OpenROAD/docs/user/Bazel-targets.md

Bazel targets

Bazel is a cross compilation system where cfg=exec is host and cfg=target is the microcontroller in a host compiler targeting a microcontroller scenario. Although there is no clear host and target scenario for OpenROAD, it is all host, the host/target concetps of Bazel brings some surprises now and then when working with OpenROAD.

What is host and what is target in an OpenROAD context?

Not surprisingly, the command below builds the cfg=target configuration:

bazelisk build -c opt :openroad

However, the tests run on the host:

bazelisk test ...

This, means that if one where to run, the commands below, OpenROAD would be built twice, first for cfg=exec and then for cfg=target:

bazelisk build -c opt :openroad
bazelisk test ...

Visualizing configurations and dependencies

This command will visualize the dependencies on :openroad:

bazelisk cquery -c opt --output=graph 'allpaths(//..., //:openroad)' | xdot /dev/stdin

To list configurations, noting cfg=exec are denoted with (exec):

$ bazelisk config
Available configurations:
0f80209fc7e3c0c40539... k8-opt-exec-ST-6f5a6fb95be7 (exec)
3a4b806bae496300ade4... k8-opt
790a1ad93f643dd7c565... k8-opt-exec-ST-d57f47055a04 (exec)
8472fe4754a50f76910e... k8-opt
f37096aa0a6acd138bec... fastbuild-noconfig