Experimental: port the JS function check at function entry from ARM to...

src/virtual-frame-ia32.cc

 // Copyright 2008 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 371 matching lines @@
       Use(target.reg());
       elements_[i] = target;
     }
   }
 }
 
 
 void VirtualFrame::Enter() {
   // Registers live on entry: esp, ebp, esi, edi.
   Comment cmnt(masm_, "[ Enter JS frame");
+
+#ifdef DEBUG
+  // Verify that edi contains a JS function.  The following code
+  // relies on eax being available for use.
+  __ test(edi, Immediate(kSmiTagMask));
+  __ Check(not_zero,
+           "VirtualFrame::Enter - edi is not a function (smi check).");
+  __ mov(eax, FieldOperand(edi, HeapObject::kMapOffset));
+  __ movzx_b(eax, FieldOperand(eax, Map::kInstanceTypeOffset));
+  __ cmp(eax, JS_FUNCTION_TYPE);
+  __ Check(equal,
+           "VirtualFrame::Enter - edi is not a function (map check).");
+#endif
+
   EmitPush(ebp);
 
   frame_pointer_ = stack_pointer_;
   __ mov(ebp, Operand(esp));
 
   // Store the context in the frame.  The context is kept in esi and a
   // copy is stored in the frame.  The external reference to esi
   // remains.
   EmitPush(esi);
 
@@ skipping 566 matching lines @@
   ASSERT(stack_pointer_ == elements_.length() - 1);
   elements_.Add(FrameElement::MemoryElement());
   stack_pointer_++;
   __ push(immediate);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal