Changeset 0a6d2045 for src/ControlStruct/MultiLevelExit.cpp

Timestamp:

Dec 20, 2023, 12:04:33 PM (7 months ago)

Author:

Andrew Beach <ajbeach@…>

Branches:

master

Children:

523e300

Parents:

9fba8e6

Message:

You can how use local control flow out of 'catch' clauses. Added a test to show that it works.

File:

• src/ControlStruct/MultiLevelExit.cpp (modified) (5 diffs)

src/ControlStruct/MultiLevelExit.cpp

@@ -35 +35 @@
         InTryWithHandler,
         InResumeHandler,
-        InTerminateHandler,
         InFinally,
 };
@@ -512 +511 @@
                 context = "catchResume clause";
                 break;
-        case ReturnContext::InTerminateHandler:
-                context = "catch clause";
-                break;
         case ReturnContext::InFinally:
                 context = "finally clause";
@@ -524 +520 @@
 }
 
+bool hasTerminate( const TryStmt * stmt ) {
+        for ( auto clause : stmt->handlers ) {
+                if ( ast::Terminate == clause->kind ) return true;
+        }
+        return false;
+}
+
 void MultiLevelExitCore::previsit( const TryStmt * stmt ) {
+        visit_children = false;
+
         bool isLabeled = ! stmt->labels.empty();
         if ( isLabeled ) {
@@ -533 +538 @@
 
         // Try statements/try blocks are only sealed with a termination handler.
-        for ( auto clause : stmt->handlers ) {
-                if ( ast::Terminate == clause->kind ) {
-                        return enterSealedContext( ReturnContext::InTryWithHandler );
-                }
-        }
+        if ( hasTerminate( stmt ) ) {
+                // This is just enterSealedContext except scoped to the block.
+                // And that is because the state must change for a single field.
+                ValueGuard< ReturnContext > guard0( ret_context );
+                ret_context = ReturnContext::InTryWithHandler;
+                auto guard = makeFuncGuard( [](){}, [this, old = std::move(enclosing_control_structures)](){ enclosing_control_structures = std::move(old); });
+                enclosing_control_structures = vector<Entry>();
+                visitor->maybe_accept( stmt, &TryStmt::body );
+        } else {
+                visitor->maybe_accept( stmt, &TryStmt::body );
+        }
+
+        visitor->maybe_accept( stmt, &TryStmt::handlers );
+        visitor->maybe_accept( stmt, &TryStmt::finally );
 }
 
@@ -551 +565 @@
 
 void MultiLevelExitCore::previsit( const CatchClause * clause ) {
-        ReturnContext context = ( ast::Terminate == clause->kind )
-                ? ReturnContext::InTerminateHandler : ReturnContext::InResumeHandler;
-        enterSealedContext( context );
+        if ( ast::Resume == clause->kind ) {
+                enterSealedContext( ReturnContext::InResumeHandler );
+        }
 }