Large circuits can run hundreds or thousands of ABCs in a single AbcPass.
For some circuits, some of those ABC runs can run for hundreds of seconds.
Running ABCs in parallel with each other and in parallel with main-thread
processing (reading and writing BLIF files, copying ABC BLIF output into
the design) can give large speedups.
The YosysHQ Verific Extensions are compiled separately using their own
stripped-down version of the Yosys headers. To maintain ABI
compatibility with older extension builds post C++-ification of Yosys's
logging APIs, which are backwards compatible on the API but not ABI
level, this commit adds ABI compatible versions of a subset of the old
logging API used by the extensions.
Conditionally include help source tracking to preserve ABI.
Docs builds can (and should) use `ENABLE_HELP_SOURCE` so that the generated sphinx docs can perform default grouping and link to source files.
Regular user-builds don't need the source tracking.
Use `chformal` as example, comparing the `autocmd` output with `ChformalPass::formal_help()`, the json dump from the `ContentListing`, the command line output, and the RST generated (using `autocmd_rst`).
Includes bullet points on each step for more information.
Should eventually end up in `yosys_internals/extending_yosys/contributing.rst`, but it currently lives in `cmd/index_internal.rst` to avoid merge conflicts since cell help documentation is still WIP.
Also exports chformal source and help output to `docs/source/generated` during `make docs/prep`.
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.
