- Wire the stack frame iterator to use stack maps for traversing objects if there are stack maps in…

vm/raw_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/raw_object.h"
 
 #include "vm/freelist.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
 #include "vm/visitor.h"
@@ skipping 210 matching lines @@
       UNREACHABLE();
       break;
   }
 
   ASSERT(size != 0);
   ASSERT(size == Size());
   return size;
 }
 
 
+bool RawObject::FindObject(FindObjectVisitor* visitor) {
+  ASSERT(visitor != NULL);
+  return visitor->FindObject(const_cast<RawObject*>(this));
+}
+
+
+bool RawObject::IsRawInstruction(RawObject* raw_obj) {
+  RawClass* raw_class = raw_obj->ptr()->class_;
+  ObjectKind instance_kind = raw_class->ptr()->instance_kind_;

[Ivan Posva, 2012/04/03 23:28:50]

This code could be inlined into the ContainsPC method.

[siva, 2012/04/07 01:22:55]

Done.

+  return (instance_kind == kInstructions);
+}
+
+
 intptr_t RawClass::VisitClassPointers(RawClass* raw_obj,
                                       ObjectPointerVisitor* visitor) {
   visitor->VisitPointers(raw_obj->from(), raw_obj->to());
   return Class::InstanceSize();
 }
 
 
 intptr_t RawUnresolvedClass::VisitUnresolvedClassPointers(
     RawUnresolvedClass* raw_obj, ObjectPointerVisitor* visitor) {
   visitor->VisitPointers(raw_obj->from(), raw_obj->to());
@@ skipping 113 matching lines @@
   uword entry_point = reinterpret_cast<uword>(obj->instructions_->ptr()) +
       Instructions::HeaderSize();
   for (intptr_t i = 0; i < length; i++) {
     int32_t offset = obj->data_[i];
     visitor->VisitPointer(reinterpret_cast<RawObject**>(entry_point + offset));
   }
   return Code::InstanceSize(length);
 }
 
 
+RawStackmap* RawCode::GetStackmap(uword pc) const {

[Ivan Posva, 2012/04/03 23:28:50]

Move this code into the Code object?

[siva, 2012/04/07 01:22:55]

Done.

Used special stack handles in the DartFrame code to be able
to access this code using the handle. These stack handles
are not visited.

On 2012/04/03 23:28:50, Ivan Posva wrote:

+  RawArray* stackmaps = ptr()->stackmaps_;
+  if (stackmaps == Array::null()) {
+    // No stack maps are present in the code object which means this
+    // frame relies on tagged pointers.
+    return Stackmap::null();
+  }
+  // A stack map is present in the code object, use the stack map to visit
+  // frame slots which are marked as having objects.
+  RawStackmap* previous_map = Stackmap::null();
+  RawStackmap* map = Stackmap::null();
+  for (intptr_t i = 0; i < stackmaps->Length(); i++) {
+    map = reinterpret_cast<RawStackmap*>(stackmaps->DataAt(i));
+    ASSERT(map != Stackmap::null());
+    if (map->PC() == pc) {
+      break;  // We found a stack map for this frame.
+    }
+    if (map->PC() > pc) {
+      // We have not found a stackmap corresponding to the PC of this frame,
+      // we will use the closest previous stack map.
+      map = previous_map;
+      break;
+    }
+    previous_map = map;
+  }
+  return map;
+}
+
+
 intptr_t RawInstructions::VisitInstructionsPointers(
     RawInstructions* raw_obj, ObjectPointerVisitor* visitor) {
   RawInstructions* obj = raw_obj->ptr();
   visitor->VisitPointer(reinterpret_cast<RawObject**>(&obj->code_));
   return Instructions::InstanceSize(obj->size_);
 }
 
 
+bool RawInstructions::ContainsPC(RawObject* raw_obj, uword pc) {
+  if (IsRawInstruction(raw_obj)) {
+    RawInstructions* raw_instr = reinterpret_cast<RawInstructions*>(raw_obj);
+    uword start_pc =
+        reinterpret_cast<uword>(raw_instr->ptr()) + Instructions::HeaderSize();
+    uword end_pc = start_pc + raw_instr->ptr()->size_;
+    ASSERT(end_pc > start_pc);
+    if ((pc >= start_pc) && (pc < end_pc)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+
 intptr_t RawPcDescriptors::VisitPcDescriptorsPointers(
     RawPcDescriptors* raw_obj, ObjectPointerVisitor* visitor) {
   RawPcDescriptors* obj = raw_obj->ptr();
   intptr_t length = Smi::Value(obj->length_);
   visitor->VisitPointer(reinterpret_cast<RawObject**>(&obj->length_));
   return PcDescriptors::InstanceSize(length);
 }
 
 
 intptr_t RawStackmap::VisitStackmapPointers(RawStackmap* raw_obj,
                                             ObjectPointerVisitor* visitor) {
   RawStackmap* obj = raw_obj->ptr();
   intptr_t size_in_bytes = Smi::Value(obj->bitmap_size_in_bytes_);
   visitor->VisitPointers(raw_obj->from(), raw_obj->to());
   return Stackmap::InstanceSize(size_in_bytes);
 }
 
 
+bool RawStackmap::IsObject(intptr_t bit_offset) const {
+  const int byte_offset = bit_offset >> kBitsPerByteLog2;
+  const int bit_remainder = bit_offset & (kBitsPerByte - 1);
+  const uint8_t byte_mask = 1U << bit_remainder;
+  const uint8_t byte = ptr()->data_[byte_offset];
+  return (byte & byte_mask);
+}
+
+
 intptr_t RawLocalVarDescriptors::VisitLocalVarDescriptorsPointers(
     RawLocalVarDescriptors* raw_obj, ObjectPointerVisitor* visitor) {
   RawLocalVarDescriptors* obj = raw_obj->ptr();
   intptr_t len = obj->length_;
   visitor->VisitPointer(reinterpret_cast<RawObject**>(&obj->names_));
   return LocalVarDescriptors::InstanceSize(len);
 }
 
 
 intptr_t RawExceptionHandlers::VisitExceptionHandlersPointers(
@@ skipping 202 matching lines @@
 
 
 intptr_t RawArray::VisitArrayPointers(RawArray* raw_obj,
                                       ObjectPointerVisitor* visitor) {
   intptr_t length = Smi::Value(raw_obj->ptr()->length_);
   visitor->VisitPointers(raw_obj->from(), raw_obj->to(length));
   return Array::InstanceSize(length);
 }
 
 
+intptr_t RawArray::Length() const {

[Ivan Posva, 2012/04/03 23:28:50]

inline into uses

[siva, 2012/04/07 01:22:55]

Not needed any more as the GetStackmap code was moved to a handle based one.

On 2012/04/03 23:28:50, Ivan Posva wrote:

+  return Smi::Value(ptr()->length_);
+}
+
+
 intptr_t RawImmutableArray::VisitImmutableArrayPointers(
     RawImmutableArray* raw_obj, ObjectPointerVisitor* visitor) {
   return RawArray::VisitArrayPointers(raw_obj, visitor);
 }
 
 
 intptr_t RawGrowableObjectArray::VisitGrowableObjectArrayPointers(
     RawGrowableObjectArray* raw_obj, ObjectPointerVisitor* visitor) {
   visitor->VisitPointers(raw_obj->from(), raw_obj->to());
   return GrowableObjectArray::InstanceSize();
@@ skipping 48 matching lines @@
 intptr_t RawJSRegExp::VisitJSRegExpPointers(RawJSRegExp* raw_obj,
                                             ObjectPointerVisitor* visitor) {
   // Make sure that we got here with the tagged pointer as this.
   ASSERT(raw_obj->IsHeapObject());
   intptr_t length = Smi::Value(raw_obj->ptr()->data_length_);
   visitor->VisitPointers(raw_obj->from(), raw_obj->to());
   return JSRegExp::InstanceSize(length);
 }
 
 }  // namespace dart