diff --git a/doc/contributing.texi b/doc/contributing.texi index a7d91724fb..f5b01f42fd 100644 --- a/doc/contributing.texi +++ b/doc/contributing.texi @@ -23,7 +23,8 @@ choice. * Building from Git:: The latest and greatest. * Running Guix Before It Is Installed:: Hacker tricks. * The Perfect Setup:: The right tools. -* Alternative Setups:: Other posible tools that do the job. +* Alternative Setups:: Other possible tools that do the job. +* Source Tree Structure:: Source code guided tour. * Packaging Guidelines:: Growing the distribution. * Coding Style:: Hygiene of the contributor. * Submitting Patches:: Share your work. @@ -546,6 +547,257 @@ In NeoVim you can even make a similar setup to Geiser using process and inject your code there live (sadly it's not packaged in Guix yet). +@node Source Tree Structure +@section Source Tree Structure + +@cindex structure, of the source tree +If you're willing to contribute to Guix beyond packages, or if you'd +like to learn how it all fits together, this section provides a guided +tour in the code base that you may find useful. + +Overall, the Guix source tree contains almost exclusively Guile +@dfn{modules}, each of which can be seen as an independent library +(@pxref{Modules,,, guile, GNU Guile Reference Manual}). + +The following table gives an overview of the main directories and what +they contain. Remember that in Guile, each module name is derived from +its file name---e.g., the module in file @file{guix/packages.scm} is +called @code{(guix packages)}. + +@table @file +@item guix +This is the location of core Guix mechanisms. To illustrate what is +meant by ``core'', here are a few examples, starting from low-level +tools and going towards higher-level tools: + +@table @code +@item (guix store) +Connecting to and interacting with the build daemon (@pxref{The Store}). +@item (guix derivations) +Creating derivations (@pxref{Derivations}). +@item (guix gexps) +Writing G-expressions (@pxref{G-Expressions}). +@item (guix packages) +Defining packages and origins (@pxref{package Reference}). +@item (guix download) +@itemx (guix git-download) +The @code{url-fetch} and @code{git-fetch} origin download methods +(@pxref{origin Reference}). +@item (guix swh) +Fetching source code from the +@uref{https://archive.softwareheritage.org,Software Heritage archive}. +@item (guix search-paths) +Implementing search paths (@pxref{Search Paths}). +@item (guix build-system) +The build system interface (@pxref{Build Systems}). +@item (guix profiles) +Implementing profiles. +@end table + +@cindex build system, directory structure +@item guix/build-system +This directory contains specific build system implementations +(@pxref{Build Systems}), such as: + +@table @code +@item (guix build-system gnu) +the GNU build system; +@item (guix build-system cmake) +the CMake build system; +@item (guix build-system pyproject) +The Python ``pyproject'' build system. +@end table + +@item guix/build +This contains code generally used on the ``build side'' +(@pxref{G-Expressions, strata of code}). This includes code used to +build packages or other operating system components, as well as +utilities: + +@table @code +@item (guix build utils) +Utilities for package definitions and more (@pxref{Build Utilities}). +@item (guix build gnu-build-system) +@itemx (guix build cmake-build-system) +@itemx (guix build pyproject-build-system) +Implementation of build systems, and in particular definition of their +build phases (@pxref{Build Phases}). +@item (guix build syscalls) +Interface to the C library and to Linux system calls. +@end table + +@cindex command-line tools, as Guile modules +@cindex command modules +@item guix/scripts +This contains modules corresponding to @command{guix} sub-commands. For +example, the @code{(guix scripts shell)} module exports the +@code{guix-shell} procedure, which directly corresponds to the +@command{guix shell} command (@pxref{Invoking guix shell}). + +@cindex importer modules +@item guix/import +This contains supporting code for the importers and updaters +(@pxref{Invoking guix import}, and @pxref{Invoking guix refresh}). For +example, @code{(guix import pypi)} defines the interface to PyPI, which +is used by the @code{guix import pypi} command. +@end table + +The directories we have seen so far all live under @file{guix/}. The +other important place is the @file{gnu/} directory, which contains +primarily package definitions as well as libraries and tools for Guix +System (@pxref{System Configuration}) and Guix Home (@pxref{Home +Configuration}), all of which build upon functionality provided by +@code{(guix @dots{})} modules@footnote{For this reason, @code{(guix +@dots{})} modules must generally not depend on @code{(gnu @dots{})} +modules, with notable exceptions: @code{(guix build-system @dots{})} +modules may look up packages at run time---e.g., @code{(guix +build-system cmake)} needs to access the @code{cmake} variable at run +time---, @code{(guix scripts @dots{})} often rely on @code{(gnu @dots{})} +modules, and the same goes for some of the @code{(guix import @dots{})} +modules.}. + +@table @file +@cindex package modules +@item gnu/packages +This is by far the most crowded directory of the source tree: it +contains @dfn{package modules} that export package definitions +(@pxref{Package Modules}). A few examples: + +@table @code +@item (gnu packages base) +Module providing ``base'' packages: @code{glibc}, @code{coreutils}, +@code{grep}, etc. +@item (gnu packages guile) +Guile and core Guile packages. +@item (gnu packages linux) +The Linux-libre kernel and related packages. +@item (gnu packages python) +Python and core Python packages. +@item (gnu packages python-xyz) +Miscellaneous Python packages (we were not very creative). +@end table + +In any case, you can jump to a package definition using @command{guix +edit} (@pxref{Invoking guix edit}) and view its location with +@command{guix show} (@pxref{Invoking guix package}). + +@findex search-patches +@item gnu/packages/patches +This directory contains patches applied against packages and obtained +using the @code{search-patches} procedure. + +@item gnu/services +This contains service definitions, primarily for Guix System +(@pxref{Services}) but some of them are adapted and reused for Guix Home +as we will see below. Examples: + +@table @code +@item (gnu services) +The service framework itself, which defines the service and service type +data types (@pxref{Service Composition}). +@item (gnu services base) +``Base'' services (@pxref{Base Services}). +@item (gnu services desktop) +``Desktop'' services (@pxref{Desktop Services}). +@item (gnu services shepherd) +Support for Shepherd services (@pxref{Shepherd Services}). +@end table + +You can jump to a service definition using @command{guix system edit} +and view its location with @command{guix system search} (@pxref{Invoking +guix system}). + +@item gnu/system +These are core Guix System modules, such as: + +@table @code +@item (gnu system) +Defines @code{operating-system} (@pxref{operating-system Reference}). +@item (gnu system file-systems) +Defines @code{file-system} (@pxref{File Systems}). +@item (gnu system mapped-devices) +Defines @code{mapped-device} (@pxref{Mapped Devices}). +@end table + +@item gnu/build +These are modules that are either used on the ``build side'' when +building operating systems or packages, or at run time by operating +systems. + +@table @code +@item (gnu build accounts) +Creating @file{/etc/passwd}, @file{/etc/shadow}, etc. (@pxref{User +Accounts}). +@item (gnu build activation) +Activating an operating system at boot time or reconfiguration time. +@item (gnu build file-systems) +Searching, checking, and mounting file systems. +@item (gnu build linux-boot) +@itemx (gnu build hurd-boot) +Booting GNU/Linux and GNU/Hurd operating systems. +@item (gnu build linux-initrd) +Creating a Linux initial RAM disk (@pxref{Initial RAM Disk}). +@end table + +@item gnu/home +This contains all things Guix Home (@pxref{Home Configuration}); +examples: + +@table @code +@item (gnu home services) +Core services such as @code{home-files-service-type}. +@item (gnu home services ssh) +SSH-related services (@pxref{Secure Shell}). +@end table + +@item gnu/installer +This contains the text-mode graphical system installer (@pxref{Guided +Graphical Installation}). + +@item gnu/machine +These are the @dfn{machine abstractions} used by @command{guix deploy} +(@pxref{Invoking guix deploy}). + +@item gnu/tests +This contains system tests---tests that spawn virtual machines to check +that system services work as expected (@pxref{Running the Test Suite}). +@end table + +Last, there's also a few directories that contain files that are +@emph{not} Guile modules: + +@table @file +@item nix +This is the C++ implementation of @command{guix-daemon}, inherited from +Nix (@pxref{Invoking guix-daemon}). + +@item tests +These are unit tests, each file corresponding more or less to one +module, in particular @code{(guix @dots{})} modules (@pxref{Running the +Test Suite}). + +@item doc +This is the documentation in the form of Texinfo files: this manual and +the Cookbook. @xref{Writing a Texinfo File,,, texinfo, GNU Texinfo}, +for information on Texinfo markup language. + +@item po +This is the location of translations of Guix itself, of package synopses +and descriptions, of the manual, and of the cookbook. Note that +@file{.po} files that live here are pulled directly from Weblate +(@pxref{Translating Guix}). + +@item etc +Miscellaneous files: shell completions, support for systemd and other +init systems, Git hooks, etc. +@end table + +With all this, a fair chunk of your operating system is at your +fingertips! Beyond @command{grep} and @command{git grep}, @pxref{The +Perfect Setup} on how to navigate code from your editor, and +@pxref{Using Guix Interactively} for information on how to use Scheme +modules interactively. Enjoy! + @node Packaging Guidelines @section Packaging Guidelines diff --git a/doc/guix.texi b/doc/guix.texi index af85d5c2a0..b353d91bd5 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -7680,7 +7680,8 @@ assembly is to C programs. The term ``derivation'' comes from the fact that build results @emph{derive} from them. This chapter describes all these APIs in turn, starting from high-level -package definitions. +package definitions. @xref{Source Tree Structure}, for a more general +overview of the source code. @menu * Package Modules:: Packages from the programmer's viewpoint.