rule_info {
  rule_name: "my_rule"
  doc_string: "This rule exercises some of the build API."
  attribute {
    name: "name"
    doc_string: "A unique name for this target."
    type: NAME
    mandatory: true
  }
  attribute {
    name: "deps"
    doc_string: "A list of dependencies."
    type: LABEL_LIST
    provider_name_group {
      provider_name: "MyInfo"
    }
    default_value: "[]"
  }
  attribute {
    name: "extra_arguments"
    type: STRING_LIST
    default_value: "[]"
  }
  attribute {
    name: "out"
    doc_string: "The output file."
    type: OUTPUT
    mandatory: true
  }
  attribute {
    name: "src"
    doc_string: "The source file."
    type: LABEL
    default_value: "None"
  }
  attribute {
    name: "tool"
    doc_string: "The location of the tool to use."
    type: LABEL
    default_value: "//foo/bar/baz:target"
  }
}
provider_info {
  provider_name: "MyInfo"
  field_info {
    name: "foo"
    doc_string: "Something foo-related."
  }
  field_info {
    name: "bar"
    doc_string: "Something bar-related."
  }
}
func_info {
  function_name: "exercise_the_api"
}
func_info {
  function_name: "my_rule_impl"
  parameter {
    name: "ctx"
    mandatory: true
  }
}