python : update the wrapper files when one of the included header file is modified

It is no more needed to manually remove the _wrap.cxx files. However, it is still necessary to re-run cmake when one of the .i file is modified.

gmshpy/CMakeLists.txt

@@ -7,6 +7,55 @@ set (SWIG_MODULES
   gmshMesh
 )
 
+# code backported from CMake git version, see CMake bug 4147
+MACRO(SWIG_GET_WRAPPER_DEPENDENCIES swigFile genWrapper language DEST_VARIABLE)
+  GET_FILENAME_COMPONENT(swig_getdeps_basename ${swigFile} NAME_WE)
+  GET_FILENAME_COMPONENT(swig_getdeps_outdir ${genWrapper} PATH)
+  GET_SOURCE_FILE_PROPERTY(swig_getdeps_extra_flags "${swigFile}" SWIG_FLAGS)
+  IF("${swig_getdeps_extra_flags}" STREQUAL "NOTFOUND")
+    SET(swig_getdeps_extra_flags "")
+  ENDIF("${swig_getdeps_extra_flags}" STREQUAL "NOTFOUND")
+
+  IF(NOT swig_getdeps_outdir)
+    SET(swig_getdeps_outdir ${CMAKE_CURRENT_BINARY_DIR})
+  ENDIF(NOT swig_getdeps_outdir)
+  SET(swig_getdeps_depsfile
+    ${swig_getdeps_outdir}/swig_${swig_getdeps_basename}_deps.txt)
+  GET_DIRECTORY_PROPERTY(swig_getdeps_include_directories INCLUDE_DIRECTORIES)
+  SET(swig_getdeps_include_dirs)
+  FOREACH(it ${swig_getdeps_include_directories})
+    SET(swig_getdeps_include_dirs ${swig_getdeps_include_dirs} "-I${it}")
+  ENDFOREACH(it)
+  EXECUTE_PROCESS(
+    COMMAND ${SWIG_EXECUTABLE}
+    -MM -MF ${swig_getdeps_depsfile} ${swig_getdeps_extra_flags}
+    ${CMAKE_SWIG_FLAGS} -${language}
+    -o ${genWrapper} ${swig_getdeps_include_dirs} ${swigFile}
+    RESULT_VARIABLE swig_getdeps_result
+    ERROR_VARIABLE swig_getdeps_error
+    OUTPUT_STRIP_TRAILING_WHITESPACE)
+  IF(NOT ${swig_getdeps_error} EQUAL 0)
+    MESSAGE(SEND_ERROR "Command \"${SWIG_EXECUTABLE} -MM -MF ${swig_getdeps_depsfile} ${swig_getdeps_extra_flags} ${CMAKE_SWIG_FLAGS} -${language} -o ${genWrapper} ${swig_getdeps_include_dirs} ${swigFile}\" failed with output:\n${swig_getdeps_error}")
+    SET(swig_getdeps_dependencies "")
+  ELSE(NOT ${swig_getdeps_error} EQUAL 0)
+    FILE(READ ${swig_getdeps_depsfile} ${DEST_VARIABLE})
+    # Remove the first line
+    STRING(REGEX REPLACE "^.+: +\\\\\n +" ""
+      ${DEST_VARIABLE} "${${DEST_VARIABLE}}")
+    # Clean the end of each line
+    STRING(REGEX REPLACE " +(\\\\)?\n" "\n" ${DEST_VARIABLE}
+      "${${DEST_VARIABLE}}")
+    # Clean beginning of each line
+    STRING(REGEX REPLACE "\n +" "\n"
+      ${DEST_VARIABLE} "${${DEST_VARIABLE}}")
+    # clean paths
+    STRING(REGEX REPLACE "\\\\\\\\" "/" ${DEST_VARIABLE}
+      "${${DEST_VARIABLE}}")
+    STRING(REGEX REPLACE "\n" ";"
+      ${DEST_VARIABLE} "${${DEST_VARIABLE}}")
+  ENDIF(NOT ${swig_getdeps_error} EQUAL 0)
+ENDMACRO(SWIG_GET_WRAPPER_DEPENDENCIES)
+
 if(ENABLE_SWIG)
   find_package(SWIG)
   if(SWIG_FOUND)
@@ -21,6 +70,11 @@ if(ENABLE_SWIG)
 
       foreach(module ${SWIG_MODULES})
         set_source_files_properties(${module}.i PROPERTIES CPLUSPLUS ON)
+
+        # code backported from CMake git version, see CMake bug 4147
+        SWIG_GET_WRAPPER_DEPENDENCIES(${CMAKE_CURRENT_SOURCE_DIR}/\${module}.i ${CMAKE_CURRENT_BINARY_DIR}/${module}PYTHON_wrap.cxx python swig_extra_dependencies)
+        LIST(APPEND SWIG_MODULE_${module}_EXTRA_DEPS ${swig_extra_dependencies})
+
         swig_add_module(${module} python ${module}.i)
         swig_link_libraries(${module} ${PYTHON_LIBRARIES} shared)
         SET(GMSH_PYTHON_MODULES_INCLUDE_CODE