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// NeedsTracing is a three-point value ordered by unneeded < unknown < needed. 6// Unneeded means that the point definitively does not need to be traced. 7 8#ifndef TOOLS_BLINK_GC_PLUGIN_NEEDS_TRACING_H_ 9#define TOOLS_BLINK_GC_PLUGIN_NEEDS_TRACING_H_ 10 11class NeedsTracing { 12 public: 13 static NeedsTracing Unneeded() { return kUnneeded; } 14 static NeedsTracing Unknown() { return kUnknown; } 15 static NeedsTracing Needed() { return kNeeded; } 16 bool IsUnneeded() { return value_ == kUnneeded; } 17 bool IsUnknown() { return value_ == kUnknown; } 18 bool IsNeeded() { return value_ == kNeeded; } 19 NeedsTracing LUB(const NeedsTracing& other) { 20 return value_ > other.value_ ? value_ : other.value_; 21 } 22 bool operator==(const NeedsTracing& other) { 23 return value_ == other.value_; 24 } 25 private: 26 enum Value { kUnneeded, kUnknown, kNeeded }; 27 NeedsTracing(Value value) : value_(value) {} 28 Value value_; 29}; 30 31#endif // TOOLS_BLINK_GC_PLUGIN_NEEDS_TRACING_H_ 32