Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 368 insertions, 0 deletions

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+.. _localization:
+
+================
+Localized Builds
+================
+
+Localization repacks
+====================
+
+To save on build time, the build system and automation collaborate to allow
+downloading a packaged en-US Firefox, performing some locale-specific
+post-processing, and re-packaging a locale-specific Firefox. Such artifacts
+are termed "single-locale language repacks". There is another concept of a
+"multi-locale language build", which is more like a regular build and less
+like a re-packaging post-processing step.
+
+.. note::
+
+  These builds rely on make targets that don't work for
+  `artifact builds <https://bugzilla.mozilla.org/show_bug.cgi?id=1387485>`_.
+
+Instructions for single-locale repacks for developers
+-----------------------------------------------------
+
+This assumes that ``$AB_CD`` is the locale you want to repack with; you
+find the available localizations on `l10n-central <https://hg.mozilla.org/l10n-central/>`_.
+
+#. You must have a built and packaged object directory, or a pre-built
+   ``en-US`` package.
+
+   .. code-block:: shell
+
+      ./mach build
+      ./mach package
+
+#. Repackage using the locale-specific changes.
+
+   .. code-block:: shell
+
+      ./mach build installers-$AB_CD
+
+You should find a re-packaged build at ``OBJDIR/dist/``, and a
+runnable binary in ``OBJDIR/dist/l10n-stage/``.
+The ``installers`` target runs quite a few things for you, including getting
+the repository for the requested locale from
+https://hg.mozilla.org/l10n-central/. It will clone them into
+``~/.mozbuild/l10n-central``. If you have an existing repository there, you
+may want to occasionally update that via ``hg pull -u``. If you prefer
+to have the l10n repositories at a different location on your disk, you
+can point to the directory via
+
+   .. code-block:: shell
+
+      ac_add_options --with-l10n-base=/make/this/a/absolute/path
+
+This build also packages a language pack.
+
+Instructions for language packs
+-------------------------------
+
+Language packs are extensions that contain just the localized resources. Building
+them doesn't require an actual build, but they're only compatible with the
+``mozilla-central`` source they're built with.
+
+
+.. code-block:: shell
+
+  ./mach build langpack-$AB_CD
+
+This target shares much of the logic of the ``installers-$AB_CD`` target above,
+and does the check-out of the localization repository etc. It doesn't require
+a package or a build, though. The generated language pack is in
+``OBJDIR/dist/$(MOZ_PKG_PLATFORM)/xpi/``.
+
+.. note::
+
+  Despite the platform-dependent location in the build directory, language packs
+  are platform independent, and the content that goes into them needs to be
+  built in a platform-independent way.
+
+Instructions for multi-locale builds
+------------------------------------
+
+If you want to create a single build with multiple locales, you will do
+
+#. Create a build and package
+
+   .. code-block:: shell
+
+      ./mach build
+      ./mach package
+
+#. Create the multi-locale package:
+
+   .. code-block:: shell
+
+      ./mach package-multi-locale --locales de it zh-TW
+
+On Android, this produces a multi-locale GeckoView AAR and multi-locale APKs,
+including GeckoViewExample.  You can test different locales by changing your
+Android OS locale and restarting GeckoViewExample.  You'll need to install with
+the ``MOZ_CHROME_MULTILOCALE`` variable set, like:
+
+   .. code-block:: shell
+
+       env MOZ_CHROME_MULTILOCALE=en-US,de,it,zh-TW ./mach android install-geckoview_example
+
+Multi-locale builds without compiling
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+For deep technical reasons, artifact builds do not support multi-locale builds.
+However, with a little work, we can achieve the same effect:
+
+#. Arrange a ``mozconfig`` without a compilation environment but with support
+   for the ``RecursiveMake`` build backend, like:
+
+   .. code-block:: shell
+
+      ac_add_options --disable-compile-environment
+      export BUILD_BACKENDS=FasterMake,RecursiveMake
+      ... other options ...
+
+#. Configure.
+
+   .. code-block:: shell
+
+      ./mach configure
+
+#. Manually provide compiled artifacts.
+
+   .. code-block:: shell
+
+      ./mach artifact install [-v]
+
+#. Build.
+
+   .. code-block:: shell
+
+      ./mach build
+
+#. Produce a multi-locale package.
+
+   .. code-block:: shell
+
+      ./mach package-multi-locale --locales de it zh-TW
+
+This build configuration is fragile and not generally useful for active
+development (for that, use a full/compiled build), but it certainly speeds
+testing multi-locale packaging.
+
+General flow of repacks
+-----------------------
+
+The general flow of the locale repacks is controlled by
+``$MOZ_BUILD_APP/locales/Makefile.in`` and ``toolkit/locales/l10n.mk``, plus
+the packaging build system. The three main entry points above all trigger
+related build flows:
+
+#. Get the localization repository, if needed
+#. Run l10n-merge with a prior clobber of the merge dir
+#. Copy l10n files to ``dist``, with minor differences here between ``l10n-%`` and ``chrome-%``
+#. Repackage and package
+
+Details on l10n-merge are described in its own section below.
+The copying of files is mainly controlled by ``jar.mn``, in the few source
+directories that include localizable files. ``l10n-%`` is used for repacks,
+``chrome-%`` for multi-locale packages. The repackaging is dedicated
+Python code in ``toolkit/mozapps/installer/l10n-repack.py``, using an existing
+package. It strips existing ``chrome`` l10n resources, and adds localizations
+and metadata.
+
+Language packs don't require repackaging. The windows installers are generated
+by merely packaging an existing repackaged zip into to an installer.
+
+Exposing strings
+================
+
+The localization flow handles a few file formats in well-known locations in the
+source tree.
+
+Alongside being built by including the directory in ``$MOZ_BUILD_APP/locales/Makefile.in``
+and respective entries in a ``jar.mn``, we also have configuration files tailored
+to localization tools and infrastructure. They're also controlling which
+files l10n-merge handles, and how.
+
+These configurations are TOML files. They're part of the bigger
+localization ecosystem at Mozilla, and `the documentation about the
+file format <http://moz-l10n-config.readthedocs.io/en/latest/fileformat.html>`_
+explains how to set them up, and what the entries mean. In short, you find
+
+.. code-block:: toml
+
+   [paths]
+   reference = browser/locales/en-US/**
+   l10n = {l}browser/**
+
+to add a directory for all localizations. Changes to these files are best
+submitted for review by :Pike or :flod.
+
+These configuration files are the future, and right now, we still have
+support for the previous way to configuring l10n, which is described below.
+
+The locations are commonly in directories like
+
+    :file:`browser/`\ ``locales/en-US/``\ :file:`subdir/file.ext`
+
+The first thing to note is that only files beneath :file:`locales/en-US` are
+exposed to localizers. The second thing to note is that only a few directories
+are exposed. Which directories are exposed is defined in files called
+``l10n.ini``, which are at a
+`few places <https://searchfox.org/mozilla-central/search?q=path%3Al10n.ini&redirect=true>`_
+in the source code.
+
+An example looks like this
+
+.. code-block:: ini
+
+    [general]
+    depth = ../..
+
+    [compare]
+    dirs = browser
+        browser/branding/official
+
+    [includes]
+    toolkit = toolkit/locales/l10n.ini
+
+This tells the l10n infrastructure three things:
+
+* resolve the paths against the directory two levels up
+* include files in :file:`browser/locales/en-US` and
+  :file:`browser/branding/official/locales/en-US`
+* load more data from :file:`toolkit/locales/l10n.ini`
+
+For projects like Thunderbird and SeaMonkey in ``comm-central``, additional
+data needs to be provided when including an ``l10n.ini`` from a different
+repository:
+
+.. code-block:: ini
+
+    [include_toolkit]
+    type = hg
+    mozilla = mozilla-central
+    repo = https://hg.mozilla.org/
+    l10n.ini = toolkit/locales/l10n.ini
+
+This tells the l10n infrastructure where to find the repository, and where inside
+that repository the ``l10n.ini`` file is. This is needed because for local
+builds, :file:`mail/locales/l10n.ini` references
+:file:`mozilla/toolkit/locales/l10n.ini`, which is where the comm-central
+build setup expects toolkit to be.
+
+Now that the directories exposed to l10n are known, we can talk about the
+supported file formats.
+
+File formats
+------------
+
+The following file formats are known to the l10n tool chains:
+
+Fluent
+    Used in Firefox UI, both declarative and programmatically.
+Properties
+    Used from JavaScript and C++. When used from js, also comes with
+    plural support (avoid if possible).
+ini
+    Used by the crashreporter and updater, avoid if possible.
+
+Adding new formats involves changing various different tools, and is strongly
+discouraged.
+
+Exceptions
+----------
+Generally, anything that exists in ``en-US`` needs a one-to-one mapping in
+all localizations. There are a few cases where that's not wanted, notably
+around locale configuration and locale-dependent metadata.
+
+For optional strings and files, l10n-merge won't add ``en-US`` content if
+the localization doesn't have that content.
+
+For the TOML files, the
+`[[filters]] documentation <https://moz-l10n-config.readthedocs.io/en/latest/fileformat.html#filters>`_
+is a good reference. In short, filters match the localized source code, optionally
+a ``key``, and an action. An example like
+
+.. code-block:: toml
+
+  [filters]
+  path = "{l}calendar/chrome/calendar/calendar-event-dialog.properties"
+  key = "re:.*Nounclass[1-9].*"
+  action = "ignore"
+
+indicates that the matching messages in ``calendar-event-dialog.properties`` are optional.
+
+For the legacy ini configuration files, there's a Python module
+``filter.py`` next to the main ``l10n.ini``, implementing :py:func:`test`, with the following
+signature
+
+.. code-block:: python
+
+    def test(mod, path, entity = None):
+        if does_not_matter:
+            return "ignore"
+        if show_but_do_not_merge:
+            return "report"
+        # default behavior, localizer or build need to do something
+        return "error"
+
+For any missing file, this function is called with ``mod`` being
+the *module*, and ``path`` being the relative path inside
+:file:`locales/en-US`. The module is the top-level dir as referenced in
+:file:`l10n.ini`.
+
+For missing strings, the :py:data:`entity` parameter is the key of the string
+in the en-US file.
+
+l10n-merge
+==========
+
+The chrome registry in Gecko doesn't support fallback from a localization to ``en-US`` at runtime.
+Thus, the build needs to ensure that the localization as it's built into
+the package has all required strings, and that the strings don't contain
+errors. To ensure that, we're *merging* the localization and ``en-US``
+at build time, nick-named l10n-merge.
+
+For Fluent, we're also removing erroneous messages. For many errors in Fluent,
+that's cosmetic, but when a localization has different values or attributes
+on a message, that's actually important so that the DOM bindings of Fluent
+can apply the translation without having to load the ``en-US`` source to
+compare against.
+
+The process can be manually triggered via
+
+.. code-block:: bash
+
+    $> ./mach build merge-$AB_CD
+
+It creates another directory in the object dir, :file:`browser/locales/merge-dir/$AB_CD`, in
+which the sanitized files are stored. The actual repackaging process only looks
+in the merged directory, so the preparation steps of l10n-merge need to ensure
+that all files are generated or copied.
+
+l10n-merge modifies a file if it supports the particular file type, and there
+are missing strings which are not filtered out, or if an existing string
+shows an error. See the Checks section below for details. If the files are
+not modified, l10n-merge copies them over to the respective location in the
+merge dir.
+
+Checks
+------
+
+As part of the build and other localization tool chains, we run a variety
+of source-based checks. Think of them as linters.
+
+The suite of checks is usually determined by file type, i.e., there's a
+suite of checks for Fluent files and one for properties files, etc.
+
+Localizations
+-------------
+
+Now that we talked in-depth about how to expose content to localizers,
+where are the localizations?
+
+We host a mercurial repository per locale. All of our
+localizations can be found on https://hg.mozilla.org/l10n-central/.
+
+You can search inside our localized files on
+`Transvision <https://transvision.mozfr.org/>`_.