How to consume "//xls/build_rules:xls_build_defs.bzl" out-of-tree?

[orpheezt]

I am exploring whether to automate xls codegen with an Makefile or to use Bazel with existing tooling.

But I had no success with it

[proppy]

@orpheezt did you try to consume the nightly binary releases?

[orpheezt]

I am doing it, and orchestrating with an makefile

I just was wondering if I could use existing bazel build system scripts

[proppy]

@orpheezt hinted at some workaround in #1863 (comment).

There is also downstream project maintained by another organization here: https://github.com/xlsynth/rules_xlsynth but I'm not sure if it works out of the boxes w/ xls binary releases or if it requires the xlsynth driver, maybe @cdleary can shed more light?

I hope that helps.

[allight]

Bazel with prebuilt tooling is not really supported but somewhat possible by

1. Copying most of the build_rules folder to a new location and updating all of the 'load' operations
2. Replace the _DEFAULT...s in https://github.com/google/xls/blob/main/xls/build_rules/xls_toolchains.bzl#L26 with the appropriate prebuilt binaries
3. using the copied build rules instead of the xls ones.

Honestly this is something we plan to add more support for eventually but for now it is a relatively low priority and we have no timeline for the work.

The thing is any machine capable of running EDA tools is capable of building xls from scratch in ~20 minutes and build caching means they won't even need to do it that often. Furthermore as long as you're doing everything in bazel anyway it's honestly easier to just have the from-scratch build as the default.

If you want to use the prebuilt tools outside of bazel (with make etc) that is fully possible since bazel just invokes the tools and copies files and so on but we don't have any support for that on our side. You can look at the bazel rule definitions and bazel aquery output to get a sense of what all of our rules are doing however.