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1 // Copyright 2015 the V8 project 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 V8_SIGNATURE_H_
6 #define V8_SIGNATURE_H_
7 
8 #include "src/zone/zone.h"
9 
10 namespace v8 {
11 namespace internal {
12 
13 // Describes the inputs and outputs of a function or call.
14 template <typename T>
15 class Signature : public ZoneObject {
16  public:
Signature(size_t return_count,size_t parameter_count,const T * reps)17   Signature(size_t return_count, size_t parameter_count, const T* reps)
18       : return_count_(return_count),
19         parameter_count_(parameter_count),
20         reps_(reps) {}
21 
return_count()22   size_t return_count() const { return return_count_; }
parameter_count()23   size_t parameter_count() const { return parameter_count_; }
24 
GetParam(size_t index)25   T GetParam(size_t index) const {
26     DCHECK(index < parameter_count_);
27     return reps_[return_count_ + index];
28   }
29 
30   T GetReturn(size_t index = 0) const {
31     DCHECK(index < return_count_);
32     return reps_[index];
33   }
34 
Equals(const Signature * that)35   bool Equals(const Signature* that) const {
36     if (this == that) return true;
37     if (this->parameter_count() != that->parameter_count()) return false;
38     if (this->return_count() != that->return_count()) return false;
39     size_t size = this->return_count() + this->parameter_count();
40     for (size_t i = 0; i < size; i++) {
41       if (this->reps_[i] != that->reps_[i]) return false;
42     }
43     return true;
44   }
45 
46   // For incrementally building signatures.
47   class Builder {
48    public:
Builder(Zone * zone,size_t return_count,size_t parameter_count)49     Builder(Zone* zone, size_t return_count, size_t parameter_count)
50         : return_count_(return_count),
51           parameter_count_(parameter_count),
52           zone_(zone),
53           rcursor_(0),
54           pcursor_(0),
55           buffer_(zone->NewArray<T>(
56               static_cast<int>(return_count + parameter_count))) {}
57 
58     const size_t return_count_;
59     const size_t parameter_count_;
60 
AddReturn(T val)61     void AddReturn(T val) {
62       DCHECK(rcursor_ < return_count_);
63       buffer_[rcursor_++] = val;
64     }
AddParam(T val)65     void AddParam(T val) {
66       DCHECK(pcursor_ < parameter_count_);
67       buffer_[return_count_ + pcursor_++] = val;
68     }
Build()69     Signature<T>* Build() {
70       DCHECK(rcursor_ == return_count_);
71       DCHECK(pcursor_ == parameter_count_);
72       return new (zone_) Signature<T>(return_count_, parameter_count_, buffer_);
73     }
74 
75    private:
76     Zone* zone_;
77     size_t rcursor_;
78     size_t pcursor_;
79     T* buffer_;
80   };
81 
82  protected:
83   size_t return_count_;
84   size_t parameter_count_;
85   const T* reps_;
86 };
87 
88 }  // namespace internal
89 }  // namespace v8
90 
91 #endif  // V8_SIGNATURE_H_
92