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(ELLIPSIS, "...", 0)                                              \
  44   T(CONDITIONAL, "?", 3)                                             \
  45   T(INC, "++", 0)                                                    \
  46   T(DEC, "--", 0)                                                    \
  47   T(ARROW, "=>", 0)                                                  \
  48                                                                      \
  49   /* Assignment operators. */                                        \
  50   /* IsAssignmentOp() and Assignment::is_compound() relies on */     \
  51   /* this block of enum values being contiguous and sorted in the */ \
  52   /* same order! */                                                  \
  53   T(INIT_VAR, "=init_var", 2)                   /* AST-use only. */  \
  54   T(INIT_LET, "=init_let", 2)                   /* AST-use only. */  \
  55   T(INIT_CONST, "=init_const", 2)               /* AST-use only. */  \
  56   T(INIT_CONST_LEGACY, "=init_const_legacy", 2) /* AST-use only. */  \
  57   T(ASSIGN, "=", 2)                                                  \
  58   T(ASSIGN_BIT_OR, "|=", 2)                                          \
  59   T(ASSIGN_BIT_XOR, "^=", 2)                                         \
  60   T(ASSIGN_BIT_AND, "&=", 2)                                         \
  61   T(ASSIGN_SHL, "<<=", 2)                                            \
  62   T(ASSIGN_SAR, ">>=", 2)                                            \
  63   T(ASSIGN_SHR, ">>>=", 2)                                           \
  64   T(ASSIGN_ADD, "+=", 2)                                             \
  65   T(ASSIGN_SUB, "-=", 2)                                             \
  66   T(ASSIGN_MUL, "*=", 2)                                             \
  67   T(ASSIGN_DIV, "/=", 2)                                             \
  68   T(ASSIGN_MOD, "%=", 2)                                             \
  69                                                                      \
  70   /* Binary operators sorted by precedence. */                       \
  71   /* IsBinaryOp() relies on this block of enum values */             \
  72   /* being contiguous and sorted in the same order! */               \
  73   T(COMMA, ",", 1)                                                   \
  74   T(OR, "||", 4)                                                     \
  75   T(AND, "&&", 5)                                                    \
  76   T(BIT_OR, "|", 6)                                                  \
  77   T(BIT_XOR, "^", 7)                                                 \
  78   T(BIT_AND, "&", 8)                                                 \
  79   T(SHL, "<<", 11)                                                   \
  80   T(SAR, ">>", 11)                                                   \
  81   T(SHR, ">>>", 11)                                                  \
  82   T(ROR, "rotate right", 11) /* only used by Crankshaft */           \
  83   T(ADD, "+", 12)                                                    \
  84   T(SUB, "-", 12)                                                    \
  85   T(MUL, "*", 13)                                                    \
  86   T(DIV, "/", 13)                                                    \
  87   T(MOD, "%", 13)                                                    \
  88                                                                      \
  89   /* Compare operators sorted by precedence. */                      \
  90   /* IsCompareOp() relies on this block of enum values */            \
  91   /* being contiguous and sorted in the same order! */               \
  92   T(EQ, "==", 9)                                                     \
  93   T(NE, "!=", 9)                                                     \
  94   T(EQ_STRICT, "===", 9)                                             \
  95   T(NE_STRICT, "!==", 9)                                             \
  96   T(LT, "<", 10)                                                     \
  97   T(GT, ">", 10)                                                     \
  98   T(LTE, "<=", 10)                                                   \
  99   T(GTE, ">=", 10)                                                   \
 100   K(INSTANCEOF, "instanceof", 10)                                    \
 101   K(IN, "in", 10)                                                    \
 102                                                                      \
 103   /* Unary operators. */                                             \
 104   /* IsUnaryOp() relies on this block of enum values */              \
 105   /* being contiguous and sorted in the same order! */               \
 106   T(NOT, "!", 0)                                                     \
 107   T(BIT_NOT, "~", 0)                                                 \
 108   K(DELETE, "delete", 0)                                             \
 109   K(TYPEOF, "typeof", 0)                                             \
 110   K(VOID, "void", 0)                                                 \
 111                                                                      \
 112   /* Keywords (ECMA-262, section 7.5.2, page 13). */                 \
 113   K(BREAK, "break", 0)                                               \
 114   K(CASE, "case", 0)                                                 \
 115   K(CATCH, "catch", 0)                                               \
 116   K(CONTINUE, "continue", 0)                                         \
 117   K(DEBUGGER, "debugger", 0)                                         \
 118   K(DEFAULT, "default", 0)                                           \
 119   /* DELETE */                                                       \
 120   K(DO, "do", 0)                                                     \
 121   K(ELSE, "else", 0)                                                 \
 122   K(FINALLY, "finally", 0)                                           \
 123   K(FOR, "for", 0)                                                   \
 124   K(FUNCTION, "function", 0)                                         \
 125   K(IF, "if", 0)                                                     \
 126   /* IN */                                                           \
 127   /* INSTANCEOF */                                                   \
 128   K(NEW, "new", 0)                                                   \
 129   K(RETURN, "return", 0)                                             \
 130   K(SWITCH, "switch", 0)                                             \
 131   K(THIS, "this", 0)                                                 \
 132   K(THROW, "throw", 0)                                               \
 133   K(TRY, "try", 0)                                                   \
 134   /* TYPEOF */                                                       \
 135   K(VAR, "var", 0)                                                   \
 136   /* VOID */                                                         \
 137   K(WHILE, "while", 0)                                               \
 138   K(WITH, "with", 0)                                                 \
 139                                                                      \
 140   /* Literals (ECMA-262, section 7.8, page 16). */                   \
 141   K(NULL_LITERAL, "null", 0)                                         \
 142   K(TRUE_LITERAL, "true", 0)                                         \
 143   K(FALSE_LITERAL, "false", 0)                                       \
 144   T(NUMBER, NULL, 0)                                                 \
 145   T(SMI, NULL, 0)                                                    \
 146   T(STRING, NULL, 0)                                                 \
 147                                                                      \
 148   /* Identifiers (not keywords or future reserved words). */         \
 149   T(IDENTIFIER, NULL, 0)                                             \
 150                                                                      \
 151   /* Future reserved words (ECMA-262, section 7.6.1.2). */           \
 152   T(FUTURE_RESERVED_WORD, NULL, 0)                                   \
 153   T(FUTURE_STRICT_RESERVED_WORD, NULL, 0)                            \
 154   K(CLASS, "class", 0)                                               \
 155   K(CONST, "const", 0)                                               \
 156   K(EXPORT, "export", 0)                                             \
 157   K(EXTENDS, "extends", 0)                                           \
 158   K(IMPORT, "import", 0)                                             \
 159   K(LET, "let", 0)                                                   \
 160   K(STATIC, "static", 0)                                             \
 161   K(YIELD, "yield", 0)                                               \
 162   K(SUPER, "super", 0)                                               \
 163                                                                      \
 164   /* Illegal token - not able to scan. */                            \
 165   T(ILLEGAL, "ILLEGAL", 0)                                           \
 166                                                                      \
 167   /* Scanner-internal use only. */                                   \
 168   T(WHITESPACE, NULL, 0)                                             \
 169   T(UNINITIALIZED, NULL, 0)                                          \
 170                                                                      \
 171   /* ES6 Template Literals */                                        \
 172   T(TEMPLATE_SPAN, NULL, 0)                                          \
 173   T(TEMPLATE_TAIL, NULL, 0)
 174
 175
 176 class Token {
 177  public:
 178   // All token values.
 179 #define T(name, string, precedence) name,
 180   enum Value {
 181     TOKEN_LIST(T, T)
 182     NUM_TOKENS
 183   };
 184 #undef T
 185
 186   // Returns a string corresponding to the C++ token name
 187   // (e.g. "LT" for the token LT).
 188   static const char* Name(Value tok) {
 189     DCHECK(tok < NUM_TOKENS);  // tok is unsigned
 190     return name_[tok];
 191   }
 192
 193   // Predicates
 194   static bool IsKeyword(Value tok) {
 195     return token_type[tok] == 'K';
 196   }
 197
 198   static bool IsIdentifier(Value tok, LanguageMode language_mode,
 199                            bool is_generator) {
 200     switch (tok) {
 201       case IDENTIFIER:
 202         return true;
 203       case FUTURE_STRICT_RESERVED_WORD:
 204       case LET:
 205       case STATIC:
 206         return is_sloppy(language_mode);
 207       case YIELD:
 208         return !is_generator && is_sloppy(language_mode);
 209       default:
 210         return false;
 211     }
 212     UNREACHABLE();
 213     return false;
 214   }
 215
 216   static bool IsAssignmentOp(Value tok) {
 217     return INIT_VAR <= tok && tok <= ASSIGN_MOD;
 218   }
 219
 220   static bool IsBinaryOp(Value op) {
 221     return COMMA <= op && op <= MOD;
 222   }
 223
 224   static bool IsTruncatingBinaryOp(Value op) {
 225     return BIT_OR <= op && op <= ROR;
 226   }
 227
 228   static bool IsCompareOp(Value op) {
 229     return EQ <= op && op <= IN;
 230   }
 231
 232   static bool IsOrderedRelationalCompareOp(Value op) {
 233     return op == LT || op == LTE || op == GT || op == GTE;
 234   }
 235
 236   static bool IsEqualityOp(Value op) {
 237     return op == EQ || op == EQ_STRICT;
 238   }
 239
 240   static bool IsInequalityOp(Value op) {
 241     return op == NE || op == NE_STRICT;
 242   }
 243
 244   static bool IsArithmeticCompareOp(Value op) {
 245     return IsOrderedRelationalCompareOp(op) ||
 246         IsEqualityOp(op) || IsInequalityOp(op);
 247   }
 248
 249   static Value NegateCompareOp(Value op) {
 250     DCHECK(IsArithmeticCompareOp(op));
 251     switch (op) {
 252       case EQ: return NE;
 253       case NE: return EQ;
 254       case EQ_STRICT: return NE_STRICT;
 255       case NE_STRICT: return EQ_STRICT;
 256       case LT: return GTE;
 257       case GT: return LTE;
 258       case LTE: return GT;
 259       case GTE: return LT;
 260       default:
 261         UNREACHABLE();
 262         return op;
 263     }
 264   }
 265
 266   static Value ReverseCompareOp(Value op) {
 267     DCHECK(IsArithmeticCompareOp(op));
 268     switch (op) {
 269       case EQ: return EQ;
 270       case NE: return NE;
 271       case EQ_STRICT: return EQ_STRICT;
 272       case NE_STRICT: return NE_STRICT;
 273       case LT: return GT;
 274       case GT: return LT;
 275       case LTE: return GTE;
 276       case GTE: return LTE;
 277       default:
 278         UNREACHABLE();
 279         return op;
 280     }
 281   }
 282
 283   static bool IsBitOp(Value op) {
 284     return (BIT_OR <= op && op <= SHR) || op == BIT_NOT;
 285   }
 286
 287   static bool IsUnaryOp(Value op) {
 288     return (NOT <= op && op <= VOID) || op == ADD || op == SUB;
 289   }
 290
 291   static bool IsCountOp(Value op) {
 292     return op == INC || op == DEC;
 293   }
 294
 295   static bool IsShiftOp(Value op) {
 296     return (SHL <= op) && (op <= SHR);
 297   }
 298
 299   // Returns a string corresponding to the JS token string
 300   // (.e., "<" for the token LT) or NULL if the token doesn't
 301   // have a (unique) string (e.g. an IDENTIFIER).
 302   static const char* String(Value tok) {
 303     DCHECK(tok < NUM_TOKENS);  // tok is unsigned.
 304     return string_[tok];
 305   }
 306
 307   // Returns the precedence > 0 for binary and compare
 308   // operators; returns 0 otherwise.
 309   static int Precedence(Value tok) {
 310     DCHECK(tok < NUM_TOKENS);  // tok is unsigned.
 311     return precedence_[tok];
 312   }
 313
 314  private:
 315   static const char* const name_[NUM_TOKENS];
 316   static const char* const string_[NUM_TOKENS];
 317   static const int8_t precedence_[NUM_TOKENS];
 318   static const char token_type[NUM_TOKENS];
 319 };
 320
 321 } }  // namespace v8::internal
 322
 323 #endif  // V8_TOKEN_H_