1// Copyright 2012 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#ifndef V8_COMPILATION_CACHE_H_
6#define V8_COMPILATION_CACHE_H_
7
8#include "src/allocation.h"
9#include "src/objects/compilation-cache.h"
10
11namespace v8 {
12namespace internal {
13
14template <typename T>
15class Handle;
16
17class RootVisitor;
18
19// The compilation cache consists of several generational sub-caches which uses
20// this class as a base class. A sub-cache contains a compilation cache tables
21// for each generation of the sub-cache. Since the same source code string has
22// different compiled code for scripts and evals, we use separate sub-caches
23// for different compilation modes, to avoid retrieving the wrong result.
24class CompilationSubCache {
25 public:
26 CompilationSubCache(Isolate* isolate, int generations)
27 : isolate_(isolate),
28 generations_(generations) {
29 tables_ = NewArray<Object>(generations);
30 }
31
32 ~CompilationSubCache() { DeleteArray(tables_); }
33
34 // Index for the first generation in the cache.
35 static const int kFirstGeneration = 0;
36
37 // Get the compilation cache tables for a specific generation.
38 Handle<CompilationCacheTable> GetTable(int generation);
39
40 // Accessors for first generation.
41 Handle<CompilationCacheTable> GetFirstTable() {
42 return GetTable(kFirstGeneration);
43 }
44 void SetFirstTable(Handle<CompilationCacheTable> value) {
45 DCHECK_LT(kFirstGeneration, generations_);
46 tables_[kFirstGeneration] = *value;
47 }
48
49 // Age the sub-cache by evicting the oldest generation and creating a new
50 // young generation.
51 void Age();
52
53 // GC support.
54 void Iterate(RootVisitor* v);
55
56 // Clear this sub-cache evicting all its content.
57 void Clear();
58
59 // Remove given shared function info from sub-cache.
60 void Remove(Handle<SharedFunctionInfo> function_info);
61
62 // Number of generations in this sub-cache.
63 inline int generations() { return generations_; }
64
65 protected:
66 Isolate* isolate() { return isolate_; }
67
68 private:
69 Isolate* isolate_;
70 int generations_; // Number of generations.
71 Object* tables_; // Compilation cache tables - one for each generation.
72
73 DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationSubCache);
74};
75
76
77// Sub-cache for scripts.
78class CompilationCacheScript : public CompilationSubCache {
79 public:
80 explicit CompilationCacheScript(Isolate* isolate);
81
82 MaybeHandle<SharedFunctionInfo> Lookup(Handle<String> source,
83 MaybeHandle<Object> name,
84 int line_offset, int column_offset,
85 ScriptOriginOptions resource_options,
86 Handle<Context> native_context,
87 LanguageMode language_mode);
88
89 void Put(Handle<String> source, Handle<Context> context,
90 LanguageMode language_mode,
91 Handle<SharedFunctionInfo> function_info);
92
93 private:
94 bool HasOrigin(Handle<SharedFunctionInfo> function_info,
95 MaybeHandle<Object> name, int line_offset, int column_offset,
96 ScriptOriginOptions resource_options);
97
98 DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheScript);
99};
100
101
102// Sub-cache for eval scripts. Two caches for eval are used. One for eval calls
103// in native contexts and one for eval calls in other contexts. The cache
104// considers the following pieces of information when checking for matching
105// entries:
106// 1. The source string.
107// 2. The shared function info of the calling function.
108// 3. Whether the source should be compiled as strict code or as sloppy code.
109// Note: Currently there are clients of CompileEval that always compile
110// sloppy code even if the calling function is a strict mode function.
111// More specifically these are the CompileString, DebugEvaluate and
112// DebugEvaluateGlobal runtime functions.
113// 4. The start position of the calling scope.
114class CompilationCacheEval: public CompilationSubCache {
115 public:
116 explicit CompilationCacheEval(Isolate* isolate)
117 : CompilationSubCache(isolate, 1) {}
118
119 InfoCellPair Lookup(Handle<String> source,
120 Handle<SharedFunctionInfo> outer_info,
121 Handle<Context> native_context,
122 LanguageMode language_mode, int position);
123
124 void Put(Handle<String> source, Handle<SharedFunctionInfo> outer_info,
125 Handle<SharedFunctionInfo> function_info,
126 Handle<Context> native_context, Handle<FeedbackCell> feedback_cell,
127 int position);
128
129 private:
130 DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheEval);
131};
132
133
134// Sub-cache for regular expressions.
135class CompilationCacheRegExp: public CompilationSubCache {
136 public:
137 CompilationCacheRegExp(Isolate* isolate, int generations)
138 : CompilationSubCache(isolate, generations) { }
139
140 MaybeHandle<FixedArray> Lookup(Handle<String> source, JSRegExp::Flags flags);
141
142 void Put(Handle<String> source,
143 JSRegExp::Flags flags,
144 Handle<FixedArray> data);
145 private:
146 DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheRegExp);
147};
148
149// The compilation cache keeps shared function infos for compiled
150// scripts and evals. The shared function infos are looked up using
151// the source string as the key. For regular expressions the
152// compilation data is cached.
153class V8_EXPORT_PRIVATE CompilationCache {
154 public:
155 // Finds the script shared function info for a source
156 // string. Returns an empty handle if the cache doesn't contain a
157 // script for the given source string with the right origin.
158 MaybeHandle<SharedFunctionInfo> LookupScript(
159 Handle<String> source, MaybeHandle<Object> name, int line_offset,
160 int column_offset, ScriptOriginOptions resource_options,
161 Handle<Context> native_context, LanguageMode language_mode);
162
163 // Finds the shared function info for a source string for eval in a
164 // given context. Returns an empty handle if the cache doesn't
165 // contain a script for the given source string.
166 InfoCellPair LookupEval(Handle<String> source,
167 Handle<SharedFunctionInfo> outer_info,
168 Handle<Context> context, LanguageMode language_mode,
169 int position);
170
171 // Returns the regexp data associated with the given regexp if it
172 // is in cache, otherwise an empty handle.
173 MaybeHandle<FixedArray> LookupRegExp(
174 Handle<String> source, JSRegExp::Flags flags);
175
176 // Associate the (source, kind) pair to the shared function
177 // info. This may overwrite an existing mapping.
178 void PutScript(Handle<String> source, Handle<Context> native_context,
179 LanguageMode language_mode,
180 Handle<SharedFunctionInfo> function_info);
181
182 // Associate the (source, context->closure()->shared(), kind) triple
183 // with the shared function info. This may overwrite an existing mapping.
184 void PutEval(Handle<String> source, Handle<SharedFunctionInfo> outer_info,
185 Handle<Context> context,
186 Handle<SharedFunctionInfo> function_info,
187 Handle<FeedbackCell> feedback_cell, int position);
188
189 // Associate the (source, flags) pair to the given regexp data.
190 // This may overwrite an existing mapping.
191 void PutRegExp(Handle<String> source,
192 JSRegExp::Flags flags,
193 Handle<FixedArray> data);
194
195 // Clear the cache - also used to initialize the cache at startup.
196 void Clear();
197
198 // Remove given shared function info from all caches.
199 void Remove(Handle<SharedFunctionInfo> function_info);
200
201 // GC support.
202 void Iterate(RootVisitor* v);
203
204 // Notify the cache that a mark-sweep garbage collection is about to
205 // take place. This is used to retire entries from the cache to
206 // avoid keeping them alive too long without using them.
207 void MarkCompactPrologue();
208
209 // Enable/disable compilation cache. Used by debugger to disable compilation
210 // cache during debugging to make sure new scripts are always compiled.
211 void Enable();
212 void Disable();
213
214 private:
215 explicit CompilationCache(Isolate* isolate);
216 ~CompilationCache() = default;
217
218 base::HashMap* EagerOptimizingSet();
219
220 // The number of sub caches covering the different types to cache.
221 static const int kSubCacheCount = 4;
222
223 bool IsEnabled() const { return FLAG_compilation_cache && enabled_; }
224
225 Isolate* isolate() const { return isolate_; }
226
227 Isolate* isolate_;
228
229 CompilationCacheScript script_;
230 CompilationCacheEval eval_global_;
231 CompilationCacheEval eval_contextual_;
232 CompilationCacheRegExp reg_exp_;
233 CompilationSubCache* subcaches_[kSubCacheCount];
234
235 // Current enable state of the compilation cache.
236 bool enabled_;
237
238 friend class Isolate;
239
240 DISALLOW_COPY_AND_ASSIGN(CompilationCache);
241};
242
243} // namespace internal
244} // namespace v8
245
246#endif // V8_COMPILATION_CACHE_H_
247