| OLD | NEW |
| 1 // Copyright 2006-2008 the V8 project authors. All rights reserved. | 1 // Copyright 2011 the V8 project authors. All rights reserved. |
| 2 // Redistribution and use in source and binary forms, with or without | 2 // Redistribution and use in source and binary forms, with or without |
| 3 // modification, are permitted provided that the following conditions are | 3 // modification, are permitted provided that the following conditions are |
| 4 // met: | 4 // met: |
| 5 // | 5 // |
| 6 // * Redistributions of source code must retain the above copyright | 6 // * Redistributions of source code must retain the above copyright |
| 7 // notice, this list of conditions and the following disclaimer. | 7 // notice, this list of conditions and the following disclaimer. |
| 8 // * Redistributions in binary form must reproduce the above | 8 // * Redistributions in binary form must reproduce the above |
| 9 // copyright notice, this list of conditions and the following | 9 // copyright notice, this list of conditions and the following |
| 10 // disclaimer in the documentation and/or other materials provided | 10 // disclaimer in the documentation and/or other materials provided |
| 11 // with the distribution. | 11 // with the distribution. |
| (...skipping 14 matching lines...) Expand all Loading... |
| 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 27 | 27 |
| 28 #ifndef V8_VARIABLES_H_ | 28 #ifndef V8_VARIABLES_H_ |
| 29 #define V8_VARIABLES_H_ | 29 #define V8_VARIABLES_H_ |
| 30 | 30 |
| 31 #include "zone.h" | 31 #include "zone.h" |
| 32 | 32 |
| 33 namespace v8 { | 33 namespace v8 { |
| 34 namespace internal { | 34 namespace internal { |
| 35 | 35 |
| 36 // Variables and AST expression nodes can track their "type" to enable | |
| 37 // optimizations and removal of redundant checks when generating code. | |
| 38 | |
| 39 class StaticType { | |
| 40 public: | |
| 41 enum Kind { | |
| 42 UNKNOWN, | |
| 43 LIKELY_SMI | |
| 44 }; | |
| 45 | |
| 46 StaticType() : kind_(UNKNOWN) {} | |
| 47 | |
| 48 bool Is(Kind kind) const { return kind_ == kind; } | |
| 49 | |
| 50 bool IsKnown() const { return !Is(UNKNOWN); } | |
| 51 bool IsUnknown() const { return Is(UNKNOWN); } | |
| 52 bool IsLikelySmi() const { return Is(LIKELY_SMI); } | |
| 53 | |
| 54 void CopyFrom(StaticType* other) { | |
| 55 kind_ = other->kind_; | |
| 56 } | |
| 57 | |
| 58 static const char* Type2String(StaticType* type); | |
| 59 | |
| 60 // LIKELY_SMI accessors | |
| 61 void SetAsLikelySmi() { | |
| 62 kind_ = LIKELY_SMI; | |
| 63 } | |
| 64 | |
| 65 void SetAsLikelySmiIfUnknown() { | |
| 66 if (IsUnknown()) { | |
| 67 SetAsLikelySmi(); | |
| 68 } | |
| 69 } | |
| 70 | |
| 71 private: | |
| 72 Kind kind_; | |
| 73 }; | |
| 74 | |
| 75 | |
| 76 // The AST refers to variables via VariableProxies - placeholders for the actual | 36 // The AST refers to variables via VariableProxies - placeholders for the actual |
| 77 // variables. Variables themselves are never directly referred to from the AST, | 37 // variables. Variables themselves are never directly referred to from the AST, |
| 78 // they are maintained by scopes, and referred to from VariableProxies and Slots | 38 // they are maintained by scopes, and referred to from VariableProxies and Slots |
| 79 // after binding and variable allocation. | 39 // after binding and variable allocation. |
| 80 | 40 |
| 81 class Variable: public ZoneObject { | 41 class Variable: public ZoneObject { |
| 82 public: | 42 public: |
| 83 enum Mode { | 43 enum Mode { |
| 84 // User declared variables: | 44 // User declared variables: |
| 85 VAR, // declared via 'var', and 'function' declarations | 45 VAR, // declared via 'var', and 'function' declarations |
| (...skipping 88 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... |
| 174 return local_if_not_shadowed_; | 134 return local_if_not_shadowed_; |
| 175 } | 135 } |
| 176 | 136 |
| 177 void set_local_if_not_shadowed(Variable* local) { | 137 void set_local_if_not_shadowed(Variable* local) { |
| 178 local_if_not_shadowed_ = local; | 138 local_if_not_shadowed_ = local; |
| 179 } | 139 } |
| 180 | 140 |
| 181 Expression* rewrite() const { return rewrite_; } | 141 Expression* rewrite() const { return rewrite_; } |
| 182 void set_rewrite(Expression* expr) { rewrite_ = expr; } | 142 void set_rewrite(Expression* expr) { rewrite_ = expr; } |
| 183 | 143 |
| 184 StaticType* type() { return &type_; } | |
| 185 | |
| 186 private: | 144 private: |
| 187 Scope* scope_; | 145 Scope* scope_; |
| 188 Handle<String> name_; | 146 Handle<String> name_; |
| 189 Mode mode_; | 147 Mode mode_; |
| 190 Kind kind_; | 148 Kind kind_; |
| 191 | 149 |
| 192 Variable* local_if_not_shadowed_; | 150 Variable* local_if_not_shadowed_; |
| 193 | 151 |
| 194 // Static type information | |
| 195 StaticType type_; | |
| 196 | |
| 197 // Code generation. | 152 // Code generation. |
| 198 // rewrite_ is usually a Slot or a Property, but may be any expression. | 153 // rewrite_ is usually a Slot or a Property, but may be any expression. |
| 199 Expression* rewrite_; | 154 Expression* rewrite_; |
| 200 | 155 |
| 201 // Valid as a LHS? (const and this are not valid LHS, for example) | 156 // Valid as a LHS? (const and this are not valid LHS, for example) |
| 202 bool is_valid_LHS_; | 157 bool is_valid_LHS_; |
| 203 | 158 |
| 204 // Usage info. | 159 // Usage info. |
| 205 bool is_accessed_from_inner_scope_; // set by variable resolver | 160 bool is_accessed_from_inner_scope_; // set by variable resolver |
| 206 bool is_used_; | 161 bool is_used_; |
| 207 }; | 162 }; |
| 208 | 163 |
| 209 | 164 |
| 210 } } // namespace v8::internal | 165 } } // namespace v8::internal |
| 211 | 166 |
| 212 #endif // V8_VARIABLES_H_ | 167 #endif // V8_VARIABLES_H_ |
| OLD | NEW |