Linking to optiongroups doesn't add *that* much, and is kind of a pain; meanwhile having the optiongroups adds an extra level of indentation.
Instead of options needing to be in an option group, they instead go in either the root node or nested in a usage node. Putting them in a usage node allows for more-or-less the previous behaviour but without making it the default.
Add `options` map for setting `ContentListing` options with key:val pairs; currently only used with `ContentListing::codeblock()` language arg.
Fix generated codeblock rst to print each line of code with indentation, and change it to use explicit an `code-block` so we can set a language on it.
Content is now added to the `ContentListing` rather than the `PrettyHelp`.
`open_*` methods return the `ContentListing` that was added instead of leaving a hanging continuation.
This allows for (e.g.) options to be added directly to optiongroups, instead of requiring that groups be closed before continuation.
This also means that all `PrettyHelp`s are a listing, with the actual log being called by the default `Pass::help()`; making the mode field redundant.
Added `PrettyHelp::log_help()` which replaces the `PrettyHelp::Mode::LOG` logic.
Added `ContentListing::back()` which just returns the last element of the underlying content vector.
Some of the content tracking was made redundant and removed, in particular `PrettyHelp::_current_listing` and `ContentListing::parent`.
Converted `ContentListing` to a class instead of a struct, adjusting constructors to match.
Added `ContentListing` constructor that accepts a `source_location`.
Update `HelpPass::dump_cmds_json()` for new log_help.
Assign root location in call to `PrettyHelp::get_current()`.
Set default `source_file` to `"unknown"`, since that appears to be the default value rather than `nullptr`.
Current modes are `LOG` and `LISTING`, which `log()` and store for conversion to json respectively.
Add `ContentListing` listing struct to (recursively) contain help data for conversion to a json object to be exported and used elsewhere (e.g. the docs).
Rather than formatting as rst we can just export with type information and do the conversion at the destination (i.e. in the python code which loads the domain for autodoc).
Implement `PrettyHelp::has_content()`.
Provide `PrettyHelp::get_content()` which returns a read-only list of the current content.
`PrettyHelp` constructor takes optional `Mode` enum to define format of help content.
Updates `PrettyHelp` methods to use a switch case for checking current mode, calling `log_abort()` in the default case (i.e. unsupported mode).
Use `std::experimental::source_location` because clang support is `??`
Add `ENABLE_SOURCE_LOCATION` make variable and corresponding `YOSYS_ENABLE_SOURCE_LOCATION` define.
Dummy out the struct if disabled and check for null instead of using `#ifdef` blocks everywhere.
Define `PrettyHelp` class with methods for declaring different parts of help message.
Currently able to produce standard help messages as expected.
Updates chformal to use (only) the new help_v2.
Currently makes use of a global static to track the current help context, allowing register.h to live in blissful ignorance and instead rely on help_v2 implementations calling `auto *help = PrettyHelp::get_current();` and `return true;` to minimise impact on rebuilds (i.e. not requiring every source file to be recompiled).
