ADD: add some useful cmake modules

cmake/Modules/compdb.cmake

@@ -0,0 +1,23 @@
+find_program(COMPDB_PATH
+      NAME compdb
+      PATHS ~/.local/bin/
+            /bin
+            /sbin
+            /usr/bin
+            /usr/sbin
+            /usr/local/bin
+            /usr/local/sbin
+  )
+
+
+
+if (COMPDB_PATH)
+  IF(NOT TARGET COMPD)
+    add_custom_target(COMPD
+      ALL
+      DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/compile_commands.json
+      WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+      COMMAND ${COMPDB_PATH} -p ${CMAKE_CURRENT_BINARY_DIR} list >compile_commands.json
+    )
+  endif()
+endif()

cmake/Modules/doxygen.cmake

@@ -0,0 +1,132 @@
+#
+# Copyright (C) 2018 by George Cave - gcave@stablecoder.ca
+#
+# 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.
+
+find_package(Doxygen)
+
+option(BUILD_DOCUMENTATION "Build API documentation using Doxygen. (make doc)"
+       ${DOXYGEN_FOUND})
+
+# Builds doxygen documentation with a default 'Doxyfile.in' or with a specified
+# one, and can make the results installable (under the `doc` install target)
+#
+# This can only be used once per project, as each target generated is as
+# `doc-${PROJECT_NAME}` unless TARGET_NAME is specified.
+# ~~~
+# Optional Arguments:
+#
+# ADD_TO_DOC
+#   If specified, adds this generated target to be a dependency of the more general
+#   `doc` target.
+#
+# INSTALLABLE
+#   Adds the generated documentation to the generic `install` target, under the
+#   `documentation` installation group.
+#
+# PROCESS_DOXYFILE
+#   If set, then will process the found Doxyfile through the CMAKE `configure_file`
+#   function for macro replacements before using it. (@ONLY)
+#
+# TARGET_NAME <str>
+#   The name to give the doc target. (Default: doc-${PROJECT_NAME})
+#
+# OUTPUT_DIR <str>
+#   The directory to place the generated output. (Default: ${CMAKE_CURRENT_BINARY_DIR}/doc)
+#
+# INSTALL_PATH <str>
+#   The path to install the documenttation under. (if not specified, defaults to
+#  'share/${PROJECT_NAME})
+#
+# DOXYFILE_PATH <str>
+#   The given doxygen file to use/process. (Defaults to'${CMAKE_CURRENT_SOURCE_DIR}/Doxyfile')
+# ~~~
+function(build_docs)
+  set(OPTIONS ADD_TO_DOC INSTALLABLE PROCESS_DOXYFILE)
+  set(SINGLE_VALUE_KEYWORDS
+      TARGET_NAME
+      INSTALL_PATH
+      DOXYFILE_PATH
+      OUTPUT_DIR)
+  set(MULTI_VALUE_KEYWORDS)
+  cmake_parse_arguments(build_docs
+                        "${OPTIONS}"
+                        "${SINGLE_VALUE_KEYWORDS}"
+                        "${MULTI_VALUE_KEYWORDS}"
+                        ${ARGN})
+
+  if(BUILD_DOCUMENTATION)
+    if(NOT DOXYGEN_FOUND)
+      message(FATAL_ERROR "Doxygen is needed to build the documentation.")
+    endif()
+
+    if(NOT build_docs_DOXYFILE_PATH)
+      set(DOXYFILE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/Doxyfile)
+    elseif(EXISTS ${build_docs_DOXYFILE_PATH})
+      set(DOXYFILE_PATH ${build_docs_DOXYFILE_PATH})
+    else()
+      set(DOXYFILE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/${build_docs_DOXYFILE_PATH})
+    endif()
+
+    if(NOT EXISTS ${DOXYFILE_PATH})
+      message(
+        SEND_ERROR
+          "Could not find Doxyfile to use for procesing documentation at: ${DOXYFILE_PATH}"
+        )
+      return()
+    endif()
+
+    if(build_docs_PROCESS_DOXYFILE)
+      set(DOXYFILE ${CMAKE_CURRENT_BINARY_DIR}/Doxyfile)
+      configure_file(${DOXYFILE_PATH} ${DOXYFILE} @ONLY)
+    else()
+      set(DOXYFILE ${DOXYFILE_PATH})
+    endif()
+
+    if(build_docs_OUTPUT_DIR)
+      set(OUT_DIR ${build_docs_OUTPUT_DIR})
+    else()
+      set(OUT_DIR ${CMAKE_CURRENT_BINARY_DIR}/doc)
+    endif()
+
+    file(MAKE_DIRECTORY ${OUT_DIR})
+
+    if(build_docs_TARGET_NAME)
+      set(TARGET_NAME ${build_docs_TARGET_NAME})
+    else()
+      set(TARGET_NAME doc-${PROJECT_NAME})
+    endif()
+
+    add_custom_target(${TARGET_NAME}
+                      COMMAND ${DOXYGEN_EXECUTABLE} ${DOXYFILE}
+                      WORKING_DIRECTORY ${OUT_DIR}
+                      VERBATIM)
+
+    if(build_docs_ADD_TO_DOC)
+      if(NOT TARGET doc)
+        add_custom_target(doc)
+      endif()
+
+      add_dependencies(doc ${TARGET_NAME})
+    endif()
+
+    if(build_docs_INSTALLABLE)
+      if(NOT build_docs_INSTALL_PATH)
+        set(build_docs_INSTALL_PATH share/${PROJECT_NAME})
+      endif()
+      install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/doc/
+              COMPONENT documentation
+              DESTINATION ${build_docs_INSTALL_PATH})
+    endif()
+  endif()
+endfunction()