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_REGEXP_REGEXP_MACRO_ASSEMBLER_H_ 6 #define V8_REGEXP_REGEXP_MACRO_ASSEMBLER_H_ 7 8 #include "src/assembler.h" 9 #include "src/regexp/regexp-ast.h" 10 11 namespace v8 { 12 namespace internal { 13 14 static const uc32 kLeadSurrogateStart = 0xd800; 15 static const uc32 kLeadSurrogateEnd = 0xdbff; 16 static const uc32 kTrailSurrogateStart = 0xdc00; 17 static const uc32 kTrailSurrogateEnd = 0xdfff; 18 static const uc32 kNonBmpStart = 0x10000; 19 static const uc32 kNonBmpEnd = 0x10ffff; 20 21 struct DisjunctDecisionRow { 22 RegExpCharacterClass cc; 23 Label* on_match; 24 }; 25 26 27 class RegExpMacroAssembler { 28 public: 29 // The implementation must be able to handle at least: 30 static const int kMaxRegister = (1 << 16) - 1; 31 static const int kMaxCPOffset = (1 << 15) - 1; 32 static const int kMinCPOffset = -(1 << 15); 33 34 static const int kTableSizeBits = 7; 35 static const int kTableSize = 1 << kTableSizeBits; 36 static const int kTableMask = kTableSize - 1; 37 38 enum IrregexpImplementation { 39 kIA32Implementation, 40 kARMImplementation, 41 kARM64Implementation, 42 kMIPSImplementation, 43 kS390Implementation, 44 kPPCImplementation, 45 kX64Implementation, 46 kX87Implementation, 47 kBytecodeImplementation 48 }; 49 50 enum StackCheckFlag { 51 kNoStackLimitCheck = false, 52 kCheckStackLimit = true 53 }; 54 55 RegExpMacroAssembler(Isolate* isolate, Zone* zone); 56 virtual ~RegExpMacroAssembler(); 57 // This function is called when code generation is aborted, so that 58 // the assembler could clean up internal data structures. AbortedCodeGeneration()59 virtual void AbortedCodeGeneration() {} 60 // The maximal number of pushes between stack checks. Users must supply 61 // kCheckStackLimit flag to push operations (instead of kNoStackLimitCheck) 62 // at least once for every stack_limit() pushes that are executed. 63 virtual int stack_limit_slack() = 0; 64 virtual bool CanReadUnaligned() = 0; 65 virtual void AdvanceCurrentPosition(int by) = 0; // Signed cp change. 66 virtual void AdvanceRegister(int reg, int by) = 0; // r[reg] += by. 67 // Continues execution from the position pushed on the top of the backtrack 68 // stack by an earlier PushBacktrack(Label*). 69 virtual void Backtrack() = 0; 70 virtual void Bind(Label* label) = 0; 71 virtual void CheckAtStart(Label* on_at_start) = 0; 72 // Dispatch after looking the current character up in a 2-bits-per-entry 73 // map. The destinations vector has up to 4 labels. 74 virtual void CheckCharacter(unsigned c, Label* on_equal) = 0; 75 // Bitwise and the current character with the given constant and then 76 // check for a match with c. 77 virtual void CheckCharacterAfterAnd(unsigned c, 78 unsigned and_with, 79 Label* on_equal) = 0; 80 virtual void CheckCharacterGT(uc16 limit, Label* on_greater) = 0; 81 virtual void CheckCharacterLT(uc16 limit, Label* on_less) = 0; 82 virtual void CheckGreedyLoop(Label* on_tos_equals_current_position) = 0; 83 virtual void CheckNotAtStart(int cp_offset, Label* on_not_at_start) = 0; 84 virtual void CheckNotBackReference(int start_reg, bool read_backward, 85 Label* on_no_match) = 0; 86 virtual void CheckNotBackReferenceIgnoreCase(int start_reg, 87 bool read_backward, bool unicode, 88 Label* on_no_match) = 0; 89 // Check the current character for a match with a literal character. If we 90 // fail to match then goto the on_failure label. End of input always 91 // matches. If the label is nullptr then we should pop a backtrack address 92 // off the stack and go to that. 93 virtual void CheckNotCharacter(unsigned c, Label* on_not_equal) = 0; 94 virtual void CheckNotCharacterAfterAnd(unsigned c, 95 unsigned and_with, 96 Label* on_not_equal) = 0; 97 // Subtract a constant from the current character, then and with the given 98 // constant and then check for a match with c. 99 virtual void CheckNotCharacterAfterMinusAnd(uc16 c, 100 uc16 minus, 101 uc16 and_with, 102 Label* on_not_equal) = 0; 103 virtual void CheckCharacterInRange(uc16 from, 104 uc16 to, // Both inclusive. 105 Label* on_in_range) = 0; 106 virtual void CheckCharacterNotInRange(uc16 from, 107 uc16 to, // Both inclusive. 108 Label* on_not_in_range) = 0; 109 110 // The current character (modulus the kTableSize) is looked up in the byte 111 // array, and if the found byte is non-zero, we jump to the on_bit_set label. 112 virtual void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set) = 0; 113 114 // Checks whether the given offset from the current position is before 115 // the end of the string. May overwrite the current character. 116 virtual void CheckPosition(int cp_offset, Label* on_outside_input); 117 // Check whether a standard/default character class matches the current 118 // character. Returns false if the type of special character class does 119 // not have custom support. 120 // May clobber the current loaded character. 121 virtual bool CheckSpecialCharacterClass(uc16 type, Label* on_no_match); 122 virtual void Fail() = 0; 123 virtual Handle<HeapObject> GetCode(Handle<String> source) = 0; 124 virtual void GoTo(Label* label) = 0; 125 // Check whether a register is >= a given constant and go to a label if it 126 // is. Backtracks instead if the label is nullptr. 127 virtual void IfRegisterGE(int reg, int comparand, Label* if_ge) = 0; 128 // Check whether a register is < a given constant and go to a label if it is. 129 // Backtracks instead if the label is nullptr. 130 virtual void IfRegisterLT(int reg, int comparand, Label* if_lt) = 0; 131 // Check whether a register is == to the current position and go to a 132 // label if it is. 133 virtual void IfRegisterEqPos(int reg, Label* if_eq) = 0; 134 virtual IrregexpImplementation Implementation() = 0; 135 virtual void LoadCurrentCharacter(int cp_offset, 136 Label* on_end_of_input, 137 bool check_bounds = true, 138 int characters = 1) = 0; 139 virtual void PopCurrentPosition() = 0; 140 virtual void PopRegister(int register_index) = 0; 141 // Pushes the label on the backtrack stack, so that a following Backtrack 142 // will go to this label. Always checks the backtrack stack limit. 143 virtual void PushBacktrack(Label* label) = 0; 144 virtual void PushCurrentPosition() = 0; 145 virtual void PushRegister(int register_index, 146 StackCheckFlag check_stack_limit) = 0; 147 virtual void ReadCurrentPositionFromRegister(int reg) = 0; 148 virtual void ReadStackPointerFromRegister(int reg) = 0; 149 virtual void SetCurrentPositionFromEnd(int by) = 0; 150 virtual void SetRegister(int register_index, int to) = 0; 151 // Return whether the matching (with a global regexp) will be restarted. 152 virtual bool Succeed() = 0; 153 virtual void WriteCurrentPositionToRegister(int reg, int cp_offset) = 0; 154 virtual void ClearRegisters(int reg_from, int reg_to) = 0; 155 virtual void WriteStackPointerToRegister(int reg) = 0; 156 157 // Compares two-byte strings case insensitively. 158 // Called from generated RegExp code. 159 static int CaseInsensitiveCompareUC16(Address byte_offset1, 160 Address byte_offset2, 161 size_t byte_length, Isolate* isolate); 162 163 // Check that we are not in the middle of a surrogate pair. 164 void CheckNotInSurrogatePair(int cp_offset, Label* on_failure); 165 166 // Controls the generation of large inlined constants in the code. set_slow_safe(bool ssc)167 void set_slow_safe(bool ssc) { slow_safe_compiler_ = ssc; } slow_safe()168 bool slow_safe() { return slow_safe_compiler_; } 169 170 enum GlobalMode { 171 NOT_GLOBAL, 172 GLOBAL_NO_ZERO_LENGTH_CHECK, 173 GLOBAL, 174 GLOBAL_UNICODE 175 }; 176 // Set whether the regular expression has the global flag. Exiting due to 177 // a failure in a global regexp may still mean success overall. set_global_mode(GlobalMode mode)178 inline void set_global_mode(GlobalMode mode) { global_mode_ = mode; } global()179 inline bool global() { return global_mode_ != NOT_GLOBAL; } global_with_zero_length_check()180 inline bool global_with_zero_length_check() { 181 return global_mode_ == GLOBAL || global_mode_ == GLOBAL_UNICODE; 182 } global_unicode()183 inline bool global_unicode() { return global_mode_ == GLOBAL_UNICODE; } 184 isolate()185 Isolate* isolate() const { return isolate_; } zone()186 Zone* zone() const { return zone_; } 187 188 private: 189 bool slow_safe_compiler_; 190 GlobalMode global_mode_; 191 Isolate* isolate_; 192 Zone* zone_; 193 }; 194 195 196 #ifndef V8_INTERPRETED_REGEXP // Avoid compiling unused code. 197 198 class NativeRegExpMacroAssembler: public RegExpMacroAssembler { 199 public: 200 // Type of input string to generate code for. 201 enum Mode { LATIN1 = 1, UC16 = 2 }; 202 203 // Result of calling generated native RegExp code. 204 // RETRY: Something significant changed during execution, and the matching 205 // should be retried from scratch. 206 // EXCEPTION: Something failed during execution. If no exception has been 207 // thrown, it's an internal out-of-memory, and the caller should 208 // throw the exception. 209 // FAILURE: Matching failed. 210 // SUCCESS: Matching succeeded, and the output array has been filled with 211 // capture positions. 212 enum Result { RETRY = -2, EXCEPTION = -1, FAILURE = 0, SUCCESS = 1 }; 213 214 NativeRegExpMacroAssembler(Isolate* isolate, Zone* zone); 215 virtual ~NativeRegExpMacroAssembler(); 216 virtual bool CanReadUnaligned(); 217 218 static Result Match(Handle<Code> regexp, 219 Handle<String> subject, 220 int* offsets_vector, 221 int offsets_vector_length, 222 int previous_index, 223 Isolate* isolate); 224 225 // Called from RegExp if the backtrack stack limit is hit. 226 // Tries to expand the stack. Returns the new stack-pointer if 227 // successful, and updates the stack_top address, or returns 0 if unable 228 // to grow the stack. 229 // This function must not trigger a garbage collection. 230 static Address GrowStack(Address stack_pointer, Address* stack_top, 231 Isolate* isolate); 232 233 static const byte* StringCharacterPosition(String* subject, int start_index); 234 235 static int CheckStackGuardState(Isolate* isolate, int start_index, 236 bool is_direct_call, Address* return_address, 237 Code* re_code, String** subject, 238 const byte** input_start, 239 const byte** input_end); 240 241 // Byte map of one byte characters with a 0xff if the character is a word 242 // character (digit, letter or underscore) and 0x00 otherwise. 243 // Used by generated RegExp code. 244 static const byte word_character_map[256]; 245 word_character_map_address()246 static Address word_character_map_address() { 247 return reinterpret_cast<Address>(&word_character_map[0]); 248 } 249 250 static Result Execute(Code* code, 251 String* input, 252 int start_offset, 253 const byte* input_start, 254 const byte* input_end, 255 int* output, 256 int output_size, 257 Isolate* isolate); 258 }; 259 260 #endif // V8_INTERPRETED_REGEXP 261 262 } // namespace internal 263 } // namespace v8 264 265 #endif // V8_REGEXP_REGEXP_MACRO_ASSEMBLER_H_ 266