Refactor the library tag handler to share code between standalone dart and the snapshot generator.

bin/process_script.h

-// Copyright (c) 2011, 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.
-
-#ifndef BIN_PROCESS_SCRIPT_H_
-#define BIN_PROCESS_SCRIPT_H_
-
-#include <stdlib.h>
-#include <string.h>
-#include <stdio.h>
-
-class CommandLineOptions {
- public:
-  explicit CommandLineOptions(int max_count)
-      : count_(0), max_count_(max_count), arguments_(NULL) {
-    static const int kWordSize = sizeof(intptr_t);
-    arguments_ = reinterpret_cast<const char **>(malloc(max_count * kWordSize));
-    if (arguments_ == NULL) {
-      max_count_ = 0;
-    }
-  }
-  ~CommandLineOptions() {
-    free(arguments_);
-    count_ = 0;
-    max_count_ = 0;
-    arguments_ = NULL;
-  }
-
-  int count() const { return count_; }
-  const char** arguments() const { return arguments_; }
-
-  const char* GetArgument(int index) const {
-    return (index >= 0 && index < count_) ? arguments_[index] : NULL;
-  }
-  void AddArgument(const char* argument) {
-    if (count_ < max_count_) {
-      arguments_[count_] = argument;
-      count_ += 1;
-    } else {
-      abort();  // We should never get into this situation.
-    }
-  }
-
-  void operator delete(void* pointer) { abort(); }
-
- private:
-  void* operator new(size_t size);
-  CommandLineOptions(const CommandLineOptions&);
-  void operator=(const CommandLineOptions&);
-
-  int count_;
-  int max_count_;
-  const char** arguments_;
-};
-
-
-extern Dart_Handle ReadStringFromFile(const char* filename);
-extern Dart_Handle LoadScript(const char* script_name);
-extern const char* GetCanonicalPath(const char* reference_dir,
-                                    const char* filename);
-
-
-#endif  // BIN_PROCESS_SCRIPT_H_