Revert "VM: New calling convention for generated code."

runtime/vm/stack_frame.cc

Index: runtime/vm/stack_frame.cc
diff --git a/runtime/vm/stack_frame.cc b/runtime/vm/stack_frame.cc
index c0fe354839bfcf4e5b90169692ccb3b0508a9dd4..bf5a05d4bdf51e2896b2415bbeaab9117691771e 100644
--- a/runtime/vm/stack_frame.cc
+++ b/runtime/vm/stack_frame.cc
@@ -22,7 +22,9 @@ namespace dart {
 
 bool StackFrame::IsStubFrame() const {
   ASSERT(!(IsEntryFrame() || IsExitFrame()));
-  return (LookupDartCode() == Code::null());
+  uword saved_pc =
+      *(reinterpret_cast<uword*>(fp() + (kPcMarkerSlotFromFp * kWordSize)));
+  return (saved_pc == 0);
 }
 
 
@@ -173,11 +175,8 @@ RawCode* StackFrame::LookupDartCode() const {
   // that the code is called while a GC is in progress, that is ok.
   NoSafepointScope no_safepoint;
   RawCode* code = GetCodeObject();
-  if ((code != Code::null()) &&
-      (code->ptr()->owner_->GetClassId() == kFunctionCid)) {
-    return code;
-  }
-  return Code::null();
+  ASSERT(code == Code::null() || code->ptr()->owner_ != Function::null());
+  return code;
 }
 
 
@@ -188,10 +187,15 @@ RawCode* StackFrame::GetCodeObject() const {
   NoSafepointScope no_safepoint;
   const uword pc_marker =
       *(reinterpret_cast<uword*>(fp() + (kPcMarkerSlotFromFp * kWordSize)));
-  ASSERT(pc_marker != 0);
-  ASSERT(reinterpret_cast<RawObject*>(pc_marker)->GetClassId() == kCodeCid ||
-         reinterpret_cast<RawObject*>(pc_marker) == Object::null());
-  return reinterpret_cast<RawCode*>(pc_marker);
+  if (pc_marker != 0) {
+    const uword entry_point =
+        (pc_marker - Assembler::EntryPointToPcMarkerOffset());
+    RawInstructions* instr = Instructions::FromEntryPoint(entry_point);
+    if (instr != Instructions::null()) {
+      return instr->ptr()->code_;
+    }
+  }
+  return Code::null();
 }