1// Copyright 2006-2009 the V8 project authors. All rights reserved. 2// Redistribution and use in source and binary forms, with or without 3// modification, are permitted provided that the following conditions are 4// met: 5// 6// * Redistributions of source code must retain the above copyright 7// notice, this list of conditions and the following disclaimer. 8// * Redistributions in binary form must reproduce the above 9// copyright notice, this list of conditions and the following 10// disclaimer in the documentation and/or other materials provided 11// with the distribution. 12// * Neither the name of Google Inc. nor the names of its 13// contributors may be used to endorse or promote products derived 14// from this software without specific prior written permission. 15// 16// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 28#ifndef V8_FUNC_NAME_INFERRER_H_ 29#define V8_FUNC_NAME_INFERRER_H_ 30 31namespace v8 { 32namespace internal { 33 34class Isolate; 35 36// FuncNameInferrer is a stateful class that is used to perform name 37// inference for anonymous functions during static analysis of source code. 38// Inference is performed in cases when an anonymous function is assigned 39// to a variable or a property (see test-func-name-inference.cc for examples.) 40// 41// The basic idea is that during parsing of LHSs of certain expressions 42// (assignments, declarations, object literals) we collect name strings, 43// and during parsing of the RHS, a function literal can be collected. After 44// parsing the RHS we can infer a name for function literals that do not have 45// a name. 46class FuncNameInferrer : public ZoneObject { 47 public: 48 FuncNameInferrer(Isolate* isolate, Zone* zone); 49 50 // Returns whether we have entered name collection state. 51 bool IsOpen() const { return !entries_stack_.is_empty(); } 52 53 // Pushes an enclosing the name of enclosing function onto names stack. 54 void PushEnclosingName(Handle<String> name); 55 56 // Enters name collection state. 57 void Enter() { 58 entries_stack_.Add(names_stack_.length(), zone()); 59 } 60 61 // Pushes an encountered name onto names stack when in collection state. 62 void PushLiteralName(Handle<String> name); 63 64 void PushVariableName(Handle<String> name); 65 66 // Adds a function to infer name for. 67 void AddFunction(FunctionLiteral* func_to_infer) { 68 if (IsOpen()) { 69 funcs_to_infer_.Add(func_to_infer, zone()); 70 } 71 } 72 73 void RemoveLastFunction() { 74 if (IsOpen() && !funcs_to_infer_.is_empty()) { 75 funcs_to_infer_.RemoveLast(); 76 } 77 } 78 79 // Infers a function name and leaves names collection state. 80 void Infer() { 81 ASSERT(IsOpen()); 82 if (!funcs_to_infer_.is_empty()) { 83 InferFunctionsNames(); 84 } 85 } 86 87 // Leaves names collection state. 88 void Leave() { 89 ASSERT(IsOpen()); 90 names_stack_.Rewind(entries_stack_.RemoveLast()); 91 if (entries_stack_.is_empty()) 92 funcs_to_infer_.Clear(); 93 } 94 95 private: 96 enum NameType { 97 kEnclosingConstructorName, 98 kLiteralName, 99 kVariableName 100 }; 101 struct Name { 102 Name(Handle<String> name, NameType type) : name(name), type(type) { } 103 Handle<String> name; 104 NameType type; 105 }; 106 107 Isolate* isolate() { return isolate_; } 108 Zone* zone() const { return zone_; } 109 110 // Constructs a full name in dotted notation from gathered names. 111 Handle<String> MakeNameFromStack(); 112 113 // A helper function for MakeNameFromStack. 114 Handle<String> MakeNameFromStackHelper(int pos, Handle<String> prev); 115 116 // Performs name inferring for added functions. 117 void InferFunctionsNames(); 118 119 Isolate* isolate_; 120 ZoneList<int> entries_stack_; 121 ZoneList<Name> names_stack_; 122 ZoneList<FunctionLiteral*> funcs_to_infer_; 123 Zone* zone_; 124 125 DISALLOW_COPY_AND_ASSIGN(FuncNameInferrer); 126}; 127 128 129} } // namespace v8::internal 130 131#endif // V8_FUNC_NAME_INFERRER_H_ 132