// Copyright 2011 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "src/parsing/func-name-inferrer.h"

#include "src/ast/ast.h"
#include "src/ast/ast-value-factory.h"
#include "src/list-inl.h"

namespace v8 {
namespace internal {

FuncNameInferrer::FuncNameInferrer(AstValueFactory* ast_value_factory,
                                   Zone* zone)
    : ast_value_factory_(ast_value_factory),
      entries_stack_(10, zone),
      names_stack_(5, zone),
      funcs_to_infer_(4, zone),
      zone_(zone) {
}


void FuncNameInferrer::PushEnclosingName(const AstRawString* name) {
  // Enclosing name is a name of a constructor function. To check
  // that it is really a constructor, we check that it is not empty
  // and starts with a capital letter.
  if (!name->IsEmpty() && unibrow::Uppercase::Is(name->FirstCharacter())) {
    names_stack_.Add(Name(name, kEnclosingConstructorName), zone());
  }
}


void FuncNameInferrer::PushLiteralName(const AstRawString* name) {
  if (IsOpen() && name != ast_value_factory_->prototype_string()) {
    names_stack_.Add(Name(name, kLiteralName), zone());
  }
}


void FuncNameInferrer::PushVariableName(const AstRawString* name) {
  if (IsOpen() && name != ast_value_factory_->dot_result_string()) {
    names_stack_.Add(Name(name, kVariableName), zone());
  }
}


const AstString* FuncNameInferrer::MakeNameFromStack() {
  return MakeNameFromStackHelper(0, ast_value_factory_->empty_string());
}

const AstString* FuncNameInferrer::MakeNameFromStackHelper(
    int pos, const AstString* prev) {
  if (pos >= names_stack_.length()) return prev;
  if (pos < names_stack_.length() - 1 &&
      names_stack_.at(pos).type == kVariableName &&
      names_stack_.at(pos + 1).type == kVariableName) {
    // Skip consecutive variable declarations.
    return MakeNameFromStackHelper(pos + 1, prev);
  } else {
    if (prev->length() > 0) {
      const AstRawString* name = names_stack_.at(pos).name;
      if (prev->length() + name->length() + 1 > String::kMaxLength) return prev;
      const AstConsString* curr = ast_value_factory_->NewConsString(
          ast_value_factory_->dot_string(), name);
      curr = ast_value_factory_->NewConsString(prev, curr);
      return MakeNameFromStackHelper(pos + 1, curr);
    } else {
      return MakeNameFromStackHelper(pos + 1, names_stack_.at(pos).name);
    }
  }
}


void FuncNameInferrer::InferFunctionsNames() {
  const AstString* func_name = MakeNameFromStack();
  for (int i = 0; i < funcs_to_infer_.length(); ++i) {
    funcs_to_infer_[i]->set_raw_inferred_name(func_name);
  }
  funcs_to_infer_.Rewind(0);
}


}  // namespace internal
}  // namespace v8