Use direct call to external tool

[Et7f3]

I put here because it touch internal of compiler.

I am ok if I have to fix project before we take decision.

[Et7f3]

I forced pushed to remove my commit and GitHub closed it 🤦‍♂️

[nojb]

Another con: -ccopt and -cclib will no longer work in general.

[Et7f3]

Why ?

  -cclib <opt>  Pass option <opt> to the C linker
  -ccopt <opt>  Pass option <opt> to the C compiler and linker

I see pass option in singular form. The argument are already splited and we concatenate them to reconstitute command line.

I have checked with clang:

% clang -Wl,'-Z -Z'
ld: unknown option: -Z -Z
clang: error: linker command failed with exit code 1 (use -v to see invocation)
% clang -Wl,-Z
ld: library not found for -lSystem
clang: error: linker command failed with exit code 1 (use -v to see invocation)

And for gcc:

% x86_64-w64-mingw32-gcc -Wl,'-E -E'
/usr/lib/gcc/x86_64-w64-mingw32/7.4.0/../../../../x86_64-w64-mingw32/bin/ld: unrecognized option '-E -E'
/usr/lib/gcc/x86_64-w64-mingw32/7.4.0/../../../../x86_64-w64-mingw32/bin/ld: use the --help option for usage information
collect2: error: ld returned 1 exit status
% x86_64-w64-mingw32-gcc -Wl,-E
/usr/lib/gcc/x86_64-w64-mingw32/7.4.0/../../../../x86_64-w64-mingw32/bin/ld: warning: --export-dynamic is not supported for PE+ targets, did you mean --export-all-symbols?
/usr/x86_64-w64-mingw32/sys-root/mingw/lib/../lib/libmingw32.a(lib64_libmingw32_a-crt0_c.o): In function `main':
/usr/src/debug/mingw64-x86_64-runtime-6.0.0-1/crt/crt0_c.c:18: undefined reference to `WinMain'
collect2: error: ld returned 1 exit status

Ok if we want the behavior of go then it might be an issue:

-extldflags flags
	Set space-separated flags to pass to the external linker.

The workaround is to split on space maybe in bonus respect quotation or ask to escape space with \x32 for instance

[nojb]

See the discussion at https://github.com/ocaml/ocaml/issues/9482

[dra27]

It's not clear to me from the esy issue you cite - are you simply offended that the process tree is deep, or does it actually cause an issue? The invocation of the linker is not - or certainly shouldn't be - the slow step of builds. It's mentioned in the discussions @nojb's linked, I think a prerequisite to calling these executables directly would be having a complete story for what to do with existing uses of -ccopt and -cclib to allow those fields to be stored as string list in .cma/.cmxa files.

[Et7f3]

I am simply offended. Ok so first I need to convert this in string list https://github.com/ocaml/ocaml/issues/9482#issuecomment-617280154 it should be a simple refactoring.