1 // Copyright 2016 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/ast/context-slot-cache.h"
6
7 #include <stdlib.h>
8
9 #include "src/ast/scopes.h"
10 #include "src/bootstrapper.h"
11 // FIXME(mstarzinger, marja): This is weird, but required because of the missing
12 // (disallowed) include: src/factory.h -> src/objects-inl.h
13 #include "src/objects-inl.h"
14 // FIXME(mstarzinger, marja): This is weird, but required because of the missing
15 // (disallowed) include: src/feedback-vector.h ->
16 // src/feedback-vector-inl.h
17 #include "src/feedback-vector-inl.h"
18
19 namespace v8 {
20 namespace internal {
21
Hash(Object * data,String * name)22 int ContextSlotCache::Hash(Object* data, String* name) {
23 // Uses only lower 32 bits if pointers are larger.
24 uintptr_t addr_hash =
25 static_cast<uint32_t>(reinterpret_cast<uintptr_t>(data)) >> 2;
26 return static_cast<int>((addr_hash ^ name->Hash()) % kLength);
27 }
28
Lookup(Object * data,String * name,VariableMode * mode,InitializationFlag * init_flag,MaybeAssignedFlag * maybe_assigned_flag)29 int ContextSlotCache::Lookup(Object* data, String* name, VariableMode* mode,
30 InitializationFlag* init_flag,
31 MaybeAssignedFlag* maybe_assigned_flag) {
32 int index = Hash(data, name);
33 Key& key = keys_[index];
34 if ((key.data == data) && key.name->Equals(name)) {
35 Value result(values_[index]);
36 if (mode != nullptr) *mode = result.mode();
37 if (init_flag != nullptr) *init_flag = result.initialization_flag();
38 if (maybe_assigned_flag != nullptr)
39 *maybe_assigned_flag = result.maybe_assigned_flag();
40 return result.index() + kNotFound;
41 }
42 return kNotFound;
43 }
44
Update(Handle<Object> data,Handle<String> name,VariableMode mode,InitializationFlag init_flag,MaybeAssignedFlag maybe_assigned_flag,int slot_index)45 void ContextSlotCache::Update(Handle<Object> data, Handle<String> name,
46 VariableMode mode, InitializationFlag init_flag,
47 MaybeAssignedFlag maybe_assigned_flag,
48 int slot_index) {
49 DisallowHeapAllocation no_gc;
50 Handle<String> internalized_name;
51 DCHECK(slot_index > kNotFound);
52 if (StringTable::InternalizeStringIfExists(name->GetIsolate(), name)
53 .ToHandle(&internalized_name)) {
54 int index = Hash(*data, *internalized_name);
55 Key& key = keys_[index];
56 key.data = *data;
57 key.name = *internalized_name;
58 // Please note value only takes a uint as index.
59 values_[index] =
60 Value(mode, init_flag, maybe_assigned_flag, slot_index - kNotFound)
61 .raw();
62 #ifdef DEBUG
63 ValidateEntry(data, name, mode, init_flag, maybe_assigned_flag, slot_index);
64 #endif
65 }
66 }
67
Clear()68 void ContextSlotCache::Clear() {
69 for (int index = 0; index < kLength; index++) keys_[index].data = nullptr;
70 }
71
72 #ifdef DEBUG
73
ValidateEntry(Handle<Object> data,Handle<String> name,VariableMode mode,InitializationFlag init_flag,MaybeAssignedFlag maybe_assigned_flag,int slot_index)74 void ContextSlotCache::ValidateEntry(Handle<Object> data, Handle<String> name,
75 VariableMode mode,
76 InitializationFlag init_flag,
77 MaybeAssignedFlag maybe_assigned_flag,
78 int slot_index) {
79 DisallowHeapAllocation no_gc;
80 Handle<String> internalized_name;
81 if (StringTable::InternalizeStringIfExists(name->GetIsolate(), name)
82 .ToHandle(&internalized_name)) {
83 int index = Hash(*data, *name);
84 Key& key = keys_[index];
85 DCHECK(key.data == *data);
86 DCHECK(key.name->Equals(*name));
87 Value result(values_[index]);
88 DCHECK(result.mode() == mode);
89 DCHECK(result.initialization_flag() == init_flag);
90 DCHECK(result.maybe_assigned_flag() == maybe_assigned_flag);
91 DCHECK(result.index() + kNotFound == slot_index);
92 }
93 }
94
95 #endif // DEBUG
96
97 } // namespace internal
98 } // namespace v8
99