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diff --git a/docs/setup/configuring_build_options.rst b/docs/setup/configuring_build_options.rst new file mode 100644 index 0000000000..fd57930022 --- /dev/null +++ b/docs/setup/configuring_build_options.rst @@ -0,0 +1,404 @@ +Configuring Build Options +========================= + ++--------------------------------------------------------------------+ +| This page is an import from MDN and the contents might be outdated | ++--------------------------------------------------------------------+ + +This document details how to configure Firefox builds. +Most of the time a ``mozconfig`` file is not required. The default +options are the most well-supported, so it is preferable to add as few +options as possible. Please read the following directions carefully +before building, and follow them in order. Skipping any step may cause +the build to fail, or the built software to be unusable. Build options, +including options not usable from the command-line, may appear in +"``confvars.sh``" files in the source tree. + + +Using a ``mozconfig`` configuration file +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The choice of which Mozilla project to build and other configuration +options can be configured in a ``mozconfig`` file. (It is possible to +manually call ``configure`` with command-line options, but this is not +recommended). The ``mozconfig`` file should be in your source directory +(that is, ``/mozilla-central/mozconfig``). + +Create a blank ``mozconfig`` file: + +.. code:: bash + + echo "# My first mozilla config" > mozconfig + +If your mozconfig isn't in your source directory, you can also use the +``MOZCONFIG`` environment variable to specify the path to your +``mozconfig``. The path you specify **must** be an **absolute** path or +else ``client.mk`` will not find it. This is useful if you choose to +have multiple ``mozconfig`` files for different projects or +configurations (see below for a full example). Note that in the +``export`` example below the filename was not ``mozconfig``. Regardless +of the name of the actual file you use, we refer to this file as the +``mozconfig`` file in the examples below. + +Setting the ``mozconfig`` path: + +.. code:: bash + + export MOZCONFIG=$HOME/mozilla/mozconfig-firefox + +.. note:: + + Calling the file ``.mozconfig`` (with a leading dot) is also + supported, but this is not recommended because it may make the file + harder to find. This will also help when troubleshooting because + people will want to know which build options you have selected and + will assume that you have put them in your ``mozconfig`` file. + + +``mozconfig`` contains two types of options: +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +- Options prefixed with ``mk_add_options`` are passed to + ``client.mk``. The most important of these is ``MOZ_OBJDIR``, which + controls where your project gets built (also known as the object + directory). +- Options prefixed with ``ac_add_options`` are passed to ``configure``, + and affect the build process. + + +Building with an objdir +~~~~~~~~~~~~~~~~~~~~~~~ + +This means that the source code and object files are not intermingled in +your directory system and you can build multiple projects (e.g., +Firefox and Thunderbird) from the same source tree. If you do not +specify a ``MOZ_OBJDIR``, it will be automatically set to +``@TOPSRCDIR@/obj-@CONFIG_GUESS@``. + +If you need to re-run ``configure``, the easiest way to do it is using +``./mach configure``; running ``configure`` manually is strongly +discouraged. + +Adding the following line to your ``mozconfig`` allows you to change the +objdir: + +.. code:: bash + + mk_add_options MOZ_OBJDIR=@TOPSRCDIR@/obj-@CONFIG_GUESS@ + +It is a good idea to have your objdir name start with ``obj`` so that +Mercurial ignores it. + +Sometimes it can be useful to build multiple versions of the source +(such as with and without diagnostic asserts). To avoid the time it +takes to do a full rebuild, you can create multiple ``mozconfig`` files +which specify different objdirs. For example, a ``mozconfig-dbg``: + +.. code:: bash + + mk_add_options MOZ_OBJDIR=@TOPSRCDIR@/obj-ff-dbg + ac_add_options --enable-debug + +and a ``mozconfig-rel-opt``: + +.. code:: bash + + mk_add_options MOZ_OBJDIR=@TOPSRCDIR@/obj-ff-rel-opt + ac_add_options --disable-debug + ac_add_options --enable-optimize + +allow for building both versions by specifying the configuration via +the ``MOZCONFIG`` environment variable: + +.. code:: bash + + $ env MOZCONFIG=/path/to/mozconfig-dbg ./mach build + $ env MOZCONFIG=/path/to/mozconfig-rel-opt ./mach build + +Don't forget to set the ``MOZCONFIG`` environment variable for the +``mach run`` command as well. + +Be aware that changing your ``mozconfig`` will require the configure +process to be rerun and therefore the build will take considerably +longer, so if you find yourself changing the same options regularly, it +may be worth having a separate ``mozconfig`` for each. The main downside +of this is that each objdir will take up a significant amount of space +on disk. + + +Parallel compilation +~~~~~~~~~~~~~~~~~~~~ + +.. note:: + + **Note**: The build system automatically makes an intelligent guess + for how many CPU cores to use when building. The option below is + typically not needed. + +Most modern systems have multiple cores or CPUs, and they can be +optionally used concurrently to make the build faster. The ``-j`` flag +controls how many parallel builds will run concurrently. You will see +(diminishing) returns up to a value approximately 1.5× to 2.0× the +number of cores on your system. + +.. code:: bash + + mk_add_options MOZ_PARALLEL_BUILD=4 + +If your machine is overheating, you might want to try a lower value. + + +Choose a project +~~~~~~~~~~~~~~~~ + +The ``--enable-project=project`` flag is used to select a project to +build. Firefox is the default. + +Choose one of the following options to add to your ``mozconfig`` file: + +Browser (Firefox) + .. code:: + + ac_add_options --enable-project=browser + + .. note:: + + **Note**: This is the default + +Mail (Thunderbird) + .. code:: + + ac_add_options --enable-project=comm/mail + +Mozilla Suite (SeaMonkey) + .. code:: + + ac_add_options --enable-project=suite + +Calendar (Lightning Extension, uses Thunderbird) + .. code:: + + ac_add_options --enable-project=comm/mail + ac_add_options --enable-calendar + + +Selecting build options +~~~~~~~~~~~~~~~~~~~~~~~ + +The build options you choose depends on what project you are +building and what you will be using the build for. If you want to use +the build regularly, you will want a release build without extra +debugging information; if you are a developer who wants to hack the +source code, you probably want a non-optimized build with extra +debugging macros. + +There are many options recognized by the configure script which are +special-purpose options intended for embedders or other special +situations, and should not be used to build the full suite/XUL +projects. The full list of options can be obtained by running +``./mach configure -- --help``. + +.. warning:: + + Do not use a configure option unless you know what it does. + The default values are usually the right ones. Each additional option + you add to your ``mozconfig`` file reduces the chance that your build + will compile and run correctly. + +The following build options are very common: + +sccache +^^^^^^^ + +`SCCache <https://github.com/mozilla/sccache>`__ allows speeding up subsequent +C / C++ builds by caching compilation results. Unlike +`ccache <https://ccache.dev>`__, it also allows caching Rust artifacts, and +supports `distributed compilation +<https://github.com/mozilla/sccache/blob/master/docs/DistributedQuickstart.md>`__. + +In order to enable ``sccache`` for Firefox builds, you can use +``ac_add_options --with-ccache=sccache``. + +Optimization +^^^^^^^^^^^^ + +``ac_add_options --enable-optimize`` + Enables the default compiler optimization options + + .. note:: + + **Note**: This is enabled by default + +``ac_add_options --enable-optimize=-O2`` + Chooses particular compiler optimization options. In most cases, this + will not give the desired results, unless you know the Mozilla + codebase very well; note, however, that if you are building with the + Microsoft compilers, you probably **do** want this as ``-O1`` will + optimize for size, unlike GCC. +``ac_add_options --enable-debug`` + Enables assertions in C++ and JavaScript, plus other debug-only code. + This can significantly slow a build, but it is invaluable when + writing patches. **People developing patches (especially in C++) + should generally use this option.** +``ac_add_options --disable-optimize`` + Disables compiler optimization. This makes it much easier to step + through code in a debugger. +``ac_add_options --enable-release`` + Enables more conservative, release engineering-oriented options. This may + slow down builds. This also turns on full optimizations for Rust. Note this + is the default when building release/beta/esr. +``ac_add_options --enable-debug-js-modules`` + Enable only JavaScript assertions. This is useful when working + locally on JavaScript-powered components like the DevTools. This will + help catch any errors introduced into the JS code, with less of a + performance impact compared to the ``--enable-debug`` option. +``export RUSTC_OPT_LEVEL=2`` + Enable full optimizations for Rust code. + +You can make an optimized build with debugging symbols. See :ref:`Building +with Debug Symbols <Building with Debug Symbols>`. + +Extensions +^^^^^^^^^^ + +``ac_add_options --enable-extensions=default|all|ext1,ext2,-skipext3`` + There are many optional pieces of code that live in {{ + Source("extensions/") }}. Many of these extensions are now considered + an integral part of the browsing experience. There is a default list + of extensions for the suite, and each app-specific ``mozconfig`` + specifies a different default set. Some extensions are not compatible + with all apps, for example: + + - ``cookie`` is not compatible with thunderbird + - ``typeaheadfind`` is not compatible with any toolkit app (Firefox, + Thunderbird) + + Unless you know which extensions are compatible with which apps, do + not use the ``--enable-extensions`` option; the build system will + automatically select the proper default set of extensions. + +Tests +^^^^^ + +``ac_add_options --disable-tests`` + By default, many auxiliary test programs are built, which can + help debug and patch the mozilla source. Disabling these tests can + speed build time and reduce disk space considerably. Developers + should generally not use this option. + +Localization +^^^^^^^^^^^^ + +``mk_add_options MOZ_CO_LOCALES=ISOcode`` + TBD. +``ac_add_options --enable-ui-locale=ISOcode`` + TBD. +``ac_add_options --with-l10n-base=/path/to/base/dir`` + TBD. + +Other Options +^^^^^^^^^^^^^ + +``mk_add_options AUTOCLOBBER=1`` + If a clobber would be required before a build, this will cause mach + to clobber and continue with the build instead of asking the user to + manually clobber and exiting. + +``ac_add_options --enable-crashreporter`` + This enables the machinery that allows Firefox to write out a + `minidump <https://docs.microsoft.com/en-us/windows/desktop/Debug/minidump-files>`__ + files when crashing as well as the tools to process and submit crash + reports to Mozilla. After enabling the crash reporter in your local + build, you will need to run mach with the --enable-crash-reporter + (note the extra dash) to enable it at runtime, like so: + ``./mach run --enable-crash-reporter`` +``ac_add_options --enable-warnings-as-errors`` + This makes compiler warnings into errors which fail the build. This + can be useful since certain warnings coincide with reviewbot lints + which must be fixed before merging. + +.. _Example_.mozconfig_Files: + +Example ``mozconfig`` Files +~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Mozilla's official builds use mozconfig files from the appropriate +directory within each repository. + +.. warning:: + + These ``mozconfig`` files are taken from production builds + and are provided as examples only. It is recommended to use the default + build options, and only change the properties from the list above as + needed. The production builds aren't really appropriate for local + builds." + +- .. rubric:: Firefox, `Debugging Build (macOS + 64bits) <http://hg.mozilla.org/mozilla-central/file/tip/browser/config/mozconfigs/macosx64/debug>`__ + :name: Firefox.2C_Default_Release_Configuration + +Building multiple projects from the same source tree +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +It is possible to build multiple projects from the same source tree, +as long as you `use a different objdir <#Building_with_an_Objdir>`__ for +each project. + +You need to create multiple ``mozconfig`` files. + +As an example, the following steps can be used to build Firefox and +Thunderbird. You should first create three ``mozconfig`` files. + +``mozconfig-common``: + +.. code:: + + # add common options here, such as making an optimized release build + mk_add_options MOZ_PARALLEL_BUILD=4 + ac_add_options --enable-optimize --disable-debug + +``mozconfig-firefox``: + +.. code:: + + # include the common mozconfig + . ./mozconfig-common + + # Build Firefox + mk_add_options MOZ_OBJDIR=@TOPSRCDIR@/obj-firefox + ac_add_options --enable-project=browser + +``mozconfig-thunderbird``: + +.. code:: + + # include the common mozconfig + . ./mozconfig-common + + # Build Thunderbird + mk_add_options MOZ_OBJDIR=@TOPSRCDIR@/obj-thunderbird + ac_add_options --enable-project=comm/mail + +To build Firefox, run the following commands: + +.. code:: + + export MOZCONFIG=/path/to/mozilla/mozconfig-firefox + ./mach build + +To build Thunderbird, run the following commands: + +.. code:: + + export MOZCONFIG=/path/to/mozilla/mozconfig-thunderbird + ./mach build + +Using mozconfigwrapper +^^^^^^^^^^^^^^^^^^^^^^ + +Mozconfigwrapper is similar to using multiple mozconfig files except +that it abstracts and hides them so you don't have to worry about where +they live or which ones you've created. It also saves you from having to +export the MOZCONFIG variable each time. For information on installing +and configuring mozconfigwrapper, see +https://github.com/ahal/mozconfigwrapper. |