cmake: check for presence of lxml and bs4 python modules

Change-Id: Ifeecfa25af36d022529c10e1914cf0dd36e8c82c
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

1 files changed, 77 insertions, 42 deletions

diff --git a/doc/CMakeLists.txt b/doc/CMakeLists.txt
index 52dfad270..e12520208 100644
--- a/doc/CMakeLists.txt
+++ b/doc/CMakeLists.txt
@@ -1,48 +1,83 @@
 if (QBS_INSTALL_HTML_DOCS OR QBS_INSTALL_QCH_DOCS)
-    get_target_property(_QBS_OUTPUT_DIR qbs RUNTIME_OUTPUT_DIRECTORY)
 
-    if (QBS_INSTALL_HTML_DOCS)
-        set(_INSTALL_HTML_DOCS true)
-    else()
-        set(_INSTALL_HTML_DOCS false)
-    endif()
+    find_package(Python3 COMPONENTS Interpreter)
+
+    function(find_python_module module)
+        string(TOUPPER ${module} module_upper)
+        if (NOT PY_${module_upper})
+            if (ARGC GREATER 1 AND ARGV1 STREQUAL "REQUIRED")
+                set(${module}_FIND_REQUIRED TRUE)
+            endif()
+            # A module's location is usually a directory, but for binary modules
+            # it's a .so file.
+            execute_process(COMMAND "${Python3_EXECUTABLE}" "-c"
+                "import re, ${module}; print(re.compile('/__init__.py.*').sub('',${module}.__file__))"
+                RESULT_VARIABLE _${module}_status
+                OUTPUT_VARIABLE _${module}_location
+                ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
+            if (NOT _${module}_status)
+                set(PY_${module_upper} ${_${module}_location} CACHE STRING
+                    "Location of Python module ${module}")
+            endif()
+        endif()
+        find_package_handle_standard_args(PY_${module} DEFAULT_MSG PY_${module_upper})
+    endfunction()
+
+    if (Python3_Interpreter_FOUND)
+        find_python_module(lxml)
+        find_python_module(bs4)
+        if (PY_LXML AND PY_BS4)
 
-    if (QBS_INSTALL_QCH_DOCS)
-        set(_INSTALL_QCH_DOCS true)
+            get_target_property(_QBS_OUTPUT_DIR qbs RUNTIME_OUTPUT_DIRECTORY)
+
+            if (QBS_INSTALL_HTML_DOCS)
+                set(_INSTALL_HTML_DOCS true)
+            else()
+                set(_INSTALL_HTML_DOCS false)
+            endif()
+
+            if (QBS_INSTALL_QCH_DOCS)
+                set(_INSTALL_QCH_DOCS true)
+            else()
+                set(_INSTALL_QCH_DOCS false)
+            endif()
+
+            get_target_property(_QT_QMAKE_EXECUTABLE Qt5::qmake IMPORTED_LOCATION)
+            get_update_path_command(UPDATE_PATH_COMMAND)
+            add_custom_target(
+                BuildQbsDocumentation ALL
+                COMMAND ${UPDATE_PATH_COMMAND}
+                COMMAND ${_QBS_OUTPUT_DIR}/qbs
+                resolve
+                --settings-dir ${PROJECT_BINARY_DIR}/settings
+                -f ${PROJECT_SOURCE_DIR}/qbs.qbs
+                -d ${PROJECT_BINARY_DIR}/
+                config:doc-build
+                qbs.installPrefix:undefined
+                qbs.buildVariant:release
+                project.withCode:false
+                project.withDocumentation:true
+                profile:none
+                modules.qbsbuildconfig.installHtml:${_INSTALL_HTML_DOCS}
+                modules.qbsbuildconfig.installQch:${_INSTALL_QCH_DOCS}
+                moduleProviders.Qt.qmakeFilePaths:${_QT_QMAKE_EXECUTABLE}
+                COMMAND ${_QBS_OUTPUT_DIR}/qbs
+                build
+                --settings-dir ${PROJECT_BINARY_DIR}/settings
+                -f ${PROJECT_SOURCE_DIR}/qbs.qbs
+                -d ${PROJECT_BINARY_DIR}/
+                config:doc-build
+                -p "qbs documentation"
+                DEPENDS qbs copy-runtime-files-qbs qbs_processlauncher
+                )
+            install(
+                DIRECTORY ${PROJECT_BINARY_DIR}/doc-build/install-root/share/doc/qbs/html/
+                DESTINATION "${QBS_DOC_INSTALL_DIR}"
+                )
+        else()
+            message(WARNING "Cannot import lxml and bs4 python modules. Qbs documentation will not be built.")
+        endif()
     else()
-        set(_INSTALL_QCH_DOCS false)
+        message(WARNING "Cannot find python3 binary. Qbs documentation will not be built.")
     endif()
-
-    get_target_property(_QT_QMAKE_EXECUTABLE Qt5::qmake IMPORTED_LOCATION)
-    get_update_path_command(UPDATE_PATH_COMMAND)
-    add_custom_target(
-        BuildQbsDocumentation ALL
-        COMMAND ${UPDATE_PATH_COMMAND}
-        COMMAND ${_QBS_OUTPUT_DIR}/qbs
-            resolve
-            --settings-dir ${PROJECT_BINARY_DIR}/settings
-            -f ${PROJECT_SOURCE_DIR}/qbs.qbs
-            -d ${PROJECT_BINARY_DIR}/
-            config:doc-build
-            qbs.installPrefix:undefined
-            qbs.buildVariant:release
-            project.withCode:false
-            project.withDocumentation:true
-            profile:none
-            modules.qbsbuildconfig.installHtml:${_INSTALL_HTML_DOCS}
-            modules.qbsbuildconfig.installQch:${_INSTALL_QCH_DOCS}
-            moduleProviders.Qt.qmakeFilePaths:${_QT_QMAKE_EXECUTABLE}
-        COMMAND ${_QBS_OUTPUT_DIR}/qbs
-            build
-            --settings-dir ${PROJECT_BINARY_DIR}/settings
-            -f ${PROJECT_SOURCE_DIR}/qbs.qbs
-            -d ${PROJECT_BINARY_DIR}/
-            config:doc-build
-            -p "qbs documentation"
-        DEPENDS qbs copy-runtime-files-qbs qbs_processlauncher
-      )
-  install(
-      DIRECTORY ${PROJECT_BINARY_DIR}/doc-build/install-root/share/doc/qbs/html/
-      DESTINATION "${QBS_DOC_INSTALL_DIR}"
-      )
 endif()