1 // Copyright 2014 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/snapshot/natives.h" 6 7 #include "src/base/logging.h" 8 #include "src/list.h" 9 #include "src/list-inl.h" 10 #include "src/snapshot/snapshot-source-sink.h" 11 #include "src/vector.h" 12 13 #ifndef V8_USE_EXTERNAL_STARTUP_DATA 14 #error natives-external.cc is used only for the external snapshot build. 15 #endif // V8_USE_EXTERNAL_STARTUP_DATA 16 17 18 namespace v8 { 19 namespace internal { 20 21 22 /** 23 * NativesStore stores the 'native' (builtin) JS libraries. 24 * 25 * NativesStore needs to be initialized before using V8, usually by the 26 * embedder calling v8::SetNativesDataBlob, which calls SetNativesFromFile 27 * below. 28 */ 29 class NativesStore { 30 public: 31 ~NativesStore() { 32 for (int i = 0; i < native_names_.length(); i++) { 33 native_names_[i].Dispose(); 34 } 35 } 36 37 int GetBuiltinsCount() { return native_ids_.length(); } 38 int GetDebuggerCount() { return debugger_count_; } 39 40 Vector<const char> GetScriptSource(int index) { 41 return native_source_[index]; 42 } 43 44 Vector<const char> GetScriptName(int index) { return native_names_[index]; } 45 46 int GetIndex(const char* id) { 47 for (int i = 0; i < native_ids_.length(); ++i) { 48 int native_id_length = native_ids_[i].length(); 49 if ((static_cast<int>(strlen(id)) == native_id_length) && 50 (strncmp(id, native_ids_[i].start(), native_id_length) == 0)) { 51 return i; 52 } 53 } 54 DCHECK(false); 55 return -1; 56 } 57 58 Vector<const char> GetScriptsSource() { 59 DCHECK(false); // Not implemented. 60 return Vector<const char>(); 61 } 62 63 static NativesStore* MakeFromScriptsSource(SnapshotByteSource* source) { 64 NativesStore* store = new NativesStore; 65 66 // We expect the libraries in the following format: 67 // int: # of debugger sources. 68 // 2N blobs: N pairs of source name + actual source. 69 // then, repeat for non-debugger sources. 70 int debugger_count = source->GetInt(); 71 for (int i = 0; i < debugger_count; ++i) 72 store->ReadNameAndContentPair(source); 73 int library_count = source->GetInt(); 74 for (int i = 0; i < library_count; ++i) 75 store->ReadNameAndContentPair(source); 76 77 store->debugger_count_ = debugger_count; 78 return store; 79 } 80 81 private: 82 NativesStore() : debugger_count_(0) {} 83 84 Vector<const char> NameFromId(const byte* id, int id_length) { 85 const char native[] = "native "; 86 const char extension[] = ".js"; 87 Vector<char> name(Vector<char>::New(id_length + sizeof(native) - 1 + 88 sizeof(extension) - 1)); 89 memcpy(name.start(), native, sizeof(native) - 1); 90 memcpy(name.start() + sizeof(native) - 1, id, id_length); 91 memcpy(name.start() + sizeof(native) - 1 + id_length, extension, 92 sizeof(extension) - 1); 93 return Vector<const char>::cast(name); 94 } 95 96 void ReadNameAndContentPair(SnapshotByteSource* bytes) { 97 const byte* id; 98 const byte* source; 99 int id_length = bytes->GetBlob(&id); 100 int source_length = bytes->GetBlob(&source); 101 Vector<const char> id_vector(reinterpret_cast<const char*>(id), id_length); 102 Vector<const char> source_vector(reinterpret_cast<const char*>(source), 103 source_length); 104 native_ids_.Add(id_vector); 105 native_source_.Add(source_vector); 106 native_names_.Add(NameFromId(id, id_length)); 107 } 108 109 List<Vector<const char> > native_ids_; 110 List<Vector<const char> > native_names_; 111 List<Vector<const char> > native_source_; 112 int debugger_count_; 113 114 DISALLOW_COPY_AND_ASSIGN(NativesStore); 115 }; 116 117 118 template<NativeType type> 119 class NativesHolder { 120 public: 121 static NativesStore* get() { 122 CHECK(holder_); 123 return holder_; 124 } 125 static void set(NativesStore* store) { 126 CHECK(store); 127 holder_ = store; 128 } 129 static bool empty() { return holder_ == NULL; } 130 static void Dispose() { 131 delete holder_; 132 holder_ = NULL; 133 } 134 135 private: 136 static NativesStore* holder_; 137 }; 138 139 template<NativeType type> 140 NativesStore* NativesHolder<type>::holder_ = NULL; 141 142 143 // The natives blob. Memory is owned by caller. 144 static StartupData* natives_blob_ = NULL; 145 146 147 /** 148 * Read the Natives blob, as previously set by SetNativesFromFile. 149 */ 150 void ReadNatives() { 151 if (natives_blob_ && NativesHolder<CORE>::empty()) { 152 SnapshotByteSource bytes(natives_blob_->data, natives_blob_->raw_size); 153 NativesHolder<CORE>::set(NativesStore::MakeFromScriptsSource(&bytes)); 154 NativesHolder<EXPERIMENTAL>::set( 155 NativesStore::MakeFromScriptsSource(&bytes)); 156 NativesHolder<EXTRAS>::set(NativesStore::MakeFromScriptsSource(&bytes)); 157 NativesHolder<EXPERIMENTAL_EXTRAS>::set( 158 NativesStore::MakeFromScriptsSource(&bytes)); 159 DCHECK(!bytes.HasMore()); 160 } 161 } 162 163 164 /** 165 * Set the Natives (library sources) blob, as generated by js2c + the build 166 * system. 167 */ 168 void SetNativesFromFile(StartupData* natives_blob) { 169 DCHECK(!natives_blob_); 170 DCHECK(natives_blob); 171 DCHECK(natives_blob->data); 172 DCHECK(natives_blob->raw_size > 0); 173 174 natives_blob_ = natives_blob; 175 ReadNatives(); 176 } 177 178 179 /** 180 * Release memory allocated by SetNativesFromFile. 181 */ 182 void DisposeNatives() { 183 NativesHolder<CORE>::Dispose(); 184 NativesHolder<EXPERIMENTAL>::Dispose(); 185 NativesHolder<EXTRAS>::Dispose(); 186 NativesHolder<EXPERIMENTAL_EXTRAS>::Dispose(); 187 } 188 189 190 // Implement NativesCollection<T> bsaed on NativesHolder + NativesStore. 191 // 192 // (The callers expect a purely static interface, since this is how the 193 // natives are usually compiled in. Since we implement them based on 194 // runtime content, we have to implement this indirection to offer 195 // a static interface.) 196 template<NativeType type> 197 int NativesCollection<type>::GetBuiltinsCount() { 198 return NativesHolder<type>::get()->GetBuiltinsCount(); 199 } 200 201 template<NativeType type> 202 int NativesCollection<type>::GetDebuggerCount() { 203 return NativesHolder<type>::get()->GetDebuggerCount(); 204 } 205 206 template<NativeType type> 207 int NativesCollection<type>::GetIndex(const char* name) { 208 return NativesHolder<type>::get()->GetIndex(name); 209 } 210 211 template <NativeType type> 212 Vector<const char> NativesCollection<type>::GetScriptSource(int index) { 213 return NativesHolder<type>::get()->GetScriptSource(index); 214 } 215 216 template<NativeType type> 217 Vector<const char> NativesCollection<type>::GetScriptName(int index) { 218 return NativesHolder<type>::get()->GetScriptName(index); 219 } 220 221 template <NativeType type> 222 Vector<const char> NativesCollection<type>::GetScriptsSource() { 223 return NativesHolder<type>::get()->GetScriptsSource(); 224 } 225 226 227 // Explicit template instantiations. 228 #define INSTANTIATE_TEMPLATES(T) \ 229 template int NativesCollection<T>::GetBuiltinsCount(); \ 230 template int NativesCollection<T>::GetDebuggerCount(); \ 231 template int NativesCollection<T>::GetIndex(const char* name); \ 232 template Vector<const char> NativesCollection<T>::GetScriptSource(int i); \ 233 template Vector<const char> NativesCollection<T>::GetScriptName(int i); \ 234 template Vector<const char> NativesCollection<T>::GetScriptsSource(); 235 INSTANTIATE_TEMPLATES(CORE) 236 INSTANTIATE_TEMPLATES(EXPERIMENTAL) 237 INSTANTIATE_TEMPLATES(EXTRAS) 238 INSTANTIATE_TEMPLATES(EXPERIMENTAL_EXTRAS) 239 #undef INSTANTIATE_TEMPLATES 240 241 } // namespace internal 242 } // namespace v8 243
