cross-compile error: undefined reference to `__atomic_load_8' #125269

Lapshin · 2024-10-10T14:55:31Z

Bug report

Bug description:

Should not configure script check if -latomic is needed?

getting build error when cross-compile:

arm-linux-gnueabi-gcc -L/opt/zlib-arm-linux-gnueabi/lib -L/opt/xz-arm-linux-gnueabi/lib -L/opt/readline-arm-linux-gnueabi/lib -L/opt/libffi-arm-linux-gnueabi/lib -L/opt/libtirpc-arm-linux-gnueabi/lib -L/opt/libuuid-arm-linux-gnueabi/lib -L/opt/zlib-arm-linux-gnueabi/lib -L/opt/xz-arm-linux-gnueabi/lib -L/opt/readline-arm-linux-gnueabi/lib -L/opt/libffi-arm-linux-gnueabi/lib -L/opt/libtirpc-arm-linux-gnueabi/lib -L/opt/libuuid-arm-linux-gnueabi/lib   -Xlinker -export-dynamic -o Programs/_testembed Programs/_testembed.o -L. -lpython3.13 -lpthread -ldl  -lpthread -lutil                          -lm 
/root/x-tools/arm-linux-gnueabi/lib/gcc/arm-linux-gnueabi/13.2.0/../../../../arm-linux-gnueabi/bin/ld: ./libpython3.13.so: undefined reference to `__atomic_load_8'
/root/x-tools/arm-linux-gnueabi/lib/gcc/arm-linux-gnueabi/13.2.0/../../../../arm-linux-gnueabi/bin/ld: ./libpython3.13.so: undefined reference to `__atomic_store_8'
/root/x-tools/arm-linux-gnueabi/lib/gcc/arm-linux-gnueabi/13.2.0/../../../../arm-linux-gnueabi/bin/ld: ./libpython3.13.so: undefined reference to `__atomic_fetch_add_8'
/root/x-tools/arm-linux-gnueabi/lib/gcc/arm-linux-gnueabi/13.2.0/../../../../arm-linux-gnueabi/bin/ld: ./libpython3.13.so: undefined reference to `__atomic_compare_exchange_8'
collect2: error: ld returned 1 exit status

configure cmd line:

./configure --prefix=/opt/python-arm-linux-gnueabi-3.13.0 --host=arm-linux-gnueabi --target=arm-linux-gnueabi --build=x86_64-linux-gnu --disable-ipv6 ac_cv_file__dev_ptmx=no ac_cv_file__dev_ptc=no  --enable-shared --with-openssl=/opt/openssl-arm-linux-gnueabi --with-build-python=/root/.pyenv/versions/3.13.0/bin/python

workaround

export LDFLAGS="-latomic $LDFLAGS"

CPython versions tested on:

3.13

Operating systems tested on:

Linux

Linked PRs

The text was updated successfully, but these errors were encountered:

colesbury · 2024-10-10T15:57:13Z

The configure script has a check for -latomic. I'm not sure why it's not working on your system:

cpython/configure.ac

Lines 7498 to 7545 in 01fc3b3

    
           AC_CACHE_CHECK([whether libatomic is needed by <pyatomic.h>], 
        
                          [ac_cv_libatomic_needed], 
        
           [AC_RUN_IFELSE([AC_LANG_SOURCE([[ 
        
           // pyatomic.h needs uint64_t and Py_ssize_t types 
        
           #include <stdint.h>  // int64_t, intptr_t 
        
           #ifdef HAVE_SYS_TYPES_H 
        
           #  include <sys/types.h> // ssize_t 
        
           #endif 
        
           // Code adapted from Include/pyport.h 
        
           #if HAVE_SSIZE_T 
        
           typedef ssize_t Py_ssize_t; 
        
           #elif SIZEOF_VOID_P == SIZEOF_SIZE_T 
        
           typedef intptr_t Py_ssize_t; 
        
           #else 
        
           #  error "unable to define Py_ssize_t" 
        
           #endif 
        
           #include "pyatomic.h" 
        
           int main() 
        
           { 
        
               uint64_t value; 
        
               _Py_atomic_store_uint64(&value, 2); 
        
               if (_Py_atomic_or_uint64(&value, 8) != 2) { 
        
                   return 1; // error 
        
               } 
        
               if (_Py_atomic_load_uint64(&value) != 10) { 
        
                   return 1; // error 
        
               } 
        
               uint8_t byte = 0xb8; 
        
               if (_Py_atomic_or_uint8(&byte, 0x2d) != 0xb8) { 
        
                   return 1; // error 
        
               } 
        
               if (_Py_atomic_load_uint8(&byte) != 0xbd) { 
        
                   return 1; // error 
        
               } 
        
               return 0; // all good 
        
           } 
        
           ]])], 
        
             [ac_cv_libatomic_needed=no],  dnl build succeeded 
        
             [ac_cv_libatomic_needed=yes], dnl build failed 
        
             [ac_cv_libatomic_needed=no])  dnl cross compilation 
        
           ]) 
        
           AS_VAR_IF([ac_cv_libatomic_needed], [yes], 
        
                     [LIBS="${LIBS} -latomic" 
        
                      LIBATOMIC=${LIBATOMIC-"-latomic"}]) 
        
           _RESTORE_VAR([CPPFLAGS])

colesbury · 2024-10-10T16:24:22Z

Oh, I guess we disabled it for cross compilation (#109211). cc @vstinner @erlend-aasland

colesbury · 2024-10-10T16:26:23Z

Could we use AC_LINK_IFELSE instead of AC_RUN_IFELSE for this check?

vstinner · 2024-10-11T09:29:01Z

Could we use AC_LINK_IFELSE instead of AC_RUN_IFELSE for this check?

I don't know, it's beyond my autotools skills :-) Maybe @erlend-aasland or @corona10 knows.

vstinner · 2024-10-11T09:30:53Z

I don't know autotools. When Python is cross-compiled, does AC_RUN_IFELSE build the program? Or does it do nothing?

erlend-aasland · 2024-10-11T09:33:25Z

IIRC, the LINK variant only runs the linker, so it should work on a correctly setup cross-compiling environment. The RUN variant also runs the resulting executable, which will fail in a cross-compiling dev environment.

erlend-aasland · 2024-10-11T09:36:09Z

Ah, the check in our configure script defaults to not requiring libatomic if we are cross compiling. Perhaps we want to change that configure branch.

colesbury · 2024-10-13T21:02:52Z

Ah, the check in our configure script defaults to not requiring libatomic if we are cross compiling. Perhaps we want to change that configure branch.

Looking at the past PRs:

Sep 8, 2023: gh-109054: configure checks if libatomic is needed #109101 added the check and made -latomic the default when cross-compiling
Sep 10, 2023: gh-109054: Don't use libatomic on cross-compilation #109211 changed the cross-compling default to not require -latomic to fix wasm32, which is cross-compiled but doesn't support -latomic.

IIRC, the LINK variant only runs the linker, so it should work on a correctly setup cross-compiling environment

I think the link time check should be sufficient for both cross-compiling and native compilation (famous last words). I'll give it a go.

We previously used `AC_RUN_IF_ELSE` with a short test program to detect if `-latomic` is needed, but that requires choosing a specific default value when cross-compiling because the test program is not run. Some cross compilation targets like `wasm32-emscripten` do not support `-latomic`, while other cross compilation targets, like `arm-linux-gnueabi` require it.

erlend-aasland · 2024-10-14T06:35:49Z

I think the link time check should be sufficient for both cross-compiling and native compilation (famous last words). I'll give it a go.

Yes, that aligns with my assumptions as well. Let's try.

…125416) We previously used `AC_RUN_IF_ELSE` with a short test program to detect if `-latomic` is needed, but that requires choosing a specific default value when cross-compiling because the test program is not run. Some cross compilation targets like `wasm32-emscripten` do not support `-latomic`, while other cross compilation targets, like `arm-linux-gnueabi` require it.

…ded (pythonGH-125416) We previously used `AC_RUN_IF_ELSE` with a short test program to detect if `-latomic` is needed, but that requires choosing a specific default value when cross-compiling because the test program is not run. Some cross compilation targets like `wasm32-emscripten` do not support `-latomic`, while other cross compilation targets, like `arm-linux-gnueabi` require it. (cherry picked from commit 8d42e2d) Co-authored-by: Sam Gross <[email protected]>

…eded (GH-125416) (#125493) gh-125269: Use `AC_LINK_IF_ELSE` to detect if `-latomic` is needed (GH-125416) We previously used `AC_RUN_IF_ELSE` with a short test program to detect if `-latomic` is needed, but that requires choosing a specific default value when cross-compiling because the test program is not run. Some cross compilation targets like `wasm32-emscripten` do not support `-latomic`, while other cross compilation targets, like `arm-linux-gnueabi` require it. (cherry picked from commit 8d42e2d) Co-authored-by: Sam Gross <[email protected]>

Lapshin added the type-bug An unexpected behavior, bug, or error label Oct 10, 2024

ZeroIntensity added build The build process and cross-build topic-free-threading labels Oct 10, 2024

colesbury added 3.13 bugs and security fixes 3.14 new features, bugs and security fixes labels Oct 13, 2024

bedevere-app bot mentioned this issue Oct 13, 2024

gh-125269: Use AC_LINK_IF_ELSE to detect if -latomic is needed #125416

Merged

bedevere-app bot mentioned this issue Oct 15, 2024

[3.13] gh-125269: Use AC_LINK_IF_ELSE to detect if -latomic is needed (GH-125416) #125493

Merged

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cross-compile error: undefined reference to `__atomic_load_8' #125269

cross-compile error: undefined reference to `__atomic_load_8' #125269

Lapshin commented Oct 10, 2024 •

edited by bedevere-app bot

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colesbury commented Oct 10, 2024

colesbury commented Oct 10, 2024

colesbury commented Oct 10, 2024

vstinner commented Oct 11, 2024

vstinner commented Oct 11, 2024

erlend-aasland commented Oct 11, 2024

erlend-aasland commented Oct 11, 2024

colesbury commented Oct 13, 2024

erlend-aasland commented Oct 14, 2024

cross-compile error: undefined reference to `__atomic_load_8' #125269

cross-compile error: undefined reference to `__atomic_load_8' #125269

Comments

Lapshin commented Oct 10, 2024 • edited by bedevere-app bot Loading

Bug report

Bug description:

workaround

CPython versions tested on:

Operating systems tested on:

Linked PRs

colesbury commented Oct 10, 2024

colesbury commented Oct 10, 2024

colesbury commented Oct 10, 2024

vstinner commented Oct 11, 2024

vstinner commented Oct 11, 2024

erlend-aasland commented Oct 11, 2024

erlend-aasland commented Oct 11, 2024

colesbury commented Oct 13, 2024

erlend-aasland commented Oct 14, 2024

Lapshin commented Oct 10, 2024 •

edited by bedevere-app bot

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