src/v8/src/token.h

   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_TOKEN_H_
   6 #define V8_TOKEN_H_
   7
   8 #include "src/base/logging.h"
   9 #include "src/globals.h"
  10
  11 namespace v8 {
  12 namespace internal {
  13
  14 // TOKEN_LIST takes a list of 3 macros M, all of which satisfy the
  15 // same signature M(name, string, precedence), where name is the
  16 // symbolic token name, string is the corresponding syntactic symbol
  17 // (or NULL, for literals), and precedence is the precedence (or 0).
  18 // The parameters are invoked for token categories as follows:
  19 //
  20 //   T: Non-keyword tokens
  21 //   K: Keyword tokens
  22
  23 // IGNORE_TOKEN is a convenience macro that can be supplied as
  24 // an argument (at any position) for a TOKEN_LIST call. It does
  25 // nothing with tokens belonging to the respective category.
  26
  27 #define IGNORE_TOKEN(name, string, precedence)
  28
  29 #define TOKEN_LIST(T, K)                                             \
  30   /* End of source indicator. */                                     \
  31   T(EOS, "EOS", 0)                                                   \
  32                                                                      \
  33   /* Punctuators (ECMA-262, section 7.7, page 15). */                \
  34   T(LPAREN, "(", 0)                                                  \
  35   T(RPAREN, ")", 0)                                                  \
  36   T(LBRACK, "[", 0)                                                  \
  37   T(RBRACK, "]", 0)                                                  \
  38   T(LBRACE, "{", 0)                                                  \
  39   T(RBRACE, "}", 0)                                                  \
  40   T(COLON, ":", 0)                                                   \
  41   T(SEMICOLON, ";", 0)                                               \
  42   T(PERIOD, ".", 0)                                                  \
  43   T(CONDITIONAL, "?", 3)                                             \
  44   T(INC, "++", 0)                                                    \
  45   T(DEC, "--", 0)                                                    \
  46   T(ARROW, "=>", 0)                                                  \
  47                                                                      \
  48   /* Assignment operators. */                                        \
  49   /* IsAssignmentOp() and Assignment::is_compound() relies on */     \
  50   /* this block of enum values being contiguous and sorted in the */ \
  51   /* same order! */                                                  \
  52   T(INIT_VAR, "=init_var", 2)                   /* AST-use only. */  \
  53   T(INIT_LET, "=init_let", 2)                   /* AST-use only. */  \
  54   T(INIT_CONST, "=init_const", 2)               /* AST-use only. */  \
  55   T(INIT_CONST_LEGACY, "=init_const_legacy", 2) /* AST-use only. */  \
  56   T(ASSIGN, "=", 2)                                                  \
  57   T(ASSIGN_BIT_OR, "|=", 2)                                          \
  58   T(ASSIGN_BIT_XOR, "^=", 2)                                         \
  59   T(ASSIGN_BIT_AND, "&=", 2)                                         \
  60   T(ASSIGN_SHL, "<<=", 2)                                            \
  61   T(ASSIGN_SAR, ">>=", 2)                                            \
  62   T(ASSIGN_SHR, ">>>=", 2)                                           \
  63   T(ASSIGN_ADD, "+=", 2)                                             \
  64   T(ASSIGN_SUB, "-=", 2)                                             \
  65   T(ASSIGN_MUL, "*=", 2)                                             \
  66   T(ASSIGN_DIV, "/=", 2)                                             \
  67   T(ASSIGN_MOD, "%=", 2)                                             \
  68                                                                      \
  69   /* Binary operators sorted by precedence. */                       \
  70   /* IsBinaryOp() relies on this block of enum values */             \
  71   /* being contiguous and sorted in the same order! */               \
  72   T(COMMA, ",", 1)                                                   \
  73   T(OR, "||", 4)                                                     \
  74   T(AND, "&&", 5)                                                    \
  75   T(BIT_OR, "|", 6)                                                  \
  76   T(BIT_XOR, "^", 7)                                                 \
  77   T(BIT_AND, "&", 8)                                                 \
  78   T(SHL, "<<", 11)                                                   \
  79   T(SAR, ">>", 11)                                                   \
  80   T(SHR, ">>>", 11)                                                  \
  81   T(ROR, "rotate right", 11) /* only used by Crankshaft */           \
  82   T(ADD, "+", 12)                                                    \
  83   T(SUB, "-", 12)                                                    \
  84   T(MUL, "*", 13)                                                    \
  85   T(DIV, "/", 13)                                                    \
  86   T(MOD, "%", 13)                                                    \
  87                                                                      \
  88   /* Compare operators sorted by precedence. */                      \
  89   /* IsCompareOp() relies on this block of enum values */            \
  90   /* being contiguous and sorted in the same order! */               \
  91   T(EQ, "==", 9)                                                     \
  92   T(NE, "!=", 9)                                                     \
  93   T(EQ_STRICT, "===", 9)                                             \
  94   T(NE_STRICT, "!==", 9)                                             \
  95   T(LT, "<", 10)                                                     \
  96   T(GT, ">", 10)                                                     \
  97   T(LTE, "<=", 10)                                                   \
  98   T(GTE, ">=", 10)                                                   \
  99   K(INSTANCEOF, "instanceof", 10)                                    \
 100   K(IN, "in", 10)                                                    \
 101                                                                      \
 102   /* Unary operators. */                                             \
 103   /* IsUnaryOp() relies on this block of enum values */              \
 104   /* being contiguous and sorted in the same order! */               \
 105   T(NOT, "!", 0)                                                     \
 106   T(BIT_NOT, "~", 0)                                                 \
 107   K(DELETE, "delete", 0)                                             \
 108   K(TYPEOF, "typeof", 0)                                             \
 109   K(VOID, "void", 0)                                                 \
 110                                                                      \
 111   /* Keywords (ECMA-262, section 7.5.2, page 13). */                 \
 112   K(BREAK, "break", 0)                                               \
 113   K(CASE, "case", 0)                                                 \
 114   K(CATCH, "catch", 0)                                               \
 115   K(CONTINUE, "continue", 0)                                         \
 116   K(DEBUGGER, "debugger", 0)                                         \
 117   K(DEFAULT, "default", 0)                                           \
 118   /* DELETE */                                                       \
 119   K(DO, "do", 0)                                                     \
 120   K(ELSE, "else", 0)                                                 \
 121   K(FINALLY, "finally", 0)                                           \
 122   K(FOR, "for", 0)                                                   \
 123   K(FUNCTION, "function", 0)                                         \
 124   K(IF, "if", 0)                                                     \
 125   /* IN */                                                           \
 126   /* INSTANCEOF */                                                   \
 127   K(NEW, "new", 0)                                                   \
 128   K(RETURN, "return", 0)                                             \
 129   K(SWITCH, "switch", 0)                                             \
 130   K(THIS, "this", 0)                                                 \
 131   K(THROW, "throw", 0)                                               \
 132   K(TRY, "try", 0)                                                   \
 133   /* TYPEOF */                                                       \
 134   K(VAR, "var", 0)                                                   \
 135   /* VOID */                                                         \
 136   K(WHILE, "while", 0)                                               \
 137   K(WITH, "with", 0)                                                 \
 138                                                                      \
 139   /* Literals (ECMA-262, section 7.8, page 16). */                   \
 140   K(NULL_LITERAL, "null", 0)                                         \
 141   K(TRUE_LITERAL, "true", 0)                                         \
 142   K(FALSE_LITERAL, "false", 0)                                       \
 143   T(NUMBER, NULL, 0)                                                 \
 144   T(STRING, NULL, 0)                                                 \
 145                                                                      \
 146   /* Identifiers (not keywords or future reserved words). */         \
 147   T(IDENTIFIER, NULL, 0)                                             \
 148                                                                      \
 149   /* Future reserved words (ECMA-262, section 7.6.1.2). */           \
 150   T(FUTURE_RESERVED_WORD, NULL, 0)                                   \
 151   T(FUTURE_STRICT_RESERVED_WORD, NULL, 0)                            \
 152   K(CLASS, "class", 0)                                               \
 153   K(CONST, "const", 0)                                               \
 154   K(EXPORT, "export", 0)                                             \
 155   K(EXTENDS, "extends", 0)                                           \
 156   K(IMPORT, "import", 0)                                             \
 157   K(LET, "let", 0)                                                   \
 158   K(STATIC, "static", 0)                                             \
 159   K(YIELD, "yield", 0)                                               \
 160   K(SUPER, "super", 0)                                               \
 161                                                                      \
 162   /* Illegal token - not able to scan. */                            \
 163   T(ILLEGAL, "ILLEGAL", 0)                                           \
 164                                                                      \
 165   /* Scanner-internal use only. */                                   \
 166   T(WHITESPACE, NULL, 0)
 167
 168
 169 class Token {
 170  public:
 171   // All token values.
 172 #define T(name, string, precedence) name,
 173   enum Value {
 174     TOKEN_LIST(T, T)
 175     NUM_TOKENS
 176   };
 177 #undef T
 178
 179   // Returns a string corresponding to the C++ token name
 180   // (e.g. "LT" for the token LT).
 181   static const char* Name(Value tok) {
 182     DCHECK(tok < NUM_TOKENS);  // tok is unsigned
 183     return name_[tok];
 184   }
 185
 186   // Predicates
 187   static bool IsKeyword(Value tok) {
 188     return token_type[tok] == 'K';
 189   }
 190
 191   static bool IsIdentifier(Value tok, StrictMode strict_mode,
 192                            bool is_generator) {
 193     switch (tok) {
 194       case IDENTIFIER:
 195         return true;
 196       case FUTURE_STRICT_RESERVED_WORD:
 197       case LET:
 198       case STATIC:
 199         return strict_mode == SLOPPY;
 200       case YIELD:
 201         return !is_generator && strict_mode == SLOPPY;
 202       default:
 203         return false;
 204     }
 205     UNREACHABLE();
 206     return false;
 207   }
 208
 209   static bool IsAssignmentOp(Value tok) {
 210     return INIT_VAR <= tok && tok <= ASSIGN_MOD;
 211   }
 212
 213   static bool IsBinaryOp(Value op) {
 214     return COMMA <= op && op <= MOD;
 215   }
 216
 217   static bool IsTruncatingBinaryOp(Value op) {
 218     return BIT_OR <= op && op <= ROR;
 219   }
 220
 221   static bool IsCompareOp(Value op) {
 222     return EQ <= op && op <= IN;
 223   }
 224
 225   static bool IsOrderedRelationalCompareOp(Value op) {
 226     return op == LT || op == LTE || op == GT || op == GTE;
 227   }
 228
 229   static bool IsEqualityOp(Value op) {
 230     return op == EQ || op == EQ_STRICT;
 231   }
 232
 233   static bool IsInequalityOp(Value op) {
 234     return op == NE || op == NE_STRICT;
 235   }
 236
 237   static bool IsArithmeticCompareOp(Value op) {
 238     return IsOrderedRelationalCompareOp(op) ||
 239         IsEqualityOp(op) || IsInequalityOp(op);
 240   }
 241
 242   static Value NegateCompareOp(Value op) {
 243     DCHECK(IsArithmeticCompareOp(op));
 244     switch (op) {
 245       case EQ: return NE;
 246       case NE: return EQ;
 247       case EQ_STRICT: return NE_STRICT;
 248       case NE_STRICT: return EQ_STRICT;
 249       case LT: return GTE;
 250       case GT: return LTE;
 251       case LTE: return GT;
 252       case GTE: return LT;
 253       default:
 254         UNREACHABLE();
 255         return op;
 256     }
 257   }
 258
 259   static Value ReverseCompareOp(Value op) {
 260     DCHECK(IsArithmeticCompareOp(op));
 261     switch (op) {
 262       case EQ: return EQ;
 263       case NE: return NE;
 264       case EQ_STRICT: return EQ_STRICT;
 265       case NE_STRICT: return NE_STRICT;
 266       case LT: return GT;
 267       case GT: return LT;
 268       case LTE: return GTE;
 269       case GTE: return LTE;
 270       default:
 271         UNREACHABLE();
 272         return op;
 273     }
 274   }
 275
 276   static bool IsBitOp(Value op) {
 277     return (BIT_OR <= op && op <= SHR) || op == BIT_NOT;
 278   }
 279
 280   static bool IsUnaryOp(Value op) {
 281     return (NOT <= op && op <= VOID) || op == ADD || op == SUB;
 282   }
 283
 284   static bool IsCountOp(Value op) {
 285     return op == INC || op == DEC;
 286   }
 287
 288   static bool IsShiftOp(Value op) {
 289     return (SHL <= op) && (op <= SHR);
 290   }
 291
 292   // Returns a string corresponding to the JS token string
 293   // (.e., "<" for the token LT) or NULL if the token doesn't
 294   // have a (unique) string (e.g. an IDENTIFIER).
 295   static const char* String(Value tok) {
 296     DCHECK(tok < NUM_TOKENS);  // tok is unsigned.
 297     return string_[tok];
 298   }
 299
 300   // Returns the precedence > 0 for binary and compare
 301   // operators; returns 0 otherwise.
 302   static int Precedence(Value tok) {
 303     DCHECK(tok < NUM_TOKENS);  // tok is unsigned.
 304     return precedence_[tok];
 305   }
 306
 307  private:
 308   static const char* const name_[NUM_TOKENS];
 309   static const char* const string_[NUM_TOKENS];
 310   static const int8_t precedence_[NUM_TOKENS];
 311   static const char token_type[NUM_TOKENS];
 312 };
 313
 314 } }  // namespace v8::internal
 315
 316 #endif  // V8_TOKEN_H_