Allow embedding of ConsString objects into code.

R=yangguo@chromium.org
BUG=v8:2803
LOG=N

Review URL: https://codereview.chromium.org/395713002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22406 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/assembler-arm-inl.h

@@ -166,7 +166,6 @@ void RelocInfo::set_target_object(Object* target,
                                   WriteBarrierMode write_barrier_mode,
                                   ICacheFlushMode icache_flush_mode) {
   ASSERT(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
-  ASSERT(!target->IsConsString());
   Assembler::set_target_address_at(pc_, host_,
                                    reinterpret_cast<Address>(target),
                                    icache_flush_mode);

src/arm64/assembler-arm64-inl.h

@@ -716,7 +716,6 @@ void RelocInfo::set_target_object(Object* target,
                                   WriteBarrierMode write_barrier_mode,
                                   ICacheFlushMode icache_flush_mode) {
   ASSERT(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
-  ASSERT(!target->IsConsString());
   Assembler::set_target_address_at(pc_, host_,
                                    reinterpret_cast<Address>(target),
                                    icache_flush_mode);

src/factory.cc

@@ -543,19 +543,6 @@ MaybeHandle<String> Factory::NewConsString(Handle<String> left,
 }
 
 
-Handle<String> Factory::NewFlatConcatString(Handle<String> first,
-                                            Handle<String> second) {
-  int total_length = first->length() + second->length();
-  if (first->IsOneByteRepresentation() && second->IsOneByteRepresentation()) {
-    return ConcatStringContent<uint8_t>(
-        NewRawOneByteString(total_length).ToHandleChecked(), first, second);
-  } else {
-    return ConcatStringContent<uc16>(
-        NewRawTwoByteString(total_length).ToHandleChecked(), first, second);
-  }
-}
-
-
 Handle<String> Factory::NewProperSubString(Handle<String> str,
                                            int begin,
                                            int end) {

src/factory.h

@@ -197,10 +197,6 @@ class Factory V8_FINAL {
   MUST_USE_RESULT MaybeHandle<String> NewConsString(Handle<String> left,
                                                     Handle<String> right);
 
-  // Create a new sequential string containing the concatenation of the inputs.
-  Handle<String> NewFlatConcatString(Handle<String> first,
-                                     Handle<String> second);
-
   // Create a new string object which holds a proper substring of a string.
   Handle<String> NewProperSubString(Handle<String> str,
                                     int begin,

src/hydrogen-instructions.cc

@@ -4067,10 +4067,9 @@ HInstruction* HStringAdd::New(Zone* zone,
       Handle<String> right_string = c_right->StringValue();
       // Prevent possible exception by invalid string length.
       if (left_string->length() + right_string->length() < String::kMaxLength) {
-        Handle<String> concat = zone->isolate()->factory()->NewFlatConcatString(
+        MaybeHandle<String> concat = zone->isolate()->factory()->NewConsString(
             c_left->StringValue(), c_right->StringValue());
-        ASSERT(!concat.is_null());
-        return HConstant::New(zone, context, concat);
+        return HConstant::New(zone, context, concat.ToHandleChecked());
       }
     }
   }

src/ia32/assembler-ia32-inl.h

@@ -141,7 +141,6 @@ void RelocInfo::set_target_object(Object* target,
                                   WriteBarrierMode write_barrier_mode,
                                   ICacheFlushMode icache_flush_mode) {
   ASSERT(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
-  ASSERT(!target->IsConsString());
   Memory::Object_at(pc_) = target;
   if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
     CpuFeatures::FlushICache(pc_, sizeof(Address));

src/ic.cc

@@ -992,9 +992,6 @@ Handle<Code> LoadIC::CompileHandler(LookupResult* lookup,
     }
     case CONSTANT: {
       Handle<Object> constant(lookup->GetConstant(), isolate());
-      // TODO(2803): Don't compute a stub for cons strings because they cannot
-      // be embedded into code.
-      if (constant->IsConsString()) break;
       return compiler.CompileLoadConstant(type, holder, name, constant);
     }
     case NORMAL:

src/mips/assembler-mips-inl.h

@@ -207,7 +207,6 @@ void RelocInfo::set_target_object(Object* target,
                                   WriteBarrierMode write_barrier_mode,
                                   ICacheFlushMode icache_flush_mode) {
   ASSERT(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
-  ASSERT(!target->IsConsString());
   Assembler::set_target_address_at(pc_, host_,
                                    reinterpret_cast<Address>(target),
                                    icache_flush_mode);

src/mips64/assembler-mips64-inl.h

@@ -201,7 +201,6 @@ void RelocInfo::set_target_object(Object* target,
                                   WriteBarrierMode write_barrier_mode,
                                   ICacheFlushMode icache_flush_mode) {
   ASSERT(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
-  ASSERT(!target->IsConsString());
   Assembler::set_target_address_at(pc_, host_,
                                    reinterpret_cast<Address>(target),
                                    icache_flush_mode);

src/objects-visiting-inl.h

@@ -237,7 +237,6 @@ template<typename StaticVisitor>
 void StaticMarkingVisitor<StaticVisitor>::VisitEmbeddedPointer(
     Heap* heap, RelocInfo* rinfo) {
   ASSERT(rinfo->rmode() == RelocInfo::EMBEDDED_OBJECT);
-  ASSERT(!rinfo->target_object()->IsConsString());
   HeapObject* object = HeapObject::cast(rinfo->target_object());
   heap->mark_compact_collector()->RecordRelocSlot(rinfo, object);
   // TODO(ulan): It could be better to record slots only for strongly embedded

src/objects.cc

@@ -16900,10 +16900,9 @@ Handle<HeapType> PropertyCell::UpdatedType(Handle<PropertyCell> cell,
                                            Handle<Object> value) {
   Isolate* isolate = cell->GetIsolate();
   Handle<HeapType> old_type(cell->type(), isolate);
-  // TODO(2803): Do not track ConsString as constant because they cannot be
-  // embedded into code.
-  Handle<HeapType> new_type = value->IsConsString() || value->IsTheHole()
-      ? HeapType::Any(isolate) : HeapType::Constant(value, isolate);
+  Handle<HeapType> new_type = value->IsTheHole()
+                                  ? HeapType::Any(isolate)
+                                  : HeapType::Constant(value, isolate);
 
   if (new_type->Is(old_type)) {
     return old_type;

src/x64/assembler-x64-inl.h

@@ -307,7 +307,6 @@ void RelocInfo::set_target_object(Object* target,
                                   WriteBarrierMode write_barrier_mode,
                                   ICacheFlushMode icache_flush_mode) {
   ASSERT(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
-  ASSERT(!target->IsConsString());
   Memory::Object_at(pc_) = target;
   if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
     CpuFeatures::FlushICache(pc_, sizeof(Address));

src/x87/assembler-x87-inl.h

@@ -142,7 +142,6 @@ void RelocInfo::set_target_object(Object* target,
                                   WriteBarrierMode write_barrier_mode,
                                   ICacheFlushMode icache_flush_mode) {
   ASSERT(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
-  ASSERT(!target->IsConsString());
   Memory::Object_at(pc_) = target;
   if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
     CpuFeatures::FlushICache(pc_, sizeof(Address));