Initial implementation

.config/clang-format

@@ -0,0 +1,69 @@
+---
+# C++ Formatting rules for Polymath Code Standard
+
+# See https://releases.llvm.org/14.0.0/tools/clang/docs/ClangFormatStyleOptions.html for documentation of these options
+BasedOnStyle: Google
+IndentWidth: 2
+ColumnLimit: 120
+
+AccessModifierOffset: -2
+AlignAfterOpenBracket: AlwaysBreak
+AlignConsecutiveAssignments: None
+AlignConsecutiveDeclarations: None
+AlignEscapedNewlines: Left
+AlignTrailingComments: false
+AllowAllArgumentsOnNextLine: true
+AllowAllParametersOfDeclarationOnNextLine: true
+AllowShortBlocksOnASingleLine: Empty
+AllowShortFunctionsOnASingleLine: false
+BinPackArguments: false
+BinPackParameters: false
+BraceWrapping:
+  AfterClass: true
+  AfterControlStatement: MultiLine
+  AfterEnum: true
+  AfterFunction: true
+  AfterNamespace: true
+  AfterStruct: true
+  AfterUnion: true
+  AfterExternBlock: true
+  BeforeCatch: false
+  BeforeElse: false
+  BeforeLambdaBody: false
+  BeforeWhile: false
+  IndentBraces: false
+  SplitEmptyFunction: false
+  SplitEmptyRecord: false
+  SplitEmptyNamespace: false
+BreakBeforeBraces: Custom
+BreakConstructorInitializers: BeforeComma
+CompactNamespaces: false
+ContinuationIndentWidth: 2
+ConstructorInitializerIndentWidth: 0
+DerivePointerAlignment: false
+EmptyLineAfterAccessModifier: Never
+EmptyLineBeforeAccessModifier: LogicalBlock
+FixNamespaceComments: true
+IncludeBlocks: Regroup
+IncludeCategories:
+  # Headers in <> with .h extension (best guess at C system headers)
+  - Regex:           '<([A-Za-z0-9\Q/-_\E])+\.h>'
+    Priority:        1
+  # Headers in <> without extension (C++ system headers)
+  - Regex:           '<([A-Za-z0-9\Q/-_\E])+>'
+    Priority:        2
+  # Headers in <> with other extensions.
+  - Regex:           '<([A-Za-z0-9.\Q/-_\E])+>'
+    Priority:        3
+  # Headers in ""
+  - Regex:           '"([A-Za-z0-9.\Q/-_\E])+"'
+    Priority:        4
+IndentAccessModifiers: false
+IndentPPDirectives: BeforeHash
+PackConstructorInitializers: Never
+PointerAlignment: Middle
+ReferenceAlignment: Middle
+ReflowComments: false
+SeparateDefinitionBlocks: Always
+SortIncludes: CaseInsensitive
+SpacesBeforeTrailingComments: 2

.config/copyright.txt

@@ -0,0 +1,13 @@
+Copyright (c) 2025-present Polymath Robotics, Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.

.cpplint.cfg

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+# Because of cpplint's config file assumptions, this can't be contained in .config/ directory
+linelength=256
+
+# TODO(emerson) we need to apply a copyright check, maybe not via this tool though
+filter=-legal/copyright
+# TODO(emerson) we want these, but the style as enforced here is probably not quite right for us
+filter=-build/header_guard
+filter=-build/c++17
+
+# Per our style guide, we want to allow the use of non-const reference passing for output parameters
+filter=-runtime/references
+
+# Disable all formatting checks, this is handled by clang-format
+filter=-readability/braces
+filter=-whitespace/braces
+filter=-whitespace/indent
+filter=-whitespace/newline
+filter=-whitespace/parens
+filter=-whitespace/semicolon

.github/workflows/build.yml

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+---
+name: Build and test
+"on":
+  pull_request:
+  push:
+    branches:
+      - main
+
+jobs:
+  build_and_test:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        ros: [humble, jazzy, kilted, rolling]
+        package: [behaviortree_cpp_pluginlib, behaviortree_cpp_pluginlib_tests]
+        include:
+          - ros: humble
+            ubuntu: jammy
+          - ros: jazzy
+            ubuntu: noble
+          - ros: kilted
+            ubuntu: noble-testing
+          - ros: rolling
+            ubuntu: noble
+    name: ${{ matrix.ros }} - ${{ matrix.package }}
+    container:
+      image: ghcr.io/ros-tooling/setup-ros-docker/setup-ros-docker-ubuntu-${{ matrix.ubuntu }}:latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ros-tooling/action-ros-ci@v0.4
+        with:
+          target-ros2-distro: ${{ matrix.ros }}
+          package-name: ${{ matrix.package }}
+          import-token: ${{ secrets.GITHUB_TOKEN }}
+      - uses: actions/upload-artifact@v4
+        with:
+          name: colcon-logs__${{ matrix.package }}__${{ matrix.ros }}
+          path: ros_ws/log

.github/workflows/pre-commit.yml

@@ -0,0 +1,16 @@
+---
+name: pre-commit
+"on":
+  pull_request:
+  push:
+    branches:
+      - main
+
+jobs:
+  pre-commit:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+      - run: sudo apt-get update && sudo apt-get install libxml2-utils
+      - uses: pre-commit/action@v3.0.1

.pre-commit-config.yaml

@@ -0,0 +1,68 @@
+---
+# See https://pre-commit.com for more information on these settings
+repos:
+  # Generally useful checks provided by pre-commit
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v5.0.0
+    hooks:
+      - id: check-added-large-files
+      - id: check-ast
+      - id: check-case-conflict
+      - id: check-merge-conflict
+      - id: check-shebang-scripts-are-executable
+      - id: check-symlinks
+      - id: check-xml
+      - id: end-of-file-fixer
+      - id: forbid-submodules
+      - id: mixed-line-ending
+      - id: trailing-whitespace
+  # C++ formatting
+  - repo: https://github.com/pre-commit/mirrors-clang-format
+    rev: v19.1.7
+    hooks:
+      - id: clang-format
+        args: ["--style=file:.config/clang-format"]
+  # C++ linting
+  - repo: https://github.com/cpplint/cpplint
+    rev: 2.0.0
+    hooks:
+      - id: cpplint
+        args: ["--config=.cpplint.cfg", --quiet, --output=sed]
+  # Markdown
+  - repo: https://github.com/jackdewinter/pymarkdown
+    rev: v0.9.28
+    hooks:
+      - id: pymarkdown
+        args: [-d, MD013, fix]
+  # XML
+  - repo: https://github.com/emersonknapp/ament_xmllint
+    rev: v0.1
+    hooks:
+      - id: ament_xmllint
+  # CMake
+  - repo: https://github.com/cmake-lint/cmake-lint
+    rev: 1.4.3
+    hooks:
+      - id: cmakelint
+        args: [--linelength=140]
+  # License headers
+  - repo: https://github.com/Lucas-C/pre-commit-hooks
+    rev: v1.5.5
+    hooks:
+      - id: insert-license
+        types_or: [cmake]
+        name: Copyright headers for Python/CMake
+        args: [
+          --license-filepath, .config/copyright.txt,
+          --comment-style, '#',
+          --allow-past-years,
+          --no-extra-eol,
+        ]
+      - id: insert-license
+        types_or: [c++, c]
+        name: Copyright headers for C/C++
+        args: [
+          --license-filepath, .config/copyright.txt,
+          --comment-style, '//',
+          --allow-past-years,
+        ]

.ruff.toml

@@ -0,0 +1,20 @@
+# Python rules for Polymath Code Standard
+
+line-length = 120
+indent-width = 4
+
+[format]
+preview = true
+quote-style = "single"
+indent-style = "space"
+skip-magic-trailing-comma = false
+line-ending = "lf"
+
+[lint]
+select = ["E4", "E7", "E9", "F", "I", "PTH"]
+# Rules intended for future application
+# select = ["N", "D", "C90", "UP", "PERF", "RUF"]
+ignore = []
+fixable = ["ALL"]
+unfixable = []
+dummy-variable-rgx = "^(_+|(_+[a-zA-Z0-9_]*[a-zA-Z0-9]+?))$"

README.md

@@ -1,2 +1,11 @@
 # behaviortree_cpp_pluginlib
-Pluginlib integration for registering and loading BehaviorTree.CPP extensions automatically
+
+Pluginlib integration for registering and loading BehaviorTree.CPP extensions automatically.
+
+This allows a workflow where any number of BT node plugins can be exposed in a distributed manner, with a single CMake call, so that no centralized plugin-exposure mechanism is needed to be kept updated.
+
+The use of pluginlib enables discovering all these nodes automatic automatically at runtime, without having to provide a list ahead of time to the factory.
+
+The packages in this repository are:
+* [behaviortree_cpp_pluginlib](./behaviortree_cpp_pluginlib/) - main implementation, see here for all information
+* [behaviortree_cpp_pluginlib_tests](./behaviortree_cpp_pluginlib_tests/) - separated test package to make sure all exposed build-system tools are working as intended for a user

behaviortree_cpp_pluginlib/CMakeLists.txt

@@ -0,0 +1,95 @@
+# Copyright (c) 2025-present Polymath Robotics, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+cmake_minimum_required(VERSION 3.22)
+project(behaviortree_cpp_pluginlib)
+
+if(NOT CMAKE_C_STANDARD)
+  set(CMAKE_C_STANDARD 99)
+endif()
+if(NOT CMAKE_CXX_STANDARD)
+  set(CMAKE_CXX_STANDARD 17)
+endif()
+if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+  add_compile_options(-Wall -Wextra -Wpedantic)
+  add_link_options(-Wl,-no-undefined)
+endif()
+
+find_package(ament_cmake_auto REQUIRED)
+ament_auto_find_build_dependencies()
+
+# Create library
+add_library(${PROJECT_NAME} SHARED
+  src/factory.cpp
+)
+target_include_directories(${PROJECT_NAME} PUBLIC
+  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+  $<INSTALL_INTERFACE:include>
+)
+target_link_libraries(${PROJECT_NAME}
+  PUBLIC
+    behaviortree_cpp::behaviortree_cpp
+    pluginlib::pluginlib
+  PRIVATE
+    rcutils::rcutils
+)
+
+# Install and export resources
+install(
+  TARGETS ${PROJECT_NAME}
+  EXPORT ${PROJECT_NAME}_TARGETS
+  ARCHIVE DESTINATION lib
+  LIBRARY DESTINATION lib
+  RUNTIME DESTINATION bin
+)
+install(
+  EXPORT ${PROJECT_NAME}_TARGETS
+  NAMESPACE ${PROJECT_NAME}::
+  DESTINATION share/${PROJECT_NAME}/cmake
+)
+install(
+  FILES src/autoregistrar.cpp.in src/plugin_description.xml.in
+  DESTINATION share/${PROJECT_NAME}
+)
+install(
+  DIRECTORY include/
+  DESTINATION include
+)
+install(
+  DIRECTORY cmake
+  DESTINATION share/${PROJECT_NAME}
+)
+
+if(BUILD_TESTING)
+  ament_auto_find_test_dependencies()
+
+  set(arg_TARGET test_register)
+  configure_file(
+    src/autoregistrar.cpp.in
+    ${PROJECT_BINARY_DIR}/test/autoregistrar.cpp
+    @ONLY
+  )
+
+  ament_add_gtest(test_register
+    test/test_register.cpp
+    ${PROJECT_BINARY_DIR}/test/autoregistrar.cpp
+  )
+  target_link_libraries(test_register ${PROJECT_NAME})
+endif()
+
+ament_export_targets(${PROJECT_NAME}_TARGETS HAS_LIBRARY_TARGET)
+ament_export_dependencies(behaviortree_cpp pluginlib)
+ament_package(
+  CONFIG_EXTRAS "${PROJECT_NAME}-extras.cmake"
+)

behaviortree_cpp_pluginlib/DEVELOPING.md

@@ -0,0 +1,21 @@
+# Implementation Details
+
+## BT Plugin Base Class
+
+[plugin.hpp](./include/behaviortree_cpp_pluginlib/plugin.hpp) defines the abstract base class `BT::BehaviorTreePlugin` which has a no-argument constructor and so can be exposed to `pluginlib`.
+
+Prerequisites for `pluginlib`:
+1. Plugins must derive from a known base class and be able to be used polymorphically
+1. Plugins must provide a no-argument constructor
+
+## C++ Registration Macros
+
+In [register_macro.hpp](./include/behaviortree_cpp_pluginlib/register_macro.hpp) we provide the macros needed to register an arbitrary number of plugin entrypoints from a single library.
+
+See the doc comments in that file for the breakdown of the implementation.
+
+## CMake Macro
+
+Follow the logic in [register_behaviortree_cpp_plugin.cmake](./cmake/register_behaviortree_cpp_plugin.cmake) for the implementation details. High level:
+1. Add `autoregistrar.cpp` to the library target
+1. Create `plugin_description.xml` file and register it with the resource index for `pluginlib` to find