Add out-of-line constant pool support to Arm.

src/heap.cc

Index: src/heap.cc
diff --git a/src/heap.cc b/src/heap.cc
index 4cb1adcbc0f1ca083ceb349e4966aadf4ef2af02..78052b91018999a7e2cce31b407632e2ce0219ee 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -4010,12 +4010,24 @@ MaybeObject* Heap::CreateCode(const CodeDesc& desc,
                               bool immovable,
                               bool crankshafted,
                               int prologue_offset) {
-  // Allocate ByteArray before the Code object, so that we do not risk
-  // leaving uninitialized Code object (and breaking the heap).
+  // Allocate ByteArray and ConstantPoolArray before the Code object, so that we
+  // do not risk leaving uninitialized Code object (and breaking the heap).
   ByteArray* reloc_info;
   MaybeObject* maybe_reloc_info = AllocateByteArray(desc.reloc_size, TENURED);
   if (!maybe_reloc_info->To(&reloc_info)) return maybe_reloc_info;
 
+  ConstantPoolArray* constant_pool;
+  if (!FLAG_enable_ool_constant_pool || desc.has_empty_constant_pool()) {
+    constant_pool = empty_constant_pool_array();
+  } else {
+    MaybeObject* maybe_constant_pool = AllocateConstantPoolArray(
+        desc.constant_pool_64bit_count,
+        desc.constant_pool_code_ptr_count,
+        desc.constant_pool_heap_ptr_count,
+        desc.constant_pool_32bit_count);
+    if (!maybe_constant_pool->To(&constant_pool)) return maybe_constant_pool;
+  }
+
   // Compute size.
   int body_size = RoundUp(desc.instr_size, kObjectAlignment);
   int obj_size = Code::SizeFor(body_size);
@@ -4062,7 +4074,11 @@ MaybeObject* Heap::CreateCode(const CodeDesc& desc,
   if (code->kind() == Code::OPTIMIZED_FUNCTION) {
     code->set_marked_for_deoptimization(false);
   }
-  code->set_constant_pool(empty_constant_pool_array());
+
+  if (FLAG_enable_ool_constant_pool) {
+    desc.origin->PopulateConstantPool(constant_pool);
+  }
+  code->set_constant_pool(constant_pool);
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
   if (code->kind() == Code::FUNCTION) {
@@ -4109,8 +4125,19 @@ MaybeObject* Heap::CopyCode(Code* code) {
   Address old_addr = code->address();
   Address new_addr = reinterpret_cast<HeapObject*>(result)->address();
   CopyBlock(new_addr, old_addr, obj_size);
-  // Relocate the copy.
   Code* new_code = Code::cast(result);
+
+  if (FLAG_enable_ool_constant_pool &&
+      code->constant_pool() != empty_constant_pool_array()) {
+    // Copy the constant pool too, since edits to the copied code may modify
+    // the constant pool.
+    maybe_result = CopyConstantPoolArray(code->constant_pool());
+    Object* constant_pool_copy;
+    if (!maybe_result->ToObject(&constant_pool_copy)) return maybe_result;
+    new_code->set_constant_pool(constant_pool_copy);
+  }
+
+  // Relocate the copy.
   ASSERT(!isolate_->code_range()->exists() ||
       isolate_->code_range()->contains(code->address()));
   new_code->Relocate(new_addr - old_addr);
@@ -4157,6 +4184,15 @@ MaybeObject* Heap::CopyCode(Code* code, Vector<byte> reloc_info) {
   Code* new_code = Code::cast(result);
   new_code->set_relocation_info(ByteArray::cast(reloc_info_array));
 
+  if (FLAG_enable_ool_constant_pool) {
+    // Copy the constant pool too, since edits to the copied code may modify
+    // the constant pool.
+    maybe_result = CopyConstantPoolArray(code->constant_pool());
+    Object* constant_pool_copy;
+    if (!maybe_result->ToObject(&constant_pool_copy)) return maybe_result;
+    new_code->set_constant_pool(constant_pool_copy);
+  }
+
   // Copy patched rinfo.
   CopyBytes(new_code->relocation_start(),
             reloc_info.start(),