4 The root directory of the |Gromacs| repository only contains :file:`CMakeLists.txt`
5 (the root file for the CMake build system), a few files supporting the build
6 system, and a few standard informative files (:file:`README` etc.). The
7 :file:`INSTALL` is generated for source packages from
8 :file:`docs/install-guide/index.rst`.
10 All other content is in the following top-level directories:
13 Contains various scripts for developer use, as well as configuration files
14 and scripts for some of the tools used.
16 Contains code fragments and find modules for CMake.
17 Some content here is copied and/or adapted from newer versions of CMake than
18 the minimum currently supported.
19 Default suppression file for valgrind is also included here.
20 See :doc:`build-system` for details of the build system.
22 Contains the build system logic and source code for all documentation, both
23 user-facing and developer-facing. Some of the documentation is generated
24 from the source code under :file:`src/`; see :ref:`dev-doc-layout`.
25 This directory also contains some developer scripts that use the Doxygen
26 documentation for their operation.
28 Contains the templates for :file:`GMXRC` script, some other installed scripts,
29 as well as installation rules for all these scripts.
31 Contains data files that will be installed under :file:`share/`. These
32 include a template for writing C++ analysis tools, and data files used by
35 Contains all source code. See :ref:`dev-source-layout`.
37 Contains build system logic for some high-level tests. Currently, only the
38 regression test build system logic, while other tests are under :file:`src/`.
40 .. _dev-source-layout:
42 Source code organization
43 ------------------------
45 The following figure shows a high-level view of components of what gets built
46 from the source code under :file:`src/` and how the code is organized.
47 Arrows indicate the direction of dependencies.
48 The build system is described in detail in :doc:`build-system`.
49 With default options, the green and white components are built as part of the
51 The gray parts are for testing, and are by default only built as part of the
52 ``tests`` target, but if ``GMX_DEVELOPER_BUILD`` is ``ON``, then these are
53 included in the default build target.
54 See :doc:`testutils` for details of the testing side.
56 .. digraph:: dev_high_level_components
59 node [ shape=box, style=filled, width=2 ]
64 label="externals\nsrc/external/", group=common, style=rounded
67 label="Google Test & Mock\nsrc/external/googletest/", group=test
68 style="rounded,filled", fillcolor="0 0 0.9"
74 label="libgromacs\nsrc/gromacs/", group=gmx, fillcolor="0.33 0.3 1"
78 label="testutils\nsrc/testutils/", group=test
79 style="rounded,filled", fillcolor="0 0 0.9"
84 label="gmx\nsrc/programs/", group=gmx, fillcolor="0.33 0.3 1"
87 label="test binaries\nsrc/.../tests/", group=test
88 style="rounded,filled", fillcolor="0 0 0.9"
91 label="analysis template\nshare/template/", group=common
92 fillcolor="0.33 0.3 1"
95 gmx -> template [ style=invis, constraint=no ]
98 libgromacs -> externals
100 testutils -> externals
102 testutils -> libgromacs
106 template -> libgromacs
108 All the source code (except for the analysis template) is under the
109 :file:`src/` directory. Only a few files related to the build system are
110 included at the root level. All actual code is in subdirectories:
113 The code under this directory is built into a single library,
114 :file:`libgromacs`. Installed headers are also located in this hierarchy.
115 This is the main part of the code, and is organized into further subdirectories
116 as *modules*. See below for details.
117 :file:`src/programs/`
118 The |Gromacs| executable ``gmx`` is built from code under this directory.
119 Also found here is some of the driver code for the ``mdrun`` module called
120 by ``gmx``, the whole of the ``gmx view`` visualization module, and numerous
121 end-to-end tests of ``gmx mdrun``.
123 :file:`src/{...}/tests/`
124 Various subdirectories under :file:`src/` contain a subdirectory named
125 :file:`tests/`. The code from each such directory is built into a test
126 binary. Some such directories also provide shared test code as object
127 libraries that is linked into multiple test binaries from different folders.
128 See :doc:`testutils` for details.
129 :file:`src/testutils/`
130 Contains shared utility code for writing Google Test tests.
131 See :doc:`testutils` for details.
132 :file:`src/external/`
133 Contains bundled source code for various libraries and
134 components that |Gromacs| uses internally. All the code from these
135 directories are built using our custom build rules into :file:`libgromacs`,
136 or in some cases into the test binaries. Some CMake options change which
137 parts of this code are included in the build.
138 See :doc:`build-system` for some explanation about how the code in this
140 :file:`src/external/build-fftw/`
141 This folder contains the build system code for
142 downloading and building FFTW to be included into :file:`libgromacs`.
144 When compiling, the include search path is set to :file:`src/`.
145 Some directories from under :file:`src/external/` may also be included,
146 depending on the compilation options.
148 Organization under :file:`src/gromacs/`
149 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
151 The :file:`libgromacs` library is built from code under :file:`src/gromacs/`.
152 Again, the top-level directory contains build and installation rules for the
153 library, and :dfn:`public API convenience headers`. These convenience headers
154 provide the main installed headers that other code can use. They do not
155 contain any declarations, but only include a suitable set of headers from the
156 subdirectories. They typically also contain high-level Doxygen documentation
157 for the subdirectory with the same name: :file:`{module}.h` corresponds to
160 The code is organized into subdirectories. These subdirectories are denoted as
161 :dfn:`modules` throughout this documentation. Each module consists of a set
162 of routines that do some well-defined task or a collection of tasks.
164 Installed headers are a subset of the headers under :file:`src/gromacs/`.
165 They are installed into a corresponding hierarchy under
166 :file:`include/gromacs/` in the installation directory.
167 Comments at the top of the header files contain a note about their visibility:
168 public (installed), intra-library (can be used from inside the library), or
169 intra-module/intra-file. All headers should compile by themselves,
170 with installed headers doing so without reference to variables
171 defined in ``config.h`` or requiring other headers to be included before it.
172 Not installed headers are allowed to include ``config.h``. Cyclic include dependencies
173 prevent this, and must be avoided because of this. This is best guaranteed
174 by including every header in some source file as the first header,
175 even before ``config.h``. This is partly enforced by :doc:`gmxtree`,
176 which is run by Jenkins and votes accordingly in Gerrit.
178 Code inside the library should not unnecessarily include headers. In
179 particular, headers should not include other headers if a forward
180 declaration of a type is enough for the header. Within the library
181 source files, include only headers from other modules that are
182 necessary for that file. You can use the public API header if you
183 really require everything declared in it.
185 See :doc:`naming` for some common naming patterns for files that can help
186 locating declarations.
188 Tests, and data required for them, are in a :file:`tests/` subdirectory under
189 the module directory.
190 See :doc:`testutils` for more details.
194 Documentation organization
195 --------------------------
197 All documentation (including this developer guide) is produced from source
198 files under :file:`docs/`, except for some command-line help that is generated
199 from the source code (by executing the compiled :file:`gmx` binary).
200 The build system provides various custom targets that build the documentation;
201 see :doc:`build-system` for details.
203 :file:`docs/fragments/`
204 Contains reStructuredText fragments used through ``.. include::`` mechanism
205 from various places in the documentation.
210 :file:`docs/install-guide/`
211 Contains reStructuredText source files for building the install guide section
212 of the user documentation, as well as the :file:`INSTALL` file for the source
214 The build rules are in :file:`docs/CMakeLists.txt`.
215 :file:`docs/reference-manual/`
216 Contains reStructuredText source files to generate the reference manual for
219 Contains LaTeX helper files to build the reference (PDF) manual.
220 :file:`docs/user-guide/`
221 Contains reStructuredText source files used to build the user guide section
222 of the user documentation.
223 The build rules are in :file:`docs/CMakeLists.txt`.
225 Contains reStructuredText source files building the how-to section of
226 the user focused documentation.
231 Man pages for programs are generated by running the :file:`gmx` executable
232 after compiling it, and then using Sphinx on the reStructuredText files that
233 :file:`gmx` writes out.
235 The build rules for the man pages are in :file:`docs/CMakeLists.txt`.
240 :file:`docs/dev-manual/`
241 Contains reStructuredText source files used to build the developer guide.
242 The build rules are in :file:`docs/CMakeLists.txt`.
244 The organization of the developer guide is explained on the :ref:`front page of
245 the guide <dev guide>`.
247 Doxygen documentation
248 ^^^^^^^^^^^^^^^^^^^^^
250 :file:`docs/doxygen/`
251 Contains the build rules and some overview content for the Doxygen
253 See :doc:`doxygen` for details of how the Doxygen documentation is built and
256 .. todo:: Create a separate page (at the front of the developer guide, and/or at
257 the main index.rst) that describes the documentation from readers'
258 perspective, and move relevant content there. This should contain just an
259 overview of how the documentation is organized in the source tree.
261 The Doxygen documentation is made of a few different parts. Use the list
262 below as a guideline on where to look for a particular kind of content.
263 Since the documentation has been written over a long period of time and the
264 approach has evolved, not all the documentation yet follows these guidelines,
265 but this is where we are aiming at.
268 These contain mainly overview content, from general-level introduction down
269 into explanation of some particular areas of individual modules.
270 These are generally the place to start familiarizing with the code or a new
272 They can be reached by links from the main page, and also through cross-links
273 from places in the documentation where that information is relevant to
274 understand the context.
276 These contain mainly techical content, explaining the general implementation of
277 a particular module and listing the classes, functions etc. in the module.
278 They complement pages that describe the concepts.
279 They can be reached from the Modules tab, and also from all individual classes,
280 functions etc. that make up the module.
282 These document the usage of an individual class, and in some cases that of
283 closely related classes. Where necessary (and time allowing), a broader
284 overview is given on a separate page and/or in the module documentation.
286 These document the individual method. Typically, the class documentation or
287 other overview content is the place to look for how different methods interact.
288 file and namespace documentation
289 These are generally only placeholders for links, and do not contain much else.
290 The main content is the list of classes and other entities declared in that