Undo "Don't include an object header for instructions in the text section."

runtime/vm/snapshot.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/snapshot.h"
 
 #include "platform/assert.h"
 #include "vm/bootstrap.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart.h"
@@ skipping 1142 matching lines @@
 #if defined(PRODUCT)
   // Instructions are only dedup in product mode because it obfuscates profiler
   // results.
   for (intptr_t i = 0; i < instructions_.length(); i++) {
     if (instructions_[i].raw_insns_ == instructions) {
       return instructions_[i].offset_;
     }
   }
 #endif
 
-  intptr_t payload_size = instructions->ptr()->size_;
-  payload_size = Utils::RoundUp(payload_size, OS::PreferredCodeAlignment());
-
+  intptr_t heap_size = instructions->Size();
   intptr_t offset = next_offset_;
-  ASSERT(Utils::IsAligned(next_offset_, OS::PreferredCodeAlignment()));
-  next_offset_ += payload_size;
-  ASSERT(Utils::IsAligned(next_offset_, OS::PreferredCodeAlignment()));
+  next_offset_ += heap_size;
   instructions_.Add(InstructionsData(instructions, code, offset));
 
   return offset;
 }
 
 
 int32_t InstructionsWriter::GetObjectOffsetFor(RawObject* raw_object) {
   intptr_t heap_size = raw_object->Size();
   intptr_t offset = next_object_offset_;
   next_object_offset_ += heap_size;
@@ skipping 48 matching lines @@
 
   Object& owner = Object::Handle(zone);
   String& str = String::Handle(zone);
 
   for (intptr_t i = 0; i < instructions_.length(); i++) {
     const Instructions& insns = *instructions_[i].insns_;
     const Code& code = *instructions_[i].code_;
 
     ASSERT(insns.raw()->Size() % sizeof(uint64_t) == 0);
 
-    // 1. Write a label at the entry point.
+    // 1. Write from the header to the entry point.
+    {
+      NoSafepointScope no_safepoint;
+
+      uword beginning = reinterpret_cast<uword>(insns.raw_ptr());
+      uword entry = beginning + Instructions::HeaderSize();
+
+      ASSERT(Utils::IsAligned(beginning, sizeof(uint64_t)));
+      ASSERT(Utils::IsAligned(entry, sizeof(uint64_t)));
+
+      // Write Instructions with the mark and VM heap bits set.
+      uword marked_tags = insns.raw_ptr()->tags_;
+      marked_tags = RawObject::VMHeapObjectTag::update(true, marked_tags);
+      marked_tags = RawObject::MarkBit::update(true, marked_tags);
+
+      WriteWordLiteral(marked_tags);
+      beginning += sizeof(uword);
+
+      for (uword* cursor = reinterpret_cast<uword*>(beginning);
+           cursor < reinterpret_cast<uword*>(entry);
+           cursor++) {
+        WriteWordLiteral(*cursor);
+      }
+    }
+
+    // 2. Write a label at the entry point.
     owner = code.owner();
     if (owner.IsNull()) {
       const char* name = StubCode::NameOfStub(insns.EntryPoint());
       assembly_stream_.Print("Precompiled_Stub_%s:\n", name);
     } else if (owner.IsClass()) {
       str = Class::Cast(owner).Name();
       const char* name = str.ToCString();
       EnsureIdentifier(const_cast<char*>(name));
       assembly_stream_.Print("Precompiled_AllocationStub_%s_%" Pd ":\n",
                              name, i);
     } else if (owner.IsFunction()) {
       const char* name = Function::Cast(owner).ToQualifiedCString();
       EnsureIdentifier(const_cast<char*>(name));
       assembly_stream_.Print("Precompiled_%s_%" Pd ":\n", name, i);
     } else {
       UNREACHABLE();
     }
 
     {
-      // 2. Write from the entry point to the end.
+      // 3. Write from the entry point to the end.
       NoSafepointScope no_safepoint;
       uword beginning = reinterpret_cast<uword>(insns.raw()) - kHeapObjectTag;
       uword entry = beginning + Instructions::HeaderSize();
       uword payload_size = insns.size();
       payload_size = Utils::RoundUp(payload_size, OS::PreferredCodeAlignment());
       uword end = entry + payload_size;
 
       ASSERT(Utils::IsAligned(beginning, sizeof(uint64_t)));
       ASSERT(Utils::IsAligned(entry, sizeof(uint64_t)));
       ASSERT(Utils::IsAligned(end, sizeof(uint64_t)));
@@ skipping 66 matching lines @@
   intptr_t instructions_length = next_offset_;
   instructions_blob_stream_.WriteWord(instructions_length);
   intptr_t header_words = InstructionsSnapshot::kHeaderSize / sizeof(uword);
   for (intptr_t i = 1; i < header_words; i++) {
     instructions_blob_stream_.WriteWord(0);
   }
 
   for (intptr_t i = 0; i < instructions_.length(); i++) {
     const Instructions& insns = *instructions_[i].insns_;
 
+    // 1. Write from the header to the entry point.
     {
-      // 2. Write from the entry point to the end.
+      NoSafepointScope no_safepoint;
+
+      uword beginning = reinterpret_cast<uword>(insns.raw_ptr());
+      uword entry = beginning + Instructions::HeaderSize();
+
+      ASSERT(Utils::IsAligned(beginning, sizeof(uint64_t)));
+      ASSERT(Utils::IsAligned(entry, sizeof(uint64_t)));
+
+      // Write Instructions with the mark and VM heap bits set.
+      uword marked_tags = insns.raw_ptr()->tags_;
+      marked_tags = RawObject::VMHeapObjectTag::update(true, marked_tags);
+      marked_tags = RawObject::MarkBit::update(true, marked_tags);
+
+      instructions_blob_stream_.WriteWord(marked_tags);
+      beginning += sizeof(uword);
+
+      for (uword* cursor = reinterpret_cast<uword*>(beginning);
+           cursor < reinterpret_cast<uword*>(entry);
+           cursor++) {
+        instructions_blob_stream_.WriteWord(*cursor);
+      }
+    }
+
+    // 2. Write from the entry point to the end.
+    {
       NoSafepointScope no_safepoint;
       uword beginning = reinterpret_cast<uword>(insns.raw()) - kHeapObjectTag;
       uword entry = beginning + Instructions::HeaderSize();
       uword payload_size = insns.size();
       payload_size = Utils::RoundUp(payload_size, OS::PreferredCodeAlignment());
       uword end = entry + payload_size;
 
       ASSERT(Utils::IsAligned(beginning, sizeof(uint64_t)));
       ASSERT(Utils::IsAligned(entry, sizeof(uint64_t)));
       ASSERT(Utils::IsAligned(end, sizeof(uint64_t)));
@@ skipping 1383 matching lines @@
   if (setjmp(*jump.Set()) == 0) {
     NoSafepointScope no_safepoint;
     WriteObject(obj.raw());
   } else {
     ThrowException(exception_type(), exception_msg());
   }
 }
 
 
 }  // namespace dart