V8 Project
variables.cc
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1 // Copyright 2011 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 #include "src/v8.h"
6 
7 #include "src/ast.h"
8 #include "src/scopes.h"
9 #include "src/variables.h"
10 
11 namespace v8 {
12 namespace internal {
13 
14 // ----------------------------------------------------------------------------
15 // Implementation Variable.
16 
17 const char* Variable::Mode2String(VariableMode mode) {
18  switch (mode) {
19  case VAR: return "VAR";
20  case CONST_LEGACY: return "CONST_LEGACY";
21  case LET: return "LET";
22  case CONST: return "CONST";
23  case MODULE: return "MODULE";
24  case DYNAMIC: return "DYNAMIC";
25  case DYNAMIC_GLOBAL: return "DYNAMIC_GLOBAL";
26  case DYNAMIC_LOCAL: return "DYNAMIC_LOCAL";
27  case INTERNAL: return "INTERNAL";
28  case TEMPORARY: return "TEMPORARY";
29  }
30  UNREACHABLE();
31  return NULL;
32 }
33 
34 
35 Variable::Variable(Scope* scope, const AstRawString* name, VariableMode mode,
36  bool is_valid_ref, Kind kind,
37  InitializationFlag initialization_flag,
38  MaybeAssignedFlag maybe_assigned_flag, Interface* interface)
39  : scope_(scope),
40  name_(name),
41  mode_(mode),
42  kind_(kind),
43  location_(UNALLOCATED),
44  index_(-1),
45  initializer_position_(RelocInfo::kNoPosition),
46  local_if_not_shadowed_(NULL),
47  is_valid_ref_(is_valid_ref),
48  force_context_allocation_(false),
49  is_used_(false),
50  initialization_flag_(initialization_flag),
51  maybe_assigned_(maybe_assigned_flag),
52  interface_(interface) {
53  // Var declared variables never need initialization.
54  DCHECK(!(mode == VAR && initialization_flag == kNeedsInitialization));
55 }
56 
57 
58 bool Variable::IsGlobalObjectProperty() const {
59  // Temporaries are never global, they must always be allocated in the
60  // activation frame.
61  return (IsDynamicVariableMode(mode_) ||
62  (IsDeclaredVariableMode(mode_) && !IsLexicalVariableMode(mode_)))
63  && scope_ != NULL && scope_->is_global_scope();
64 }
65 
66 
67 int Variable::CompareIndex(Variable* const* v, Variable* const* w) {
68  int x = (*v)->index();
69  int y = (*w)->index();
70  // Consider sorting them according to type as well?
71  return x - y;
72 }
73 
74 } } // namespace v8::internal
v8::internal::Scope::is_global_scope
bool is_global_scope() const
Definition: scopes.h:267
v8::internal::Variable::Mode2String
static const char * Mode2String(VariableMode mode)
Definition: variables.cc:17
v8::internal::Variable::mode
VariableMode mode() const
Definition: variables.h:73
v8::internal::Variable::Variable
Variable(Scope *scope, const AstRawString *name, VariableMode mode, bool is_valid_ref, Kind kind, InitializationFlag initialization_flag, MaybeAssignedFlag maybe_assigned_flag=kNotAssigned, Interface *interface=Interface::NewValue())
Definition: variables.cc:35
v8::internal::Variable::initialization_flag
InitializationFlag initialization_flag() const
Definition: variables.h:126
v8::internal::Variable::IsGlobalObjectProperty
bool IsGlobalObjectProperty() const
Definition: variables.cc:58
v8::internal::Variable::mode_
VariableMode mode_
Definition: variables.h:141
v8::internal::Variable::CompareIndex
static int CompareIndex(Variable *const *v, Variable *const *w)
Definition: variables.cc:67
name
enable harmony numeric enable harmony object literal extensions Optimize object Array DOM strings and string trace pretenuring decisions of HAllocate instructions Enables optimizations which favor memory size over execution speed maximum source size in bytes considered for a single inlining maximum cumulative number of AST nodes considered for inlining trace the tracking of allocation sites deoptimize every n garbage collections perform array bounds checks elimination analyze liveness of environment slots and zap dead values flushes the cache of optimized code for closures on every GC allow uint32 values on optimize frames if they are used only in safe operations track concurrent recompilation artificial compilation delay in ms do not emit check maps for constant values that have a leaf deoptimize the optimized code if the layout of the maps changes enable context specialization in TurboFan execution budget before interrupt is triggered max percentage of megamorphic generic ICs to allow optimization enable use of SAHF instruction if enable use of VFP3 instructions if available enable use of NEON instructions if enable use of SDIV and UDIV instructions if enable use of MLS instructions if enable loading bit constant by means of movw movt instruction enable unaligned accesses for enable use of d16 d31 registers on ARM this requires VFP3 force all emitted branches to be in long enable alignment of csp to bytes on platforms which prefer the register to always be expose gc extension under the specified name show built in functions in stack traces use random jit cookie to mask large constants minimum length for automatic enable preparsing CPU profiler sampling interval in microseconds trace out of bounds accesses to external arrays default size of stack region v8 is allowed to maximum length of function source code printed in a stack trace min size of a semi the new space consists of two semi spaces print one trace line following each garbage collection do not print trace line after scavenger collection print cumulative GC statistics in name
Definition: flag-definitions.h:504
mode
enable harmony numeric enable harmony object literal extensions Optimize object Array DOM strings and string trace pretenuring decisions of HAllocate instructions Enables optimizations which favor memory size over execution speed maximum source size in bytes considered for a single inlining maximum cumulative number of AST nodes considered for inlining trace the tracking of allocation sites deoptimize every n garbage collections perform array bounds checks elimination analyze liveness of environment slots and zap dead values flushes the cache of optimized code for closures on every GC allow uint32 values on optimize frames if they are used only in safe operations track concurrent recompilation artificial compilation delay in ms do not emit check maps for constant values that have a leaf deoptimize the optimized code if the layout of the maps changes enable context specialization in TurboFan execution budget before interrupt is triggered max percentage of megamorphic generic ICs to allow optimization enable use of SAHF instruction if enable use of VFP3 instructions if available enable use of NEON instructions if enable use of SDIV and UDIV instructions if enable use of MLS instructions if enable loading bit constant by means of movw movt instruction enable unaligned accesses for enable use of d16 d31 registers on ARM this requires VFP3 force all emitted branches to be in long mode(MIPS only)") DEFINE_BOOL(enable_always_align_csp
NULL
enable harmony numeric enable harmony object literal extensions Optimize object Array DOM strings and string trace pretenuring decisions of HAllocate instructions Enables optimizations which favor memory size over execution speed maximum source size in bytes considered for a single inlining maximum cumulative number of AST nodes considered for inlining trace the tracking of allocation sites deoptimize every n garbage collections perform array bounds checks elimination analyze liveness of environment slots and zap dead values flushes the cache of optimized code for closures on every GC allow uint32 values on optimize frames if they are used only in safe operations track concurrent recompilation artificial compilation delay in ms do not emit check maps for constant values that have a leaf deoptimize the optimized code if the layout of the maps changes enable context specialization in TurboFan execution budget before interrupt is triggered max percentage of megamorphic generic ICs to allow optimization enable use of SAHF instruction if enable use of VFP3 instructions if available enable use of NEON instructions if enable use of SDIV and UDIV instructions if enable use of MLS instructions if enable loading bit constant by means of movw movt instruction enable unaligned accesses for enable use of d16 d31 registers on ARM this requires VFP3 force all emitted branches to be in long enable alignment of csp to bytes on platforms which prefer the register to always be NULL
Definition: flag-definitions.h:407
UNREACHABLE
#define UNREACHABLE()
Definition: logging.h:30
DCHECK
#define DCHECK(condition)
Definition: logging.h:205
v8::internal::InitializationFlag
InitializationFlag
Definition: globals.h:751
v8::internal::kNeedsInitialization
@ kNeedsInitialization
Definition: globals.h:752
v8::internal::IsLexicalVariableMode
bool IsLexicalVariableMode(VariableMode mode)
Definition: globals.h:710
v8::internal::IsDeclaredVariableMode
bool IsDeclaredVariableMode(VariableMode mode)
Definition: globals.h:705
v8::internal::DYNAMIC_GLOBAL
@ DYNAMIC_GLOBAL
Definition: globals.h:689
v8::internal::DYNAMIC_LOCAL
@ DYNAMIC_LOCAL
Definition: globals.h:693
v8::internal::CONST_LEGACY
@ CONST_LEGACY
Definition: globals.h:671
v8::internal::IsDynamicVariableMode
bool IsDynamicVariableMode(VariableMode mode)
Definition: globals.h:700
v8
Debugger support for the V8 JavaScript engine.
Definition: accessors.cc:20