Fix source position for stack traces with optimized top function.

runtime/vm/deopt_instructions.cc

 // Copyright (c) 2013, 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/deopt_instructions.h"
 
 #include "vm/assembler_macros.h"
 #include "vm/code_patcher.h"
 #include "vm/intermediate_language.h"
 #include "vm/locations.h"
@@ skipping 192 matching lines @@
   void Execute(DeoptimizationContext* deopt_context, intptr_t to_index) {
     Function& function = Function::Handle(deopt_context->isolate());
     function ^= deopt_context->ObjectAt(object_table_index_);
     const Code& code =
         Code::Handle(deopt_context->isolate(), function.unoptimized_code());
     uword continue_at_pc = code.GetDeoptAfterPcAtDeoptId(deopt_id_);
     intptr_t* to_addr = deopt_context->GetToFrameAddressAt(to_index);
     *to_addr = continue_at_pc;
   }
 
-  static void GetEncodedValues(intptr_t from_index,
-                               intptr_t* object_table_index,
-                               intptr_t* deopt_id) {
-    *object_table_index = ObjectTableIndex::decode(from_index);
-    *deopt_id = DeoptId::decode(from_index);
-  }
+  intptr_t object_table_index() const { return object_table_index_; }
+  intptr_t deopt_id() const { return deopt_id_; }
 
  private:
   static const intptr_t kFieldWidth = kBitsPerWord / 2;
   class ObjectTableIndex : public BitField<intptr_t, 0, kFieldWidth> { };
   class DeoptId : public BitField<intptr_t, kFieldWidth, kFieldWidth> { };
 
   const intptr_t object_table_index_;
   const intptr_t deopt_id_;
 
   DISALLOW_COPY_AND_ASSIGN(DeoptRetAfterAddressInstr);
@@ skipping 312 matching lines @@
 
   virtual const char* ToCString() const {
     const char* format = "suffix %"Pd":%"Pd;
     intptr_t len = OS::SNPrint(NULL, 0, format, info_number_, suffix_length_);
     char* chars = Isolate::Current()->current_zone()->Alloc<char>(len + 1);
     OS::SNPrint(chars, len + 1, format, info_number_, suffix_length_);
     return chars;
   }
 
   void Execute(DeoptimizationContext* deopt_context, intptr_t to_index) {
-    // The deoptimization info is uncompresses by translating away suffixes
+    // The deoptimization info is uncompressed by translating away suffixes
     // before executing the instructions.
     UNREACHABLE();
   }
 
  private:
   // Static decoder functions in DeoptInstr have access to the bitfield
   // definitions.
   friend class DeoptInstr;
 
   static const intptr_t kFieldWidth = kBitsPerWord / 2;
   class InfoNumber : public BitField<intptr_t, 0, kFieldWidth> { };
   class SuffixLength : public BitField<intptr_t, kFieldWidth, kFieldWidth> { };
 
   const intptr_t info_number_;
   const intptr_t suffix_length_;
 
   DISALLOW_COPY_AND_ASSIGN(DeoptSuffixInstr);
 };
 
 
 intptr_t DeoptInstr::DecodeSuffix(intptr_t from_index, intptr_t* info_number) {
   *info_number = DeoptSuffixInstr::InfoNumber::decode(from_index);
   return DeoptSuffixInstr::SuffixLength::decode(from_index);
 }
 
 
-uword DeoptInstr::GetRetAfterAddress(intptr_t from_index,
+uword DeoptInstr::GetRetAfterAddress(DeoptInstr* instr,
                                      const Array& object_table,
                                      Function* func) {
+  ASSERT(instr->kind() == kRetAfterAddress);
+  DeoptRetAfterAddressInstr* ret_after_instr =
+      static_cast<DeoptRetAfterAddressInstr*>(instr);
   ASSERT(!object_table.IsNull());
   ASSERT(func != NULL);
-  intptr_t object_table_index;
-  intptr_t deopt_id;
-  DeoptRetAfterAddressInstr::GetEncodedValues(from_index,
-                                              &object_table_index,
-                                              &deopt_id);
-  *func ^= object_table.At(object_table_index);
+  *func ^= object_table.At(ret_after_instr->object_table_index());
   const Code& code = Code::Handle(func->unoptimized_code());
-  return code.GetDeoptAfterPcAtDeoptId(deopt_id);
+  return code.GetDeoptAfterPcAtDeoptId(ret_after_instr->deopt_id());
 }
 
 
 DeoptInstr* DeoptInstr::Create(intptr_t kind_as_int, intptr_t from_index) {
   Kind kind = static_cast<Kind>(kind_as_int);
   switch (kind) {
     case kStackSlot: return new DeoptStackSlotInstr(from_index);
     case kDoubleStackSlot: return new DeoptDoubleStackSlotInstr(from_index);
     case kInt64StackSlot: return new DeoptInt64StackSlotInstr(from_index);
     case kRetAfterAddress: return new DeoptRetAfterAddressInstr(from_index);
@@ skipping 221 matching lines @@
                           Smi* offset,
                           DeoptInfo* info,
                           Smi* reason) {
   intptr_t i = index * kEntrySize;
   *offset ^= table.At(i);
   *info ^= table.At(i + 1);
   *reason ^= table.At(i + 2);
 }
 
 }  // namespace dart