Bazel targets

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

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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
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