Re: [feature/native-comp] breakage on build

[Eli Zaretskii <eliz@gnu.org>]

> From: Phillip Lord <phillip.lord@russet.org.uk>
> Date: Fri, 05 Feb 2021 21:29:53 +0000
> Cc: emacs-devel@gnu.org
> 
> Second, is native-comp. It appears that, as well as the DLLs, libgccjit
> also needs some tools locally (as, ld at least). I don't know what those
> all are yet, and that is going to need some working out.

I think libgccjit assumes that the user has a fully-functional
installation of GCC, Binutils, and runtime libraries in the "usual
places".  The library names you saw in the error message you posted
earlier (the names which begin with "-l", like -lmingw32 and -lgcc_s,
and object files like crtbegin.o), are the set of the runtime
libraries and object files needed for native-compilation.

As for their places, GCC on Windows generally looks for its files
relatively to the parent directory of the directory where its
executable gcc.exe lives.  Which means you will have to have
directories like lib/, libexec/, and share/ under the same parent
directory where you have bin/libgccjit-0.dll, and you will need to
populate those by the programs and libraries GCC uses when compiling.
For example, I assume you will have to have
libexec/gcc/mingw32/10.0.0/cc1.exe (assuming your GCC version is
10.0.0).  Is this the kind of tree you have there?

In any case, an important command to see if you have a required file
in place is "gcc -print-file-name=LIBRARY".  If this shows a full
absolute file name, you are set with regards to that LIBRARY; if it
just echoes LIBRARY as you typed it, it means GCC cannot find it.