mirror of
https://github.com/YosysHQ/yosys
synced 2025-11-23 06:01:27 +00:00
314 lines
10 KiB
ReStructuredText
314 lines
10 KiB
ReStructuredText
Generated help messages and documentation
|
|
=========================================
|
|
|
|
- (virtually) all Yosys commands and built-in cell types have help text
|
|
- see `help` (or call ``yosys -h help``)
|
|
- this help text is also used to generate the :doc:`/cmd_ref` and
|
|
:doc:`/cell_index` documentation, available online via `ReadtheDocs`_
|
|
|
|
.. _ReadtheDocs: https://about.readthedocs.com/
|
|
|
|
Command help
|
|
------------
|
|
|
|
- `help` without arguments
|
|
|
|
- lists all commands with their ``Pass::short_help``
|
|
|
|
- ``help <command>``
|
|
|
|
- provides command specific help content
|
|
- as an example, the help content for `chformal` is shown below
|
|
|
|
.. _chformal autocmd:
|
|
|
|
.. autocmd:: chformal
|
|
:noindex:
|
|
|
|
The ``Pass::help()`` method
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
- call ``log()`` directly to print and format help text
|
|
- arbitrary formatting is possible, though some recommendations for consistency
|
|
and correct parsing during RST generation
|
|
|
|
+ see `Dumping command help to json`_ for details
|
|
|
|
The ``Pass::formatted_help()`` method
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
- ``PrettyHelp::get_current()``
|
|
- ``PrettyHelp::set_group()``
|
|
|
|
+ used with ``.. autocmdgroup:: <group>``
|
|
+ can assign group and return false
|
|
+ if no group is set, will try to use ``source_location`` and assign group
|
|
from path to source file
|
|
|
|
- return value
|
|
|
|
+ true means help content added to current ``PrettyHelp``
|
|
+ false to use ``Pass::help()``
|
|
|
|
- adding content
|
|
|
|
+ help content is a list of ``ContentListing`` nodes, each one having a type,
|
|
body, and its own list of children ``ContentListing``\ s
|
|
+ ``PrettyHelp::get_root()`` returns the root ``ContentListing`` (``type="root"``)
|
|
+ ``ContentListing::{usage, option, codeblock, paragraph}`` each add a
|
|
``ContentListing`` to the current node, with type the same as the method
|
|
|
|
* the first argument is the body of the new node
|
|
* ``usage`` shows how to call the command (i.e. its "signature")
|
|
* ``paragraph`` content is formatted as a paragraph of text with line breaks
|
|
added automatically
|
|
* ``codeblock`` content is displayed verbatim, use line breaks as desired;
|
|
takes an optional ``language`` argument for assigning the language in RST
|
|
output for code syntax highlighting (use ``yoscrypt`` for yosys script
|
|
syntax highlighting)
|
|
* ``option`` lists a single option for the command, usually starting with a
|
|
dash (``-``); takes an optional second argument which adds a paragraph
|
|
node as a means of description
|
|
|
|
+ ``ContentListing::open_usage`` creates and returns a new usage node, can be
|
|
used to e.g. add text/options specific to a given usage of the command
|
|
+ ``ContentListing::open_option`` creates and returns a new option node, can
|
|
be used to e.g. add multiple paragraphs to an option's description
|
|
+ paragraphs are treated as raw RST, allowing for inline formatting and
|
|
references as if it were written in the RST file itself
|
|
|
|
.. literalinclude:: /generated/chformal.cc
|
|
:language: c++
|
|
:start-at: bool formatted_help()
|
|
:end-before: void execute
|
|
:caption: ``ChformalPass::formatted_help()`` from :file:`passes/cmds/chformal.cc`
|
|
|
|
|
|
Dumping command help to json
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
- `help -dump-cmds-json cmds.json`
|
|
|
|
+ generates a ``ContentListing`` for each command registered in Yosys
|
|
+ tries to parse unformatted ``Pass::help()`` output if
|
|
``Pass::formatted_help()`` is unimplemented or returns false
|
|
|
|
* if a line starts with four spaces followed by the name of the command then
|
|
a space, it is parsed as a signature (usage node)
|
|
* if a line is indented and starts with a dash (``-``), it is parsed as an
|
|
option
|
|
* anything else is parsed as a codeblock and added to either the root node
|
|
or the current option depending on the indentation
|
|
|
|
+ dictionary of command name to ``ContentListing``
|
|
|
|
* uses ``ContentListing::to_json()`` recursively for each node in root
|
|
* root node used for source location of class definition
|
|
* includes flags set during pass constructor (e.g. ``experimental_flag`` set
|
|
by ``Pass::experimental()``)
|
|
* also title (``short_help`` argument in ``Pass::Pass``), group, and class
|
|
name
|
|
|
|
+ dictionary of group name to list of commands in that group
|
|
|
|
- used by sphinx autodoc to generate help content
|
|
|
|
.. literalinclude:: /generated/cmds.json
|
|
:language: json
|
|
:start-at: "chformal": {
|
|
:end-before: "chparam": {
|
|
:caption: `chformal` in generated :file:`cmds.json`
|
|
|
|
.. note:: Synthesis command scripts are special cased
|
|
|
|
If the final block of help output starts with the string `"The following
|
|
commands are executed by this synthesis command:\n"`, then the rest of the
|
|
code block is formatted as ``yoscrypt`` (e.g. `synth_ice40`). The caveat
|
|
here is that if the ``script()`` calls ``run()`` on any commands *prior* to
|
|
the first ``check_label`` then the auto detection will break and revert to
|
|
unformatted code (e.g. `synth_fabulous`).
|
|
|
|
|
|
Command line rendering
|
|
~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
- if ``Pass::formatted_help()`` returns true, will call
|
|
``PrettyHelp::log_help()``
|
|
|
|
+ traverse over the children of the root node and render as plain text
|
|
+ effectively the reverse of converting unformatted ``Pass::help()`` text
|
|
+ lines are broken at 80 characters while maintaining indentation (controlled
|
|
by ``MAX_LINE_LEN`` in :file:`kernel/log_help.cc`)
|
|
+ each line is broken into words separated by spaces, if a given word starts
|
|
and ends with backticks they will be stripped
|
|
|
|
- if it returns false it will call ``Pass::help()`` which should call ``log()``
|
|
directly to print and format help text
|
|
|
|
+ if ``Pass::help()`` is not overridden then a default message about missing
|
|
help will be displayed
|
|
|
|
.. literalinclude:: /generated/chformal.log
|
|
:lines: 2-
|
|
|
|
|
|
RST generated from autocmd
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
- below is the raw RST output from ``autocmd`` (``YosysCmdDocumenter`` class in
|
|
:file:`docs/util/cmd_documenter.py`) for `chformal` command
|
|
- heading will be rendered as a subheading of the most recent heading (see
|
|
`chformal autocmd`_ above rendered under `Command help`_)
|
|
- ``.. cmd:def:: <cmd>`` line is indexed for cross references with ``:cmd:ref:``
|
|
directive (`chformal autocmd`_ above uses ``:noindex:`` option so that
|
|
`chformal` still links to the correct location)
|
|
|
|
+ ``:title:`` option controls text that appears when hovering over the
|
|
`chformal` link
|
|
|
|
- commands with warning flags (experimental or internal) add a ``.. warning``
|
|
block before any of the help content
|
|
- if a command has no ``source_location`` the ``.. note`` at the bottom will
|
|
instead link to :doc:`/cmd/index_other`
|
|
|
|
.. autocmd_rst:: chformal
|
|
|
|
|
|
Cell help
|
|
---------
|
|
|
|
- :file:`techlibs/common/simcells.v` and :file:`techlibs/common/simlib.v`
|
|
- parsed by :file:`techlibs/common/cellhelp.py`
|
|
- comments preceding cell type converted to a ``SimHelper`` struct, defined in
|
|
:file:`kernel/register.cc`
|
|
- ``#include``d in :file:`kernel/register.cc`, creating a map of cell types to
|
|
their ``SimHelper`` struct.
|
|
|
|
- ``help -cells``
|
|
|
|
- lists all cells with their input/output ports
|
|
|
|
- ``help <celltype>``
|
|
|
|
- prints help message for ``<celltype>``
|
|
- constructed from ``SimHelper`` content depending on version
|
|
|
|
- ``help <celltype>+``
|
|
|
|
- prints verilog code for ``<celltype>``
|
|
|
|
v1 (default)
|
|
~~~~~~~~~~~~
|
|
|
|
- Legacy format
|
|
- Expects formatting as follows:
|
|
|
|
.. code-block:: verilog
|
|
|
|
//-
|
|
//- $<celltype> (<ports>)
|
|
//* group <cellgroup>
|
|
//-
|
|
//- <cell description>
|
|
//-
|
|
module \$<celltype> (<ports>);
|
|
// ...
|
|
endmodule
|
|
|
|
- ``//* group`` line is generally after the cell signature, but can appear
|
|
anywhere in the comment block
|
|
|
|
- determines where the cell is included in sphinx
|
|
- check :file:`docs/source/cell` for current groups
|
|
- a missing group will raise an error
|
|
- assigning an unused group will result in the cell not being included in the
|
|
sphinx docs
|
|
|
|
- the port signature line (``//- $<celltype> (<ports>)``) must start with (at
|
|
least) 4 spaces (not tabs)
|
|
|
|
- the empty lines (``//-``) before/after the signature are required
|
|
|
|
- cell description can be multiple lines, but each line must start with ``//-``
|
|
and a space
|
|
|
|
- description should have a trailing empty line
|
|
- line breaks are preserved in `help` calls but will be rendered as text in
|
|
sphinx docs, with empty lines being required between paragraphs
|
|
|
|
- cells in :file:`techlibs/common/simcells.v` can have optional truth table at
|
|
the end of the cell description which is rendered in sphinx docs as a literal
|
|
code block
|
|
- e.g. `$_NOT_`:
|
|
|
|
.. code-block:: verilog
|
|
|
|
//-
|
|
//- $_NOT_ (A, Y)
|
|
//* group comb_simple
|
|
//-
|
|
//- An inverter gate.
|
|
//-
|
|
//- Truth table: A | Y
|
|
//- ---+---
|
|
//- 0 | 1
|
|
//- 1 | 0
|
|
//-
|
|
|
|
v2 (more expressive)
|
|
~~~~~~~~~~~~~~~~~~~~
|
|
|
|
- each field of the ``SimHelper`` struct can be assigned with:
|
|
|
|
.. code-block:: verilog
|
|
|
|
//* <name> <value>
|
|
|
|
- ``ver`` must be explicitly set as ``2``
|
|
- optional fields ``title`` and ``tags``
|
|
|
|
- title used for better displaying of cell
|
|
- tags is a space-separated list of :doc:`/cell/properties`
|
|
|
|
- the port signature is automatically generated from the ``module`` definition
|
|
- cell description is the same as v1
|
|
- can link to commands or passes using backticks (`````)
|
|
- e.g. `$nex`:
|
|
|
|
.. code-block:: verilog
|
|
|
|
//* ver 2
|
|
//* title Case inequality
|
|
//* group binary
|
|
//* tags x-aware
|
|
//- This corresponds to the Verilog '!==' operator.
|
|
//-
|
|
//- Refer to `$eqx` for more details.
|
|
//-
|
|
|
|
- code blocks can be included as following:
|
|
|
|
.. code-block:: verilog
|
|
|
|
//- text
|
|
//- ::
|
|
//-
|
|
//- monospaced text
|
|
//-
|
|
//- indentation and line length will be preserved, giving a scroll bar if necessary for the browser window
|
|
//-
|
|
//- more text
|
|
|
|
- the empty line after the ``::`` and before the text continues are required
|
|
- the ``::`` line will be ignored in the `help` call while sphinx docs will
|
|
treat everything that follows as a literal block until the next unindented
|
|
line:
|
|
|
|
text
|
|
::
|
|
|
|
monospaced text
|
|
|
|
indentation and line length will be preserved, giving a scroll bar if necessary for the browser window
|
|
|
|
more text
|