V8 API Reference, 7.2.502.16 (for Deno 0.2.4)
func-name-inferrer.h
1 // Copyright 2006-2009 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_PARSING_FUNC_NAME_INFERRER_H_
6 #define V8_PARSING_FUNC_NAME_INFERRER_H_
7 
8 #include <vector>
9 
10 #include "src/base/macros.h"
11 #include "src/pointer-with-payload.h"
12 
13 namespace v8 {
14 namespace internal {
15 
16 class AstConsString;
17 class AstRawString;
18 class AstValueFactory;
19 class FunctionLiteral;
20 
21 enum class InferName { kYes, kNo };
22 
23 template <>
25  static constexpr int value = 2;
26 };
27 
28 // FuncNameInferrer is a stateful class that is used to perform name
29 // inference for anonymous functions during static analysis of source code.
30 // Inference is performed in cases when an anonymous function is assigned
31 // to a variable or a property (see test-func-name-inference.cc for examples.)
32 //
33 // The basic idea is that during parsing of LHSs of certain expressions
34 // (assignments, declarations, object literals) we collect name strings,
35 // and during parsing of the RHS, a function literal can be collected. After
36 // parsing the RHS we can infer a name for function literals that do not have
37 // a name.
39  public:
40  explicit FuncNameInferrer(AstValueFactory* ast_value_factory);
41 
42  // To enter function name inference state, put a FuncNameInferrer::State
43  // on the stack.
44  class State {
45  public:
46  explicit State(FuncNameInferrer* fni)
47  : fni_(fni), top_(fni->names_stack_.size()) {
48  ++fni_->scope_depth_;
49  }
50  ~State() {
51  DCHECK(fni_->IsOpen());
52  fni_->names_stack_.resize(top_);
53  --fni_->scope_depth_;
54  }
55 
56  private:
57  FuncNameInferrer* fni_;
58  size_t top_;
59 
60  DISALLOW_COPY_AND_ASSIGN(State);
61  };
62 
63  // Returns whether we have entered name collection state.
64  bool IsOpen() const { return scope_depth_ > 0; }
65 
66  // Pushes an enclosing the name of enclosing function onto names stack.
67  void PushEnclosingName(const AstRawString* name);
68 
69  // Pushes an encountered name onto names stack when in collection state.
70  void PushLiteralName(const AstRawString* name);
71 
72  void PushVariableName(const AstRawString* name);
73 
74  // Adds a function to infer name for.
75  void AddFunction(FunctionLiteral* func_to_infer) {
76  if (IsOpen()) {
77  funcs_to_infer_.push_back(func_to_infer);
78  }
79  }
80 
81  void RemoveLastFunction() {
82  if (IsOpen() && !funcs_to_infer_.empty()) funcs_to_infer_.pop_back();
83  }
84 
85  void RemoveAsyncKeywordFromEnd();
86 
87  // Infers a function name and leaves names collection state.
88  void Infer() {
89  DCHECK(IsOpen());
90  if (!funcs_to_infer_.empty()) InferFunctionsNames();
91  }
92 
93  private:
94  enum NameType : uint8_t {
95  kEnclosingConstructorName,
96  kLiteralName,
97  kVariableName
98  };
99  struct Name {
100  // Needed for names_stack_.resize()
101  Name() { UNREACHABLE(); }
102  Name(const AstRawString* name, NameType type)
103  : name_and_type_(name, type) {}
104 
105  PointerWithPayload<const AstRawString, NameType, 2> name_and_type_;
106  inline const AstRawString* name() const {
107  return name_and_type_.GetPointer();
108  }
109  inline NameType type() const { return name_and_type_.GetPayload(); }
110  };
111 
112  // Constructs a full name in dotted notation from gathered names.
113  const AstConsString* MakeNameFromStack();
114 
115  // Performs name inferring for added functions.
116  void InferFunctionsNames();
117 
118  AstValueFactory* ast_value_factory_;
119  std::vector<Name> names_stack_;
120  std::vector<FunctionLiteral*> funcs_to_infer_;
121  size_t scope_depth_ = 0;
122 
123  DISALLOW_COPY_AND_ASSIGN(FuncNameInferrer);
124 };
125 
126 
127 } // namespace internal
128 } // namespace v8
129 
130 #endif // V8_PARSING_FUNC_NAME_INFERRER_H_
Definition: libplatform.h:13