tools/clang/blink_gc_plugin/JsonWriter.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef TOOLS_BLINK_GC_PLUGIN_JSON_WRITER_H_
   6 #define TOOLS_BLINK_GC_PLUGIN_JSON_WRITER_H_
   7
   8 #include "llvm/Support/raw_ostream.h"
   9
  10 // Helper to write information for the points-to graph.
  11 class JsonWriter {
  12  public:
  13   static JsonWriter* from(std::unique_ptr<llvm::raw_ostream> os) {
  14     return os ? new JsonWriter(std::move(os)) : 0;
  15   }
  16   void OpenList() {
  17     Separator();
  18     *os_ << "[";
  19     state_.push(false);
  20   }
  21   void OpenList(const std::string key) {
  22     Write(key);
  23     *os_ << ":";
  24     OpenList();
  25   }
  26   void CloseList() {
  27     *os_ << "]";
  28     state_.pop();
  29   }
  30   void OpenObject() {
  31     Separator();
  32     *os_ << "{";
  33     state_.push(false);
  34   }
  35   void CloseObject() {
  36     *os_ << "}\n";
  37     state_.pop();
  38   }
  39   void Write(const size_t val) {
  40     Separator();
  41     *os_ << val;
  42   }
  43   void Write(const std::string val) {
  44     Separator();
  45     *os_ << "\"" << val << "\"";
  46   }
  47   void Write(const std::string key, const size_t val) {
  48     Separator();
  49     *os_ << "\"" << key << "\":" << val;
  50   }
  51   void Write(const std::string key, const std::string val) {
  52     Separator();
  53     *os_ << "\"" << key << "\":\"" << val << "\"";
  54   }
  55  private:
  56   JsonWriter(std::unique_ptr<llvm::raw_ostream> os) : os_(std::move(os)) {}
  57   void Separator() {
  58     if (state_.empty())
  59       return;
  60     if (state_.top()) {
  61       *os_ << ",";
  62       return;
  63     }
  64     state_.top() = true;
  65   }
  66   std::unique_ptr<llvm::raw_ostream> os_;
  67   std::stack<bool> state_;
  68 };
  69
  70 #endif // TOOLS_BLINK_GC_PLUGIN_JSON_WRITER_H_