Fix for issue 7757

runtime/vm/object.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/bigint_operations.h"
@@ skipping 7090 matching lines @@
 void Code::set_object_table(const Array& array) const {
   StorePointer(&raw_ptr()->object_table_, array.raw());
 }
 
 
 void Code::set_static_calls_target_table(const Array& value) const {
   StorePointer(&raw_ptr()->static_calls_target_table_, value.raw());
 }
 
 
+RawDeoptInfo* Code::GetDeoptInfoAtPc(uword pc, intptr_t* deopt_reason) const {
+  ASSERT(is_optimized());
+  const Instructions& instrs = Instructions::Handle(instructions());
+  uword code_entry = instrs.EntryPoint();
+  const Array& table = Array::Handle(deopt_info_array());
+  ASSERT(!table.IsNull());
+  // Linear search for the PC offset matching the target PC.
+  intptr_t length = DeoptTable::GetLength(table);
+  Smi& offset = Smi::Handle();
+  Smi& reason = Smi::Handle();
+  DeoptInfo& info = DeoptInfo::Handle();
+  for (intptr_t i = 0; i < length; ++i) {
+    DeoptTable::GetEntry(table, i, &offset, &info, &reason);
+    if (pc == (code_entry + offset.Value())) {
+      ASSERT(!info.IsNull());
+      *deopt_reason = reason.Value();
+      return info.raw();
+    }
+  }
+  *deopt_reason = kDeoptUnknown;
+  return DeoptInfo::null();
+}
+
+
 RawFunction* Code::GetStaticCallTargetFunctionAt(uword pc) const {
   RawObject* raw_code_offset =
       reinterpret_cast<RawObject*>(Smi::New(pc - EntryPoint()));
   const Array& array =
       Array::Handle(raw_ptr()->static_calls_target_table_);
   for (intptr_t i = 0; i < array.Length(); i += kSCallTableEntryLength) {
     if (array.At(i) == raw_code_offset) {
       Function& function = Function::Handle();
       function ^= array.At(i + kSCallTableFunctionEntry);
       return function.raw();
@@ skipping 5307 matching lines @@
   }
   return result.raw();
 }
 
 
 const char* WeakProperty::ToCString() const {
   return "_WeakProperty";
 }
 
 }  // namespace dart