ager@chromium.org | 9258b6b | 2008-09-11 09:11:10 +0000 | [diff] [blame] | 1 | // Copyright 2006-2008 the V8 project authors. All rights reserved. |
christian.plesner.hansen | 43d26ec | 2008-07-03 15:10:15 +0000 | [diff] [blame] | 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_SCOPEINFO_H_ |
| 29 | #define V8_SCOPEINFO_H_ |
| 30 | |
| 31 | #include "variables.h" |
| 32 | |
| 33 | namespace v8 { namespace internal { |
| 34 | |
| 35 | // Scope information represents information about a functions's |
| 36 | // scopes (currently only one, because we don't do any inlining) |
| 37 | // and the allocation of the scope's variables. Scope information |
| 38 | // is stored in a compressed form with Code objects and is used |
| 39 | // at runtime (stack dumps, deoptimization, etc.). |
| 40 | // |
| 41 | // Historical note: In other VMs built by this team, ScopeInfo was |
| 42 | // usually called DebugInfo since the information was used (among |
| 43 | // other things) for on-demand debugging (Self, Smalltalk). However, |
| 44 | // DebugInfo seems misleading, since this information is primarily used |
| 45 | // in debugging-unrelated contexts. |
| 46 | |
| 47 | // Forward defined as |
| 48 | // template <class Allocator = FreeStoreAllocationPolicy> class ScopeInfo; |
| 49 | template<class Allocator> |
| 50 | class ScopeInfo BASE_EMBEDDED { |
| 51 | public: |
| 52 | // Create a ScopeInfo instance from a scope. |
| 53 | explicit ScopeInfo(Scope* scope); |
| 54 | |
| 55 | // Create a ScopeInfo instance from a Code object. |
| 56 | explicit ScopeInfo(Code* code); |
| 57 | |
| 58 | // Write the ScopeInfo data into a Code object, and returns the |
| 59 | // amount of space that was needed. If no Code object is provided |
| 60 | // (NULL handle), Serialize() only returns the amount of space needed. |
| 61 | // |
| 62 | // This operations requires that the Code object has the correct amount |
| 63 | // of space for the ScopeInfo data; otherwise the operation fails (fatal |
| 64 | // error). Any existing scope info in the Code object is simply overwritten. |
| 65 | int Serialize(Code* code); |
| 66 | |
| 67 | // Garbage collection support for scope info embedded in Code objects. |
| 68 | // This code is in ScopeInfo because only here we should have to know |
| 69 | // about the encoding. |
| 70 | static void IterateScopeInfo(Code* code, ObjectVisitor* v); |
| 71 | |
| 72 | |
| 73 | // -------------------------------------------------------------------------- |
| 74 | // Lookup |
| 75 | |
| 76 | Handle<String> function_name() const { return function_name_; } |
| 77 | |
| 78 | bool supports_eval() const { return supports_eval_; } |
| 79 | |
| 80 | Handle<String> parameter_name(int i) const { return parameters_[i]; } |
| 81 | int number_of_parameters() const { return parameters_.length(); } |
| 82 | |
| 83 | Handle<String> stack_slot_name(int i) const { return stack_slots_[i]; } |
| 84 | int number_of_stack_slots() const { return stack_slots_.length(); } |
| 85 | |
| 86 | Handle<String> context_slot_name(int i) const { |
| 87 | return context_slots_[i - Context::MIN_CONTEXT_SLOTS]; |
| 88 | } |
| 89 | int number_of_context_slots() const { |
| 90 | int l = context_slots_.length(); |
| 91 | return l == 0 ? 0 : l + Context::MIN_CONTEXT_SLOTS; |
| 92 | } |
| 93 | |
| 94 | Handle<String> LocalName(int i) const; |
| 95 | int NumberOfLocals() const; |
| 96 | |
| 97 | |
| 98 | // -------------------------------------------------------------------------- |
| 99 | // The following functions provide quick access to scope info details |
| 100 | // for runtime routines w/o the need to explicitly create a ScopeInfo |
| 101 | // object. |
| 102 | // |
| 103 | // ScopeInfo is the only class which should have to know about the |
| 104 | // encoding of it's information in a Code object, which is why these |
| 105 | // functions are in this class. |
| 106 | |
| 107 | static bool SupportsEval(Code* code); |
| 108 | |
| 109 | // Return the number of stack slots for code. |
| 110 | static int NumberOfStackSlots(Code* code); |
| 111 | |
| 112 | // Return the number of context slots for code. |
| 113 | static int NumberOfContextSlots(Code* code); |
| 114 | |
| 115 | // Lookup support for scope info embedded in Code objects. Returns |
| 116 | // the stack slot index for a given slot name if the slot is |
| 117 | // present; otherwise returns a value < 0. The name must be a symbol |
| 118 | // (canonicalized). |
| 119 | static int StackSlotIndex(Code* code, String* name); |
| 120 | |
| 121 | // Lookup support for scope info embedded in Code objects. Returns the |
| 122 | // context slot index for a given slot name if the slot is present; otherwise |
| 123 | // returns a value < 0. The name must be a symbol (canonicalized). |
| 124 | // If the slot is present and mode != NULL, sets *mode to the corresponding |
| 125 | // mode for that variable. |
| 126 | static int ContextSlotIndex(Code* code, String* name, Variable::Mode* mode); |
| 127 | |
| 128 | // Lookup support for scope info embedded in Code objects. Returns the |
| 129 | // parameter index for a given parameter name if the parameter is present; |
| 130 | // otherwise returns a value < 0. The name must be a symbol (canonicalized). |
| 131 | static int ParameterIndex(Code* code, String* name); |
| 132 | |
| 133 | // Lookup support for scope info embedded in Code objects. Returns the |
| 134 | // function context slot index if the function name is present (named |
| 135 | // function expressions, only), otherwise returns a value < 0. The name |
| 136 | // must be a symbol (canonicalized). |
| 137 | static int FunctionContextSlotIndex(Code* code, String* name); |
| 138 | |
| 139 | |
| 140 | // -------------------------------------------------------------------------- |
| 141 | // Debugging support |
| 142 | |
| 143 | #ifdef DEBUG |
| 144 | void Print(); |
| 145 | #endif |
| 146 | |
| 147 | private: |
| 148 | Handle<String> function_name_; |
| 149 | bool supports_eval_; |
| 150 | List<Handle<String>, Allocator > parameters_; |
| 151 | List<Handle<String>, Allocator > stack_slots_; |
| 152 | List<Handle<String>, Allocator > context_slots_; |
| 153 | List<Variable::Mode, Allocator > context_modes_; |
| 154 | }; |
| 155 | |
| 156 | } } // namespace v8::internal |
| 157 | |
| 158 | #endif // V8_SCOPEINFO_H_ |