Add cmake files for building docs

cmake/FindSphinx.cmake

@@ -0,0 +1,16 @@
+find_program(SPHINX_EXECUTABLE NAMES sphinx-build
+  HINTS
+  $ENV{SPHINX_DIR}
+  PATH_SUFFIXES bin
+  DOC "Sphinx documentation generator"
+)
+
+include(FindPackageHandleStandardArgs)
+
+find_package_handle_standard_args(Sphinx DEFAULT_MSG
+  SPHINX_EXECUTABLE
+)
+
+mark_as_advanced(
+  SPHINX_EXECUTABLE
+)

docs/CMakeLists.txt

@@ -0,0 +1,31 @@
+find_package(Sphinx REQUIRED)
+ 
+if(NOT DEFINED SPHINX_THEME)
+    set(SPHINX_THEME default)
+endif()
+ 
+if(NOT DEFINED SPHINX_THEME_DIR)
+    set(SPHINX_THEME_DIR)
+endif()
+ 
+# configured documentation tools and intermediate build results
+set(BINARY_BUILD_DIR "${CMAKE_CURRENT_BINARY_DIR}/_build")
+ 
+# Sphinx cache with pickled ReST documents
+set(SPHINX_CACHE_DIR "${CMAKE_CURRENT_BINARY_DIR}/_doctrees")
+ 
+# HTML output directory
+set(SPHINX_HTML_DIR "${CMAKE_CURRENT_BINARY_DIR}/html")
+ 
+configure_file(
+    "${CMAKE_CURRENT_SOURCE_DIR}/conf.py"
+    "${BINARY_BUILD_DIR}/conf.py"
+    @ONLY)
+ 
+add_custom_target(docs ALL
+    ${SPHINX_EXECUTABLE}
+    -b html
+    -c "${BINARY_BUILD_DIR}"
+    "${CMAKE_CURRENT_SOURCE_DIR}"
+    "${SPHINX_HTML_DIR}"
+    COMMENT "Building HTML documentation with Sphinx")