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(llvm::raw_fd_ostream* os) {
  14     return os ? new JsonWriter(os) : 0;
  15   }
  16   ~JsonWriter() {
  17     os_.close();
  18   }
  19   void OpenList() {
  20     Separator();
  21     os_ << "[";
  22     state_.push(false);
  23   }
  24   void OpenList(const std::string key) {
  25     Write(key);
  26     os_ << ":";
  27     OpenList();
  28   }
  29   void CloseList() {
  30     os_ << "]";
  31     state_.pop();
  32   }
  33   void OpenObject() {
  34     Separator();
  35     os_ << "{";
  36     state_.push(false);
  37   }
  38   void CloseObject() {
  39     os_ << "}\n";
  40     state_.pop();
  41   }
  42   void Write(const size_t val) {
  43     Separator();
  44     os_ << val;
  45   }
  46   void Write(const std::string val) {
  47     Separator();
  48     os_ << "\"" << val << "\"";
  49   }
  50   void Write(const std::string key, const size_t val) {
  51     Separator();
  52     os_ << "\"" << key << "\":" << val;
  53   }
  54   void Write(const std::string key, const std::string val) {
  55     Separator();
  56     os_ << "\"" << key << "\":\"" << val << "\"";
  57   }
  58  private:
  59   JsonWriter(llvm::raw_fd_ostream* os) : os_(*os) {}
  60   void Separator() {
  61     if (state_.empty())
  62       return;
  63     if (state_.top()) {
  64       os_ << ",";
  65       return;
  66     }
  67     state_.top() = true;
  68   }
  69   llvm::raw_fd_ostream& os_;
  70   std::stack<bool> state_;
  71 };
  72
  73 #endif // TOOLS_BLINK_GC_PLUGIN_JSON_WRITER_H_