Add exception handling

Add XML elements specifying an exception handling mode to type system,
complex type entries (classes) and function modifications.

From the mode and the exception specification as detected
by Clang, deduce whether to generate try/catch code.

Task-number: PYSIDE-62
Change-Id: Ib76adc21cefd81bf9f82f819a3c151056c33a3b7
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Christian Tismer <tismer@stackless.com>

1 files changed, 36 insertions, 3 deletions

diff --git a/sources/shiboken2/generator/shiboken2/cppgenerator.cpp b/sources/shiboken2/generator/shiboken2/cppgenerator.cpp
index 2d4ea068d..0f94793e9 100644
--- a/sources/shiboken2/generator/shiboken2/cppgenerator.cpp
+++ b/sources/shiboken2/generator/shiboken2/cppgenerator.cpp
@@ -301,6 +301,8 @@ void CppGenerator::generateClass(QTextStream &s, GeneratorContext &classContext)
     // needs the 'set' class from C++ STL.
     if (hasMultipleInheritanceInAncestry(metaClass))
         s << "#include <set>" << endl;
+    if (metaClass->generateExceptionHandling())
+        s << "#include <exception>" << endl;
 
     s << endl << "// module include" << endl << "#include \"" << getModuleHeaderFileName() << '"' << endl;
 
@@ -3077,6 +3079,17 @@ QString CppGenerator::argumentNameFromIndex(const AbstractMetaFunction* func, in
     return pyArgName;
 }
 
+static QStringList defaultExceptionHandling()
+{
+    static const QStringList result{
+        QLatin1String("} catch (const std::exception &e) {"),
+        QLatin1String("    PyErr_SetString(PyExc_RuntimeError, e.what());"),
+        QLatin1String("} catch (...) {"),
+        QLatin1String("    PyErr_SetString(PyExc_RuntimeError, \"An unknown exception was caught\");"),
+        QLatin1String("}")};
+    return result;
+}
+
 void CppGenerator::writeMethodCall(QTextStream &s, const AbstractMetaFunction *func,
                                    GeneratorContext &context, int maxArgs)
 {
@@ -3334,8 +3347,17 @@ void CppGenerator::writeMethodCall(QTextStream &s, const AbstractMetaFunction *f
 
         if (!injectedCodeCallsCppFunction(func)) {
             const bool allowThread = func->allowThread();
-            if (allowThread)
+            const bool generateExceptionHandling = func->generateExceptionHandling();
+            if (generateExceptionHandling) {
+                s << INDENT << "try {\n";
+                ++INDENT.indent;
+                if (allowThread) {
+                    s << INDENT << "Shiboken::ThreadStateSaver threadSaver;\n"
+                        << INDENT << "threadSaver.save();\n";
+                }
+            } else if (allowThread) {
                 s << INDENT << BEGIN_ALLOW_THREADS << endl;
+            }
             s << INDENT;
             if (isCtor) {
                 s << (useVAddr.isEmpty() ?
@@ -3369,9 +3391,13 @@ void CppGenerator::writeMethodCall(QTextStream &s, const AbstractMetaFunction *f
             } else {
                 s << methodCall << ';' << endl;
             }
-            if (allowThread)
-                s << INDENT << END_ALLOW_THREADS << endl;
 
+            if (allowThread) {
+                s << INDENT << (generateExceptionHandling
+                                ? "threadSaver.restore();" : END_ALLOW_THREADS) << '\n';
+            }
+
+            // Convert result
             if (!func->conversionRule(TypeSystem::TargetLangCode, 0).isEmpty()) {
                 writeConversionRule(s, func, TypeSystem::TargetLangCode, QLatin1String(PYTHON_RETURN_VAR));
             } else if (!isCtor && !func->isInplaceOperator() && func->type()
@@ -3385,6 +3411,13 @@ void CppGenerator::writeMethodCall(QTextStream &s, const AbstractMetaFunction *f
                 }
                 s << ';' << endl;
             }
+
+            if (generateExceptionHandling) { // "catch" code
+                --INDENT.indent;
+                const QStringList handlingCode = defaultExceptionHandling();
+                for (const auto &line : handlingCode)
+                    s << INDENT << line << '\n';
+            }
         }
     }