Build fails on macOS: `make: objcopy: No such file or directory`

[snej]

Cloned the repo and ran make:

cc -std=c99 -O3 -Wall -Wextra -pedantic -DBASE64_STATIC_DEFINE -o bin/base64.o -c bin/base64.c
bin/base64.c:544:10: warning: missing field 'has_arg' initializer [-Wmissing-field-initializers]
                { NULL }
                       ^
1 warning generated.
cp -f lib/exports.txt lib/exports.build.txt
cc -std=c99 -O3 -Wall -Wextra -pedantic -DBASE64_STATIC_DEFINE -Ilib  -o lib/arch/avx512/codec.o -c lib/arch/avx512/codec.c
cc -std=c99 -O3 -Wall -Wextra -pedantic -DBASE64_STATIC_DEFINE -Ilib  -o lib/arch/avx2/codec.o -c lib/arch/avx2/codec.c
cc -std=c99 -O3 -Wall -Wextra -pedantic -DBASE64_STATIC_DEFINE -Ilib -o lib/arch/generic/codec.o -c lib/arch/generic/codec.c
cc -std=c99 -O3 -Wall -Wextra -pedantic -DBASE64_STATIC_DEFINE -Ilib  -o lib/arch/neon32/codec.o -c lib/arch/neon32/codec.c
cc -std=c99 -O3 -Wall -Wextra -pedantic -DBASE64_STATIC_DEFINE -Ilib  -o lib/arch/neon64/codec.o -c lib/arch/neon64/codec.c
cc -std=c99 -O3 -Wall -Wextra -pedantic -DBASE64_STATIC_DEFINE -Ilib  -o lib/arch/ssse3/codec.o -c lib/arch/ssse3/codec.c
cc -std=c99 -O3 -Wall -Wextra -pedantic -DBASE64_STATIC_DEFINE -Ilib  -o lib/arch/sse41/codec.o -c lib/arch/sse41/codec.c
cc -std=c99 -O3 -Wall -Wextra -pedantic -DBASE64_STATIC_DEFINE -Ilib  -o lib/arch/sse42/codec.o -c lib/arch/sse42/codec.c
cc -std=c99 -O3 -Wall -Wextra -pedantic -DBASE64_STATIC_DEFINE -Ilib  -o lib/arch/avx/codec.o -c lib/arch/avx/codec.c
cc -std=c99 -O3 -Wall -Wextra -pedantic -DBASE64_STATIC_DEFINE -Ilib -o lib/lib.o -c lib/lib.c
cc -std=c99 -O3 -Wall -Wextra -pedantic -DBASE64_STATIC_DEFINE -Ilib -o lib/codec_choose.o -c lib/codec_choose.c
cc -std=c99 -O3 -Wall -Wextra -pedantic -DBASE64_STATIC_DEFINE -Ilib -o lib/tables/tables.o -c lib/tables/tables.c
ld -r -o lib/libbase64.o lib/arch/avx512/codec.o lib/arch/avx2/codec.o lib/arch/generic/codec.o lib/arch/neon32/codec.o lib/arch/neon64/codec.o lib/arch/ssse3/codec.o lib/arch/sse41/codec.o lib/arch/sse42/codec.o lib/arch/avx/codec.o lib/lib.o lib/codec_choose.o lib/tables/tables.o
objcopy --keep-global-symbols=lib/exports.build.txt lib/libbase64.o
make: objcopy: No such file or directory
make: *** [lib/libbase64.o] Error 1

Never heard of objcopy before; looks like it's part of a GNU Binary Utilities library. I'm not sure if this tool supports macOS, i.e. Mach-O executables, or how to install it if it does.

(I'm running macOS 14.3.1 on an M1 MacBook Pro.)

[snej]

I just noticed that CMake is supported, and builds fine for me, so I'll be using that instead of make. It would still be nice if the Makefile were made compatible.

[aklomp]

The objcopy step is not really necessary and can be commented out. It hides any symbols not listed in lib/exports.build.txt, so that internal symbols are not exposed by accident.

The objcopy step is a bit of a hack and shouldn't be necessary once symbol visibility is handled by good design and language features. See also #54.

Keeping this issue open as a reminder that the Makefile build is broken on MacOS.