In the toplevel code generator, suppor local context allocation...

src/arm/fast-codegen-arm.cc

 // Copyright 2009 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 53 matching lines @@
     int locals_count = fun->scope()->num_stack_slots();
     if (locals_count > 0) {
       __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
     }
     __ LoadRoot(r2, Heap::kStackLimitRootIndex);
     for (int i = 0; i < locals_count; i++) {
       __ push(ip);
     }
   }
 
+  // Possibly allocate a local context.
+  if (fun->scope()->num_heap_slots() > 0) {
+    Comment cmnt(masm_, "[ Allocate local context");
+    // Argument to NewContext is the function, still in r1.
+    __ push(r1);
+    __ CallRuntime(Runtime::kNewContext, 1);
+    // Context is returned in both r0 and cp.  It replaces the context
+    // passed to us.  It's saved in the stack and kept live in cp.
+    __ str(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
+#ifdef DEBUG
+    // Assert we do not have to copy any parameters into the context.
+    for (int i = 0, len = fun->scope()->num_parameters(); i < len; i++) {
+      Slot* slot = fun->scope()->parameter(i)->slot();
+      ASSERT(slot != NULL && slot->type() != Slot::CONTEXT);
+    }
+#endif
+  }
+
   // Check the stack for overflow or break request.
   // Put the lr setup instruction in the delay slot.  The kInstrSize is
   // added to the implicit 8 byte offset that always applies to operations
   // with pc and gives a return address 12 bytes down.
   Comment cmnt(masm_, "[ Stack check");
   __ add(lr, pc, Operand(Assembler::kInstrSize));
   __ cmp(sp, Operand(r2));
   StackCheckStub stub;
   __ mov(pc,
          Operand(reinterpret_cast<intptr_t>(stub.GetCode().location()),
@@ skipping 1209 matching lines @@
   true_label_ = saved_true;
   false_label_ = saved_false;
   // Convert current context to test context: End post-test code.
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal