;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2019 Marius Bakke <mbakke@fastmail.com>
;;;
;;; 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 chromium)
  #:use-module ((guix licenses) #:prefix license:)
  #:use-module (guix packages)
  #:use-module (guix gexp)
  #:use-module (guix store)
  #:use-module (guix monads)
  #:use-module (guix download)
  #:use-module (guix git-download)
  #:use-module (guix utils)
  #:use-module (guix build-system gnu)
  #:use-module (gnu packages)
  #:use-module (gnu packages assembly)
  #:use-module (gnu packages base)
  #:use-module (gnu packages bison)
  #:use-module (gnu packages build-tools)
  #:use-module (gnu packages compression)
  #:use-module (gnu packages cups)
  #:use-module (gnu packages curl)
  #:use-module (gnu packages fontutils)
  #:use-module (gnu packages gcc)
  #:use-module (gnu packages ghostscript)
  #:use-module (gnu packages gl)
  #:use-module (gnu packages glib)
  #:use-module (gnu packages gnome)
  #:use-module (gnu packages gnuzilla)
  #:use-module (gnu packages gperf)
  #:use-module (gnu packages gtk)
  #:use-module (gnu packages icu4c)
  #:use-module (gnu packages image)
  #:use-module (gnu packages libevent)
  #:use-module (gnu packages libffi)
  #:use-module (gnu packages linux)
  #:use-module (gnu packages kerberos)
  #:use-module (gnu packages ninja)
  #:use-module (gnu packages node)
  #:use-module (gnu packages pciutils)
  #:use-module (gnu packages pkg-config)
  #:use-module (gnu packages pulseaudio)
  #:use-module (gnu packages python)
  #:use-module (gnu packages python-web)
  #:use-module (gnu packages python-xyz)
  #:use-module (gnu packages regex)
  #:use-module (gnu packages serialization)
  #:use-module (gnu packages speech)
  #:use-module (gnu packages tls)
  #:use-module (gnu packages valgrind)
  #:use-module (gnu packages vulkan)
  #:use-module (gnu packages video)
  #:use-module (gnu packages xiph)
  #:use-module (gnu packages xml)
  #:use-module (gnu packages xdisorg)
  #:use-module (gnu packages xorg))

(define %preserved-third-party-files
  '("base/third_party/dmg_fp" ;X11-style
    "base/third_party/dynamic_annotations" ;BSD-2
    "base/third_party/icu" ;Unicode, X11-style
    "base/third_party/superfasthash" ;BSD-3
    "base/third_party/symbolize" ;BSD-3
    "base/third_party/xdg_mime" ;LGPL2.1+ or Academic 2.0
    "base/third_party/xdg_user_dirs" ;Expat
    "chrome/third_party/mozilla_security_manager" ;MPL-1.1/GPL2+/LGPL2.1+
    "courgette/third_party/bsdiff" ;BSD-2, BSD protection license
    "courgette/third_party/divsufsort" ;Expat
    "net/third_party/http2" ;BSD-3
    "net/third_party/mozilla_security_manager" ;MPL-1.1/GPL2+/LGPL2.1+
    "net/third_party/nss" ;MPL-2.0
    "net/third_party/quic" ;BSD-3
    "net/third_party/spdy" ;BSD-3
    "net/third_party/uri_template" ;ASL2.0
    "third_party/abseil-cpp" ;ASL2.0
    "third_party/adobe/flash/flapper_version.h" ;no license, trivial
    "third_party/angle" ;BSD-3
    "third_party/angle/src/common/third_party/base" ;BSD-3
    "third_party/angle/src/common/third_party/smhasher" ;Public domain
    "third_party/angle/src/common/third_party/xxhash" ;BSD-2
    "third_party/angle/src/third_party/compiler" ;BSD-2
    "third_party/angle/src/third_party/libXNVCtrl" ;Expat
    "third_party/angle/src/third_party/trace_event" ;BSD-3
    "third_party/angle/third_party/glslang" ;BSD-3
    "third_party/angle/third_party/spirv-headers" ;Expat
    "third_party/angle/third_party/spirv-tools" ;Expat
    "third_party/angle/third_party/vulkan-headers" ;ASL2.0
    "third_party/angle/third_party/vulkan-loader" ;ASL2.0
    "third_party/angle/third_party/vulkan-tools" ;ASL2.0
    "third_party/angle/third_party/vulkan-validation-layers" ;ASL2.0
    "third_party/apple_apsl" ;APSL2.0
    "third_party/blink" ;BSD-3
    "third_party/boringssl" ;OpenSSL/ISC (Google additions are ISC)
    "third_party/boringssl/src/third_party/fiat" ;Expat
    "third_party/breakpad" ;BSD-3
    "third_party/brotli" ;Expat
    "third_party/cacheinvalidation" ;ASL2.0
    "third_party/catapult" ;BSD-3
    "third_party/catapult/common/py_vulcanize/third_party/rcssmin" ;ASL2.0
    "third_party/catapult/common/py_vulcanize/third_party/rjsmin" ;ASL2.0
    "third_party/catapult/third_party/polymer" ;BSD-3
    "third_party/catapult/tracing/third_party/d3" ;BSD-3
    "third_party/catapult/tracing/third_party/gl-matrix" ;Expat
    "third_party/catapult/tracing/third_party/jszip" ;Expat or GPL3
    "third_party/catapult/tracing/third_party/mannwhitneyu" ;Expat
    "third_party/catapult/tracing/third_party/oboe" ;BSD-2
    "third_party/catapult/tracing/third_party/pako" ;Expat
    "third_party/ced" ;BSD-3
    "third_party/cld_3" ;ASL2.0
    "third_party/closure_compiler" ;ASL2.0
    "third_party/crashpad" ;ASL2.0
    "third_party/crashpad/crashpad/third_party/zlib/zlib_crashpad.h" ;Zlib
    "third_party/crc32c" ;BSD-3
    "third_party/cros_system_api" ;BSD-3
    "third_party/dom_distiller_js" ;BSD-3
    "third_party/fips181" ;BSD-3
    "third_party/flatbuffers" ;ASL2.0
    "third_party/google_input_tools" ;ASL2.0
    "third_party/google_input_tools/third_party/closure_library" ;ASL2.0
    "third_party/google_input_tools/third_party/closure_library/third_party/closure" ;Expat
    "third_party/googletest" ;BSD-3
    "third_party/hunspell" ;MPL1.1/GPL2+/LGPL2.1+
    "third_party/iccjpeg" ;IJG
    "third_party/inspector_protocol" ;BSD-3
    "third_party/jinja2" ;BSD-3
    "third_party/jstemplate" ;ASL2.0
    "third_party/khronos" ;Expat, SGI
    "third_party/leveldatabase" ;BSD-3
    "third_party/libXNVCtrl" ;Expat
    "third_party/libaddressinput" ;ASL2.0
    "third_party/libaom" ;BSD-2 or "Alliance for Open Media Patent License 1.0"
    "third_party/libaom/source/libaom/third_party/vector" ;Expat
    "third_party/libaom/source/libaom/third_party/x86inc" ;ISC
    "third_party/libjingle_xmpp" ;BSD-3
    "third_party/libphonenumber" ;ASL2.0
    "third_party/libsecret" ;LGPL2.1+
    "third_party/libsrtp" ;BSD-3
    "third_party/libsync" ;ASL2.0
    "third_party/libudev" ;LGPL2.1+
    "third_party/libwebm" ;BSD-3
    "third_party/libxml/chromium" ;BSD-3
    "third_party/libyuv" ;BSD-3
    "third_party/lss" ;BSD-3
    "third_party/markupsafe" ;BSD-3
    "third_party/mesa_headers" ;Expat, SGI
    "third_party/metrics_proto" ;BSD-3
    "third_party/modp_b64" ;BSD-3
    "third_party/nasm" ;BSD-2
    "third_party/node" ;Expat
    "third_party/node/node_modules/polymer-bundler/lib/third_party/UglifyJS2" ;BSD-2
    "third_party/ots" ;BSD-3
    "third_party/pdfium" ;BSD-3
    "third_party/pdfium/third_party/agg23" ;Expat
    "third_party/pdfium/third_party/base" ;BSD-3
    "third_party/pdfium/third_party/bigint" ;Public domain, BSD-3
    "third_party/pdfium/third_party/skia_shared" ;BSD-3
    "third_party/pdfium/third_party/freetype/include/pstables.h" ;FreeType
    "third_party/ply" ;BSD-3
    "third_party/polymer" ;BSD-3
    "third_party/protobuf" ;BSD-3
    "third_party/protobuf/third_party/six" ;Expat
    "third_party/pyjson5" ;ASL2.0
    "third_party/qcms" ;Expat
    "third_party/rnnoise" ;BSD-3
    "third_party/s2cellid" ;ASL2.0
    "third_party/sfntly" ;ASL2.0
    "third_party/skia" ;BSD-3
    "third_party/skia/third_party/gif" ;MPL1.1/GPL2+/LGPL2.1+
    "third_party/skia/third_party/skcms" ;BSD-3
    "third_party/skia/third_party/vulkan" ;BSD-3
    "third_party/smhasher" ;Expat, public domain
    "third_party/speech-dispatcher" ;GPL2+
    "third_party/spirv-headers" ;ASL2.0
    "third_party/SPIRV-Tools" ;ASL2.0
    "third_party/sqlite" ;Public domain
    "third_party/ungoogled" ;BSD-3
    "third_party/usb_ids" ;BSD-3
    "third_party/usrsctp" ;BSD-2
    "third_party/web-animations-js" ;ASL2.0
    "third_party/webdriver" ;ASL2.0
    "third_party/webrtc" ;BSD-3
    "third_party/webrtc/common_audio/third_party/fft4g" ;Non-copyleft
    "third_party/webrtc/common_audio/third_party/spl_sqrt_floor" ;Public domain
    "third_party/webrtc/modules/third_party/fft" ;Non-copyleft
    "third_party/webrtc/modules/third_party/g711" ;Public domain
    "third_party/webrtc/modules/third_party/g722" ;Public domain
    "third_party/webrtc/rtc_base/third_party/base64" ;Non-copyleft
    "third_party/webrtc/rtc_base/third_party/sigslot" ;Public domain
    "third_party/widevine/cdm/widevine_cdm_version.h" ;BSD-3
    "third_party/widevine/cdm/widevine_cdm_common.h" ;BSD-3
    "third_party/woff2" ;ASL2.0
    "third_party/xdg-utils" ;Expat
    "third_party/yasm/run_yasm.py" ;BSD-2 or BSD-3
    "third_party/zlib/google" ;BSD-3
    "url/third_party/mozilla" ;BSD-3, MPL1.1/GPL2+/LGPL2.1+
    "v8/src/third_party/utf8-decoder" ;Expat
    "v8/src/third_party/valgrind" ;BSD-4
    "v8/third_party/inspector_protocol" ;BSD-3
    "v8/third_party/v8/builtins")) ;PSFL

(define* (computed-origin-method gexp-promise hash-algo hash
                                 #:optional (name "source")
                                 #:key (system (%current-system))
                                 (guile (default-guile)))
  "Return a derivation that executes the G-expression that results
from forcing GEXP-PROMISE."
  (mlet %store-monad ((guile (package->derivation guile system)))
    (gexp->derivation (or name "computed-origin")
                      (force gexp-promise)
                      #:system system
                      #:guile-for-build guile)))

(define %chromium-version "72.0.3626.81")
(define %ungoogled-revision "f9b9074c322a67b04baf0982797cd7b7e09614b5")

;; This is a computed origin that does the following:
;; 1) Runs the Ungoogled scripts on a pristine Chromium tarball.
;; 2) Prunes all third_party folders that are not explicitly preserved.
;; 3) Adjusts "GN" build files such that system libraries are preferred.
(define ungoogled-chromium-source
  (let* ((chromium-source
          (origin
            (method url-fetch)
            (uri (string-append "https://commondatastorage.googleapis.com"
                                "/chromium-browser-official/chromium-"
                                %chromium-version ".tar.xz"))
            (sha256
             (base32
              "01l0vlvcckpag376mjld7qprv63l0z8li689k0h6v3h0i7irzs6z"))))
         (ungoogled-source
          (origin
            (method git-fetch)
            (uri (git-reference (url "https://github.com/mbakke/ungoogled-chromium")
                                (commit %ungoogled-revision)))
            (file-name (git-file-name "ungoogled-chromium"
                                      (string-take %ungoogled-revision 7)))
            (sha256
             (base32
              "0gmk1n3i7lbm7rw8zl4df171yhvrlimj8ksj096bf2dlfhbd44rb")))))

    (origin
      (method computed-origin-method)
      (file-name (string-append "ungoogled-chromium-" %chromium-version ".tar.xz"))
      (sha256 #f)
      (uri
       (delay
         (with-imported-modules '((guix build utils))
           #~(begin
               (use-modules (guix build utils))
               (let ((chromium-dir    (string-append "chromium-" #$%chromium-version))
                     (preserved-files (list #$@%preserved-third-party-files)))

                 (mkdir "/tmp/bin")
                 (set-path-environment-variable
                  "PATH" '("bin")
                  (list "/tmp"
                        #+(canonical-package patch)
                        #+(canonical-package xz)
                        #+(canonical-package tar)
                        #+python-2
                        #+python))

                 (copy-recursively #+ungoogled-source "/tmp/ungoogled")

                 (with-directory-excursion "/tmp/ungoogled"

                   (format #t "Unpacking chromium tarball...~%")
                   (force-output)
                   (invoke "tar" "xf" #+chromium-source)

                   (format #t "Ungooglifying...~%")
                   (force-output)
                   (invoke "python3" "run_buildkit_cli.py" "prune"
                           "-b" "config_bundles/guix" chromium-dir)
                   (invoke "python3" "run_buildkit_cli.py" "patches" "apply"
                           "-b" "config_bundles/guix" chromium-dir)
                   (invoke "python3" "run_buildkit_cli.py" "domains" "apply"
                           "-b" "config_bundles/linux_rooted"
                           "-c" "/tmp/domainscache.tar.gz" chromium-dir)

                   (with-directory-excursion chromium-dir
                     (format #t "Pruning third party files...~%")
                     (force-output)
                     (apply invoke "python"
                             "build/linux/unbundle/remove_bundled_libraries.py"
                             "--do-remove" preserved-files)

                     (format #t "Replacing GN files...~%")
                     (force-output)
                     (invoke "python3" "build/linux/unbundle/replace_gn_files.py"
                             "--system-libraries" "ffmpeg" "flac" "fontconfig"
                             "freetype" "harfbuzz-ng" "icu" "libdrm" "libevent"
                             "libjpeg" "libpng" "libvpx" "libwebp" "libxml"
                             "libxslt" "openh264" "opus" "re2" "snappy" "yasm"
                             "zlib"))

                   (format #t (string-append "Packing new Ungoogled tarball ...~%"))
                   (force-output)
                   (invoke "tar" "cvfa" #$output
                           ;; Avoid non-determinism in the archive.
                           "--mtime=@0"
                           "--owner=root:0"
                           "--group=root:0"
                           "--sort=name"
                           chromium-dir)

                   #t)))))))))

(define opus+custom
  (package/inherit opus
    (name "opus+custom")
    (arguments
     (substitute-keyword-arguments (package-arguments opus)
       ((#:configure-flags flags ''())
        ;; Opus Custom is an optional extension of the Opus
        ;; specification that allows for unsupported frame
        ;; sizes.  Chromium requires that this is enabled.
        `(cons "--enable-custom-modes"
               ,flags))))))

(define libvpx/chromium
  ;; Chromium 66 and later requires an unreleased libvpx, so we take the
  ;; commit from "third_party/libvpx/README.chromium" in the tarball.
  (let ((version (package-version libvpx))
        (commit "e188b5435de71bcd602c378f1ac0441111f0f915")
        (revision "0"))
    (package/inherit libvpx
      (name "libvpx-chromium")
      (version (git-version version revision commit))
      (source (origin
                (method git-fetch)
                (uri (git-reference
                      (url "https://chromium.googlesource.com/webm/libvpx")
                      (commit commit)))
                (file-name (git-file-name name version))
                (sha256
                 (base32
                  "0v7lzvgy45zh7zwzmmzkvbcqmhs4xa97z0h97hd3j6myrxcfz1n9")))))))

;; Transitional package until HarfBuzz 2.2 is available in Guix master branch.
(define harfbuzz/chromium
  (package/inherit harfbuzz
    (version "2.2.0")
    (source (origin
              (inherit (package-source harfbuzz))
              (uri (string-append "https://www.freedesktop.org/software/harfbuzz"
                                  "/release/harfbuzz-" version ".tar.bz2"))
              (sha256
               (base32
                "047q63jr513azf3g1y7f5xn60b4jdjs9zsmrx04sfw5rasyzrk5p"))))))

(define-public ungoogled-chromium
  (package
    (name "ungoogled-chromium")
    (version %chromium-version)
    (synopsis "Graphical web browser")
    (source ungoogled-chromium-source)
    (build-system gnu-build-system)
    (arguments
     `(#:tests? #f
       ;; FIXME: There is a "gn" option specifically for setting -rpath, but
       ;; it overrides the RUNPATH set by the linker.
       #:validate-runpath? #f
       #:modules ((guix build gnu-build-system)
                  (guix build utils)
                  (ice-9 ftw)
                  (ice-9 regex)
                  (srfi srfi-26))
       #:configure-flags
       ;; See tools/gn/docs/cookbook.md and
       ;; https://www.chromium.org/developers/gn-build-configuration
       ;; for usage.  Run "./gn args . --list" in the Release
       ;; directory for an exhaustive list of supported flags.
       ;; (Note: The 'configure' phase will do that for you.)
       (list "is_debug=false"
             "use_gold=false"
             "use_lld=false"
             "linux_use_bundled_binutils=false"
             "use_custom_libcxx=false"
             "use_sysroot=false"
             "enable_precompiled_headers=false"
             "goma_dir=\"\""
             "enable_nacl=false"
             "enable_nacl_nonsfi=false"
             "use_allocator=\"none\""   ;don't use tcmalloc
             "use_unofficial_version_number=false"

             ;; Define a custom toolchain that simply looks up CC, AR and
             ;; friends from the environment.
             "custom_toolchain=\"//build/toolchain/linux/unbundle:default\""
             "host_toolchain=\"//build/toolchain/linux/unbundle:default\""

             ;; Don't assume it's clang.
             "is_clang=false"

             ;; Optimize for building everything at once, as opposed to
             ;; incrementally for development.  See "docs/jumbo.md".
             "use_jumbo_build=true"

             ;; Disable type-checking for the Web UI to avoid a Java dependency.
             "closure_compile=false"

             ;; Disable debugging features to save space.
             "blink_symbol_level=0"
             "enable_iterator_debugging=false"

             ;; Some of the unbundled libraries throws deprecation
             ;; warnings, etc.  Ignore it.
             "treat_warnings_as_errors=false"

             ;; Don't add any API keys.  End users can set them in the
             ;; environment if desired.  See
             ;; <https://www.chromium.org/developers/how-tos/api-keys>.
             "use_official_google_api_keys=false"

             ;; Disable "safe browsing", which pulls in a dependency on
             ;; the nonfree "unrar" program (as of m66).
             "safe_browsing_mode=0"

             ;; Disable "field trials".
             "fieldtrial_testing_like_official_build=true"

             ;; Ungoogled components.
             "enable_mdns=false"
             "enable_one_click_signin=false"
             "enable_reading_list=false"
             "enable_remoting=false"
             "enable_reporting=false"
             "enable_service_discovery=false"
             "enable_swiftshader=false"
             "use_vaapi=true"

             ;; Use system libraries where possible.
             "use_system_freetype=true"
             "use_system_harfbuzz=true"
             "use_system_lcms2=true"
             "use_system_libdrm=true"
             "use_system_libjpeg=true"
             "use_system_libpng=true"
             ;;"use_system_libsync=true"
             "use_system_zlib=true"

             "use_gnome_keyring=false"  ;deprecated by libsecret
             "use_openh264=true"
             "use_pulseaudio=true"
             "link_pulseaudio=true"

             ;; Don't arbitrarily restrict formats supported by system ffmpeg.
             "proprietary_codecs=true"
             "ffmpeg_branding=\"Chrome\""

             ;; WebRTC stuff.
             "rtc_use_h264=true"
             ;; Don't use bundled sources.
             "rtc_build_json=false"
             "rtc_build_libevent=false"
             "rtc_build_libvpx=false"
             "rtc_build_opus=false"
             "rtc_build_ssl=false"

             "rtc_build_libsrtp=true"   ;FIXME: fails to find headers
             "rtc_build_usrsctp=true"   ;TODO: package this
             (string-append "rtc_jsoncpp_root=\""
                            (assoc-ref %build-inputs "jsoncpp")
                            "/include/jsoncpp/json\"")
             (string-append "rtc_ssl_root=\""
                            (assoc-ref %build-inputs "openssl")
                            "/include/openssl\""))
       #:phases
       (modify-phases %standard-phases
         (add-after 'unpack 'patch-stuff
           (lambda* (#:key inputs #:allow-other-keys)
             (substitute* "printing/cups_config_helper.py"
               (("cups_config =.*")
                (string-append "cups_config = '" (assoc-ref inputs "cups")
                               "/bin/cups-config'\n")))

             (substitute*
                 '("base/process/launch_posix.cc"
                   "base/third_party/dynamic_annotations/dynamic_annotations.c"
                   "sandbox/linux/seccomp-bpf/sandbox_bpf.cc"
                   "sandbox/linux/services/credentials.cc"
                   "sandbox/linux/services/namespace_utils.cc"
                   "sandbox/linux/services/syscall_wrappers.cc"
                   "sandbox/linux/syscall_broker/broker_host.cc")
               (("include \"base/third_party/valgrind/") "include \"valgrind/"))

             (for-each (lambda (file)
                         (substitute* file
                           ;; Fix opus include path.
                           ;; Do not substitute opus_private.h.
                           (("#include \"opus\\.h\"")
                            "#include \"opus/opus.h\"")
                           (("#include \"opus_custom\\.h\"")
                            "#include \"opus/opus_custom.h\"")
                           (("#include \"opus_defines\\.h\"")
                            "#include \"opus/opus_defines.h\"")
                           (("#include \"opus_multistream\\.h\"")
                            "#include \"opus/opus_multistream.h\"")
                           (("#include \"opus_types\\.h\"")
                            "#include \"opus/opus_types.h\"")))
                       (find-files (string-append "third_party/webrtc/modules"
                                                  "/audio_coding/codecs/opus")))

             (substitute* "chrome/common/chrome_paths.cc"
               (("/usr/share/chromium/extensions")
                ;; TODO: Add ~/.guix-profile.
                "/run/current-system/profile/share/chromium/extensions"))

             ;; XXX: Should be unnecessary when use_system_lcms2=true.
             (substitute* "third_party/pdfium/core/fxcodec/codec/ccodec_iccmodule.h"
               (("include \"third_party/lcms/include/lcms2\\.h\"")
                "include \"lcms2.h\""))

             (substitute*
                 "third_party/breakpad/breakpad/src/common/linux/libcurl_wrapper.h"
               (("include \"third_party/curl") "include \"curl"))

             (substitute* "third_party/webrtc/rtc_base/strings/json.h"
               (("#include \"third_party/jsoncpp/") "#include \"json/"))

             (substitute* "media/base/decode_capabilities.cc"
               (("third_party/libvpx/source/libvpx/") ""))

             (substitute* "ui/gfx/skia_util.h"
               (("third_party/vulkan/include/") ""))

             ;; Building chromedriver embeds some files using the ZIP
             ;; format which doesn't support timestamps before
             ;; 1980. Therefore, advance the timestamps of the files
             ;; which are included so that building chromedriver
             ;; works.
             (let ((circa-1980 (* 10 366 24 60 60)))
               (for-each (lambda (file)
                           (utime file circa-1980 circa-1980))
                         '("chrome/test/chromedriver/extension/background.js"
                           "chrome/test/chromedriver/extension/manifest.json")))

             #t))
         (add-before 'configure 'prepare-build-environment
           (lambda* (#:key inputs #:allow-other-keys)

             ;; Make sure the right build tools are used.
             (setenv "AR" "ar") (setenv "NM" "nm")
             (setenv "CC" "gcc") (setenv "CXX" "g++")

             ;; Work around <https://bugs.gnu.org/30756>.
             (unsetenv "C_INCLUDE_PATH")
             (unsetenv "CPLUS_INCLUDE_PATH")

             ;; TODO: pre-compile instead. Avoids a race condition.
             (setenv "PYTHONDONTWRITEBYTECODE" "1")

             ;; XXX: How portable is this.
             (mkdir-p "third_party/node/linux/node-linux-x64")
             (symlink (string-append (assoc-ref inputs "node") "/bin")
                      "third_party/node/linux/node-linux-x64/bin")

             #t))
         (replace 'configure
           (lambda* (#:key configure-flags #:allow-other-keys)
             (let ((args (string-join configure-flags " ")))
               ;; Generate ninja build files.
               (invoke "gn" "gen" "out/Release"
                       (string-append "--args=" args))

               ;; Print the full list of supported arguments as well as
               ;; their current status for convenience.
               (format #t "Dumping configure flags...\n")
               (invoke "gn" "args" "out/Release" "--list"))))
         (replace 'build
           (lambda* (#:key outputs #:allow-other-keys)
             (invoke "ninja" "-C" "out/Release"
                     "-j" (number->string (parallel-job-count))
                     "chrome"
                     "chromedriver")))
         (replace 'install
           (lambda* (#:key inputs outputs #:allow-other-keys)
             (let* ((out            (assoc-ref outputs "out"))
                    (bin            (string-append out "/bin"))
                    (exe            (string-append bin "/chromium"))
                    (lib            (string-append out "/lib"))
                    (man            (string-append out "/share/man/man1"))
                    (applications   (string-append out "/share/applications"))
                    (install-regexp (make-regexp "\\.(bin|pak)$"))
                    (locales        (string-append lib "/locales"))
                    (resources      (string-append lib "/resources"))
                    (preferences    (assoc-ref inputs "master-preferences"))
                    (gtk+           (assoc-ref inputs "gtk+"))
                    (mesa           (assoc-ref inputs "mesa"))
                    (nss            (assoc-ref inputs "nss"))
                    (udev           (assoc-ref inputs "udev"))
                    (sh             (which "sh")))

               (substitute* '("chrome/app/resources/manpage.1.in"
                              "chrome/installer/linux/common/desktop.template")
                 (("@@MENUNAME@@") "Chromium")
                 (("@@PACKAGE@@") "chromium")
                 (("/usr/bin/@@USR_BIN_SYMLINK_NAME@@") exe))

               (mkdir-p man)
               (copy-file "chrome/app/resources/manpage.1.in"
                          (string-append man "/chromium.1"))

               (mkdir-p applications)
               (copy-file "chrome/installer/linux/common/desktop.template"
                          (string-append applications "/chromium.desktop"))

               (mkdir-p lib)
               (copy-file preferences (string-append lib "/master_preferences"))

               (with-directory-excursion "out/Release"
                 (for-each (lambda (file)
                             (install-file file lib))
                           (scandir "." (cut regexp-exec install-regexp <>)))
                 (copy-file "chrome" (string-append lib "/chromium"))

                 ;; TODO: Install icons from "../../chrome/app/themes" into
                 ;; "out/share/icons/hicolor/$size".
                 (install-file
                  "product_logo_48.png"
                  (string-append out "/share/icons/48x48/chromium.png"))

                 (copy-recursively "locales" locales)
                 (copy-recursively "resources" resources)

                 (mkdir-p bin)
                 (symlink "../lib/chromium" exe)
                 (install-file "chromedriver" bin)

                 (wrap-program exe
                   ;; TODO: Get these in RUNPATH.
                   `("LD_LIBRARY_PATH" ":" prefix
                     (,(string-append lib ":" nss "/lib/nss:" gtk+ "/lib:"
                                      mesa "/lib:" udev "/lib")))
                   ;; Avoid file manager crash.  See <https://bugs.gnu.org/26593>.
                   `("XDG_DATA_DIRS" ":" prefix (,(string-append gtk+ "/share"))))
                 #t)))))))
    (native-inputs
     `(("bison" ,bison)
       ("gcc" ,gcc-8)
       ("gn" ,gn)
       ("gperf" ,gperf)
       ("ninja" ,ninja)
       ("node" ,node)
       ("pkg-config" ,pkg-config)
       ("which" ,which)
       ("yasm" ,yasm)

       ;; This file contains defaults for new user profiles.
       ("master-preferences" ,(local-file "aux-files/chromium/master-preferences.json"))

       ("python-beautifulsoup4" ,python2-beautifulsoup4)
       ("python-html5lib" ,python2-html5lib)
       ("python" ,python-2)))
    (inputs
     `(("alsa-lib" ,alsa-lib)
       ("atk" ,atk)
       ("cups" ,cups)
       ("curl" ,curl)
       ("dbus" ,dbus)
       ("dbus-glib" ,dbus-glib)
       ("expat" ,expat)
       ("flac" ,flac)
       ("ffmpeg" ,ffmpeg)
       ("fontconfig" ,fontconfig)
       ("freetype" ,freetype)
       ("gdk-pixbuf" ,gdk-pixbuf)
       ("glib" ,glib)
       ("gtk+" ,gtk+)
       ("harfbuzz" ,harfbuzz/chromium)
       ("icu4c" ,icu4c)
       ("jsoncpp" ,jsoncpp)
       ("lcms" ,lcms)
       ("libevent" ,libevent)
       ("libffi" ,libffi)
       ("libjpeg-turbo" ,libjpeg-turbo)
       ("libpng" ,libpng)
       ("libva" ,libva)
       ("libvpx" ,libvpx/chromium)
       ("libwebp" ,libwebp)
       ("libx11" ,libx11)
       ("libxcb" ,libxcb)
       ("libxcomposite" ,libxcomposite)
       ("libxcursor" ,libxcursor)
       ("libxdamage" ,libxdamage)
       ("libxext" ,libxext)
       ("libxfixes" ,libxfixes)
       ("libxi" ,libxi)
       ("libxml2" ,libxml2)
       ("libxrandr" ,libxrandr)
       ("libxrender" ,libxrender)
       ("libxscrnsaver" ,libxscrnsaver)
       ("libxslt" ,libxslt)
       ("libxtst" ,libxtst)
       ("mesa" ,mesa)
       ("minizip" ,minizip)
       ("mit-krb5" ,mit-krb5)
       ("nss" ,nss)
       ("openh264" ,openh264)
       ("openjpeg" ,openjpeg)                          ;PDFium only
       ("openssl" ,openssl)
       ("opus" ,opus+custom)
       ("pango" ,pango)
       ("pciutils" ,pciutils)
       ("pulseaudio" ,pulseaudio)
       ("re2" ,re2)
       ("snappy" ,snappy)
       ("speech-dispatcher" ,speech-dispatcher)
       ("udev" ,eudev)
       ("valgrind" ,valgrind)
       ("vulkan-headers" ,vulkan-headers)))
    (home-page "https://www.chromium.org/")
    (description
     "Ungoogled-Chromium is the Chromium web browser, sans integration with
Google web services.")
    ;; Chromium is developed as BSD-3, but bundles a large number of third-party
    ;; components with other licenses.  For full information, see chrome://credits.
    (license (list license:bsd-3
                   license:bsd-2
                   license:expat
                   license:asl2.0
                   license:mpl1.1
                   license:mpl2.0
                   license:public-domain
                   license:isc
                   (license:non-copyleft "chrome://credits"
                                         "See chrome://credits for more information.")
                   license:lgpl2.1+))))