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