[bug#47006] [PATCH 2/2] gnu: Add zig.

[Liliana Marie Prikler]

Hi Sarah,

Am Donnerstag, den 09.09.2021, 09:31 -0700 schrieb Sarah Morgensen:
> Liliana Prikler <liliana.prikler@gmail.com> writes:
> 
> > * gnu/packages/zig.scm: New file.
> > * gnu/local.mk (GNU_SYSTEM_MODULES): Add it here.
> > ---
> >  gnu/local.mk         |  1 +
> >  gnu/packages/zig.scm | 83
> > ++++++++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 84 insertions(+)
> >  create mode 100644 gnu/packages/zig.scm
> > 
> > diff --git a/gnu/local.mk b/gnu/local.mk
> > index 2a56c4a9e2..710e5bd9df 100644
> > --- a/gnu/local.mk
> > +++ b/gnu/local.mk
> > @@ -598,6 +598,7 @@ GNU_SYSTEM_MODULES =                            
> > \
> >    %D%/packages/xdisorg.scm                 \
> >    %D%/packages/xorg.scm                            \
> >    %D%/packages/xfce.scm                            \
> > +  %D%/packages/zig.scm                             \
> >    %D%/packages/zile.scm                            \
> >    %D%/packages/zwave.scm                   \
> >                                             \
> > diff --git a/gnu/packages/zig.scm b/gnu/packages/zig.scm
> > new file mode 100644
> > index 0000000000..8b9a863b4d
> > --- /dev/null
> > +++ b/gnu/packages/zig.scm
> > @@ -0,0 +1,83 @@
> > +;;; GNU Guix --- Functional package management for GNU
> > +;;; Copyright © 2021 Leo Prikler <leo.prikler@student.tugraz.at>
> > +;;;
> > +;;; This file is part of GNU Guix.
> > +;;;
> > +;;; GNU Guix is free software; you can redistribute it and/or
> > modify it
> > +;;; under the terms of the GNU General Public License as published
> > by
> > +;;; the Free Software Foundation; either version 3 of the License,
> > or (at
> > +;;; your option) any later version.
> > +;;;
> > +;;; GNU Guix is distributed in the hope that it will be useful,
> > but
> > +;;; WITHOUT ANY WARRANTY; without even the implied warranty of
> > +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > +;;; GNU General Public License for more details.
> > +;;;
> > +;;; You should have received a copy of the GNU General Public
> > License
> > +;;; along with GNU Guix.  If not, see <
> > http://www.gnu.org/licenses/>;.
> > +
> > +(define-module (gnu packages zig)
> > +  #:use-module (guix packages)
> > +  #:use-module (guix git-download)
> > +  #:use-module ((guix licenses) #:prefix license:)
> > +  #:use-module (guix build-system cmake)
> > +  #:use-module (gnu packages)
> > +  #:use-module (gnu packages llvm))
> > +
> > +(define-public zig
> > +  (package
> > +    (name "zig")
> > +    (version "0.8.1")
> > +    (source
> > +     (origin
> > +       (method git-fetch)
> > +       (uri (git-reference
> > +             (url "https://github.com/ziglang/zig.git";)
> > +             (commit version)))
> > +       (file-name (git-file-name name version))
> > +       (sha256
> > +        (base32
> > "147qx7xgj0r353wh5ragzn6kmm1vrf31i8038z3zqwjnqqgqxi6c"))))
> > +    (build-system cmake-build-system)
> > +    ;; Zig is based on and builds itself using the Clang
> > toolchain,
> > +    ;; so add it both as inputs and native-inputs.
> > +    (inputs
> > +     `(("clang" ,clang-12)
> > +       ("lld" ,lld-12)
> > +       ("llvm" ,llvm-12)))
> > +    (native-inputs
> > +     `(("clang" ,clang-12)
> > +       ("lld" ,lld-12)
> > +       ("llvm" ,llvm-12)))
> 
> Zig is perfectly happy compiling itself with GCC, and I believe it's
> the default.  I'm pretty sure it either needs no native tools, or
> only llvm, but I wasn't able to test without compiling a whole GCC
> cross-toolchain.
> 
> For cross compiling, you will also need to add "-DZIG_TARGET_TRIPLE=" 
> to configure flags, and you might want to look into adding
> "-DZIG_TARGET_MCPU" (should take the same values as LLVM's -mcpu) to
> change the baseline CPU for ARM systems since we build for ARM7 by
> default.
I don't think we set mcpu for LLVM or Clang, so that one should be
fine.  As for ZIG_TARGET_TRIPLET and the native inputs, do you have an
amended patch already lying around?

> > +    (arguments
> > +     `(#:tests? #f                       ; no check target
> 
> Did you mean to leave this in? ;)
Pretty sure that was a copypaste error at some point, good catch.

> > +       #:phases
> > +       (modify-phases %standard-phases
> > +         (add-after 'unpack 'save-unpack-dir
> > +           (lambda _
> > +             ;; HACK: Passing unpacked source directory to 'check
> > phase.
> > +             (setenv "ZIG_SOURCE_DIR" (getcwd))
> > +             #t))
> > +         (add-after 'configure 'set-home
> > +           (lambda _
> > +             (setenv "HOME" (getcwd))    ; zig writes to
> > $HOME/.cache
> > +             #t))
> > +         (delete 'check)
> > +         (add-after 'install 'check
> > +           (lambda* (#:key outputs tests? #:allow-other-keys)
> > +             (when tests?
> > +               (with-directory-excursion (getenv "ZIG_SOURCE_DIR")
> > +                 (invoke (string-append (assoc-ref outputs) "out")
> > "/bin/zig"
> > +                         "build" "test"))))))))
> 
> Full tests take quite a while, (it's supposed to be "an hour or two")
> so it may eventually be a good idea to limit what we test, such as
> using "-Dskip-release", which tests without optimization.  IMO that
> should be enough for catching any Guix-based issues with Zig.
Is that a configure flag or a test flag?

> > +    (synopsis "General purpose programming language and
> > toolchain")
> > +    (description "Zig is a general-purpose programming language
> > and
> > +toolchain.  Among other features it provides
> > +@itemize
> > +@item an Optional type instead of null pointers,
> > +@item manual memory management,
> > +@item generic data structures and functions,
> > +@item compile-time reflection and compile-time code execution,
> > +@item integration with C using zig as a C compiler, and
> > +@item concurrency via async functions.
> > +@end itemize")
> > +    (home-page "https://github.com/ziglang/zig";)
> > +    (license license:expat)))
> 
> I don't know if it affects the license, but Zig bundles the source
> for *many* components, such as glibc, musl, mingw, wasi, and from
> LLVM: libcxx, libcxxabi, libunwind, and tsan.
Good catch, could we unbundle some/all of those?

> Zig doesn't seem to honor LIBRARY_PATH, but oddly enough it honors
> NIX_LDFLAGS and NIX_CFLAGS_COMPILE, so if we want it to see external
> libraries, something like this is needed:
> 
> --8<---------------cut here---------------start------------->8---
>          (add-after 'check 'wrap-binary
>            (lambda* (#:key outputs #:allow-other-keys)
>              ;; TODO: test with 'zig cc'
>              (wrap-program (string-append (assoc-ref outputs "out")
> "/bin/zig")
>                `("NIX_LDFLAGS" prefix
>                  ("${LIBRARY_PATH:+-L${LIBRARY_PATH//:/ -L}}"))
>                `("NIX_CFLAGS_COMPILE" prefix
>                  (,(string-append
>                     "${CPLUS_INCLUDE_PATH:+-isystem "
>                     "${CPLUS_INCLUDE_PATH//:/ -isystem }}"))))))
> --8<---------------cut here---------------end--------------->8---
That is rather inelegant.  I'd prefer we patch zig to honor
LIBRARY_PATH, CPLUS_INCLUDE_FLAGS and what other important environment
variables we find.

Thanks