The current directory structure in Drake is organized to (1) group functional components, (2) limit dependencies, and (3) prevent circular dependencies.
All code that implements core functionality in Drake must adhere to the strict
code standards described in :ref:`Developer Notes <developer_notes>`, and must
have unit test coverage via code implemented in a test
subdirectory
immediately below the core implementation.
To promote rapid development of research ideas within the code base,
we allow for some exceptions to this rule for experimental code. This includes
any subdirectory labeled dev
and directories with a special README.md
file describing the protocol for that directory. For PRs that affect only these
experimental directories, one feature review is sufficient; platform review is
not required. If build or test targets in these directories break, and the PR
author or on-call build cop cannot trivially resolve them, a GitHub issue will
be assigned to the author of the code. If the issue is not resolved within 24
hours, the core development team may disable the offending targets.
The BUILD.bazel
rules for special directories must live within the
directory itself, not a parent directory. (For example, foo/BUILD.bazel
must not say srcs = ["dev/bar.cc"],
; instead, foo/dev/BUILD.bazel
must exist and must say srcs = ["bar.cc"],
.) This ensures that all dev
code has a package name that clearly denotes it as such.
We would like to avoid circular dependencies in the source code tree. For
example, some code in drake/systems
depends on code in drake/solvers
, so
code in drake/solvers
should not depend on drake/systems
.
The drake/examples
directories are logically after all of the core libraries
in drake
. test
directories located throughout the code are logically
last in the dependency tree -- they are allowed to depend on any of the other
directories. For example, test
code is allowed to use models/code from
the examples
directories to test core functionality, as long as that
dependency is explicitly declared in the build system rules for that test.