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      1 // Copyright 2011 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 #include "v8.h"
     29 
     30 #include "ast.h"
     31 #include "scopes.h"
     32 #include "variables.h"
     33 
     34 namespace v8 {
     35 namespace internal {
     36 
     37 // ----------------------------------------------------------------------------
     38 // Implementation Variable.
     39 
     40 const char* Variable::Mode2String(VariableMode mode) {
     41   switch (mode) {
     42     case VAR: return "VAR";
     43     case CONST: return "CONST";
     44     case LET: return "LET";
     45     case CONST_HARMONY: return "CONST_HARMONY";
     46     case MODULE: return "MODULE";
     47     case DYNAMIC: return "DYNAMIC";
     48     case DYNAMIC_GLOBAL: return "DYNAMIC_GLOBAL";
     49     case DYNAMIC_LOCAL: return "DYNAMIC_LOCAL";
     50     case INTERNAL: return "INTERNAL";
     51     case TEMPORARY: return "TEMPORARY";
     52   }
     53   UNREACHABLE();
     54   return NULL;
     55 }
     56 
     57 
     58 Variable::Variable(Scope* scope,
     59                    Handle<String> name,
     60                    VariableMode mode,
     61                    bool is_valid_LHS,
     62                    Kind kind,
     63                    InitializationFlag initialization_flag,
     64                    Interface* interface)
     65   : scope_(scope),
     66     name_(name),
     67     mode_(mode),
     68     kind_(kind),
     69     location_(UNALLOCATED),
     70     index_(-1),
     71     initializer_position_(RelocInfo::kNoPosition),
     72     local_if_not_shadowed_(NULL),
     73     is_valid_LHS_(is_valid_LHS),
     74     force_context_allocation_(false),
     75     is_used_(false),
     76     initialization_flag_(initialization_flag),
     77     interface_(interface) {
     78   // Names must be canonicalized for fast equality checks.
     79   ASSERT(name->IsInternalizedString());
     80   // Var declared variables never need initialization.
     81   ASSERT(!(mode == VAR && initialization_flag == kNeedsInitialization));
     82 }
     83 
     84 
     85 bool Variable::IsGlobalObjectProperty() const {
     86   // Temporaries are never global, they must always be allocated in the
     87   // activation frame.
     88   return (IsDynamicVariableMode(mode_) ||
     89           (IsDeclaredVariableMode(mode_) && !IsLexicalVariableMode(mode_)))
     90       && scope_ != NULL && scope_->is_global_scope();
     91 }
     92 
     93 
     94 int Variable::CompareIndex(Variable* const* v, Variable* const* w) {
     95   int x = (*v)->index();
     96   int y = (*w)->index();
     97   // Consider sorting them according to type as well?
     98   return x - y;
     99 }
    100 
    101 } }  // namespace v8::internal
    102