Partial ia32 implementation of optimized try/catch (by Kevin Millikin)

src/frames.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 600 matching lines @@
 bool StandardFrame::IsExpressionInsideHandler(int n) const {
   Address address = GetExpressionAddress(n);
   for (StackHandlerIterator it(this, top_handler()); !it.done(); it.Advance()) {
     if (it.handler()->includes(address)) return true;
   }
   return false;
 }
 
 
 void OptimizedFrame::Iterate(ObjectVisitor* v) const {
-#ifdef DEBUG
-  // Make sure that optimized frames do not contain any stack handlers.
-  StackHandlerIterator it(this, top_handler());
-  ASSERT(it.done());
-#endif
-
   // Make sure that we're not doing "safe" stack frame iteration. We cannot
   // possibly find pointers in optimized frames in that state.
   ASSERT(!SafeStackFrameIterator::is_active(isolate()));
 
   // Compute the safepoint information.
   unsigned stack_slots = 0;
   SafepointEntry safepoint_entry;
   Code* code = StackFrame::GetSafepointData(
       isolate(), pc(), &safepoint_entry, &stack_slots);
   unsigned slot_space = stack_slots * kPointerSize;
@@ skipping 25 matching lines @@
       }
     }
     // Skip the words containing the register values.
     parameters_base += kNumSafepointRegisters;
   }
 
   // We're done dealing with the register bits.
   uint8_t* safepoint_bits = safepoint_entry.bits();
   safepoint_bits += kNumSafepointRegisters >> kBitsPerByteLog2;
 
-  // Visit the rest of the parameters.
-  v->VisitPointers(parameters_base, parameters_limit);
+  // Visit the rest of the parameters and the exception handlers.
+  StackHandlerIterator handler_iterator(this, top_handler());
+  Object** next_parameter = parameters_base;
+  while (!handler_iterator.done()) {
+    // For each handler, visit the parameters down to the top of the handler
+    // and the handler itself.
+    StackHandler* handler = handler_iterator.handler();
+    Address handler_top = handler->address();
+    v->VisitPointers(next_parameter, reinterpret_cast<Object**>(handler_top));
+    handler->Iterate(v, code);
+    next_parameter =
+        reinterpret_cast<Object**>(handler_top + StackHandlerConstants::kSize);
+    handler_iterator.Advance();
+  }
+  // And visit all remaining parameters.
+  v->VisitPointers(next_parameter, parameters_limit);
 
   // Visit pointer spill slots and locals.
   for (unsigned index = 0; index < stack_slots; index++) {
     int byte_index = index >> kBitsPerByteLog2;
     int bit_index = index & (kBitsPerByte - 1);
     if ((safepoint_bits[byte_index] & (1U << bit_index)) != 0) {
       v->VisitPointer(parameters_limit + index);
     }
   }
 
@@ skipping 187 matching lines @@
   // in the deoptimization translation are ordered bottom-to-top.
   bool is_constructor = IsConstructor();
   int i = jsframe_count;
   while (i > 0) {
     opcode = static_cast<Translation::Opcode>(it.Next());
     if (opcode == Translation::JS_FRAME) {
       i--;
       BailoutId ast_id = BailoutId(it.Next());
       JSFunction* function = LiteralAt(literal_array, it.Next());
       it.Next();  // Skip height.
+      it.Next();  // Skip handler count.
 
       // The translation commands are ordered and the receiver is always
       // at the first position. Since we are always at a call when we need
       // to construct a stack trace, the receiver is always in a stack slot.
       opcode = static_cast<Translation::Opcode>(it.Next());
       ASSERT(opcode == Translation::STACK_SLOT ||
              opcode == Translation::LITERAL);
       int index = it.Next();
 
       // Get the correct receiver in the optimized frame.
@@ skipping 104 matching lines @@
 
   // We insert the frames in reverse order because the frames
   // in the deoptimization translation are ordered bottom-to-top.
   while (jsframe_count > 0) {
     opcode = static_cast<Translation::Opcode>(it.Next());
     if (opcode == Translation::JS_FRAME) {
       jsframe_count--;
       it.Next();  // Skip ast id.
       JSFunction* function = LiteralAt(literal_array, it.Next());
       it.Next();  // Skip height.
+      it.Next();  // Skip handler count;
       functions->Add(function);
     } else {
       // Skip over operands to advance to the next opcode.
       it.Skip(Translation::NumberOfOperandsFor(opcode));
     }
   }
 }
 
 
 int ArgumentsAdaptorFrame::GetNumberOfIncomingArguments() const {
@@ skipping 421 matching lines @@
   ZoneList<StackFrame*> list(10, zone);
   for (StackFrameIterator it; !it.done(); it.Advance()) {
     StackFrame* frame = AllocateFrameCopy(it.frame(), zone);
     list.Add(frame, zone);
   }
   return list.ToVector();
 }
 
 
 } }  // namespace v8::internal