Graphiz path example

This is an example of how to use the doxygen alongside graphviz to generate inheritance diagrams for C++ classes. By default, doxygen looks for the dot executable in the system path, meaning that a system installation of graphviz will work out of the box. If you want to make the build fully hermetic, you can specify the path to the dot executable in the doxygen rule, making it point to a dot binary of your choosing.

bazel build //doxyfile:doxygen

Custom dot binary

To ensure the dot binary is available to the rule, make sure to add it to the sources of the macro. Also, remember to add the have_dot = True parameter, otherwise no graphs will be produced.

load("@doxygen//:doxygen.bzl", "doxygen")

# Assuming the binary is located in the same folder

filegroup(
    name = "dot_executable",
    srcs = select(
        {
            "@platforms//os:linux": ["dot"],
            "@platforms//os:macos": ["dot"],
            "@platforms//os:windows": ["dot"],
        },
        "Unsupported platform",
    ),
)

# Ideally, instead of using a local filegroup, you would want and external module, like "@graphviz//:bin/dot"

doxygen(
    name = "doxygen",
    srcs = glob([
        "*.h",
        "*.cpp",
        "*.sh",
    ]) + [":dot_executable"],
    dot_executable = ":dot_executable",
    have_dot = True,
    project_name = "graphviz",
)