Re: [PATCH 02/11] gnu: cross-build: i686-w64-mingw32: new cross target.

[Andy Wingo]

On Wed 18 May 2016 00:30, Jan Nieuwenhuizen <address@hidden> writes:

> Yay...looks like we're almost there!

Yeah almost!  Just two (?) more nits -- I seem to keep finding these.
Sorry about that.

> @@ -19,12 +19,17 @@
>  ;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
>  
>  (define-module (gnu packages cross-base)
> -  #:use-module (guix licenses)
> +  #:use-module ((guix licenses) #:prefix license:)
>    #:use-module (gnu packages)
> -  #:use-module (gnu packages gcc)
>    #:use-module (gnu packages base)
> +  #:use-module (gnu packages bash)
> +  #:use-module (gnu packages gawk)
> +  #:use-module (gnu packages gcc)
>    #:use-module (gnu packages commencement)
> +  #:use-module (gnu packages compression)
>    #:use-module (gnu packages linux)
> +  #:use-module (gnu packages mingw)
> +  #:use-module (gnu packages multiprecision)
>    #:use-module (guix packages)
>    #:use-module (guix download)
>    #:use-module (guix utils)

It seems that of these additions, only mingw is necessary.  Can you check?

> +                         ;; libc is false, so we are building xgcc-sans-libc
> +                         ;; Add essential headers from mingw-w64.
> +                         (let ((mingw-source (assoc-ref inputs 
> "mingw-source"))
> +                               (mingw-headers
> +                                (string-append (getcwd) 
> "/mingw-w64-v5.0-rc2/mingw-w64-headers")))
> +                           (system* "tar" "xf" mingw-source)
> +                           ;; We need _mingw.h which will gets built from
> +                           ;; _mingw.h.in by mingw-w64's configure.  We 
> cannot
> +                           ;; configure mingw-w64 until we have
> +                           ;; xgcc-sans-libc; substitute to the rescue.
> +                           (copy-file (string-append mingw-headers 
> "/crt/_mingw.h.in")
> +                                      (string-append mingw-headers 
> "/crt/_mingw.h"))
> +                           (substitute* (string-append mingw-headers 
> "/crt/_mingw.h")
> +                             (("@MINGW_HAS_SECURE_API@") "#define 
> MINGW_HAS_SECURE_API 1"))

Humm, this v5.0-rc2 version is definitely going to break in the future.
OK, we're depending on the internal structure of a tarball, we know it's
going to be a bit fragile, but uf...  If you have the bandwidth, a fix
would be nice.  Maybe:

  (define (unpacked-mingw-dir)
    (match (scandir "." (lambda (name) (string-contains name "mingw-w64")))
      ((mingw-dir)
       (string-append (getcwd) "/" mingw-dir "/mingw-w64-headers"))))

You'll need to add (ice-9 match) and (ice-9 ftw) to #:modules, and you'd
have to invoke this function after unpacking the tarball.

Andy