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

src/virtual-frame-arm.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 203 matching lines @@
 void VirtualFrame::MergeMoveRegistersToRegisters(VirtualFrame* expected) {
 }
 
 
 void VirtualFrame::MergeMoveMemoryToRegisters(VirtualFrame *expected) {
 }
 
 
 void VirtualFrame::Enter() {
   Comment cmnt(masm_, "[ Enter JS frame");
+
 #ifdef DEBUG
-  { Label done, fail;
+  // Verify that r1 contains a JS function.  The following code relies
+  // on r2 being available for use.
+  { Label map_check, done;
     __ tst(r1, Operand(kSmiTagMask));
-    __ b(eq, &fail);
+    __ b(ne, &map_check);
+    __ stop("VirtualFrame::Enter - r1 is not a function (smi check).");
+    __ bind(&map_check);
     __ ldr(r2, FieldMemOperand(r1, HeapObject::kMapOffset));
     __ ldrb(r2, FieldMemOperand(r2, Map::kInstanceTypeOffset));
     __ cmp(r2, Operand(JS_FUNCTION_TYPE));
     __ b(eq, &done);
-    __ bind(&fail);
-    __ stop("CodeGenerator::EnterJSFrame - r1 not a function");
+    __ stop("VirtualFrame::Enter - r1 is not a function (map check).");
     __ bind(&done);
   }
 #endif  // DEBUG
 
   // We are about to push four values to the frame.
   Adjust(4);
   __ stm(db_w, sp, r1.bit() | cp.bit() | fp.bit() | lr.bit());
   // Adjust FP to point to saved FP.
   frame_pointer_ = elements_.length() - 2;
   __ add(fp, sp, Operand(2 * kPointerSize));
@@ skipping 224 matching lines @@
   ASSERT(stack_pointer_ == elements_.length() - 1);
   elements_.Add(FrameElement::MemoryElement());
   stack_pointer_++;
   __ push(reg);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal