -march=armv7a" -DCMAKE_C_FLAGS="--target=arm-linux-gnueabihf -march=armv7a"
> >>
> >> now "ninja builtins" at least starts working, but fails after a while (see below). The error seems similar to http://lists.llvm.org/pipermail/llvm-dev/2011-September/043289.html to me, so it might still be some variant of the problem from before: Using a x86-header where an ARM one would be needed.
> >>
> >> The ninja builtins output:
> >>
> >> root at christian-forschung-virtual-machine:/home/llvm_all/buildrtonly# ninja builtins
> >> [147/207] Building C object lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/emutls.c.o
> >> FAILED: lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/emutls.c.o
> >> /usr/local/myclang/bin/clang --target=arm-linux-gnueabihf -DVISIBILITY_HIDDEN --target=arm-linux-gnueabihf -march=armv7a -Wall -Wno-unused-parameter -fno-lto -std=c11 -fPIC -fno-builtin -fvisibility=hidden -fomit-frame-pointer -fomit-frame-pointer -DCOMPILER_RT_ARMHF_TARGET -MD -MT lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/emutls.c.o -MF lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/emutls.c.o.d -o lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/emutls.c.o -c /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/emutls.c
> >> In file included from /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/emutls.c:41:
> >> /usr/include/pthread.h:682:6: error: 'regparm' is not valid on this platform
> >> __cleanup_fct_attribute;
> >> ^~~~~~~~~~~~~~~~~~~~~~~
> >> /usr/include/bits/pthreadtypes-arch.h:103:50: note: expanded from macro '__cleanup_fct_attribute'
> >> # define __cleanup_fct_attribute __attribute__ ((__regparm__ (1)))
> >> ^ ~
> >> In file included from /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/emutls.c:41:
> >> /usr/include/pthread.h:694:3: error: 'regparm' is not valid on this platform
> >> __cleanup_fct_attribute;
> >> ^~~~~~~~~~~~~~~~~~~~~~~
> >> /usr/include/bits/pthreadtypes-arch.h:103:50: note: expanded from macro '__cleanup_fct_attribute'
> >> # define __cleanup_fct_attribute __attribute__ ((__regparm__ (1)))
> >> ^ ~
> >> In file included from /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/emutls.c:41:
> >> /usr/include/pthread.h:735:6: error: 'regparm' is not valid on this platform
> >> __cleanup_fct_attribute __attribute__ ((__noreturn__))
> >> ^~~~~~~~~~~~~~~~~~~~~~~
> >> /usr/include/bits/pthreadtypes-arch.h:103:50: note: expanded from macro '__cleanup_fct_attribute'
> >> # define __cleanup_fct_attribute __attribute__ ((__regparm__ (1)))
> >> ^ ~
> >> 3 errors generated.
> >> [148/207] Building C object lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/gcc_personality_v0.c.o
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/gcc_personality_v0.c:148:47: warning: declaration of 'struct _Unwind_Exception' will not be visible outside of this function [-Wvisibility]
> >> _Unwind_Reason_Code __gnu_unwind_frame(struct _Unwind_Exception *,
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/gcc_personality_v0.c:153:23: warning: declaration of 'struct _Unwind_Exception' will not be visible outside of this function [-Wvisibility]
> >> continueUnwind(struct _Unwind_Exception *exceptionObject,
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/gcc_personality_v0.c:160:28: warning: incompatible pointer types passing 'struct _Unwind_Exception *' to parameter of type 'struct _Unwind_Exception *' [-Wincompatible-pointer-types]
> >> if (__gnu_unwind_frame(exceptionObject, context) != _URC_OK)
> >> ^~~~~~~~~~~~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/gcc_personality_v0.c:148:66: note: passing argument to parameter here
> >> _Unwind_Reason_Code __gnu_unwind_frame(struct _Unwind_Exception *,
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/gcc_personality_v0.c:184:38: warning: declaration of 'struct _Unwind_Exception' will not be visible outside of this function [-Wvisibility]
> >> _Unwind_State state, struct _Unwind_Exception *exceptionObject,
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/gcc_personality_v0.c:202:31: warning: incompatible pointer types passing 'struct _Unwind_Exception *' to parameter of type 'struct _Unwind_Exception *' [-Wincompatible-pointer-types]
> >> return continueUnwind(exceptionObject, context);
> >> ^~~~~~~~~~~~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/gcc_personality_v0.c:153:42: note: passing argument to parameter 'exceptionObject' here
> >> continueUnwind(struct _Unwind_Exception *exceptionObject,
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/gcc_personality_v0.c:207:31: warning: incompatible pointer types passing 'struct _Unwind_Exception *' to parameter of type 'struct _Unwind_Exception *' [-Wincompatible-pointer-types]
> >> return continueUnwind(exceptionObject, context);
> >> ^~~~~~~~~~~~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/gcc_personality_v0.c:153:42: note: passing argument to parameter 'exceptionObject' here
> >> continueUnwind(struct _Unwind_Exception *exceptionObject,
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/gcc_personality_v0.c:250:27: warning: incompatible pointer types passing 'struct _Unwind_Exception *' to parameter of type 'struct _Unwind_Exception *' [-Wincompatible-pointer-types]
> >> return continueUnwind(exceptionObject, context);
> >> ^~~~~~~~~~~~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/gcc_personality_v0.c:153:42: note: passing argument to parameter 'exceptionObject' here
> >> continueUnwind(struct _Unwind_Exception *exceptionObject,
> >> ^
> >> 7 warnings generated.
> >> [152/207] Building ASM object lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/aeabi_cdcmp.S.o
> >> ninja: build stopped: subcommand failed.
> >>
> >> Almost there! Thanks in advance!
> >>
> >> Christian
> >>
> >>
> >>
> >> On 07.12.2018 17:40, Peter Smith wrote:
> >>
> >> Hello Christian,
> >>
> >> I've put some comments inline
> >>
> >> On Fri, 7 Dec 2018 at 15:48, Christian Richter via llvm-dev
> >> <llvm-dev at lists.llvm.org> wrote:
> >>
> >> Hello,
> >>
> >> on the problems cross-building compiler-rt: Tried to follow https://llvm.org/docs/HowToCrossCompileBuiltinsOnArm.html which lead to this cmake:
> >>
> >> cmake -G "Ninja" ../llvm/projects/compiler-rt/ -DCOMPILER_RT_BUILD_BUILTINS=ON -DCOMPILER_RT_BUILD_SANITIZERS=OFF -DCOMPILER_RT_BUILD_XRAY=OFF -DCOMPILER_RT_BUILD_LIBFUZZER=OFF -DCOMPILER_RT_BUILD_PROFILE=OFF -DCMAKE_C_COMPILER=/usr/local/myclang/bin/clang -DCMAKE_AR=/usr/local/myclang/bin/llvm-ar -DCMAKE_NM=/usr/local/myclang/bin/llvm-nm -DCMAKE_RANLIB=/usr/local/myclang/bin/llvm-ranlib -DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY -DCMAKE_C_COMPILER_TARGET="arm-linux-gnueabihf" -DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON -DLLVM_CONFIG_PATH=/usr/local/myclang/bin/llvm-config -DCMAKE_C_FLAGS="--target=arm-linux-gnueabihf -march=armv7a --gcc-toolchain=/usr/arm-linux-gnueabihf --sysroot=/usr/arm-linux-gnueabihf/lib"
> >>
> >> Some small notes:
> >>
> >> - Used -DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY instead of -DCMAKE_EXE_LINKER_FLAGS="-fuse-ld=lld" as Peter Smith suggested because it actually is a library and therefore does not need to be linked. If I do not change that, the cmake does not work (see below).
> >>
> >> - used -G "Ninja" although not explicitly stated in the tutorial as they use "ninja builtins" next.
> >>
> >> - had to change --march=armv7a to -march=armv7a as clang did not accept the first one.
> >>
> >> the cmake was successful, but the ninja builtins was not (see both outputs below). Am I doing the --gcc-toolchain / --sysroot part right? These are just the places where the result of "apt install arm-linux-gnueabihf" lives.
> >>
> >> cmake output with -DCMAKE_EXE_LINKER_FLAGS="-fuse-ld=lld":
> >>
> >> Thanks for the comments. I will try and revisit that document next
> >> week and will post an update.
> >>
> >> root at christian-forschung-virtual-machine:/home/llvm_all/buildrtonly# cmake -G "Ninja" ../llvm/projects/compiler-rt/ -DCOMPILER_RT_BUILD_BUILTINS=ON -DCOMPILER_RT_BUILD_SANITIZERS=OFF -DCOMPILER_RT_BUILD_XRAY=OFF -DCOMPILER_RT_BUILD_LIBFUZZER=OFF -DCOMPILER_RT_BUILD_PROFILE=OFF -DCMAKE_C_COMPILER=/usr/local/myclang/bin/clang -DCMAKE_AR=/usr/local/myclang/bin/llvm-ar -DCMAKE_NM=/usr/local/myclang/bin/llvm-nm -DCMAKE_RANLIB=/usr/local/myclang/bin/llvm-ranlib -DCMAKE_EXE_LINKER_FLAGS="-fuse-ld=lld" -DCMAKE_C_COMPILER_TARGET="arm-linux-gnueabihf" -DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON -DLLVM_CONFIG_PATH=/usr/local/myclang/bin/llvm-config -DCMAKE_C_FLAGS="--target=arm-linux-gnueabihf -march=armv7a --gcc-toolchain=/usr/arm-linux-gnueabihf --sysroot=/usr/arm-linux-gnueabihf/lib"
> >> -- The C compiler identification is Clang 8.0.0
> >> -- The CXX compiler identification is Clang 8.0.0
> >> -- The ASM compiler identification is unknown
> >> -- Found assembler: /usr/local/myclang/bin/clang
> >> -- Check for working C compiler: /usr/local/myclang/bin/clang
> >> -- Check for working C compiler: /usr/local/myclang/bin/clang -- broken
> >> CMake Error at /usr/share/cmake-3.10/Modules/CMakeTestCCompiler.cmake:52 (message):
> >> The C compiler
> >>
> >> "/usr/local/myclang/bin/clang"
> >>
> >> is not able to compile a simple test program.
> >>
> >> It fails with the following output:
> >>
> >> Change Dir: /home/llvm_all/buildrtonly/CMakeFiles/CMakeTmp
> >>
> >> Run Build Command:"/usr/bin/ninja" "cmTC_22d97"
> >> [1/2] Building C object CMakeFiles/cmTC_22d97.dir/testCCompiler.c.o
> >> [2/2] Linking C executable cmTC_22d97
> >> FAILED: cmTC_22d97
> >> : && /usr/local/myclang/bin/clang --target=arm-linux-gnueabihf --target=arm-linux-gnueabihf -march=armv7a --gcc-toolchain=/usr/arm-linux-gnueabihf --sysroot=/usr/arm-linux-gnueabihf/lib -fuse-ld=lld CMakeFiles/cmTC_22d97.dir/testCCompiler.c.o -o cmTC_22d97 && :
> >> ld.lld: error: cannot open crt1.o: No such file or directory
> >> ld.lld: error: cannot open crti.o: No such file or directory
> >> ld.lld: error: cannot open crtbegin.o: No such file or directory
> >> ld.lld: error: unable to find library -lgcc
> >> ld.lld: error: unable to find library -lgcc_s
> >> ld.lld: error: unable to find library -lc
> >> ld.lld: error: unable to find library -lgcc
> >> ld.lld: error: unable to find library -lgcc_s
> >> ld.lld: error: cannot open crtend.o: No such file or directory
> >> ld.lld: error: cannot open crtn.o: No such file or directory
> >> clang-8: error: linker command failed with exit code 1 (use -v to see invocation)
> >> ninja: build stopped: subcommand failed.
> >>
> >> CMake will not be able to correctly generate this project.
> >> Call Stack (most recent call first):
> >> CMakeLists.txt:10 (project)
> >> -- Configuring incomplete, errors occurred!
> >> See also "/home/llvm_all/buildrtonly/CMakeFiles/CMakeOutput.log".
> >> See also "/home/llvm_all/buildrtonly/CMakeFiles/CMakeError.log".
> >>
> >>
> >> Note: Googling this error suggested installing gcc-multilib or linking "sudo ln -s /usr/lib/x86_64-linux-gnu /usr/lib64" (which both did not fix it). But the crt1.o that lld does not seem to find is probably the one from arm-linux-gnueabihf, right? "Locate" says it's right in /usr/arm-linux-gnueabihf/lib.
> >>
> >> The instructions to use --gcc-toolchain and --sysroot work well for a
> >> separate toolchain install directory. They don't seem to work as well
> >> for a debian multiarch style installation. I think it will be worth
> >> trying to compile helloworld outside of cmake. If you can get that to
> >> work then this might help guide us to what flags to use.
> >>
> >> On my ubuntu 16.04 machine I've got /usr/arm-linux-gnueabihf and
> >> /usr/include/arm-linux-gnueabihf and /usr/lib/arm-linux-gnueabihf
> >> With this configuration the clang linux driver is able to find the
> >> libraries without the sysroot and gcc-toolchain as it is effectively
> >> root. Can you try with a simple helloworld program:
> >> clang --target=arm-linux-gnueabihf hello.c -o hello -fuse-ld=lld
> >> qemu-arm -L /usr/arm-linux-gnueabihf hello
> >> If all is well you should see qemu-arm print Hello World. You may need
> >> to install the package qemu-user if you've not already done so.
> >>
> >> With the -v option clang will tell you where it is searching for
> >> headers and libraries, I've often found that useful in trying to find
> >> out what is going.
> >>
> >> Assuming that this has worked for you can you try removing
> >> "--gcc-toolchain=/usr/arm-linux-gnueabihf
> >> --sysroot=/usr/arm-linux-gnueabihf/lib" from your flags in the cmake
> >> build.
> >>
> >> For the errors below it looks like clang is using the default target
> >> for assembler, note that --target=arm-linux-gnueabihf is missing. I
> >> have seen that before, and the solution I found was to pass
> >> -DCMAKE_ASM_FLAGS="same as C flags including
> >> --target=arm-linux-gnueabihf and -march=armv7a"
> >>
> >> Thanks for reporting the problems. If I get time next week I'll have a
> >> go at improving the documentation.
> >>
> >> Peter
> >>
> >> Thanks so far!
> >>
> >> Christian
> >>
> >>
> >> cmake output with STATIC_LIBRARY:
> >>
> >> -- The C compiler identification is Clang 8.0.0
> >> -- The CXX compiler identification is Clang 8.0.0
> >> -- The ASM compiler identification is Clang
> >> -- Found assembler: /usr/local/myclang/bin/clang
> >> -- Check for working C compiler: /usr/local/myclang/bin/clang
> >> -- Check for working C compiler: /usr/local/myclang/bin/clang -- works
> >> -- Detecting C compiler ABI info
> >> -- Detecting C compiler ABI info - done
> >> -- Detecting C compile features
> >> -- Detecting C compile features - done
> >> -- Check for working CXX compiler: /usr/local/myclang/bin/clang++
> >> -- Check for working CXX compiler: /usr/local/myclang/bin/clang++ -- works
> >> -- Detecting CXX compiler ABI info
> >> -- Detecting CXX compiler ABI info - done
> >> -- Detecting CXX compile features
> >> -- Detecting CXX compile features - done
> >> -- Looking for unwind.h
> >> -- Looking for unwind.h - found
> >> -- Found PythonInterp: /usr/bin/python2.7 (found version "2.7.15")
> >> -- Looking for fopen in c
> >> -- Looking for fopen in c - found
> >> -- Looking for __gcc_personality_v0 in gcc_s
> >> -- Looking for __gcc_personality_v0 in gcc_s - found
> >> -- Performing Test COMPILER_RT_HAS_NODEFAULTLIBS_FLAG
> >> -- Performing Test COMPILER_RT_HAS_NODEFAULTLIBS_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_FFREESTANDING_FLAG
> >> -- Performing Test COMPILER_RT_HAS_FFREESTANDING_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_FPIC_FLAG
> >> -- Performing Test COMPILER_RT_HAS_FPIC_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_FPIE_FLAG
> >> -- Performing Test COMPILER_RT_HAS_FPIE_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_FNO_BUILTIN_FLAG
> >> -- Performing Test COMPILER_RT_HAS_FNO_BUILTIN_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_FNO_EXCEPTIONS_FLAG
> >> -- Performing Test COMPILER_RT_HAS_FNO_EXCEPTIONS_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_FOMIT_FRAME_POINTER_FLAG
> >> -- Performing Test COMPILER_RT_HAS_FOMIT_FRAME_POINTER_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_FUNWIND_TABLES_FLAG
> >> -- Performing Test COMPILER_RT_HAS_FUNWIND_TABLES_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_FNO_STACK_PROTECTOR_FLAG
> >> -- Performing Test COMPILER_RT_HAS_FNO_STACK_PROTECTOR_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_FNO_SANITIZE_SAFE_STACK_FLAG
> >> -- Performing Test COMPILER_RT_HAS_FNO_SANITIZE_SAFE_STACK_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_FVISIBILITY_HIDDEN_FLAG
> >> -- Performing Test COMPILER_RT_HAS_FVISIBILITY_HIDDEN_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_FRTTI_FLAG
> >> -- Performing Test COMPILER_RT_HAS_FRTTI_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_FNO_RTTI_FLAG
> >> -- Performing Test COMPILER_RT_HAS_FNO_RTTI_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_FNO_FUNCTION_SECTIONS_FLAG
> >> -- Performing Test COMPILER_RT_HAS_FNO_FUNCTION_SECTIONS_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_STD_CXX11_FLAG
> >> -- Performing Test COMPILER_RT_HAS_STD_CXX11_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_FTLS_MODEL_INITIAL_EXEC
> >> -- Performing Test COMPILER_RT_HAS_FTLS_MODEL_INITIAL_EXEC - Success
> >> -- Performing Test COMPILER_RT_HAS_FNO_LTO_FLAG
> >> -- Performing Test COMPILER_RT_HAS_FNO_LTO_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_MSSE3_FLAG
> >> -- Performing Test COMPILER_RT_HAS_MSSE3_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_MSSE4_2_FLAG
> >> -- Performing Test COMPILER_RT_HAS_MSSE4_2_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_SYSROOT_FLAG
> >> -- Performing Test COMPILER_RT_HAS_SYSROOT_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_MCRC_FLAG
> >> -- Performing Test COMPILER_RT_HAS_MCRC_FLAG - Failed
> >> -- Performing Test COMPILER_RT_HAS_FVISIBILITY_INLINES_HIDDEN_FLAG
> >> -- Performing Test COMPILER_RT_HAS_FVISIBILITY_INLINES_HIDDEN_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_GR_FLAG
> >> -- Performing Test COMPILER_RT_HAS_GR_FLAG - Failed
> >> -- Performing Test COMPILER_RT_HAS_GS_FLAG
> >> -- Performing Test COMPILER_RT_HAS_GS_FLAG - Failed
> >> -- Performing Test COMPILER_RT_HAS_MT_FLAG
> >> -- Performing Test COMPILER_RT_HAS_MT_FLAG - Failed
> >> -- Performing Test COMPILER_RT_HAS_Oy_FLAG
> >> -- Performing Test COMPILER_RT_HAS_Oy_FLAG - Failed
> >> -- Performing Test COMPILER_RT_HAS_GLINE_TABLES_ONLY_FLAG
> >> -- Performing Test COMPILER_RT_HAS_GLINE_TABLES_ONLY_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_G_FLAG
> >> -- Performing Test COMPILER_RT_HAS_G_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_Zi_FLAG
> >> -- Performing Test COMPILER_RT_HAS_Zi_FLAG - Failed
> >> -- Performing Test COMPILER_RT_HAS_WALL_FLAG
> >> -- Performing Test COMPILER_RT_HAS_WALL_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_WERROR_FLAG
> >> -- Performing Test COMPILER_RT_HAS_WERROR_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_WFRAME_LARGER_THAN_FLAG
> >> -- Performing Test COMPILER_RT_HAS_WFRAME_LARGER_THAN_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_WGLOBAL_CONSTRUCTORS_FLAG
> >> -- Performing Test COMPILER_RT_HAS_WGLOBAL_CONSTRUCTORS_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_WC99_EXTENSIONS_FLAG
> >> -- Performing Test COMPILER_RT_HAS_WC99_EXTENSIONS_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_WGNU_FLAG
> >> -- Performing Test COMPILER_RT_HAS_WGNU_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_WNON_VIRTUAL_DTOR_FLAG
> >> -- Performing Test COMPILER_RT_HAS_WNON_VIRTUAL_DTOR_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_WVARIADIC_MACROS_FLAG
> >> -- Performing Test COMPILER_RT_HAS_WVARIADIC_MACROS_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_WUNUSED_PARAMETER_FLAG
> >> -- Performing Test COMPILER_RT_HAS_WUNUSED_PARAMETER_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_WCOVERED_SWITCH_DEFAULT_FLAG
> >> -- Performing Test COMPILER_RT_HAS_WCOVERED_SWITCH_DEFAULT_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_W4_FLAG
> >> -- Performing Test COMPILER_RT_HAS_W4_FLAG - Failed
> >> -- Performing Test COMPILER_RT_HAS_WX_FLAG
> >> -- Performing Test COMPILER_RT_HAS_WX_FLAG - Failed
> >> -- Performing Test COMPILER_RT_HAS_WD4146_FLAG
> >> -- Performing Test COMPILER_RT_HAS_WD4146_FLAG - Failed
> >> -- Performing Test COMPILER_RT_HAS_WD4291_FLAG
> >> -- Performing Test COMPILER_RT_HAS_WD4291_FLAG - Failed
> >> -- Performing Test COMPILER_RT_HAS_WD4221_FLAG
> >> -- Performing Test COMPILER_RT_HAS_WD4221_FLAG - Failed
> >> -- Performing Test COMPILER_RT_HAS_WD4391_FLAG
> >> -- Performing Test COMPILER_RT_HAS_WD4391_FLAG - Failed
> >> -- Performing Test COMPILER_RT_HAS_WD4722_FLAG
> >> -- Performing Test COMPILER_RT_HAS_WD4722_FLAG - Failed
> >> -- Performing Test COMPILER_RT_HAS_WD4800_FLAG
> >> -- Performing Test COMPILER_RT_HAS_WD4800_FLAG - Failed
> >> -- Looking for __func__
> >> -- Looking for __func__ - found
> >> -- Looking for dlopen in dl
> >> -- Looking for dlopen in dl - found
> >> -- Looking for shm_open in rt
> >> -- Looking for shm_open in rt - found
> >> -- Looking for pow in m
> >> -- Looking for pow in m - found
> >> -- Looking for pthread_create in pthread
> >> -- Looking for pthread_create in pthread - found
> >> -- Looking for setupterm in terminfo
> >> -- Looking for setupterm in terminfo - found
> >> -- Looking for __cxa_throw in c++
> >> -- Looking for __cxa_throw in c++ - found
> >> -- Looking for __cxa_throw in stdc++
> >> -- Looking for __cxa_throw in stdc++ - found
> >> -- Compiler-RT supported architectures: armhf
> >> -- Performing Test COMPILER_RT_HAS_STD_C11_FLAG
> >> -- Performing Test COMPILER_RT_HAS_STD_C11_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_VISIBILITY_HIDDEN_FLAG
> >> -- Performing Test COMPILER_RT_HAS_VISIBILITY_HIDDEN_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_OMIT_FRAME_POINTER_FLAG
> >> -- Performing Test COMPILER_RT_HAS_OMIT_FRAME_POINTER_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_FREESTANDING_FLAG
> >> -- Performing Test COMPILER_RT_HAS_FREESTANDING_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_XRAY_COMPILER_FLAG
> >> -- Performing Test COMPILER_RT_HAS_XRAY_COMPILER_FLAG - Success
> >> -- Performing Test COMPILER_RT_HAS_ATOMIC_KEYWORD
> >> -- Performing Test COMPILER_RT_HAS_ATOMIC_KEYWORD - Success
> >> -- Builtin supported architectures: armhf
> >> -- Looking for __VFP_FP__
> >> -- Looking for __VFP_FP__ - found
> >> -- Configuring done
> >> -- Generating done
> >> -- Build files have been written to: /home/llvm_all/buildrtonly
> >>
> >> --------------------------------------
> >>
> >> ninja output:
> >>
> >>
> >> root at christian-forschung-virtual-machine:/home/llvm_all/buildrtonly# ninja builtins
> >>
> >> [1/207] Building ASM object lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/bswapsi2.S.o
> >> FAILED: lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/bswapsi2.S.o
> >> /usr/local/myclang/bin/clang -DVISIBILITY_HIDDEN -fno-lto -std=c11 -fPIC -fno-builtin -fvisibility=hidden -fomit-frame-pointer -fomit-frame-pointer -DCOMPILER_RT_ARMHF_TARGET -MD -MT lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/bswapsi2.S.o -MF lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/bswapsi2.S.o.d -o lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/bswapsi2.S.o -c /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/bswapsi2.S
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/bswapsi2.S:12:2: error: unknown directive
> >> .syntax unified
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/bswapsi2.S:25:3: error: invalid instruction mnemonic 'eor'
> >> eor r1, r0, r0, ror #16
> >> ^~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/bswapsi2.S:26:15: error: unknown token in expression
> >> bic r1, r1, #0xff0000
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/bswapsi2.S:27:3: error: unknown use of instruction mnemonic without a size suffix
> >> mov r1, r1, lsr #8
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/bswapsi2.S:28:3: error: invalid instruction mnemonic 'eor'
> >> eor r0, r1, r0, ror #8
> >> ^~~
> >> [2/207] Building ASM object lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/bswapdi2.S.o
> >> FAILED: lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/bswapdi2.S.o
> >> /usr/local/myclang/bin/clang -DVISIBILITY_HIDDEN -fno-lto -std=c11 -fPIC -fno-builtin -fvisibility=hidden -fomit-frame-pointer -fomit-frame-pointer -DCOMPILER_RT_ARMHF_TARGET -MD -MT lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/bswapdi2.S.o -MF lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/bswapdi2.S.o.d -o lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/bswapdi2.S.o -c /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/bswapdi2.S
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/bswapdi2.S:12:2: error: unknown directive
> >> .syntax unified
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/bswapdi2.S:26:5: error: invalid instruction mnemonic 'eor'
> >> eor r2, r0, r0, ror #16
> >> ^~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/bswapdi2.S:27:17: error: unknown token in expression
> >> bic r2, r2, #0xff0000
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/bswapdi2.S:28:5: error: unknown use of instruction mnemonic without a size suffix
> >> mov r2, r2, lsr #8
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/bswapdi2.S:29:5: error: invalid instruction mnemonic 'eor'
> >> eor r2, r2, r0, ror #8
> >> ^~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/bswapdi2.S:31:5: error: invalid instruction mnemonic 'eor'
> >> eor r0, r1, r1, ror #16
> >> ^~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/bswapdi2.S:32:17: error: unknown token in expression
> >> bic r0, r0, #0xff0000
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/bswapdi2.S:33:5: error: unknown use of instruction mnemonic without a size suffix
> >> mov r0, r0, lsr #8
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/bswapdi2.S:34:5: error: invalid instruction mnemonic 'eor'
> >> eor r0, r0, r1, ror #8
> >> ^~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/bswapdi2.S:39:5: error: unknown use of instruction mnemonic without a size suffix
> >> mov r1, r2
> >> ^
> >> [3/207] Building ASM object lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/comparesf2.S.o
> >> FAILED: lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/comparesf2.S.o
> >> /usr/local/myclang/bin/clang -DVISIBILITY_HIDDEN -fno-lto -std=c11 -fPIC -fno-builtin -fvisibility=hidden -fomit-frame-pointer -fomit-frame-pointer -DCOMPILER_RT_ARMHF_TARGET -MD -MT lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/comparesf2.S.o -MF lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/comparesf2.S.o.d -o lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/comparesf2.S.o -c /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:41:2: error: unknown directive
> >> .syntax unified
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:45:1: error: unexpected token at start of statement
> >> @ int __eqsf2(float a, float b)
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:50:5: error: invalid operand for instruction
> >> vmov r0, s0
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:51:5: error: invalid operand for instruction
> >> vmov r1, s1
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:53:5: error: unknown use of instruction mnemonic without a size suffix
> >> mov r2, r0, lsl #1
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:54:5: error: unknown use of instruction mnemonic without a size suffix
> >> mov r3, r1, lsl #1
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:56:5: error: invalid instruction mnemonic 'orrs'
> >> orrs r12, r2, r3, lsr #1
> >> ^~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:58:5: error: invalid instruction mnemonic 'it'
> >> it ne
> >> ^~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:59:5: error: invalid instruction mnemonic 'eorsne'
> >> eorsne r12, r0, r1
> >> ^~~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:61:5: error: invalid instruction mnemonic 'it'
> >> it pl
> >> ^~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:62:5: error: invalid instruction mnemonic 'subspl'
> >> subspl r0, r2, r3
> >> ^~~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:64:5: error: invalid instruction mnemonic 'it'
> >> it lo
> >> ^~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:65:5: error: invalid instruction mnemonic 'mvnlo'
> >> mvnlo r0, r1, asr #31
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:67:5: error: invalid instruction mnemonic 'it'
> >> it hi
> >> ^~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:68:5: error: invalid instruction mnemonic 'movhi'
> >> movhi r0, r1, asr #31
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:70:5: error: invalid instruction mnemonic 'it'
> >> it ne
> >> ^~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:71:19: error: unknown token in expression
> >> orrne r0, r0, #1
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:167:13: error: unknown token in expression
> >> cmp r2, #0xff000000
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:168:5: error: invalid instruction mnemonic 'ite'
> >> ite ls
> >> ^~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:169:15: error: unknown token in expression
> >> cmpls r3, #0xff000000
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:170:15: error: unknown token in expression
> >> movhi r0, #1
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:179:1: error: unexpected token at start of statement
> >> @ int __gtsf2(float a, float b)
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:188:5: error: invalid operand for instruction
> >> vmov r0, s0
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:189:5: error: invalid operand for instruction
> >> vmov r1, s1
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:191:5: error: unknown use of instruction mnemonic without a size suffix
> >> mov r2, r0, lsl #1
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:192:5: error: unknown use of instruction mnemonic without a size suffix
> >> mov r3, r1, lsl #1
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:193:5: error: invalid instruction mnemonic 'orrs'
> >> orrs r12, r2, r3, lsr #1
> >> ^~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:194:5: error: invalid instruction mnemonic 'it'
> >> it ne
> >> ^~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:195:5: error: invalid instruction mnemonic 'eorsne'
> >> eorsne r12, r0, r1
> >> ^~~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:196:5: error: invalid instruction mnemonic 'it'
> >> it pl
> >> ^~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:197:5: error: invalid instruction mnemonic 'subspl'
> >> subspl r0, r2, r3
> >> ^~~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:198:5: error: invalid instruction mnemonic 'it'
> >> it lo
> >> ^~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:199:5: error: invalid instruction mnemonic 'mvnlo'
> >> mvnlo r0, r1, asr #31
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:200:5: error: invalid instruction mnemonic 'it'
> >> it hi
> >> ^~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:201:5: error: invalid instruction mnemonic 'movhi'
> >> movhi r0, r1, asr #31
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:202:5: error: invalid instruction mnemonic 'it'
> >> it ne
> >> ^~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:203:19: error: unknown token in expression
> >> orrne r0, r0, #1
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:204:13: error: unknown token in expression
> >> cmp r2, #0xff000000
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:205:5: error: invalid instruction mnemonic 'ite'
> >> ite ls
> >> ^~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:206:15: error: unknown token in expression
> >> cmpls r3, #0xff000000
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:207:15: error: unknown token in expression
> >> movhi r0, #-1
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:214:1: error: unexpected token at start of statement
> >> @ int __unordsf2(float a, float b)
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:220:5: error: invalid operand for instruction
> >> vmov r0, s0
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:221:5: error: invalid operand for instruction
> >> vmov r1, s1
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:224:18: error: unknown token in expression
> >> lsls r2, r0, #1
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:225:18: error: unknown token in expression
> >> lsls r3, r1, #1
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:226:14: error: unknown token in expression
> >> movs r0, #0
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:277:13: error: unknown token in expression
> >> cmp r2, #0xff000000
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:278:5: error: invalid instruction mnemonic 'ite'
> >> ite ls
> >> ^~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:279:15: error: unknown token in expression
> >> cmpls r3, #0xff000000
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:280:15: error: unknown token in expression
> >> movhi r0, #1
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:287:2: error: invalid operand for instruction
> >> vmov s0, r0
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:288:2: error: invalid operand for instruction
> >> vmov s1, r1
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/comparesf2.S:289:2: error: invalid instruction mnemonic 'b'
> >> b __unordsf2
> >> ^
> >> [4/207] Building ASM object lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/clzsi2.S.o
> >> FAILED: lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/clzsi2.S.o
> >> /usr/local/myclang/bin/clang -DVISIBILITY_HIDDEN -fno-lto -std=c11 -fPIC -fno-builtin -fvisibility=hidden -fomit-frame-pointer -fomit-frame-pointer -DCOMPILER_RT_ARMHF_TARGET -MD -MT lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/clzsi2.S.o -MF lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/clzsi2.S.o.d -o lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/clzsi2.S.o -c /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzsi2.S
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzsi2.S:16:2: error: unknown directive
> >> .syntax unified
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzsi2.S:33:2: error: unknown use of instruction mnemonic without a size suffix
> >> mov r1, 1
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzsi2.S:35:2: error: invalid instruction mnemonic 'lsrs'
> >> lsrs r2, r0, 16; movne r0, r2; addeq r1, 16
> >> ^~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzsi2.S:35:19: error: invalid instruction mnemonic 'movne'
> >> lsrs r2, r0, 16; movne r0, r2; addeq r1, 16
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzsi2.S:35:33: error: invalid instruction mnemonic 'addeq'
> >> lsrs r2, r0, 16; movne r0, r2; addeq r1, 16
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzsi2.S:36:2: error: invalid instruction mnemonic 'lsrs'
> >> lsrs r2, r0, 8; movne r0, r2; addeq r1, 8
> >> ^~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzsi2.S:36:18: error: invalid instruction mnemonic 'movne'
> >> lsrs r2, r0, 8; movne r0, r2; addeq r1, 8
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzsi2.S:36:32: error: invalid instruction mnemonic 'addeq'
> >> lsrs r2, r0, 8; movne r0, r2; addeq r1, 8
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzsi2.S:37:2: error: invalid instruction mnemonic 'lsrs'
> >> lsrs r2, r0, 4; movne r0, r2; addeq r1, 4
> >> ^~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzsi2.S:37:18: error: invalid instruction mnemonic 'movne'
> >> lsrs r2, r0, 4; movne r0, r2; addeq r1, 4
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzsi2.S:37:32: error: invalid instruction mnemonic 'addeq'
> >> lsrs r2, r0, 4; movne r0, r2; addeq r1, 4
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzsi2.S:38:2: error: invalid instruction mnemonic 'lsrs'
> >> lsrs r2, r0, 2; movne r0, r2; addeq r1, 2
> >> ^~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzsi2.S:38:18: error: invalid instruction mnemonic 'movne'
> >> lsrs r2, r0, 2; movne r0, r2; addeq r1, 2
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzsi2.S:38:32: error: invalid instruction mnemonic 'addeq'
> >> lsrs r2, r0, 2; movne r0, r2; addeq r1, 2
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzsi2.S:40:2: error: unknown use of instruction mnemonic without a size suffix
> >> sub r0, r1, r0, lsr #1
> >> ^
> >> [5/207] Building ASM object lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/clzdi2.S.o
> >> FAILED: lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/clzdi2.S.o
> >> /usr/local/myclang/bin/clang -DVISIBILITY_HIDDEN -fno-lto -std=c11 -fPIC -fno-builtin -fvisibility=hidden -fomit-frame-pointer -fomit-frame-pointer -DCOMPILER_RT_ARMHF_TARGET -MD -MT lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/clzdi2.S.o -MF lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/clzdi2.S.o.d -o lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/clzdi2.S.o -c /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzdi2.S
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzdi2.S:16:2: error: unknown directive
> >> .syntax unified
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzdi2.S:50:2: error: unknown use of instruction mnemonic without a size suffix
> >> cmp r1, 0
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzdi2.S:51:2: error: invalid instruction mnemonic 'movne'
> >> movne r0, r1
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzdi2.S:53:2: error: invalid instruction mnemonic 'movne'
> >> movne r1, 1
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzdi2.S:54:2: error: invalid instruction mnemonic 'moveq'
> >> moveq r1, 33
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzdi2.S:56:2: error: invalid instruction mnemonic 'lsrs'
> >> lsrs r2, r0, 16; movne r0, r2; addeq r1, 16
> >> ^~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzdi2.S:56:19: error: invalid instruction mnemonic 'movne'
> >> lsrs r2, r0, 16; movne r0, r2; addeq r1, 16
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzdi2.S:56:33: error: invalid instruction mnemonic 'addeq'
> >> lsrs r2, r0, 16; movne r0, r2; addeq r1, 16
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzdi2.S:57:2: error: invalid instruction mnemonic 'lsrs'
> >> lsrs r2, r0, 8; movne r0, r2; addeq r1, 8
> >> ^~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzdi2.S:57:18: error: invalid instruction mnemonic 'movne'
> >> lsrs r2, r0, 8; movne r0, r2; addeq r1, 8
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzdi2.S:57:32: error: invalid instruction mnemonic 'addeq'
> >> lsrs r2, r0, 8; movne r0, r2; addeq r1, 8
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzdi2.S:58:2: error: invalid instruction mnemonic 'lsrs'
> >> lsrs r2, r0, 4; movne r0, r2; addeq r1, 4
> >> ^~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzdi2.S:58:18: error: invalid instruction mnemonic 'movne'
> >> lsrs r2, r0, 4; movne r0, r2; addeq r1, 4
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzdi2.S:58:32: error: invalid instruction mnemonic 'addeq'
> >> lsrs r2, r0, 4; movne r0, r2; addeq r1, 4
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzdi2.S:59:2: error: invalid instruction mnemonic 'lsrs'
> >> lsrs r2, r0, 2; movne r0, r2; addeq r1, 2
> >> ^~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzdi2.S:59:18: error: invalid instruction mnemonic 'movne'
> >> lsrs r2, r0, 2; movne r0, r2; addeq r1, 2
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzdi2.S:59:32: error: invalid instruction mnemonic 'addeq'
> >> lsrs r2, r0, 2; movne r0, r2; addeq r1, 2
> >> ^~~~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/clzdi2.S:61:2: error: unknown use of instruction mnemonic without a size suffix
> >> sub r0, r1, r0, lsr #1
> >> ^
> >> [6/207] Building ASM object lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/divmodsi4.S.o
> >> FAILED: lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/divmodsi4.S.o
> >> /usr/local/myclang/bin/clang -DVISIBILITY_HIDDEN -fno-lto -std=c11 -fPIC -fno-builtin -fvisibility=hidden -fomit-frame-pointer -fomit-frame-pointer -DCOMPILER_RT_ARMHF_TARGET -MD -MT lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/divmodsi4.S.o -MF lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/divmodsi4.S.o.d -o lib/builtins/CMakeFiles/clang_rt.builtins-armhf.dir/arm/divmodsi4.S.o -c /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S:24:2: error: unknown directive
> >> .syntax unified
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S:28:1: error: unexpected token at start of statement
> >> @ int __divmodsi4(int divident, int divisor, int *remainder)
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S:29:1: error: unexpected token at start of statement
> >> @ Calculate the quotient and remainder of the (signed) division. The return
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S:30:1: error: unexpected token at start of statement
> >> @ value is the quotient, the remainder is placed in the variable.
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S:46:11: error: Invalid rounding mode.
> >> push {r4-r7, lr} ; add r7, sp, #12
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S:46:36: error: unknown token in expression
> >> push {r4-r7, lr} ; add r7, sp, #12
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S:49:5: error: invalid instruction mnemonic 'eor'
> >> eor r4, r0, r1
> >> ^~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S:50:5: error: unknown use of instruction mnemonic without a size suffix
> >> mov r5, r0
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S:51:5: error: unknown use of instruction mnemonic without a size suffix
> >> mov r6, r2
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S:53:5: error: invalid instruction mnemonic 'eor'
> >> eor ip, r0, r0, asr #31
> >> ^~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S:54:5: error: invalid instruction mnemonic 'eor'
> >> eor lr, r1, r1, asr #31
> >> ^~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S:55:5: error: unknown use of instruction mnemonic without a size suffix
> >> sub r0, ip, r0, asr #31
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S:56:5: error: unknown use of instruction mnemonic without a size suffix
> >> sub r1, lr, r1, asr #31
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S:58:5: error: invalid instruction mnemonic 'bl'
> >> bl __udivmodsi4
> >> ^~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S:60:5: error: invalid instruction mnemonic 'ldr'
> >> ldr r1, [r6]
> >> ^~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S:61:5: error: invalid instruction mnemonic 'eor'
> >> eor r0, r0, r4, asr #31
> >> ^~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S:62:5: error: invalid instruction mnemonic 'eor'
> >> eor r1, r1, r5, asr #31
> >> ^~~
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S:63:5: error: unknown use of instruction mnemonic without a size suffix
> >> sub r0, r0, r4, asr #31
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S:64:5: error: unknown use of instruction mnemonic without a size suffix
> >> sub r1, r1, r5, asr #31
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S:65:5: error: unknown use of instruction mnemonic without a size suffix
> >> str r1, [r6]
> >> ^
> >> /home/llvm_all/llvm/projects/compiler-rt/lib/builtins/arm/divmodsi4.S:66:10: error: Invalid rounding mode.
> >> pop {r4-r7, pc}
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >> On 04.12.2018 15:54, Peter Smith via llvm-dev wrote:
> >>
> >> Hello,
> >>
> >> Just a few quick observations.
> >> - It looks like you may have downloaded the linux arm toolchain. For bare metal you probably wanted the Arm embedded toolchain, https://developer.arm.com/open-source/gnu-toolchain/gnu-rm
> >> -- That toolchain will have newlib rather than glibc, I don't know whether it will have one pre-compiled for v4 though. If not you may have to find an older toolchain or build newlib youtself.
> >> - The bare-metal driver in clang (arm-none-eabi) is not multilib aware and won't put the paths to the libraries on the link line, the -L flag
> >> -- I have found that following the samples in the gnu embedded toolchain with gcc using the -v flag to get the paths it is using, then use these with lld.
> >>
> >> If you can let us know what problems you are seeing building compiler-rt then we may be able to help. I'm not sure there is anyone building it for arm v4 so you may be hitting new problems. I'm away at a conference today and tomorrow but I can try later in the week.
> >>
> >> Peter
> >>
> >> On Tue, 4 Dec 2018 at 12:21, cscheuer via llvm-dev <llvm-dev at lists.llvm.org> wrote:
> >>
> >> I am currently trying to compile a pretty simple program to work on an
> >> experimental board. It contains an (FPGA-version of) an ARMv4 processor.
> >> So basically, I try this (on my Ubuntu 18.04.1 LTS):
> >> clang -v --target=arm-none-eabi -c barehello.c -o barehelloCLANG.o
> >> clang -v --target=arm-none-eabi -c io.c -o io.o
> >> clang -v --target=arm-none-eabi barehelloCLANG.o io.o -o
> >> helloCLANGstatic -static -fuse-ld=lld
> >>
> >> Which results in
> >>
> >> clang version 8.0.0 (https://git.llvm.org/git/clang.git/
> >> a152c7a4b7ba8f4cb9532ead9a38a7121db43d50)
> >> (https://git.llvm.org/git/llvm.git/
> >> 1959ce6f3e01241919968ac1911fd45660239d23)
> >> Target: arm-none-unknown-eabi
> >> Thread model: posix
> >> InstalledDir: /usr/local/my_clang/bin
> >> "/usr/local/my_clang/bin/ld.lld" barehelloCLANG.o io.o -Bstatic
> >> -L/usr/local/my_clang/lib/clang/8.0.0/lib/baremetal -lc -lm
> >> -lclang_rt.builtins-arm.a -o helloCLANGstatic
> >> ld.lld: error: unable to find library -lc
> >> ld.lld: error: unable to find library -lm
> >> ld.lld: error: unable to find library -lclang_rt.builtins-arm.a
> >> clang-8: error: ld.lld command failed with exit code 1 (use -v to see
> >> invocation)
> >>
> >> on the linking part. I downloaded a sysroot from
> >> https://developer.arm.com/open-source/gnu-toolchain/gnu-a/downloads/8-2-2018-08
> >> and tried to include it via --sysroot=/my/path/to/it, but clang acted
> >> unimpressed with the same errors. So I'm missing clang_rt.builtins-arm.a
> >> I guess, but that does not exist on my system.
> >> So next, I tried basically every version of "how to cross-compile
> >> llvm/clang/compiler-rt" That google came up with, but was not able to
> >> get a single one to actually work. Any ideas how to get this running?
> >> Thanks in advance!
> >> _______________________________________________
> >> LLVM Developers mailing list
> >> llvm-dev at lists.llvm.org
> >> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
> >>
> >>
> >> _______________________________________________
> >> LLVM Developers mailing list
> >> llvm-dev at lists.llvm.org
> >> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
> >>
> >>
> >> _______________________________________________
> >> LLVM Developers mailing list
> >> llvm-dev at lists.llvm.org
> >> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
> >>
> >>
> >>
> >>
> >>
>
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