Toward precompiled snapshots.

runtime/vm/raw_object.h

 // 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.
 
 #ifndef VM_RAW_OBJECT_H_
 #define VM_RAW_OBJECT_H_
 
 #include "platform/assert.h"
 #include "vm/atomic.h"
 #include "vm/globals.h"
@@ skipping 565 matching lines @@
   friend class Object;
   friend class OneByteString;  // StoreSmi
   friend class RawExternalTypedData;
   friend class RawInstructions;
   friend class RawInstance;
   friend class RawTypedData;
   friend class Scavenger;
   friend class ScavengerVisitor;
   friend class SizeExcludingClassVisitor;  // GetClassId
   friend class RetainingPathVisitor;  // GetClassId
+  friend class InstructionsReader;  // tags_ check
   friend class SnapshotReader;
   friend class SnapshotWriter;
   friend class String;
   friend class TypedData;
   friend class TypedDataView;
   friend class WeakProperty;  // StorePointer
   friend class Instance;  // StorePointer
 
   DISALLOW_ALLOCATION();
   DISALLOW_IMPLICIT_CONSTRUCTORS(RawObject);
@@ skipping 395 matching lines @@
   // Else, owner_ is a regular Dart Function.
   RawObject* owner_;  // Function, Null, or a Class.
   RawExceptionHandlers* exception_handlers_;
   RawPcDescriptors* pc_descriptors_;
   RawArray* deopt_info_array_;
   RawArray* static_calls_target_table_;  // (code-offset, function, code).
   RawArray* stackmaps_;
   RawLocalVarDescriptors* var_descriptors_;
   RawArray* inlined_metadata_;
   RawArray* comments_;
   // If return_address_info_ is a Smi, it is the offset to the prologue.

[siva, 2015/09/01 20:58:49]

The comment here says 'If return_address_info_' which return_address_info_ is it
referring to?

[rmacnak, 2015/09/01 23:43:47]

What choice is there other than return_address_metadata_?

   // Else, return_address_info_ is null.
   RawObject* return_address_metadata_;
   RawObject** to() {
-    return reinterpret_cast<RawObject**>(&ptr()->comments_);
+    return reinterpret_cast<RawObject**>(&ptr()->return_address_metadata_);
   }
   uword entry_point_;
 
   // Compilation timestamp.
   int64_t compile_timestamp_;
 
   // state_bits_ is a bitfield with three fields:
   // The optimized bit, the alive bit, and a count of the number of pointer
   // offsets.
   // Alive: If true, the embedded object pointers will be visited during GC.
@@ skipping 25 matching lines @@
       RawObject* raw_obj_;
       uword raw_value_;
     };
   };
   Entry* data() { OPEN_ARRAY_START(Entry, Entry); }
   Entry const* data() const { OPEN_ARRAY_START(Entry, Entry); }
 
   Entry* first_entry() { return &ptr()->data()[0]; }
 
   friend class Object;
+  friend class SnapshotReader;
 };
 
 
 class RawInstructions : public RawObject {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Instructions);
 
   RawObject** from() {
     return reinterpret_cast<RawObject**>(&ptr()->code_);
   }
   RawCode* code_;
@@ skipping 10 matching lines @@
   // code which iterates over dart frames is also called during GC and
   // is not allowed to create handles.
   static bool ContainsPC(RawObject* raw_obj, uword pc);
 
   friend class RawCode;
   friend class RawFunction;
   friend class Code;
   friend class StackFrame;
   friend class MarkingVisitor;
   friend class Function;
+  friend class InstructionsReader;
 };
 
 
 class RawPcDescriptors : public RawObject {
  public:
   enum Kind {
     kDeopt           = 1,  // Deoptimization continuation point.
     kIcCall          = kDeopt << 1,  // IC call.
     kUnoptStaticCall = kIcCall << 1,  // Call to a known target via stub.
     kRuntimeCall     = kUnoptStaticCall << 1,  // Runtime call.
@@ skipping 37 matching lines @@
  private:
   RAW_HEAP_OBJECT_IMPLEMENTATION(PcDescriptors);
 
   int32_t length_;  // Number of descriptors.
 
   // Variable length data follows here.
   uint8_t* data() { OPEN_ARRAY_START(uint8_t, intptr_t); }
   const uint8_t* data() const { OPEN_ARRAY_START(uint8_t, intptr_t); }
 
   friend class Object;
+  friend class SnapshotReader;
 };
 
 
 // Stackmap is an immutable representation of the layout of the stack at a
 // PC. The stack map representation consists of a bit map which marks each
 // live object index starting from the base of the frame.
 //
-// The Stackmap also consists of a link to the code object corresponding to
-// the frame which the stack map is describing.  The bit map representation
-// is optimized for dense and small bit maps, without any upper bound.
+// The bit map representation is optimized for dense and small bit maps, without
+// any upper bound.
 class RawStackmap : public RawObject {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Stackmap);
 
   // Regarding changing this to a bitfield: ARM64 requires register_bit_count_
   // to be as large as 96, meaning 7 bits, leaving 25 bits for the length, or
   // as large as ~33 million entries. If that is sufficient, then these two
   // fields can be merged into a BitField.
   int32_t length_;  // Length of payload, in bits.
   int32_t register_bit_count_;  // Live register bits, included in length_.
 
   // Offset from code entry point corresponding to this stack map
   // representation.
   uint32_t pc_offset_;
 
   // Variable length data follows here (bitmap of the stack layout).
   uint8_t* data() { OPEN_ARRAY_START(uint8_t, uint8_t); }
   const uint8_t* data() const { OPEN_ARRAY_START(uint8_t, uint8_t); }
+
+  friend class SnapshotReader;
 };
 
 
 class RawLocalVarDescriptors : public RawObject {
  public:
   enum VarInfoKind {
     kStackVar = 1,
     kContextVar,
     kContextLevel,
     kSavedCurrentContext,
@@ skipping 54 matching lines @@
   RawObject** to(intptr_t num_entries) {
     return reinterpret_cast<RawObject**>(nameAddrAt(num_entries - 1));
   }
 
   // Variable info with [num_entries_] entries.
   VarInfo* data() {
     return reinterpret_cast<VarInfo*>(nameAddrAt(ptr()->num_entries_));
   }
 
   friend class Object;
+  friend class SnapshotReader;
 };
 
 
 class RawExceptionHandlers : public RawObject {
  public:
   // The index into the ExceptionHandlers table corresponds to
   // the try_index of the handler.
   struct HandlerInfo {
     uint32_t handler_pc_offset;  // PC offset value of handler.
     int16_t outer_try_index;   // Try block index of enclosing try block.
     int8_t needs_stacktrace;   // True if a stacktrace is needed.
     int8_t has_catch_all;      // Catches all exceptions.
   };
 
  private:
   RAW_HEAP_OBJECT_IMPLEMENTATION(ExceptionHandlers);
 
   // Number of exception handler entries.
   int32_t num_entries_;
 
   // Array with [num_entries_] entries. Each entry is an array of all handled
   // exception types.
   RawArray* handled_types_data_;
 
   // Exception handler info of length [num_entries_].
   const HandlerInfo* data() const { OPEN_ARRAY_START(HandlerInfo, intptr_t); }
   HandlerInfo* data() { OPEN_ARRAY_START(HandlerInfo, intptr_t); }
 
   friend class Object;
+  friend class SnapshotReader;
 };
 
 
 class RawContext : public RawObject {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Context);
 
   int32_t num_variables_;
 
   RawObject** from() { return reinterpret_cast<RawObject**>(&ptr()->parent_); }
   RawContext* parent_;
@@ skipping 917 matching lines @@
   COMPILE_ASSERT(kExternalTypedDataInt8ArrayCid ==
                  kTypedDataInt8ArrayViewCid + 15);
   COMPILE_ASSERT(kByteBufferCid == kExternalTypedDataInt8ArrayCid + 14);
   COMPILE_ASSERT(kNullCid == kByteBufferCid + 1);
   return (kNullCid - kTypedDataInt8ArrayCid);
 }
 
 }  // namespace dart
 
 #endif  // VM_RAW_OBJECT_H_