Merge pull request #5768 from hannes-steffenhagen-diffblue/cmake/fix-doxygen

Fix doxygen in cmake

Author: hannes-steffenhagen-diffblue

.github/workflows/pull-request-checks.yaml

@@ -70,7 +70,7 @@ jobs:
           # user input
           DEBIAN_FRONTEND: noninteractive
         run: |
-          sudo apt-get install --no-install-recommends -yq cmake ninja-build gcc g++ maven flex bison libxml2-utils dpkg-dev ccache
+          sudo apt-get install --no-install-recommends -yq cmake ninja-build gcc g++ maven flex bison libxml2-utils dpkg-dev ccache doxygen
       - name: Prepare ccache
         uses: actions/cache@v2
         with:
@@ -88,6 +88,10 @@ jobs:
           mkdir build
           cd build
           cmake .. -G Ninja -DCMAKE_BUILD_TYPE=Release -DCMAKE_C_COMPILER=/usr/bin/gcc -DCMAKE_CXX_COMPILER=/usr/bin/g++
+      - name: Check that doc task works
+        run: |
+          cd build
+          ninja doc
       - name: Zero ccache stats and limit in size
         run: ccache -z --max-size=500M
       - name: Build with Ninja

src/CMakeLists.txt

@@ -5,10 +5,26 @@ find_package(FLEX REQUIRED)
 
 find_package(Doxygen)
 if(DOXYGEN_FOUND)
-    add_custom_target(doc
-        "${DOXYGEN_EXECUTABLE}" "${CMAKE_CURRENT_SOURCE_DIR}/doxygen.cfg"
-        WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}"
-    )
+  set(ROOT_BINARY_DIR "${CMAKE_CURRENT_BINARY_DIR}/..")
+  set(ROOT_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/..")
+  set(ORIGINAL_DOXYFILE "${CMAKE_CURRENT_SOURCE_DIR}/doxyfile")
+  set(CONFIGURED_DOXYFILE "${ROOT_BINARY_DIR}/doxyfile")
+  set(DOC_INPUT_DIRECTORY "${ROOT_SOURCE_DIR}/doc")
+  set(DOC_OUTPUT_DIRECTORY "${ROOT_BINARY_DIR}/doc")
+
+  configure_file("${CMAKE_CURRENT_SOURCE_DIR}/doxyfile.override.in" "${CONFIGURED_DOXYFILE}")
+  add_custom_target(doc
+      COMMAND "${CMAKE_COMMAND}" -E remove_directory "${DOC_OUTPUT_DIRECTORY}"
+      COMMAND "${CMAKE_COMMAND}" -E copy_directory "${DOC_INPUT_DIRECTORY}" "${DOC_OUTPUT_DIRECTORY}"
+      COMMAND "${DOXYGEN_EXECUTABLE}" "${CONFIGURED_DOXYFILE}"
+      WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}")
+
+  unset(DOC_OUTPUT_DIRECTORY)
+  unset(DOC_INPUT_DIRECTORY)
+  unset(CONFIGURED_DOXYFILE)
+  unset(ORIGINAL_DOXYFILE)
+  unset(ROOT_SOURCE_DIR)
+  unset(ROOT_BINARY_DIR)
 endif(DOXYGEN_FOUND)
 
 #   Add a bison target named 'parser'.

src/doxyfile.override.in

@@ -0,0 +1,12 @@
+# Overrides for cmake out of source builds specifically, we
+# want to avoid copying files into the main doc directory,
+# instead we should be generating the doxygen docs in our
+# cmake output directory
+
+# Note: This file is intended to be used with cmake
+# configure_file; variables like @this@ are replaced by
+# cmake variables.
+
+@INCLUDE = @ORIGINAL_DOXYFILE@
+
+OUTPUT_DIRECTORY = @DOC_OUTPUT_DIRECTORY@