Enable register allocation for return statements. Make sure to...

src/virtual-frame-ia32.cc

Index: src/virtual-frame-ia32.cc
===================================================================
--- src/virtual-frame-ia32.cc	(revision 1034)
+++ src/virtual-frame-ia32.cc	(working copy)
@@ -594,11 +594,13 @@
   // copy is stored in the frame.  The external reference to esi
   // remains in addition to the cached copy in the frame.
   Push(esi);
+  SyncElementAt(elements_.length() - 1);
 
-  // Store the function in the frame.  The frame owns the register reference
-  // now (ie, it can keep it in edi or spill it later).
+  // Store the function in the frame.  The frame owns the register
+  // reference now (ie, it can keep it in edi or spill it later).
   Push(edi);
   cgen_->allocator()->Unuse(edi);
+  SpillElementAt(elements_.length() - 1);
 }
 
 
@@ -626,6 +628,21 @@
 }
 
 
+void VirtualFrame::PrepareForReturn() {
+  // Spill all locals. This is necessary to make sure all locals have
+  // the right value when breaking at the return site in the debugger.
+  for (int i = 0; i < expression_base_index(); i++) SpillElementAt(i);
+
+  // Forget all about non-local stack elements.
+  Forget(height());

[Kevin Millikin (Chromium), 2009/01/07 10:25:12]

As discussed offline, Forget as it currently stands probably isn't the right
thing here.  It assumes that it is forgetting things below the actual stack
pointer, and it doesn't adjust the stack pointer itself but assumes someone else
has or will.

+
+  // Validate state: The expression stack should be empty and the
+  // stack pointer should have been updated to reflect this.
+  ASSERT(height() == 0);
+  ASSERT(stack_pointer_ == expression_base_index() - 1);
+}
+
+
 void VirtualFrame::AllocateStackSlots(int count) {
   ASSERT(height() == 0);
   local_count_ = count;