2.5: python module name for import had trailing "."
[blender.git] / source / blender / python / intern / bpy_interface.c
1
2 #include <stdio.h>
3 #include <stdlib.h>
4 #include <string.h>
5 #include <sys/stat.h>
6
7 #ifndef WIN32
8 #include <dirent.h>
9 #else
10 #include "BLI_winstuff.h"
11 #endif
12
13 #include <Python.h>
14 #include "compile.h"            /* for the PyCodeObject */
15 #include "eval.h"               /* for PyEval_EvalCode */
16
17 #include "bpy_compat.h"
18
19 #include "bpy_rna.h"
20 #include "bpy_operator.h"
21 #include "bpy_ui.h"
22 #include "bpy_util.h"
23
24 #include "DNA_anim_types.h"
25 #include "DNA_space_types.h"
26 #include "DNA_text_types.h"
27
28 #include "MEM_guardedalloc.h"
29
30 #include "BLI_util.h"
31 #include "BLI_fileops.h"
32 #include "BLI_string.h"
33
34 #include "BKE_context.h"
35 #include "BKE_fcurve.h"
36 #include "BKE_text.h"
37
38 #include "BPY_extern.h"
39
40 #include "../generic/bpy_internal_import.h" // our own imports
41 /* external util modules */
42
43 #include "../generic/Mathutils.h"
44 #include "../generic/Geometry.h"
45 #include "../generic/BGL.h"
46
47
48 void BPY_free_compiled_text( struct Text *text )
49 {
50         if( text->compiled ) {
51                 Py_DECREF( ( PyObject * ) text->compiled );
52                 text->compiled = NULL;
53         }
54 }
55
56 /*****************************************************************************
57 * Description: Creates the bpy module and adds it to sys.modules for importing
58 *****************************************************************************/
59 static void bpy_init_modules( void )
60 {
61         PyObject *mod;
62         
63         mod = PyModule_New("bpy");
64         
65         PyModule_AddObject( mod, "data", BPY_rna_module() );
66         /* PyModule_AddObject( mod, "doc", BPY_rna_doc() ); */
67         PyModule_AddObject( mod, "types", BPY_rna_types() );
68         PyModule_AddObject( mod, "props", BPY_rna_props() );
69         PyModule_AddObject( mod, "__ops__", BPY_operator_module() ); /* ops is now a python module that does the conversion from SOME_OT_foo -> some.foo */
70         PyModule_AddObject( mod, "ui", BPY_ui_module() ); // XXX very experimental, consider this a test, especially PyCObject is not meant to be permanent
71         
72         /* add the module so we can import it */
73         PyDict_SetItemString(PySys_GetObject("modules"), "bpy", mod);
74         Py_DECREF(mod);
75
76
77         /* stand alone utility modules not related to blender directly */
78         Geometry_Init("Geometry");
79         Mathutils_Init("Mathutils");
80         BGL_Init("BGL");
81 }
82
83 #if (PY_VERSION_HEX < 0x02050000)
84 PyObject *PyImport_ImportModuleLevel(char *name, void *a, void *b, void *c, int d)
85 {
86         return PyImport_ImportModule(name);
87 }
88 #endif
89
90 void BPY_update_modules( void )
91 {
92         PyObject *mod= PyImport_ImportModuleLevel("bpy", NULL, NULL, NULL, 0);
93         PyModule_AddObject( mod, "data", BPY_rna_module() );
94         PyModule_AddObject( mod, "types", BPY_rna_types() );
95 }
96
97 /*****************************************************************************
98 * Description: This function creates a new Python dictionary object.
99 *****************************************************************************/
100 static PyObject *CreateGlobalDictionary( bContext *C )
101 {
102         PyObject *mod;
103         PyObject *dict = PyDict_New(  );
104         PyObject *item = PyUnicode_FromString( "__main__" );
105         PyDict_SetItemString( dict, "__builtins__", PyEval_GetBuiltins(  ) );
106         PyDict_SetItemString( dict, "__name__", item );
107         Py_DECREF(item);
108         
109         // XXX - evil, need to access context
110         BPy_SetContext(C);
111         
112         // XXX - put somewhere more logical
113         {
114                 PyMethodDef *ml;
115                 static PyMethodDef bpy_prop_meths[] = {
116                         {"FloatProperty", (PyCFunction)BPy_FloatProperty, METH_VARARGS|METH_KEYWORDS, ""},
117                         {"IntProperty", (PyCFunction)BPy_IntProperty, METH_VARARGS|METH_KEYWORDS, ""},
118                         {"BoolProperty", (PyCFunction)BPy_BoolProperty, METH_VARARGS|METH_KEYWORDS, ""},
119                         {"StringProperty", (PyCFunction)BPy_StringProperty, METH_VARARGS|METH_KEYWORDS, ""},
120                         {NULL, NULL, 0, NULL}
121                 };
122                 
123                 for(ml = bpy_prop_meths; ml->ml_name; ml++) {
124                         PyDict_SetItemString( dict, ml->ml_name, PyCFunction_New(ml, NULL));
125                 }
126         }
127         
128         /* add bpy to global namespace */
129         mod= PyImport_ImportModuleLevel("bpy", NULL, NULL, NULL, 0);
130         PyDict_SetItemString( dict, "bpy", mod );
131         Py_DECREF(mod);
132         
133         return dict;
134 }
135
136 /* Use this so we can include our own python bundle */
137 #if 0
138 wchar_t* Py_GetPath(void)
139 {
140         int i;
141         static wchar_t py_path[FILE_MAXDIR] = L"";
142         char *dirname= BLI_gethome_folder("python");
143         if(dirname) {
144                 i= mbstowcs(py_path, dirname, FILE_MAXDIR);
145                 printf("py path %s, %d\n", dirname, i);
146         }
147         return py_path;
148 }
149 #endif
150
151
152 /* must be called before Py_Initialize */
153 void BPY_start_python_path(void)
154 {
155         char *py_path_bundle= BLI_gethome_folder("python");
156
157         if(py_path_bundle==NULL)
158                 return;
159
160         /* set the environment path */
161         printf("found bundled python: %s\n", py_path_bundle);
162
163         BLI_setenv("PYTHONHOME", py_path_bundle);
164         BLI_setenv("PYTHONPATH", py_path_bundle);
165 }
166
167
168 void BPY_start_python( int argc, char **argv )
169 {
170         PyThreadState *py_tstate = NULL;
171         
172         BPY_start_python_path(); /* allow to use our own included python */
173
174         Py_Initialize(  );
175         
176 #if (PY_VERSION_HEX < 0x03000000)
177         PySys_SetArgv( argc, argv);
178 #else
179         /* sigh, why do python guys not have a char** version anymore? :( */
180         {
181                 int i;
182                 PyObject *py_argv= PyList_New(argc);
183
184                 for (i=0; i<argc; i++)
185                         PyList_SET_ITEM(py_argv, i, PyUnicode_FromString(argv[i]));
186
187                 PySys_SetObject("argv", py_argv);
188                 Py_DECREF(py_argv);
189         }
190 #endif
191         
192         /* Initialize thread support (also acquires lock) */
193         PyEval_InitThreads();
194         
195         
196         /* bpy.* and lets us import it */
197         bpy_init_modules(); 
198
199         { /* our own import and reload functions */
200                 PyObject *item;
201                 //PyObject *m = PyImport_AddModule("__builtin__");
202                 //PyObject *d = PyModule_GetDict(m);
203                 PyObject *d = PyEval_GetBuiltins(  );
204                 PyDict_SetItemString(d, "reload",               item=PyCFunction_New(bpy_reload_meth, NULL));   Py_DECREF(item);
205                 PyDict_SetItemString(d, "__import__",   item=PyCFunction_New(bpy_import_meth, NULL));   Py_DECREF(item);
206         }
207         
208         py_tstate = PyGILState_GetThisThreadState();
209         PyEval_ReleaseThread(py_tstate);
210 }
211
212 void BPY_end_python( void )
213 {
214         PyGILState_Ensure(); /* finalizing, no need to grab the state */
215         
216         // free other python data.
217         //BPY_rna_free_types();
218         
219         Py_Finalize(  );
220         
221         return;
222 }
223
224 /* Can run a file or text block */
225 int BPY_run_python_script( bContext *C, const char *fn, struct Text *text, struct ReportList *reports)
226 {
227         PyObject *py_dict, *py_result;
228         PyGILState_STATE gilstate;
229         
230         if (fn==NULL && text==NULL) {
231                 return 0;
232         }
233         
234         //BPY_start_python();
235         
236         gilstate = PyGILState_Ensure();
237
238         BPY_update_modules(); /* can give really bad results if this isnt here */
239         bpy_import_main_set(CTX_data_main(C));
240         
241         py_dict = CreateGlobalDictionary(C);
242
243         if (text) {
244                 
245                 if( !text->compiled ) { /* if it wasn't already compiled, do it now */
246                         char *buf = txt_to_buf( text );
247
248                         text->compiled =
249                                 Py_CompileString( buf, text->id.name+2, Py_file_input );
250
251                         MEM_freeN( buf );
252
253                         if( PyErr_Occurred(  ) ) {
254                                 BPy_errors_to_report(reports);
255                                 BPY_free_compiled_text( text );
256                                 PyGILState_Release(gilstate);
257                                 return 0;
258                         }
259                 }
260                 py_result =  PyEval_EvalCode( text->compiled, py_dict, py_dict );
261                 
262         } else {
263                 char pystring[512];
264                 /* TODO - look into a better way to run a file */
265                 sprintf(pystring, "exec(open(r'%s').read())", fn);      
266                 py_result = PyRun_String( pystring, Py_file_input, py_dict, py_dict );                  
267         }
268         
269         if (!py_result) {
270                 BPy_errors_to_report(reports);
271         } else {
272                 Py_DECREF( py_result );
273         }
274         
275         Py_DECREF(py_dict);
276         PyGILState_Release(gilstate);
277         bpy_import_main_set(NULL);
278         
279         //BPY_end_python();
280         return py_result ? 1:0;
281 }
282
283
284 /* TODO - move into bpy_space.c ? */
285 /* GUI interface routines */
286
287 /* Copied from Draw.c */
288 static void exit_pydraw( SpaceScript * sc, short err )
289 {
290         Script *script = NULL;
291
292         if( !sc || !sc->script )
293                 return;
294
295         script = sc->script;
296
297         if( err ) {
298                 BPy_errors_to_report(NULL); // TODO, reports
299                 script->flags = 0;      /* mark script struct for deletion */
300                 SCRIPT_SET_NULL(script);
301                 script->scriptname[0] = '\0';
302                 script->scriptarg[0] = '\0';
303 // XXX 2.5              error_pyscript();
304 // XXX 2.5              scrarea_queue_redraw( sc->area );
305         }
306
307 #if 0 // XXX 2.5
308         BPy_Set_DrawButtonsList(sc->but_refs);
309         BPy_Free_DrawButtonsList(); /*clear all temp button references*/
310 #endif
311
312         sc->but_refs = NULL;
313         
314         Py_XDECREF( ( PyObject * ) script->py_draw );
315         Py_XDECREF( ( PyObject * ) script->py_event );
316         Py_XDECREF( ( PyObject * ) script->py_button );
317
318         script->py_draw = script->py_event = script->py_button = NULL;
319 }
320
321 static int bpy_run_script_init(bContext *C, SpaceScript * sc)
322 {
323         if (sc->script==NULL) 
324                 return 0;
325         
326         if (sc->script->py_draw==NULL && sc->script->scriptname[0] != '\0')
327                 BPY_run_python_script(C, sc->script->scriptname, NULL, NULL);
328                 
329         if (sc->script->py_draw==NULL)
330                 return 0;
331         
332         return 1;
333 }
334
335 int BPY_run_script_space_draw(const struct bContext *C, SpaceScript * sc)
336 {
337         if (bpy_run_script_init( (bContext *)C, sc)) {
338                 PyGILState_STATE gilstate = PyGILState_Ensure();
339                 PyObject *result = PyObject_CallObject( sc->script->py_draw, NULL );
340                 
341                 if (result==NULL)
342                         exit_pydraw(sc, 1);
343                         
344                 PyGILState_Release(gilstate);
345         }
346         return 1;
347 }
348
349 // XXX - not used yet, listeners dont get a context
350 int BPY_run_script_space_listener(bContext *C, SpaceScript * sc)
351 {
352         if (bpy_run_script_init(C, sc)) {
353                 PyGILState_STATE gilstate = PyGILState_Ensure();
354                 
355                 PyObject *result = PyObject_CallObject( sc->script->py_draw, NULL );
356                 
357                 if (result==NULL)
358                         exit_pydraw(sc, 1);
359                         
360                 PyGILState_Release(gilstate);
361         }
362         return 1;
363 }
364
365 void BPY_DECREF(void *pyob_ptr)
366 {
367         Py_DECREF((PyObject *)pyob_ptr);
368 }
369
370 #if 0
371 /* called from the the scripts window, assume context is ok */
372 int BPY_run_python_script_space(const char *modulename, const char *func)
373 {
374         PyObject *py_dict, *py_result= NULL;
375         char pystring[512];
376         PyGILState_STATE gilstate;
377         
378         /* for calling the module function */
379         PyObject *py_func, 
380         
381         gilstate = PyGILState_Ensure();
382         
383         py_dict = CreateGlobalDictionary(C);
384         
385         PyObject *module = PyImport_ImportModule(scpt->script.filename);
386         if (module==NULL) {
387                 PyErr_SetFormat(PyExc_SystemError, "could not import '%s'", scpt->script.filename);
388         }
389         else {
390                 py_func = PyObject_GetAttrString(modulename, func);
391                 if (py_func==NULL) {
392                         PyErr_SetFormat(PyExc_SystemError, "module has no function '%s.%s'\n", scpt->script.filename, func);
393                 }
394                 else {
395                         Py_DECREF(py_func);
396                         if (!PyCallable_Check(py_func)) {
397                                 PyErr_SetFormat(PyExc_SystemError, "module item is not callable '%s.%s'\n", scpt->script.filename, func);
398                         }
399                         else {
400                                 py_result= PyObject_CallObject(py_func, NULL); // XXX will need args eventually
401                         }
402                 }
403         }
404         
405         if (!py_result) {
406                 BPy_errors_to_report(NULL); // TODO - reports
407         } else
408                 Py_DECREF( py_result );
409         
410         Py_XDECREF(module);
411         
412         Py_DECREF(py_dict);
413         
414         PyGILState_Release(gilstate);
415         return 1;
416 }
417 #endif
418
419 // #define TIME_REGISTRATION
420
421 #ifdef TIME_REGISTRATION
422 #include "PIL_time.h"
423 #endif
424
425 /* for use by BPY_run_ui_scripts only */
426 static int bpy_import_module(char *modname, int reload)
427 {
428         PyObject *mod= PyImport_ImportModuleLevel(modname, NULL, NULL, NULL, 0);
429         if (mod) {
430                 if (reload) {
431                         PyObject *mod_orig= mod;
432                         mod= PyImport_ReloadModule(mod);
433                         Py_DECREF(mod_orig);
434                 }
435         }
436
437         if(mod) {
438                 Py_DECREF(mod); /* could be NULL from reloading */
439                 return 0;
440         } else {
441                 return -1;
442         }
443 }
444
445 /* XXX this is temporary, need a proper script registration system for 2.5 */
446 void BPY_run_ui_scripts(bContext *C, int reload)
447 {
448 #ifdef TIME_REGISTRATION
449         double time = PIL_check_seconds_timer();
450 #endif
451         DIR *dir; 
452         struct dirent *de;
453         char *file_extension;
454         char *dirname;
455         char path[FILE_MAX];
456         char *dirs[] = {"ui", "io", NULL};
457         int a, err;
458         
459         PyGILState_STATE gilstate;
460         PyObject *sys_path;
461
462         gilstate = PyGILState_Ensure();
463         
464         // XXX - evil, need to access context
465         BPy_SetContext(C);
466         bpy_import_main_set(CTX_data_main(C));
467
468
469         sys_path= PySys_GetObject("path"); /* borrow */
470         PyList_Insert(sys_path, 0, Py_None); /* place holder, resizes the list */
471
472         for(a=0; dirs[a]; a++) {
473                 dirname= BLI_gethome_folder(dirs[a]);
474
475                 if(!dirname)
476                         continue;
477
478                 dir = opendir(dirname);
479
480                 if(!dir)
481                         continue;
482                 
483                 /* set the first dir in the sys.path for fast importing of modules */
484                 PyList_SetItem(sys_path, 0, PyUnicode_FromString(dirname)); /* steals the ref */
485                         
486                 while((de = readdir(dir)) != NULL) {
487                         /* We could stat the file but easier just to let python
488                          * import it and complain if theres a problem */
489                         err = 0;
490
491                         if (de->d_name[0] == '.') {
492                                 /* do nothing, probably .svn */
493                         }
494                         else if ((file_extension = strstr(de->d_name, ".py"))) {
495                                 /* normal py files? */
496                                 if(file_extension && file_extension[3] == '\0') {
497                                         de->d_name[(file_extension - de->d_name)] = '\0';
498                                         err= bpy_import_module(de->d_name, reload);
499                                 }
500                         }
501 #ifndef __linux__
502                         else if( BLI_join_dirfile(path, dirname, de->d_name), S_ISDIR(BLI_exists(path))) {
503 #else
504                         else if(de->d_type==DT_DIR) {
505                                 BLI_join_dirfile(path, dirname, de->d_name);
506 #endif
507                                 /* support packages */
508                                 BLI_join_dirfile(path, path, "__init__.py");
509
510                                 if(BLI_exists(path)) {
511                                         err= bpy_import_module(de->d_name, reload);
512                                 }
513                         }
514
515                         if(err==-1) {
516                                 BPy_errors_to_report(NULL);
517                                 fprintf(stderr, "unable to import %s/%s\n", dirname, de->d_name);
518                         }
519                 }
520
521                 closedir(dir);
522         }
523         
524         PyList_SetSlice(sys_path, 0, 1, NULL); /* remove the first item */
525
526         bpy_import_main_set(NULL);
527         
528         PyGILState_Release(gilstate);
529 #ifdef TIME_REGISTRATION
530         printf("script time %f\n", (PIL_check_seconds_timer()-time));
531 #endif
532 }
533
534 /* ****************************************** */
535 /* Drivers - PyExpression Evaluation */
536
537 /* for pydrivers (drivers using one-line Python expressions to express relationships between targets) */
538 PyObject *bpy_pydriver_Dict = NULL;
539
540 /* For faster execution we keep a special dictionary for pydrivers, with
541  * the needed modules and aliases. 
542  */
543 static int bpy_pydriver_create_dict(void)
544 {
545         PyObject *d, *mod;
546         
547         /* validate namespace for driver evaluation */
548         if (bpy_pydriver_Dict) return -1;
549
550         d = PyDict_New();
551         if (d == NULL) 
552                 return -1;
553         else
554                 bpy_pydriver_Dict = d;
555
556         /* import some modules: builtins, bpy, math, (Blender.noise )*/
557         PyDict_SetItemString(d, "__builtins__", PyEval_GetBuiltins());
558
559         mod = PyImport_ImportModule("math");
560         if (mod) {
561                 PyDict_Merge(d, PyModule_GetDict(mod), 0); /* 0 - dont overwrite existing values */
562                 
563                 /* Only keep for backwards compat! - just import all math into root, they are standard */
564                 PyDict_SetItemString(d, "math", mod);
565                 PyDict_SetItemString(d, "m", mod);
566                 Py_DECREF(mod);
567         } 
568         
569         /* add bpy to global namespace */
570         mod= PyImport_ImportModuleLevel("bpy", NULL, NULL, NULL, 0);
571         if (mod) {
572                 PyDict_SetItemString(bpy_pydriver_Dict, "bpy", mod);
573                 Py_DECREF(mod);
574         }
575         
576         
577 #if 0 // non existant yet
578         mod = PyImport_ImportModule("Blender.Noise");
579         if (mod) {
580                 PyDict_SetItemString(d, "noise", mod);
581                 PyDict_SetItemString(d, "n", mod);
582                 Py_DECREF(mod);
583         } else {
584                 PyErr_Clear();
585         }
586         
587         /* If there's a Blender text called pydrivers.py, import it.
588          * Users can add their own functions to this module. 
589          */
590         if (G.f & G_DOSCRIPTLINKS) {
591                 mod = importText("pydrivers"); /* can also use PyImport_Import() */
592                 if (mod) {
593                         PyDict_SetItemString(d, "pydrivers", mod);
594                         PyDict_SetItemString(d, "p", mod);
595                         Py_DECREF(mod);
596                 } else {
597                         PyErr_Clear();
598                 }
599         }
600 #endif // non existant yet
601         
602         return 0;
603 }
604
605 /* Update function, it gets rid of pydrivers global dictionary, forcing
606  * BPY_pydriver_eval to recreate it. This function is used to force
607  * reloading the Blender text module "pydrivers.py", if available, so
608  * updates in it reach pydriver evaluation. 
609  */
610 void BPY_pydriver_update(void)
611 {
612         PyGILState_STATE gilstate = PyGILState_Ensure();
613
614         if (bpy_pydriver_Dict) { /* free the global dict used by pydrivers */
615                 PyDict_Clear(bpy_pydriver_Dict);
616                 Py_DECREF(bpy_pydriver_Dict);
617                 bpy_pydriver_Dict = NULL;
618         }
619
620         PyGILState_Release(gilstate);
621
622         return;
623 }
624
625 /* error return function for BPY_eval_pydriver */
626 static float pydriver_error(ChannelDriver *driver) 
627 {
628         if (bpy_pydriver_Dict) { /* free the global dict used by pydrivers */
629                 PyDict_Clear(bpy_pydriver_Dict);
630                 Py_DECREF(bpy_pydriver_Dict);
631                 bpy_pydriver_Dict = NULL;
632         }
633
634         driver->flag |= DRIVER_FLAG_INVALID; /* py expression failed */
635         fprintf(stderr, "\nError in Driver: The following Python expression failed:\n\t'%s'\n\n", driver->expression);
636         
637         BPy_errors_to_report(NULL); // TODO - reports
638
639         return 0.0f;
640 }
641
642 /* This evals py driver expressions, 'expr' is a Python expression that
643  * should evaluate to a float number, which is returned. 
644  */
645 float BPY_pydriver_eval (ChannelDriver *driver)
646 {
647         PyObject *driver_vars=NULL;
648         PyObject *retval;
649         PyGILState_STATE gilstate;
650         
651         DriverTarget *dtar;
652         float result = 0.0f; /* default return */
653         char *expr = NULL;
654         short targets_ok= 1;
655         
656         /* sanity checks - should driver be executed? */
657         if ((driver == NULL) /*|| (G.f & G_DOSCRIPTLINKS)==0*/) 
658                 return result;
659         
660         /* get the py expression to be evaluated */
661         expr = driver->expression; 
662         if ((expr == NULL) || (expr[0]=='\0')) 
663                 return result;
664
665         gilstate = PyGILState_Ensure();
666         
667         /* init global dictionary for py-driver evaluation settings */
668         if (!bpy_pydriver_Dict) {
669                 if (bpy_pydriver_create_dict() != 0) {
670                         fprintf(stderr, "Pydriver error: couldn't create Python dictionary");
671                         PyGILState_Release(gilstate);
672                         return result;
673                 }
674         }
675         
676         /* add target values to a dict that will be used as '__locals__' dict */
677         driver_vars = PyDict_New(); // XXX do we need to decref this?
678         for (dtar= driver->targets.first; dtar; dtar= dtar->next) {
679                 PyObject *driver_arg = NULL;
680                 float tval = 0.0f;
681                 
682                 /* try to get variable value */
683                 tval= driver_get_target_value(driver, dtar);
684                 driver_arg= PyFloat_FromDouble((double)tval);
685                 
686                 /* try to add to dictionary */
687                 if (PyDict_SetItemString(driver_vars, dtar->name, driver_arg)) {
688                         /* this target failed - bad name */
689                         if (targets_ok) {
690                                 /* first one - print some extra info for easier identification */
691                                 fprintf(stderr, "\nBPY_pydriver_eval() - Error while evaluating PyDriver:\n");
692                                 targets_ok= 0;
693                         }
694                         
695                         fprintf(stderr, "\tBPY_pydriver_eval() - couldn't add variable '%s' to namespace \n", dtar->name);
696                         BPy_errors_to_report(NULL); // TODO - reports
697                 }
698         }
699         
700         /* execute expression to get a value */
701         retval = PyRun_String(expr, Py_eval_input, bpy_pydriver_Dict, driver_vars);
702         
703         /* decref the driver vars first...  */
704         Py_DECREF(driver_vars);
705         
706         /* process the result */
707         if (retval == NULL) {
708                 result = pydriver_error(driver);
709                 PyGILState_Release(gilstate);
710                 return result;
711         }
712
713         result = (float)PyFloat_AsDouble(retval);
714         Py_DECREF(retval);
715         
716         if ((result == -1) && PyErr_Occurred()) {
717                 result = pydriver_error(driver);
718                 PyGILState_Release(gilstate);
719                 return result;
720         }
721         
722         /* all fine, make sure the "invalid expression" flag is cleared */
723         driver->flag &= ~DRIVER_FLAG_INVALID;
724
725         PyGILState_Release(gilstate);
726
727         return result;
728 }