python: 'sub-module' for binding sources and documentation meta information

cmake/OpenCVModule.cmake

@@ -104,7 +104,7 @@ macro(ocv_add_dependencies full_modname)
   list(FIND OPENCV_MODULE_${full_modname}_WRAPPERS "python" __python_idx)
   if (NOT __python_idx EQUAL -1)
     list(REMOVE_ITEM OPENCV_MODULE_${full_modname}_WRAPPERS "python")
-    list(APPEND OPENCV_MODULE_${full_modname}_WRAPPERS "python2" "python3")
+    list(APPEND OPENCV_MODULE_${full_modname}_WRAPPERS "python_bindings_generator" "python2" "python3")
   endif()
   unset(__python_idx)
 

doc/CMakeLists.txt

@@ -33,7 +33,7 @@ endif(HAVE_DOC_GENERATOR)
 
 if(BUILD_DOCS AND DOXYGEN_FOUND)
   # not documented modules list
-  list(APPEND blacklist "ts" "java" "python2" "python3" "js" "world")
+  list(APPEND blacklist "ts" "java" "python_bindings_generator" "python2" "python3" "js" "world")
   unset(CMAKE_DOXYGEN_TUTORIAL_CONTRIB_ROOT)
   unset(CMAKE_DOXYGEN_TUTORIAL_JS_ROOT)
 
@@ -104,7 +104,6 @@ if(BUILD_DOCS AND DOXYGEN_FOUND)
         list(APPEND deps ${bib_file})
       endif()
       # Reference entry
-    #   set(one_ref "@ref ${m} | ${m}\n")
       set(one_ref "\t- ${m}. @ref ${m}\n")
       list(FIND EXTRA_MODULES ${m} _pos)
       if(${_pos} EQUAL -1)
@@ -205,9 +204,8 @@ if(BUILD_DOCS AND DOXYGEN_FOUND)
     list(APPEND js_tutorials_assets_deps "${f}" "${opencv_tutorial_html_dir}/${fname}")
   endforeach()
 
-  set(doxygen_result "${CMAKE_CURRENT_BINARY_DIR}/doxygen/html/modules.html")
-
-  add_custom_target(doxygen_cpp
+  add_custom_target(
+    doxygen_cpp
     COMMAND ${DOXYGEN_EXECUTABLE} ${doxyfile}
     DEPENDS ${doxyfile} ${rootfile} ${bibfile} ${deps} ${js_tutorials_assets_deps}
     COMMENT "Generate Doxygen documentation"
@@ -218,18 +216,27 @@ if(BUILD_DOCS AND DOXYGEN_FOUND)
     COMPONENT "docs" OPTIONAL
   )
 
-  if(PYTHON2_EXECUTABLE)
-    add_custom_target(doxygen_python
-      COMMAND ${PYTHON2_EXECUTABLE} "${CMAKE_CURRENT_SOURCE_DIR}/tools/add_signatures.py" "${CMAKE_CURRENT_BINARY_DIR}/doxygen/html/" "${OPENCV_PYTHON2_SIGNATURES_FILE}" "python"
-      DEPENDS "${doxygen_result}" gen_opencv_python2
-    )
-    add_custom_target(doxygen
-      DEPENDS doxygen_cpp doxygen_python
-    )
-  elseif(PYTHON3_EXECUTABLE)
+  if(NOT DEFINED HAVE_PYTHON_BS4 AND PYTHON_DEFAULT_EXECUTABLE)
+    # Documentation post-processing tool requires BuautifulSoup Python package
+    execute_process(COMMAND "${PYTHON_DEFAULT_EXECUTABLE}" -c "import bs4; from bs4 import BeautifulSoup; print(bs4.__version__)"
+                    RESULT_VARIABLE _result
+                    OUTPUT_VARIABLE _bs4_version
+                    OUTPUT_STRIP_TRAILING_WHITESPACE)
+
+    if(NOT _result EQUAL 0)
+      set(HAVE_PYTHON_BS4 0 CACHE INTERNAL "")
+    else()
+      message(STATUS "Python BeautifulSoup (bs4) version: ${_bs4_version}")
+      set(HAVE_PYTHON_BS4 1 CACHE INTERNAL "")
+    endif()
+  endif()
+
+  if(PYTHON_DEFAULT_EXECUTABLE AND HAVE_PYTHON_BS4
+      AND OPENCV_PYTHON_SIGNATURES_FILE AND TARGET gen_opencv_python_source)
     add_custom_target(doxygen_python
-      COMMAND ${PYTHON3_EXECUTABLE} "${CMAKE_CURRENT_SOURCE_DIR}/tools/add_signatures.py" "${CMAKE_CURRENT_BINARY_DIR}/doxygen/html/" "${OPENCV_PYTHON3_SIGNATURES_FILE}" "python"
-      DEPENDS "${doxygen_result}" gen_opencv_python3
+      COMMAND ${PYTHON_DEFAULT_EXECUTABLE} "${CMAKE_CURRENT_SOURCE_DIR}/tools/add_signatures.py" "${CMAKE_CURRENT_BINARY_DIR}/doxygen/html/" "${OPENCV_PYTHON_SIGNATURES_FILE}" "python"
+      DEPENDS doxygen_cpp gen_opencv_python_source
+      COMMENT "Inject Python signatures into documentation"
     )
     add_custom_target(doxygen
       DEPENDS doxygen_cpp doxygen_python

modules/python/CMakeLists.txt

@@ -2,6 +2,8 @@
 #  CMake file for python support
 # ----------------------------------------------------------------------------
 
+add_subdirectory(bindings)
+
 if(ANDROID OR APPLE_FRAMEWORK OR WINRT)
   set(__disable_python2 ON)
   set(__disable_python3 ON)

modules/python/bindings/CMakeLists.txt

+set(MODULE_NAME "python_bindings_generator")
+ocv_add_module(${MODULE_NAME} INTERNAL)
+
+set(OPENCV_PYTHON_SIGNATURES_FILE "${CMAKE_CURRENT_BINARY_DIR}/pyopencv_signatures.json" CACHE INTERNAL "")
+set(OPENCV_PYTHON_BINDINGS_DIR "${CMAKE_CURRENT_BINARY_DIR}" CACHE INTERNAL "")
+
+# This file is included from a subdirectory
+set(PYTHON_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/../")
+
+# get list of modules to wrap
+set(OPENCV_PYTHON_MODULES)
+foreach(m ${OPENCV_MODULES_BUILD})
+  if (";${OPENCV_MODULE_${m}_WRAPPERS};" MATCHES ";${MODULE_NAME};" AND HAVE_${m})
+    list(APPEND OPENCV_PYTHON_MODULES ${m})
+    #message(STATUS "\t${m}")
+  endif()
+endforeach()
+
+set(opencv_hdrs "")
+set(opencv_userdef_hdrs "")
+foreach(m ${OPENCV_PYTHON_MODULES})
+  list(APPEND opencv_hdrs ${OPENCV_MODULE_${m}_HEADERS})
+  file(GLOB userdef_hdrs ${OPENCV_MODULE_${m}_LOCATION}/misc/python/pyopencv*.hpp)
+  list(APPEND opencv_userdef_hdrs ${userdef_hdrs})
+endforeach(m)
+
+# header blacklist
+ocv_list_filterout(opencv_hdrs "modules/.*\\\\.h$")
+ocv_list_filterout(opencv_hdrs "modules/core/.*/cuda")
+ocv_list_filterout(opencv_hdrs "modules/cuda.*")
+ocv_list_filterout(opencv_hdrs "modules/cudev")
+ocv_list_filterout(opencv_hdrs "modules/core/.*/hal/")
+ocv_list_filterout(opencv_hdrs "modules/.+/utils/.*")
+ocv_list_filterout(opencv_hdrs "modules/.*\\\\.inl\\\\.h*")
+ocv_list_filterout(opencv_hdrs "modules/.*_inl\\\\.h*")
+ocv_list_filterout(opencv_hdrs "modules/.*\\\\.details\\\\.h*")
+ocv_list_filterout(opencv_hdrs "modules/.*/detection_based_tracker\\\\.hpp") # Conditional compilation
+
+set(cv2_generated_hdrs
+    "${CMAKE_CURRENT_BINARY_DIR}/pyopencv_generated_include.h"
+    "${CMAKE_CURRENT_BINARY_DIR}/pyopencv_generated_funcs.h"
+    "${CMAKE_CURRENT_BINARY_DIR}/pyopencv_generated_types.h"
+    "${CMAKE_CURRENT_BINARY_DIR}/pyopencv_generated_type_reg.h"
+    "${CMAKE_CURRENT_BINARY_DIR}/pyopencv_generated_ns_reg.h"
+)
+
+set(cv2_generated_files ${cv2_generated_hdrs}
+    "${OPENCV_PYTHON_SIGNATURES_FILE}"
+)
+
+string(REPLACE ";" "\n" opencv_hdrs_ "${opencv_hdrs}")
+file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/headers.txt" "${opencv_hdrs_}")
+add_custom_command(
+    OUTPUT ${cv2_generated_files}
+    COMMAND ${PYTHON_DEFAULT_EXECUTABLE} "${PYTHON_SOURCE_DIR}/src2/gen2.py" ${CMAKE_CURRENT_BINARY_DIR} "${CMAKE_CURRENT_BINARY_DIR}/headers.txt"
+    DEPENDS ${PYTHON_SOURCE_DIR}/src2/gen2.py
+    DEPENDS ${PYTHON_SOURCE_DIR}/src2/hdr_parser.py
+    DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/headers.txt
+    DEPENDS ${opencv_hdrs}
+    COMMENT "Generate files for Python bindings and documentation"
+)
+
+add_custom_target(gen_opencv_python_source DEPENDS ${cv2_generated_files})
+
+set(cv2_custom_hdr "${CMAKE_CURRENT_BINARY_DIR}/pyopencv_custom_headers.h")
+file(WRITE ${cv2_custom_hdr} "//user-defined headers\n")
+foreach(uh ${opencv_userdef_hdrs})
+    file(APPEND ${cv2_custom_hdr} "#include \"${uh}\"\n")
+endforeach(uh)

modules/python/common.cmake

 # This file is included from a subdirectory
 set(PYTHON_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/../")
 
-# try to use dynamic symbols linking with libpython.so
-set(OPENCV_FORCE_PYTHON_LIBS OFF CACHE BOOL "")
-string(REPLACE "-Wl,--no-undefined" "" CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS}")
-if(NOT WIN32 AND NOT APPLE AND NOT OPENCV_PYTHON_SKIP_LINKER_EXCLUDE_LIBS)
-  set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -Wl,--exclude-libs=ALL")
-endif()
-
-ocv_add_module(${MODULE_NAME} BINDINGS)
+ocv_add_module(${MODULE_NAME} BINDINGS PRIVATE_REQUIRED opencv_python_bindings_generator)
 
 ocv_module_include_directories(
     "${${PYTHON}_INCLUDE_PATH}"
+)
+include_directories(
     ${${PYTHON}_NUMPY_INCLUDE_DIRS}
     "${PYTHON_SOURCE_DIR}/src2"
-    )
-
-# get list of modules to wrap
-# message(STATUS "Wrapped in ${MODULE_NAME}:")
-set(OPENCV_PYTHON_MODULES)
-foreach(m ${OPENCV_MODULES_BUILD})
-  if (";${OPENCV_MODULE_${m}_WRAPPERS};" MATCHES ";${MODULE_NAME};" AND HAVE_${m})
-    list(APPEND OPENCV_PYTHON_MODULES ${m})
-    # message(STATUS "\t${m}")
-  endif()
-endforeach()
-
-set(opencv_hdrs "")
-set(opencv_userdef_hdrs "")
-foreach(m ${OPENCV_PYTHON_MODULES})
-  list(APPEND opencv_hdrs ${OPENCV_MODULE_${m}_HEADERS})
-  file(GLOB userdef_hdrs ${OPENCV_MODULE_${m}_LOCATION}/misc/python/pyopencv*.hpp)
-  list(APPEND opencv_userdef_hdrs ${userdef_hdrs})
-endforeach(m)
-
-# header blacklist
-ocv_list_filterout(opencv_hdrs "modules/.*\\\\.h$")
-ocv_list_filterout(opencv_hdrs "modules/core/.*/cuda")
-ocv_list_filterout(opencv_hdrs "modules/cuda.*")
-ocv_list_filterout(opencv_hdrs "modules/cudev")
-ocv_list_filterout(opencv_hdrs "modules/core/.*/hal/")
-ocv_list_filterout(opencv_hdrs "modules/.+/utils/.*")
-ocv_list_filterout(opencv_hdrs "modules/.*\\\\.inl\\\\.h*")
-ocv_list_filterout(opencv_hdrs "modules/.*_inl\\\\.h*")
-ocv_list_filterout(opencv_hdrs "modules/.*\\\\.details\\\\.h*")
-ocv_list_filterout(opencv_hdrs "modules/.*/detection_based_tracker\\\\.hpp") # Conditional compilation
-
-set(cv2_generated_hdrs
-    "${CMAKE_CURRENT_BINARY_DIR}/pyopencv_generated_include.h"
-    "${CMAKE_CURRENT_BINARY_DIR}/pyopencv_generated_funcs.h"
-    "${CMAKE_CURRENT_BINARY_DIR}/pyopencv_generated_types.h"
-    "${CMAKE_CURRENT_BINARY_DIR}/pyopencv_generated_type_reg.h"
-    "${CMAKE_CURRENT_BINARY_DIR}/pyopencv_generated_ns_reg.h"
-)
-
-set(OPENCV_${PYTHON}_SIGNATURES_FILE "${CMAKE_CURRENT_BINARY_DIR}/pyopencv_signatures.json" CACHE INTERNAL "")
-
-set(cv2_generated_files ${cv2_generated_hdrs}
-    "${OPENCV_${PYTHON}_SIGNATURES_FILE}"
-)
-
-string(REPLACE ";" "\n" opencv_hdrs_ "${opencv_hdrs}")
-file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/headers.txt" "${opencv_hdrs_}")
-add_custom_command(
-    OUTPUT ${cv2_generated_files}
-    COMMAND ${PYTHON_DEFAULT_EXECUTABLE} "${PYTHON_SOURCE_DIR}/src2/gen2.py" ${CMAKE_CURRENT_BINARY_DIR} "${CMAKE_CURRENT_BINARY_DIR}/headers.txt" "${PYTHON}"
-    DEPENDS ${PYTHON_SOURCE_DIR}/src2/gen2.py
-    DEPENDS ${PYTHON_SOURCE_DIR}/src2/hdr_parser.py
-    DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/headers.txt
-    DEPENDS ${opencv_hdrs}
-    COMMENT "Generate files for ${the_module}"
+    "${OPENCV_PYTHON_BINDINGS_DIR}"
 )
 
-add_custom_target(gen_${the_module} DEPENDS ${cv2_generated_files})
-
-set(cv2_custom_hdr "${CMAKE_CURRENT_BINARY_DIR}/pyopencv_custom_headers.h")
-file(WRITE ${cv2_custom_hdr} "//user-defined headers\n")
-foreach(uh ${opencv_userdef_hdrs})
-    file(APPEND ${cv2_custom_hdr} "#include \"${uh}\"\n")
-endforeach(uh)
+# try to use dynamic symbols linking with libpython.so
+set(OPENCV_FORCE_PYTHON_LIBS OFF CACHE BOOL "")
+string(REPLACE "-Wl,--no-undefined" "" CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS}")
+if(NOT WIN32 AND NOT APPLE AND NOT OPENCV_PYTHON_SKIP_LINKER_EXCLUDE_LIBS)
+  set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -Wl,--exclude-libs=ALL")
+endif()
 
 ocv_add_library(${the_module} MODULE ${PYTHON_SOURCE_DIR}/src2/cv2.cpp ${cv2_generated_hdrs} ${opencv_userdef_hdrs} ${cv2_custom_hdr})
-add_dependencies(${the_module} gen_${the_module})
+add_dependencies(${the_module} gen_opencv_python_source)
 
 if(APPLE)
   set_target_properties(${the_module} PROPERTIES LINK_FLAGS "-undefined dynamic_lookup")
@@ -92,7 +31,10 @@ elseif(WIN32 OR OPENCV_FORCE_PYTHON_LIBS)
     ocv_target_link_libraries(${the_module} LINK_PRIVATE ${${PYTHON}_LIBRARIES})
   endif()
 endif()
-ocv_target_link_libraries(${the_module} LINK_PRIVATE ${OPENCV_MODULE_${the_module}_DEPS})
+
+set(deps ${OPENCV_MODULE_${the_module}_DEPS})
+list(REMOVE_ITEM deps opencv_python_bindings_generator) # don't add dummy module to target_link_libraries list
+ocv_target_link_libraries(${the_module} LINK_PRIVATE ${deps})
 
 if(DEFINED ${PYTHON}_CVPY_SUFFIX)
   set(CVPY_SUFFIX "${${PYTHON}_CVPY_SUFFIX}")

modules/python/src2/cv2.cpp

@@ -9,6 +9,12 @@
 #define NPY_NO_DEPRECATED_API NPY_1_7_API_VERSION
 #include <numpy/ndarrayobject.h>
 
+#if PY_MAJOR_VERSION >= 3
+#  define CV_PYTHON_TYPE_HEAD_INIT() PyVarObject_HEAD_INIT(&PyType_Type, 0)
+#else
+#  define CV_PYTHON_TYPE_HEAD_INIT() PyObject_HEAD_INIT(&PyType_Type) 0,
+#endif
+
 #include "pyopencv_generated_include.h"
 #include "opencv2/core/types_c.h"
 

modules/python/src2/gen2.py

@@ -46,20 +46,7 @@ gen_template_func_body = Template("""$code_decl
     }
 """)
 
-py_major_version = sys.version_info[0]
-if __name__ == "__main__":
-    if len(sys.argv) > 3:
-        if sys.argv[3] == 'PYTHON3':
-            py_major_version = 3
-        elif sys.argv[3] == 'PYTHON2':
-            py_major_version = 2
-        else:
-            raise Exception('Incorrect argument: expected PYTHON2 or PYTHON3, received: ' + sys.argv[3])
-if py_major_version >= 3:
-    head_init_str = "PyVarObject_HEAD_INIT(&PyType_Type, 0)"
-else:
-    head_init_str = """PyObject_HEAD_INIT(&PyType_Type)
-0,"""
+head_init_str = "CV_PYTHON_TYPE_HEAD_INIT()"
 
 gen_template_simple_type_decl = Template("""
 struct pyopencv_${name}_t