[bug#47006] [bug#50449] [bug#47006] [PATCH 2/2] gnu: Add zig.

[Sarah Morgensen]

Liliana Marie Prikler <liliana.prikler@gmail.com> writes:

>> 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?

Sure, I'll attach it.

>> 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?

It's a test flag.  You can check out build.zig for all the flags.

>> 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?

I know they do modify some of them, so it would require some care.

>> 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.

Yeah, it's inelegant.  I've never written Zig, so I didn't want to
accidentally introduce any bugs.  If you want to take a stab at it, take
a look at lib/std/zig/system.zig, lines 30-140.

--
Sarah

>From 3cfaaf2023bf5a9915d625963140039c711207ae Mon Sep 17 00:00:00 2001
Message-Id: 
<3cfaaf2023bf5a9915d625963140039c711207ae.1631213249.git.iskarian@mgsn.dev>
From: Liliana Prikler <liliana.prikler@gmail.com>
Date: Thu, 9 Sep 2021 15:32:22 +0200
Subject: [PATCH] gnu: Add zig.

* gnu/packages/zig.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add it here.
---
 gnu/local.mk         |  1 +
 gnu/packages/zig.scm | 96 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 97 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..5f64c8367d
--- /dev/null
+++ b/gnu/packages/zig.scm
@@ -0,0 +1,96 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2021 Liliana Prikler <liliana.prikler@gmail.com>
+;;; Copyright © 2021 Sarah Morgensen <iskarian@mgsn.dev>
+;;;
+;;; 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 uses Clang and LLVM libraries, and (may) use LLVM to compile along
+    ;; with GCC.
+    (inputs
+     `(("clang" ,clang-12)
+       ("lld" ,lld-12)
+       ("llvm" ,llvm-12)))
+    (native-inputs
+     `(("llvm" ,llvm-12)))
+    (arguments
+     `(,@(if (%current-target-system)
+             ;; TODO: set -DZIG_TARGET_CPU for aarch64/armhf
+             `(#:configure-flags (,(string-append "-DZIG_TARGET_TRIPLE="
+                                                  (%current-target-system))))
+             '())
+       #: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"))))))))
+    (native-search-paths
+     ;; XXX: I don't think Zig can distinguishes between C/C++ includes,
+     ;; so just include both.
+     (list
+      (search-path-specification
+       (variable "CPLUS_INCLUDE_PATH")
+       (files '("include/c++" "include")))
+      (search-path-specification
+       (variable "LIBRARY_PATH")
+       (files '("lib" "lib64")))))
+    (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)))

base-commit: a8555e01740d04e714fa9d70008f469f0db55d9a
-- 
2.33.0