undefined symbols for x86_64 compiled on Apple M3 Max

[Ronald Fenner]

I've compiled v8 for x86_64 on an Apple M3 Max macbook pro. When I try to link the static libraies into an app i get the following undefined symbols

  _Cr_z_adler32_simd_, referenced from:
      _Cr_z_adler32_z in libchrome_zlib.a[2](adler32.o)
  _Cr_z_crc32_sse42_simd_, referenced from:
      _Cr_z_crc32_z in libchrome_zlib.a[5](crc32.o)
  _Cr_z_crc_fold_512to32, referenced from:
      _Cr_z_crc_finalize in libchrome_zlib.a[5](crc32.o)
  _Cr_z_crc_fold_copy, referenced from:
      _Cr_z_copy_with_crc in libchrome_zlib.a[5](crc32.o)
  _Cr_z_crc_fold_init, referenced from:
      _Cr_z_crc_reset in libchrome_zlib.a[5](crc32.o)
  _Cr_z_inflate, referenced from:
      zlib_internal::UncompressHelper(zlib_internal::WrapperType, unsigned char*, unsigned long*, unsigned char const*, unsigned long) in libcompression_utils_portable.a[2](compression_utils_portable.o)
  _Cr_z_inflateEnd, referenced from:
      zlib_internal::UncompressHelper(zlib_internal::WrapperType, unsigned char*, unsigned long*, unsigned char const*, unsigned long) in libcompression_utils_portable.a[2](compression_utils_portable.o)
      zlib_internal::UncompressHelper(zlib_internal::WrapperType, unsigned char*, unsigned long*, unsigned char const*, unsigned long) in libcompression_utils_portable.a[2](compression_utils_portable.o)
  _Cr_z_inflateInit2_, referenced from:
      zlib_internal::UncompressHelper(zlib_internal::WrapperType, unsigned char*, unsigned long*, unsigned char const*, unsigned long) in libcompression_utils_portable.a[2](compression_utils_portable.o)
  _glibc_cos, referenced from:
      v8::base::ieee754::libm_cos(double) in libv8_base_without_compiler.a[63](external-reference.o)
  _glibc_sin, referenced from:
      v8::base::ieee754::libm_sin(double) in libv8_base_without_compiler.a[63](external-reference.o)

When i run nm on the libchome_zlib.a i see a number of U's for symbols of which the above are inclluded.

I'm wondering what I need to add to get these to be not undefined and I suspect it might be cause I'm cross compiling.

Haven't been able to test the arm64 versions cause bazel is wanting to build x86_64 instead of arm64 when i try to build my app.

[Ronald Fenner]

Ok got bazel to use the arm64 version of the libs and they are reproting some undefined ones as well

  _Cr_z_adler32_simd_, referenced from:
      _Cr_z_adler32_z in libchrome_zlib.a[2](adler32.o)

  _Cr_z_armv8_crc32_little, referenced from:

      _Cr_z_crc32_z in libchrome_zlib.a[5](crc32.o)

      _Cr_z_crc32 in libchrome_zlib.a[5](crc32.o)
  _Cr_z_armv8_crc32_pmull_little, referenced from:

      _Cr_z_crc32_z in libchrome_zlib.a[5](crc32.o)

      _Cr_z_crc32 in libchrome_zlib.a[5](crc32.o)

  _Cr_z_inflate, referenced from:
      zlib_internal::UncompressHelper(zlib_internal::WrapperType, unsigned char*, unsigned long*, unsigned char const*, unsigned long) in libcompression_utils_portable.a[2](compression_utils_portable.o)
  _Cr_z_inflateEnd, referenced from:
      zlib_internal::UncompressHelper(zlib_internal::WrapperType, unsigned char*, unsigned long*, unsigned char const*, unsigned long) in libcompression_utils_portable.a[2](compression_utils_portable.o)
      zlib_internal::UncompressHelper(zlib_internal::WrapperType, unsigned char*, unsigned long*, unsigned char const*, unsigned long) in libcompression_utils_portable.a[2](compression_utils_portable.o)
  _Cr_z_inflateInit2_, referenced from:
      zlib_internal::UncompressHelper(zlib_internal::WrapperType, unsigned char*, unsigned long*, unsigned char const*, unsigned long) in libcompression_utils_portable.a[2](compression_utils_portable.o)
  _glibc_cos, referenced from:
      v8::base::ieee754::libm_cos(double) in libv8_base_without_compiler.a[63](external-reference.o)
  _glibc_sin, referenced from:
      v8::base::ieee754::libm_sin(double) in libv8_base_without_compiler.a[63](external-reference.o)

[Ronald Fenner]

Ok after switching over to my windows build machine I'm getting some of the same link errors as on the mac. It would see after i poked around on the mac side that some of the .o files for zlib are not bundled into the static library that is generated. I'm going to assume that it's probably the same for the windows as well. 

My arg file for windows are these

gn_args_release = {
'is_debug': 'false',
'is_component_build': 'false',
'v8_monolithic': 'false',
'v8_use_external_startup_data': 'true',
'is_clang': 'false',
'dcheck_always_on': 'false',
'v8_static_library': 'true',
'v8_enable_pointer_compression_shared_cage ':'false',
}

gn_args_debug = {
'is_debug': 'true',
'is_component_build': 'false',
'v8_monolithic': 'false',
'v8_use_external_startup_data': 'true',
'is_clang': 'false',
'v8_enable_backtrace': 'true',
'v8_enable_slow_dchecks': 'false',
'v8_optimized_debug': 'false',
'v8_static_library': 'true',
'v8_enable_pointer_compression_shared_cage ': 'false',
'enable_iterator_debugging':'true'
}

And mac

gn_args_release = {
'is_debug': 'false',
'is_component_build': 'false',
'v8_monolithic': 'false',
'v8_use_external_startup_data': 'true',
'dcheck_always_on': 'false',
'use_custom_libcxx': 'false',
'v8_static_library': 'true',
'v8_enable_pointer_compression_shared_cage ': 'false',
}

gn_args_debug = {
'is_debug': 'true',
'is_component_build': 'false',
'v8_monolithic': 'false',
'v8_use_external_startup_data': 'true',
'v8_enable_backtrace': 'true',
'v8_enable_slow_dchecks': 'true',
'v8_optimized_debug': 'false',
'use_custom_libcxx': 'false',
'v8_static_library': 'true',
'v8_enable_pointer_compression_shared_cage ': 'false',
'enable_iterator_debugging': 'true'
}

I'm also asking for it to only build these modules

build_v8_modules = [
'v8_compiler',
'v8_base_without_compiler',
'v8_libplatform',
'v8_libbase',
'torque_generated_initializers',
'torque_generated_definitions',
'v8_bigint',
'v8_heap_base',
'v8_heap_base_headers',
'v8_snapshot',
'cppgc_base',
'inspector'
]

I guess for now i'll modify my build process to bundle the missing .o files into their own lib but I'm not sure how to handle the glibc ones on the mac.

[Ronald Fenner]

Ok after looking into the glib_c ones i found that on the mac v8_use_libm_trig_functions is true on the mac 

this causes this conditional to be defined since i'm building as a stati clibrary

#if defined(V8_USE_LIBM_TRIG_FUNCTIONS)
// To ensure there aren't problems with libm's sin/cos, both implementations
// are shipped. The plan is to transition to libm once we ensure there are no
// compatibility or performance issues.
V8_BASE_EXPORT double fdlibm_sin(double x);
V8_BASE_EXPORT double fdlibm_cos(double x);

#if !defined(BUILDING_V8_BASE_SHARED) && !defined(USING_V8_BASE_SHARED)
inline double libm_sin(double x) { return glibc_sin(x); }
inline double libm_cos(double x) { return glibc_cos(x); }
#else
V8_BASE_EXPORT double libm_sin(double x);
V8_BASE_EXPORT double libm_cos(double x);
#endif
#else
V8_BASE_EXPORT double cos(double x);
V8_BASE_EXPORT double sin(double x);
#endif

so on a mac it should either default to off or  additional check is needed when not using glibc to define it as seomthing else.

I set v8_use_libm_trig_functions to false and was able to link with not problem now.