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+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2022-2023 Pierre Langlois <pierre.langlois@gmx.com>
+;;;
+;;; 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 wasm)
+ #:use-module (guix base32)
+ #:use-module (guix gexp)
+ #:use-module (guix packages)
+ #:use-module ((guix licenses) #:prefix license:)
+ #:use-module (guix utils)
+ #:use-module (guix git-download)
+ #:use-module (guix build-system cmake)
+ #:use-module (guix build-system gnu)
+ #:use-module (guix build-system trivial)
+ #:use-module (gnu packages bash)
+ #:use-module (gnu packages llvm)
+ #:use-module (gnu packages python))
+
+(define-public wasi-libc
+ (package
+ (name "wasi-libc")
+ (version "sdk-19")
+ (source
+ (origin
+ (method git-fetch)
+ (uri (git-reference
+ (url "https://github.com/WebAssembly/wasi-libc")
+ (commit (string-append "wasi-" version))
+ (recursive? #t)))
+ (file-name (git-file-name name version))
+ (sha256
+ (base32 "0bnpz8wk9wiic938296gxp4vz820bvpi1w41jksjzz5552hql169"))))
+ (build-system gnu-build-system)
+ (native-inputs (list clang-15))
+ (arguments
+ (list
+ #:tests? #f ;No test suite
+ ;; Firefox uses wasm2c to compile WebAssembly to C code, and it
+ ;; does not support the memory.copy opcode.
+ ;; See https://bugzilla.mozilla.org/show_bug.cgi?id=1773200#c4
+ #:make-flags ''("BULK_MEMORY_SOURCES=")
+ #:phases #~(modify-phases %standard-phases
+ (delete 'configure)
+ (add-before 'build 'set-sysroot-include
+ (lambda _
+ (setenv "C_INCLUDE_PATH"
+ (string-append (getcwd) "/sysroot/include"))))
+ (add-before 'install 'set-install-dir
+ (lambda _
+ (setenv "INSTALL_DIR"
+ (string-append #$output "/wasm32-wasi")))))))
+ (home-page "https://wasi.dev")
+ (synopsis "WASI libc implementation for WebAssembly")
+ (description
+ "WASI Libc is a libc for WebAssembly programs built on top of WASI
+system calls. It provides a wide array of POSIX-compatible C APIs, including
+support for standard I/O, file I/O, filesystem manipulation, memory
+management, time, string, environment variables, program startup, and many
+other APIs.")
+ (license (list
+ ;; For wasi-libc, with LLVM exceptions
+ license:asl2.0
+ ;; For malloc.c.
+ license:cc0
+ ;; For cloudlibc.
+ license:bsd-2
+ ;; For wasi-libc and musl-libc.
+ license:expat))))
+
+(define-public wasm32-wasi-clang-runtime
+ (package (inherit clang-runtime-15)
+ (native-inputs
+ (list clang-15
+ wasi-libc))
+ (inputs (list llvm-15))
+ (arguments
+ (list
+ #:build-type "Release"
+ #:tests? #f
+ ;; Stripping binaries breaks wasm linking, resulting in the following
+ ;; error: "archive has no index; run ranlib to add one".
+ #:strip-binaries? #f
+ #:configure-flags
+ #~(list "-DCMAKE_C_COMPILER=clang"
+ "-DCMAKE_C_COMPILER_TARGET=wasm32-wasi"
+ (string-append
+ "-DCMAKE_SYSROOT=" #$wasi-libc "/wasm32-wasi")
+ (string-append
+ "-DCMAKE_C_FLAGS=-I " #$wasi-libc "/wasm32-wasi/include")
+
+ "-DCOMPILER_RT_OS_DIR=wasi"
+
+ "-DCOMPILER_RT_BAREMETAL_BUILD=On"
+ "-DCOMPILER_RT_DEFAULT_TARGET_ONLY=On"
+
+ ;; WASM only needs libclang_rt.builtins-wasm32.a from
+ ;; compiler-rt.
+ "../source/compiler-rt/lib/builtins")))))
+
+;; FIXME: Ideally we wouldn't need to build a separate compiler because clang
+;; can support multiple targets at runtime. However Guix patches the default
+;; clang with a specific clang-runtime package. It would be good to improve
+;; upstream Guix's support for cross-compiling with clang.
+
+(define clang-from-llvm (@@ (gnu packages llvm) clang-from-llvm))
+(define llvm-monorepo (@@ (gnu packages llvm) llvm-monorepo))
+
+(define-public wasm32-wasi-clang
+ (let ((base (clang-from-llvm llvm-15 wasm32-wasi-clang-runtime)))
+ (package
+ (inherit base)
+ (name "wasm32-wasi-clang")
+ (inputs (modify-inputs (package-inputs base)
+ (prepend wasi-libc)))
+ (arguments
+ (substitute-keyword-arguments (package-arguments base)
+ ((#:configure-flags flags)
+ #~(list "-DCLANG_INCLUDE_TESTS=True"
+ ;; Use a sane default include directory.
+ (string-append "-DC_INCLUDE_DIRS="
+ #$wasi-libc "/wasm32-wasi/include")))
+ ((#:phases phases)
+ `(modify-phases ,phases
+ (delete 'symlink-cfi_ignorelist))))))))
+
+(define-public wasm32-wasi-libcxx
+ (package
+ (name "wasm32-wasi-libcxx")
+ (version (package-version llvm-15))
+ (source
+ (llvm-monorepo version))
+ (build-system cmake-build-system)
+ (arguments
+ (list
+ #:configure-flags #~(list (string-append "-S ../source/runtimes")
+
+ "-DLLVM_ENABLE_RUNTIMES=libcxx;libcxxabi"
+
+ (string-append "-DCMAKE_SYSROOT="
+ #$wasi-libc "/wasm32-wasi")
+
+ (string-append "-DCMAKE_INCLUDE_PATH="
+ #$wasi-libc
+ "/wasm32-wasi/include")
+
+ (string-append "-DCMAKE_STAGING_PREFIX="
+ #$output "/wasm32-wasi")
+
+ "-DCMAKE_C_COMPILER=clang"
+ "-DCMAKE_C_COMPILER_WORKS=ON"
+ "-DCMAKE_CXX_COMPILER=clang++"
+ "-DCMAKE_CXX_COMPILER_WORKS=ON"
+ "-DCMAKE_C_COMPILER_TARGET=wasm32-wasi"
+ "-DCMAKE_CXX_COMPILER_TARGET=wasm32-wasi"
+
+ "-DLIBCXX_LIBDIR_SUFFIX=/wasm32-wasi"
+
+ "-DLIBCXX_ENABLE_EXCEPTIONS=OFF"
+ "-DLIBCXX_ENABLE_SHARED=OFF"
+ "-DLIBCXX_ENABLE_THREADS=OFF"
+ "-DLIBCXX_ENABLE_FILESYSTEM=OFF"
+
+ "-DLIBCXXABI_LIBDIR_SUFFIX=/wasm32-wasi"
+
+ "-DLIBCXXABI_ENABLE_EXCEPTIONS=OFF"
+ "-DLIBCXXABI_ENABLE_SHARED=OFF"
+ "-DLIBCXXABI_ENABLE_THREADS=OFF"
+ "-DLIBCXXABI_ENABLE_FILESYSTEM=OFF")
+ #:tests? #f
+ #:phases #~(modify-phases %standard-phases
+ (add-after 'set-paths 'adjust-CPLUS_INCLUDE_PATH
+ (lambda _
+ (setenv "CPLUS_INCLUDE_PATH"
+ (string-append #$wasi-libc
+ "/wasm32-wasi/include:"
+ (getenv "CPLUS_INCLUDE_PATH"))))))))
+ (native-inputs (list lld python wasm32-wasi-clang))
+ (inputs (list wasi-libc))
+ (home-page "https://libcxx.llvm.org")
+ (synopsis "C++ standard library for WebAssembly")
+ (description
+ "This package provides an implementation of the C++ standard library for
+use with Clang, targeting C++11, C++14 and above. This package targets
+WebAssembly with WASI.")
+ (license license:expat)))
+
+(define-public wasm32-wasi-clang-toolchain
+ (package
+ (name "wasm32-wasi-clang-toolchain")
+ (version (package-version wasm32-wasi-clang))
+ (source
+ #f)
+ (build-system trivial-build-system)
+ (arguments
+ (list
+ #:builder (with-imported-modules '((guix build union)
+ (guix build utils))
+ #~(begin
+ (use-modules (guix build union)
+ (guix build utils))
+ (union-build #$output
+ (list #$wasm32-wasi-clang-runtime
+ #$wasi-libc
+ #$wasm32-wasi-libcxx))
+ (mkdir-p (string-append #$output
+ "/bin"))
+
+ ;; We provide clang and clang++ via a wrapped program that sets
+ ;; include paths correctly so that it does not include paths from
+ ;; the host.
+
+ ;; FIXME: Review how we can provide better support for
+ ;; cross-compiling with clang in Guix, maybe adding support for
+ ;; the CROSS_C_INCLUDE_PATH and CROSS_CPLUS_INCLUDE_PATH
+ ;; environment variables like GCC.
+
+ (for-each (lambda (bin)
+ (symlink (string-append #$wasm32-wasi-clang
+ bin)
+ (string-append #$output
+ bin))
+ (wrap-program (string-append #$output
+ bin)
+ #:sh (string-append #$bash-minimal
+ "/bin/bash")
+ `("C_INCLUDE_PATH"
+ ":" =
+ (,(string-append #$output
+ "/wasm32-wasi/include")))
+ `("CPLUS_INCLUDE_PATH"
+ ":" =
+ ;; Make sure inclure/c++/v1 comes first for #include_next
+ ;; to work.
+ (,(string-append #$output
+ "/wasm32-wasi/include/c++/v1") ,
+ (string-append #$output
+ "/wasm32-wasi/include")))))
+ '("/bin/clang"
+ "/bin/clang++"))
+
+ (symlink (string-append #$lld
+ "/bin/wasm-ld")
+ (string-append #$output
+ "/bin/wasm-ld"))))))
+ (inputs (list bash-minimal
+ lld
+ wasi-libc
+ wasm32-wasi-clang
+ wasm32-wasi-clang-runtime
+ wasm32-wasi-libcxx))
+ (license (cons (package-license wasm32-wasi-clang)
+ (package-license wasi-libc)))
+ (home-page "https://clang.llvm.org")
+ (synopsis
+ "Complete Clang toolchain for C/C++ development, for WebAssembly.")
+ (description
+ "This package provides a complete Clang toolchain for C/C++
+development targeting WebAssembly with WASI. This includes Clang, as well as
+libc, libc++ and wasm-ld.")))