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Absolute path in pthread and libc linker scripts break cross-compilation #64

Description

@jardon-u

I get the following error when cross compiling my program:

opened script file /home/ugo/dev/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/arm-linux-gnueabihf/libc/usr/lib/arm-linux-gnueabihf/libpthread.so
opened script file /home/ugo/dev/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/arm-linux-gnueabihf/libc/usr/lib/arm-linux-gnueabihf/libpthread.so
attempt to open /lib/arm-linux-gnueabihf/libpthread.so.0 failed
attempt to open /usr/lib/arm-linux-gnueabihf/libpthread_nonshared.a failed
/home/ugo/dev/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin/../lib/gcc/arm-linux-gnueabihf/4.8.3/../../../../arm-linux-gnueabihf/bin/ld: cannot find /lib/arm-linux-gnueabihf/libpthread.so.0
/home/ugo/dev/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin/../lib/gcc/arm-linux-gnueabihf/4.8.3/../../../../arm-linux-gnueabihf/bin/ld: cannot find /usr/lib/arm-linux-gnueabihf/libpthread_nonshared.a

Part of cmake Toolchain:

SET(CMAKE_FIND_ROOT_PATH $ENV{ROOTFS_DIR} $ENV{CROSSROOT_DIR})
SET(CMAKE_CXX_FLAGS  "${CMAKE_CXX_FLAGS} -march=armv6 -mtune=arm1176jzf-s -mfloat-abi=hard -mfpu=vfp --sysroot=$ENV{ROOTFS_DIR}" CACHE STRING "cache it")
SET(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} --sysroot=$ENV{ROOTFS_DIR}" CACHE STRING "cache it")
SET(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} --sysroot=$ENV{ROOTFS_DIR}" CACHE STRING "cache it")
SET(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} --sysroot=$ENV{ROOTFS_DIR}" CACHE STRING "cache it")

ld cannot find pthread even though the library seems to correctly match the location in sysroot.
i.e. $ENV{ROOTFS_DIR}/lib/arm-linux-gnueabihf/libpthread.so.0 exists

The solution given in the following links is to remove the relative paths from pthread (and libc) linker scripts (tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/arm-linux-gnueabihf/libc/usr/lib/arm-linux-gnueabihf/libpthread.so):
http://go-robot.blogspot.fr/2014_09_01_archive.html
http://linux.bytesex.org/cross-compiler.html
http://www.mira-project.org/MIRA-doc/CrossCompilePage.html
...

It fixed my problem. Does it make sense to send a pull request removing this absolute path on the repository ?

Activity

  1. previn-lvt-zz commented on Jun 25, 2018

    @previn-lvt-zz

    Any updates on this? I have seen this same issue and editing the paths also fixed it. Is there a reason these absolute paths were used in the repo?

  2. rkfg commented on Aug 20, 2018

    @rkfg

    For those who have the same error but changing paths doesn't fix it: if you use a Raspbian chroot for libraries and stuff (like I do) you have to change these paths there as well. I built the toolchain myself with crosstool-ng, fixed the absolute path in ${TOOLCHAIN_ROOT}/arm-rpi-linux-gnueabihf/sysroot/usr/lib/libpthread.so and it was NOT enough (or rather, it might've been pointless), but it linked after I did the same in ${RASPBIAN_CHROOT}/usr/lib/arm-linux-gnueabihf/libpthread.so and ${RASPBIAN_CHROOT}/usr/lib/arm-linux-gnueabihf/libc.so.

  3. RDL-28 commented on Apr 3, 2022

    @RDL-28

    It is not necessary to specify the full path, just go up a level: (../)

    for libc.so

    /* GNU ld script
       Use the shared library, but some functions are only in
       the static library, so try that secondarily.  */
    OUTPUT_FORMAT(elf64-x86-64)
    GROUP ( ../lib64/libc.so.6 /usr/lib64/libc_nonshared.a  AS_NEEDED ( ../lib64/ld-linux-x86-64.so.2 ) )
    

    for libpthread.so

    /* GNU ld script
       Use the shared library, but some functions are only in
       the static library, so try that secondarily.  */
    OUTPUT_FORMAT(elf64-x86-64)
    GROUP ( ../lib/libpthread.so.0 ../lib64/libpthread_nonshared.a )
    
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