Add support for VirtualErrorHandlers in core sip

Unfortunately requires a bunch of code to be duplicated from QgsPythonUtilsImpl::getTraceback() into core.sip, but there's no way to avoid this
qgis · Jun 23, 2017 · d63d560 · d63d560
1 parent 53e7ef8
commit d63d560
Showing 1 changed file with 91 additions and 0 deletions.
diff --git a/python/core/core.sip b/python/core/core.sip
@@ -1,6 +1,93 @@
 %Module(name=qgis._core,
         keyword_arguments="Optional")
 
+%ModuleCode
+
+#include "qgsprocessingexception.h"
+
+QString getTraceback()
+{
+#define TRACEBACK_FETCH_ERROR(what) {errMsg = what; goto done;}
+
+  // acquire global interpreter lock to ensure we are in a consistent state
+  PyGILState_STATE gstate;
+  gstate = PyGILState_Ensure();
+
+  QString errMsg;
+  QString result;
+
+  PyObject *modStringIO = nullptr;
+  PyObject *modTB = nullptr;
+  PyObject *obStringIO = nullptr;
+  PyObject *obResult = nullptr;
+
+  PyObject *type, *value, *traceback;
+
+  PyErr_Fetch( &type, &value, &traceback );
+  PyErr_NormalizeException( &type, &value, &traceback );
+
+  const char *iomod = "io";
+
+  modStringIO = PyImport_ImportModule( iomod );
+  if ( !modStringIO )
+    TRACEBACK_FETCH_ERROR( QString( "can't import %1" ).arg( iomod ) );
+
+  obStringIO = PyObject_CallMethod( modStringIO, ( char * ) "StringIO", nullptr );
+
+  /* Construct a cStringIO object */
+  if ( !obStringIO )
+    TRACEBACK_FETCH_ERROR( "cStringIO.StringIO() failed" );
+
+  modTB = PyImport_ImportModule( "traceback" );
+  if ( !modTB )
+    TRACEBACK_FETCH_ERROR( "can't import traceback" );
+
+  obResult = PyObject_CallMethod( modTB, ( char * ) "print_exception",
+                                  ( char * ) "OOOOO",
+                                  type, value ? value : Py_None,
+                                  traceback ? traceback : Py_None,
+                                  Py_None,
+                                  obStringIO );
+
+  if ( !obResult )
+    TRACEBACK_FETCH_ERROR( "traceback.print_exception() failed" );
+
+  Py_DECREF( obResult );
+
+  obResult = PyObject_CallMethod( obStringIO, ( char * ) "getvalue", nullptr );
+  if ( !obResult )
+    TRACEBACK_FETCH_ERROR( "getvalue() failed." );
+
+  /* And it should be a string all ready to go - duplicate it. */
+  if ( !PyUnicode_Check( obResult ) )
+    TRACEBACK_FETCH_ERROR( "getvalue() did not return a string" );
+
+  result = QString::fromUtf8( PyUnicode_AsUTF8( obResult ) );
+
+done:
+
+  // All finished - first see if we encountered an error
+  if ( result.isEmpty() && !errMsg.isEmpty() )
+  {
+    result = errMsg;
+  }
+
+  Py_XDECREF( modStringIO );
+  Py_XDECREF( modTB );
+  Py_XDECREF( obStringIO );
+  Py_XDECREF( obResult );
+  Py_XDECREF( value );
+  Py_XDECREF( traceback );
+  Py_XDECREF( type );
+
+  // we are done calling python API, release global interpreter lock
+  PyGILState_Release( gstate );
+
+  return result;
+}
+
+%End
+
 %Import QtXml/QtXmlmod.sip
 %Import QtNetwork/QtNetworkmod.sip
 %Import QtSql/QtSqlmod.sip
@@ -413,3 +500,7 @@
 %Include expression/qgsexpressionnodeimpl.sip
 %Include expression/qgsexpressionnode.sip
 %Include expression/qgsexpressionfunction.sip
+
+%VirtualErrorHandler processing_exception_handler
+    throw QgsProcessingException( getTraceback() );
+%End