Global cycle detection analysis.

tools/clang/blink_gc_plugin/JsonWriter.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef TOOLS_BLINK_GC_PLUGIN_JSON_WRITER_H_
+#define TOOLS_BLINK_GC_PLUGIN_JSON_WRITER_H_
+
+#include "llvm/Support/raw_ostream.h"
+
+// Helper to write information for the points-to graph.
+class JsonWriter {
+ public:
+  static JsonWriter* from(llvm::raw_fd_ostream* os) {
+    return os ? new JsonWriter(os) : 0;
+  }
+  ~JsonWriter() {
+    os_.close();
+  }
+  void OpenList() {
+    Separator();
+    os_ << "[";
+    state_.push(false);
+  }
+  void OpenList(const std::string key) {
+    Write(key);
+    os_ << ":";
+    OpenList();
+  }
+  void CloseList() {
+    os_ << "]";
+    state_.pop();
+  }
+  void OpenObject() {
+    Separator();
+    os_ << "{";
+    state_.push(false);
+  }
+  void CloseObject() {
+    os_ << "}\n";
+    state_.pop();
+  }
+  void Write(const size_t val) {
+    Separator();
+    os_ << val;
+  }
+  void Write(const std::string val) {
+    Separator();
+    os_ << "\"" << val << "\"";
+  }
+  void Write(const std::string key, const size_t val) {
+    Separator();
+    os_ << "\"" << key << "\":" << val;
+  }
+  void Write(const std::string key, const std::string val) {
+    Separator();
+    os_ << "\"" << key << "\":\"" << val << "\"";
+  }
+ private:
+  JsonWriter(llvm::raw_fd_ostream* os) : os_(*os) {}
+  void Separator() {
+    if (state_.empty())
+      return;
+    if (state_.top()) {
+      os_ << ",";
+      return;
+    }
+    state_.top() = true;
+  }
+  llvm::raw_fd_ostream& os_;
+  std::stack<bool> state_;
+};
+
+#endif // TOOLS_BLINK_GC_PLUGIN_JSON_WRITER_H_