CppEditor: Support try/catch in built-in indenter

Fixes: QTCREATORBUG-29452
Change-Id: Icf3d86a6080aeb741436800ae77af7c8bec3155c
Reviewed-by: Christian Stenger <christian.stenger@qt.io>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>

src/plugins/cppeditor/cppcodeformatter.cpp

@@ -284,6 +284,8 @@ void CodeFormatter::recalculateStateAfter(const QTextBlock &block)
                     && m_currentState.at(m_currentState.size() - 2).type == declaration_start) {
                     leave();
                     leave();
+                } else if (m_currentState.top().type == catch_statement) {
+                    turnInto(substatement);
                 }
                 break;
             default:            tryExpression(); break;
@@ -414,6 +416,11 @@ void CodeFormatter::recalculateStateAfter(const QTextBlock &block)
             default:            leave(true); continue;
             } break;
 
+        case catch_statement:
+            switch (kind) {
+            case T_LPAREN:      enter(arglist_open); break;
+            } break;
+
         case for_statement_paren_open:
             enter(for_statement_init); continue;
 
@@ -965,6 +972,12 @@ bool CodeFormatter::tryStatement()
         enter(do_statement);
         enter(substatement);
         return true;
+    case T_TRY:
+        enter(substatement);
+        return true;
+    case T_CATCH:
+        enter(catch_statement);
+        return true;
     case T_CASE:
     case T_DEFAULT:
         enter(case_start);

src/plugins/cppeditor/cppcodeformatter.h

@@ -119,6 +119,8 @@ public: // must be public to make Q_GADGET introspection work
         for_statement_condition, // The condition part of the for statement
         for_statement_expression, // The expression part of the for statement
 
+        catch_statement,
+
         switch_statement, // After 'switch' token
         case_start, // after a 'case' or 'default' token
         case_cont, // after the colon in a case/default

tests/auto/cplusplus/codeformatter/tst_codeformatter.cpp

@@ -109,6 +109,7 @@ private Q_SLOTS:
     void structuredBinding();
     void subscriptOperatorInFunctionCall();
     void statementMacros();
+    void tryCatchClause();
 };
 
 struct Line {
@@ -2231,6 +2232,45 @@ void tst_CodeFormatter::statementMacros()
     checkIndent(data, settings);
 }
 
+void tst_CodeFormatter::tryCatchClause()
+{
+    CppCodeStyleSettings settings;
+    settings.indentFunctionBody = true;
+    settings.indentFunctionBraces = false;
+    settings.indentBlockBody = false;
+    settings.indentBlockBraces = true;
+    QList<Line> data;
+    data << Line("int main()")
+         << Line("{")
+         << Line("    try")
+         << Line("        {")
+         << Line("        throw;")
+         << Line("        }")
+         << Line("    catch (const E &e)")
+         << Line("        {")
+         << Line("        handle(e);")
+         << Line("        }")
+         << Line("    catch (...)")
+         << Line("        {")
+         << Line("        handle();")
+         << Line("        }")
+         << Line("}");
+    checkIndent(data, settings);
+
+    data.clear();
+    data << Line("int main()")
+         << Line("{")
+         << Line("    try {")
+         << Line("        throw;")
+         << Line("    } catch (const E &e) {")
+         << Line("        handle(e);")
+         << Line("    } catch (...) {")
+         << Line("        handle();")
+         << Line("    }")
+         << Line("}");
+    checkIndent(data);
+}
+
 QTEST_GUILESS_MAIN(tst_CodeFormatter)
 
 #include "tst_codeformatter.moc"