Support using sphinxcontrib-hdl-diagrams on MSYS2

[umarcor]

This was significantly more painful than I had expected, but I got something.

In this PR, 5 modifications are contributed:

• A CI workflow named MSYS2.
  • netlistsvg is installed on the host, using the NodeJs available on the environment.
  • MSYS2 is setup with Action setup-msys2, and the following packages are installed through pacman: gcc, git, make, *-python-lxml, *-python-pip, *-python-sphinx, *-python-wheel, *-yosys.
    • All of them, except make, *-python-sphinx and *-yosys, are required because sphinx_symbiflow_theme is installed from sources, instead of using a package from pip.
  • nmigen and sphinx_symbiflow_theme are installed using pip.
  • The paths of nodejs and netlistsvg are added to the PATH, and the docs are built.
  • Artifacts are uploaded.
• docs/Makefile had to be modified, for avoiding the Conda environment setup. Target html was added. make -C docs html allows building the docs using locally available tools.
• docs/conf.py: in order to use the yosys installation on the system, hdl_diagram_yosys = 'system' is added.
• yosys-bb and yosys-aig types produce failures. I think this is not related to this plugin, but an issue/bug that Yosys has internally.
• Passing the yosys command as an string in sphinxcontrib_hdl_diagrams/__init__.py is broken. I modified it for using a list of arguments instead.

Therefore, I will mark this PR as a draft. The following issues need to be solved:

• Currently, the paths of nodejs and netlistsvg are added to the PATH manually (hardcoded). Those are saved in a file named extra.paths, but I could not have them added to the PATH programmatically. I have problems when reading C:/Program Files/nodejs, because of the space between "Program" and "Files" and because of the /. See step "Build Docs" of the workflow.
• In docs/Makefile, I think that SPHINXBUILD should not setup Conda by default. That's non idiomatic. Instead SPHINXBUILD should allow a regular/typical Sphinx build; what any user would expect in any Sphinx other project. Then, a custom target or envvar can be used for explicitly enabling Conda.
• Need to investigate why Yosys fails when doing dot ... && move ... internally. To start with, move seems not to exist.
• I believe that passing the yosys command as a list, instead of an string, can be considered a fix to be applied independently of this PR. @mithro @nobodywasishere @daniellimws, what do you think?

Ref: #72

[nobodywasishere]

I'm running into issues with passing the yosys command as a list to subprocess.check_output(). What errors were you running into using it as it is? For some reason on my machine if it's passed a list, it will only run the first element of the list and ignore everything else.

For instance:

Python 3.9.3 (default, Apr  8 2021, 23:35:02) 
[GCC 10.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import subprocess as sp
>>> sp.check_output('yosys --help', shell=True)
b'\nUsage: yosys [options] [<infile> [..]]\n\n    -Q\n        suppress printing of banner (copyright, disclaimer, version)\n\n    -T\n        
... # returns normally
>>> sp.check_output(['yosys --help'], shell=True)
b'\nUsage: yosys [options] [<infile> [..]]\n\n    -Q\n        suppress printing of banner (copyright, disclaimer, version)\n\n    -T\n        
... # returns normally
>>> sp.check_output(['yosys', '--help'], shell=True)
# I press CTRL + D as it's stuck at the yosys prompt
... 
Yosys 0.9+4052 (open-tool-forge build) (git sha1 dce037a6, gcc 9.3.0-17ubuntu1~20.04 -Os)\n\n\nyosys> exit\nEnd of script. 
...
>>> sp.check_output(['echo look at me', 'yosys', '--help'], shell=True)
b'look at me\n'
# returns normally
>>>

It does this when I try build the docs (which uses conda python) as well.

[umarcor]

@nobodywasishere. try with shell=False. I tried the following:

#!/usr/bin/env python3

import subprocess as sp
print('First')
print(sp.check_output(['yosys', '--version'], shell=True).decode("utf-8"))
print('Second')
print(sp.check_output('yosys --version', shell=True).decode("utf-8"))
print('Third')
print(sp.check_output(['yosys', '--version'], shell=False).decode("utf-8"))
print('Fourth')
print(sp.check_output('yosys --version', shell=False).decode("utf-8"))

On MSYS2 (MINGW64):

# ./test.py 
First
Yosys 0.9+4052 (git sha1 0ccc7229c, x86_64-w64-mingw32-g++ 10.2.0 -march=x86-64 -mtune=generic -O2 -Os)

Second
Yosys 0.9+4052 (git sha1 0ccc7229c, x86_64-w64-mingw32-g++ 10.2.0 -march=x86-64 -mtune=generic -O2 -Os)

Third
Yosys 0.9+4052 (git sha1 0ccc7229c, x86_64-w64-mingw32-g++ 10.2.0 -march=x86-64 -mtune=generic -O2 -Os)

Fourth
Yosys 0.9+4052 (git sha1 0ccc7229c, x86_64-w64-mingw32-g++ 10.2.0 -march=x86-64 -mtune=generic -O2 -Os)

On a container (hdlc/yosys):

First
# Is frozen...

Second
Yosys 0.9+4052 (git sha1 a5adb007, clang 7.0.1-8+deb10u2 -fPIC -Os)

Third
Yosys 0.9+4052 (git sha1 a5adb007, clang 7.0.1-8+deb10u2 -fPIC -Os)

Fourth
Traceback (most recent call last):
  File "./test.py", line 11, in <module>
    print(sp.check_output('yosys --version', shell=False).decode("utf-8"))
  File "/usr/lib/python3.7/subprocess.py", line 395, in check_output
    **kwargs).stdout
  File "/usr/lib/python3.7/subprocess.py", line 472, in run
    with Popen(*popenargs, **kwargs) as process:
  File "/usr/lib/python3.7/subprocess.py", line 775, in __init__
    restore_signals, start_new_session)
  File "/usr/lib/python3.7/subprocess.py", line 1522, in _execute_child
    raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No such file or directory: 'yosys --version': 'yosys --version'

So, on Linux it seems that the list requires Shell false and the string needs shell true.

[umarcor]

What errors were you running into using it as it is?

This is running make -C docs html on branch https://github.com/umarcor/sphinxcontrib-hdl-diagrams/commits/make/msys2:

...
reading sources... [100%] index
looking for now-outdated files... none found
pickling environment... done
checking consistency... done
preparing documents... WARNING: unsupported theme option 'color_primary' given
WARNING: unsupported theme option 'color_accent' given
done
Exiting file: T:/symbiflow/sphinxcontrib-hdl-diagrams/docs/_build/html/_images/hdl-diagram-52-code-verilog-counter.svg
Exiting file: T:/symbiflow/sphinxcontrib-hdl-diagrams/docs/_build/html/_images/hdl-diagram-70-code-nmigen-counter.svg
Exiting file: T:/symbiflow/sphinxcontrib-hdl-diagrams/docs/_build/html/_images/hdl-diagram-100-code-rtlil-counter.svg
Running yosys: yosys -p 'prep -top top ; cd top; ; show -format svg -prefix T:/symbiflow/sphinxcontrib-hdl-diagrams/docs/_build/html/_images/hdl-diagram-123-code-verilog-dff' T:/symbiflow/sphinxcontrib-hdl-diagrams/docs/code/verilog/dff.v
[00000.012737] ERROR: Can't guess frontend for input file `top' (missing -f option)!