Precompilation: don't include an object header for instructions in the text section.

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/cpu.h"
@@ skipping 12954 matching lines @@
   // larger than the previously added one.
   for (intptr_t i = kSCallTableEntryLength;
       i < value.Length();
       i += kSCallTableEntryLength) {
     ASSERT(value.At(i - kSCallTableEntryLength) < value.At(i));
   }
 #endif  // DEBUG
 }
 
 
+uword Code::EntryPoint() const {
+  RawObject* instr = instructions();
+  if (!instr->IsHeapObject()) {
+    return active_entry_point();
+  } else {
+    return Instructions::EntryPoint(instructions());
+  }
+}
+
+
+intptr_t Code::Size() const {
+  RawObject* instr = instructions();
+  if (!instr->IsHeapObject()) {
+    return Smi::Value(raw_ptr()->precompiled_instructions_size_);
+  } else {
+    return instructions()->ptr()->size_;
+  }
+}
+
+
 bool Code::HasBreakpoint() const {
   if (!FLAG_support_debugger) {
     return false;
   }
   return Isolate::Current()->debugger()->HasBreakpoint(*this);
 }
 
 
 TokenPosition Code::GetTokenPositionAt(intptr_t offset) const {
   const CodeSourceMap& map = CodeSourceMap::Handle(code_source_map());
@@ skipping 325 matching lines @@
     for (intptr_t i = 0; i < pointer_offsets.length(); i++) {
       intptr_t offset_in_instrs = pointer_offsets[i];
       code.SetPointerOffsetAt(i, offset_in_instrs);
       uword addr = region.start() + offset_in_instrs;
       const Object* object = *reinterpret_cast<Object**>(addr);
       instrs.raw()->StorePointer(reinterpret_cast<RawObject**>(addr),
                                  object->raw());
     }
 
     // Hook up Code and Instructions objects.
+    code.set_instructions(instrs.raw());
     code.SetActiveInstructions(instrs.raw());
-    code.set_instructions(instrs.raw());
     code.set_is_alive(true);
 
+    ASSERT(code.EntryPoint() == instrs.EntryPoint());
+    ASSERT(code.Size() == instrs.size());
+
     // Set object pool in Instructions object.
     INC_STAT(Thread::Current(),
              total_code_size, object_pool.Length() * sizeof(uintptr_t));
     code.set_object_pool(object_pool.raw());
 
     if (FLAG_write_protect_code) {
       uword address = RawObject::ToAddr(instrs.raw());
       bool status = VirtualMemory::Protect(
           reinterpret_cast<void*>(address),
           instrs.raw()->Size(),
@@ skipping 177 matching lines @@
 
 bool Code::IsFunctionCode() const {
   const Object& obj = Object::Handle(owner());
   return obj.IsFunction();
 }
 
 
 void Code::DisableDartCode() const {
   DEBUG_ASSERT(IsMutatorOrAtSafepoint());
   ASSERT(IsFunctionCode());
-  ASSERT(instructions() == active_instructions());
+  ASSERT(!IsDisabled());
   const Code& new_code =
       Code::Handle(StubCode::FixCallersTarget_entry()->code());
+  ASSERT(new_code.instructions()->IsVMHeapObject());
   SetActiveInstructions(new_code.instructions());
 }
 
 
 void Code::DisableStubCode() const {
   ASSERT(Thread::Current()->IsMutatorThread());
   ASSERT(IsAllocationStubCode());
-  ASSERT(instructions() == active_instructions());
+  ASSERT(!IsDisabled());
   const Code& new_code =
       Code::Handle(StubCode::FixAllocationStubTarget_entry()->code());
+  ASSERT(new_code.instructions()->IsVMHeapObject());
   SetActiveInstructions(new_code.instructions());
 }
 
 
 void Code::SetActiveInstructions(RawInstructions* instructions) const {
   DEBUG_ASSERT(IsMutatorOrAtSafepoint() || !is_alive());
   // RawInstructions are never allocated in New space and hence a
   // store buffer update is not needed here.
-  StorePointer(&raw_ptr()->active_instructions_, instructions);
   StoreNonPointer(&raw_ptr()->entry_point_,
                   reinterpret_cast<uword>(instructions->ptr()) +
                   Instructions::HeaderSize());
 }
 
 
 uword Code::GetLazyDeoptPc() const {
   return (lazy_deopt_pc_offset() != kInvalidPc)
       ? EntryPoint() + lazy_deopt_pc_offset() : 0;
 }
@@ skipping 8188 matching lines @@
   return UserTag::null();
 }
 
 
 const char* UserTag::ToCString() const {
   const String& tag_label = String::Handle(label());
   return tag_label.ToCString();
 }
 
 }  // namespace dart