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      1 // Copyright 2012 the V8 project authors. All rights reserved.
      2 // Redistribution and use in source and binary forms, with or without
      3 // modification, are permitted provided that the following conditions are
      4 // met:
      5 //
      6 //     * Redistributions of source code must retain the above copyright
      7 //       notice, this list of conditions and the following disclaimer.
      8 //     * Redistributions in binary form must reproduce the above
      9 //       copyright notice, this list of conditions and the following
     10 //       disclaimer in the documentation and/or other materials provided
     11 //       with the distribution.
     12 //     * Neither the name of Google Inc. nor the names of its
     13 //       contributors may be used to endorse or promote products derived
     14 //       from this software without specific prior written permission.
     15 //
     16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27 
     28 #ifndef V8_TOKEN_H_
     29 #define V8_TOKEN_H_
     30 
     31 #include "checks.h"
     32 
     33 namespace v8 {
     34 namespace internal {
     35 
     36 // TOKEN_LIST takes a list of 3 macros M, all of which satisfy the
     37 // same signature M(name, string, precedence), where name is the
     38 // symbolic token name, string is the corresponding syntactic symbol
     39 // (or NULL, for literals), and precedence is the precedence (or 0).
     40 // The parameters are invoked for token categories as follows:
     41 //
     42 //   T: Non-keyword tokens
     43 //   K: Keyword tokens
     44 
     45 // IGNORE_TOKEN is a convenience macro that can be supplied as
     46 // an argument (at any position) for a TOKEN_LIST call. It does
     47 // nothing with tokens belonging to the respective category.
     48 
     49 #define IGNORE_TOKEN(name, string, precedence)
     50 
     51 #define TOKEN_LIST(T, K)                                                \
     52   /* End of source indicator. */                                        \
     53   T(EOS, "EOS", 0)                                                      \
     54                                                                         \
     55   /* Punctuators (ECMA-262, section 7.7, page 15). */                   \
     56   T(LPAREN, "(", 0)                                                     \
     57   T(RPAREN, ")", 0)                                                     \
     58   T(LBRACK, "[", 0)                                                     \
     59   T(RBRACK, "]", 0)                                                     \
     60   T(LBRACE, "{", 0)                                                     \
     61   T(RBRACE, "}", 0)                                                     \
     62   T(COLON, ":", 0)                                                      \
     63   T(SEMICOLON, ";", 0)                                                  \
     64   T(PERIOD, ".", 0)                                                     \
     65   T(CONDITIONAL, "?", 3)                                                \
     66   T(INC, "++", 0)                                                       \
     67   T(DEC, "--", 0)                                                       \
     68                                                                         \
     69   /* Assignment operators. */                                           \
     70   /* IsAssignmentOp() and Assignment::is_compound() relies on */        \
     71   /* this block of enum values being contiguous and sorted in the */    \
     72   /* same order! */                                                     \
     73   T(INIT_VAR, "=init_var", 2)  /* AST-use only. */                      \
     74   T(INIT_LET, "=init_let", 2)  /* AST-use only. */                      \
     75   T(INIT_CONST, "=init_const", 2)  /* AST-use only. */                  \
     76   T(INIT_CONST_HARMONY, "=init_const_harmony", 2)  /* AST-use only. */  \
     77   T(ASSIGN, "=", 2)                                                     \
     78   T(ASSIGN_BIT_OR, "|=", 2)                                             \
     79   T(ASSIGN_BIT_XOR, "^=", 2)                                            \
     80   T(ASSIGN_BIT_AND, "&=", 2)                                            \
     81   T(ASSIGN_SHL, "<<=", 2)                                               \
     82   T(ASSIGN_SAR, ">>=", 2)                                               \
     83   T(ASSIGN_SHR, ">>>=", 2)                                              \
     84   T(ASSIGN_ADD, "+=", 2)                                                \
     85   T(ASSIGN_SUB, "-=", 2)                                                \
     86   T(ASSIGN_MUL, "*=", 2)                                                \
     87   T(ASSIGN_DIV, "/=", 2)                                                \
     88   T(ASSIGN_MOD, "%=", 2)                                                \
     89                                                                         \
     90   /* Binary operators sorted by precedence. */                          \
     91   /* IsBinaryOp() relies on this block of enum values */                \
     92   /* being contiguous and sorted in the same order! */                  \
     93   T(COMMA, ",", 1)                                                      \
     94   T(OR, "||", 4)                                                        \
     95   T(AND, "&&", 5)                                                       \
     96   T(BIT_OR, "|", 6)                                                     \
     97   T(BIT_XOR, "^", 7)                                                    \
     98   T(BIT_AND, "&", 8)                                                    \
     99   T(SHL, "<<", 11)                                                      \
    100   T(SAR, ">>", 11)                                                      \
    101   T(SHR, ">>>", 11)                                                     \
    102   T(ADD, "+", 12)                                                       \
    103   T(SUB, "-", 12)                                                       \
    104   T(MUL, "*", 13)                                                       \
    105   T(DIV, "/", 13)                                                       \
    106   T(MOD, "%", 13)                                                       \
    107                                                                         \
    108   /* Compare operators sorted by precedence. */                         \
    109   /* IsCompareOp() relies on this block of enum values */               \
    110   /* being contiguous and sorted in the same order! */                  \
    111   T(EQ, "==", 9)                                                        \
    112   T(NE, "!=", 9)                                                        \
    113   T(EQ_STRICT, "===", 9)                                                \
    114   T(NE_STRICT, "!==", 9)                                                \
    115   T(LT, "<", 10)                                                        \
    116   T(GT, ">", 10)                                                        \
    117   T(LTE, "<=", 10)                                                      \
    118   T(GTE, ">=", 10)                                                      \
    119   K(INSTANCEOF, "instanceof", 10)                                       \
    120   K(IN, "in", 10)                                                       \
    121                                                                         \
    122   /* Unary operators. */                                                \
    123   /* IsUnaryOp() relies on this block of enum values */                 \
    124   /* being contiguous and sorted in the same order! */                  \
    125   T(NOT, "!", 0)                                                        \
    126   T(BIT_NOT, "~", 0)                                                    \
    127   K(DELETE, "delete", 0)                                                \
    128   K(TYPEOF, "typeof", 0)                                                \
    129   K(VOID, "void", 0)                                                    \
    130                                                                         \
    131   /* Keywords (ECMA-262, section 7.5.2, page 13). */                    \
    132   K(BREAK, "break", 0)                                                  \
    133   K(CASE, "case", 0)                                                    \
    134   K(CATCH, "catch", 0)                                                  \
    135   K(CONTINUE, "continue", 0)                                            \
    136   K(DEBUGGER, "debugger", 0)                                            \
    137   K(DEFAULT, "default", 0)                                              \
    138   /* DELETE */                                                          \
    139   K(DO, "do", 0)                                                        \
    140   K(ELSE, "else", 0)                                                    \
    141   K(FINALLY, "finally", 0)                                              \
    142   K(FOR, "for", 0)                                                      \
    143   K(FUNCTION, "function", 0)                                            \
    144   K(IF, "if", 0)                                                        \
    145   /* IN */                                                              \
    146   /* INSTANCEOF */                                                      \
    147   K(NEW, "new", 0)                                                      \
    148   K(RETURN, "return", 0)                                                \
    149   K(SWITCH, "switch", 0)                                                \
    150   K(THIS, "this", 0)                                                    \
    151   K(THROW, "throw", 0)                                                  \
    152   K(TRY, "try", 0)                                                      \
    153   /* TYPEOF */                                                          \
    154   K(VAR, "var", 0)                                                      \
    155   /* VOID */                                                            \
    156   K(WHILE, "while", 0)                                                  \
    157   K(WITH, "with", 0)                                                    \
    158                                                                         \
    159   /* Literals (ECMA-262, section 7.8, page 16). */                      \
    160   K(NULL_LITERAL, "null", 0)                                            \
    161   K(TRUE_LITERAL, "true", 0)                                            \
    162   K(FALSE_LITERAL, "false", 0)                                          \
    163   T(NUMBER, NULL, 0)                                                    \
    164   T(STRING, NULL, 0)                                                    \
    165                                                                         \
    166   /* Identifiers (not keywords or future reserved words). */            \
    167   T(IDENTIFIER, NULL, 0)                                                \
    168                                                                         \
    169   /* Future reserved words (ECMA-262, section 7.6.1.2). */              \
    170   T(FUTURE_RESERVED_WORD, NULL, 0)                                      \
    171   T(FUTURE_STRICT_RESERVED_WORD, NULL, 0)                               \
    172   K(CONST, "const", 0)                                                  \
    173   K(EXPORT, "export", 0)                                                \
    174   K(IMPORT, "import", 0)                                                \
    175   K(LET, "let", 0)                                                      \
    176                                                                         \
    177   /* Illegal token - not able to scan. */                               \
    178   T(ILLEGAL, "ILLEGAL", 0)                                              \
    179                                                                         \
    180   /* Scanner-internal use only. */                                      \
    181   T(WHITESPACE, NULL, 0)
    182 
    183 
    184 class Token {
    185  public:
    186   // All token values.
    187 #define T(name, string, precedence) name,
    188   enum Value {
    189     TOKEN_LIST(T, T)
    190     NUM_TOKENS
    191   };
    192 #undef T
    193 
    194   // Returns a string corresponding to the C++ token name
    195   // (e.g. "LT" for the token LT).
    196   static const char* Name(Value tok) {
    197     ASSERT(tok < NUM_TOKENS);  // tok is unsigned
    198     return name_[tok];
    199   }
    200 
    201   // Predicates
    202   static bool IsKeyword(Value tok) {
    203     return token_type[tok] == 'K';
    204   }
    205 
    206   static bool IsAssignmentOp(Value tok) {
    207     return INIT_VAR <= tok && tok <= ASSIGN_MOD;
    208   }
    209 
    210   static bool IsBinaryOp(Value op) {
    211     return COMMA <= op && op <= MOD;
    212   }
    213 
    214   static bool IsCompareOp(Value op) {
    215     return EQ <= op && op <= IN;
    216   }
    217 
    218   static bool IsOrderedRelationalCompareOp(Value op) {
    219     return op == LT || op == LTE || op == GT || op == GTE;
    220   }
    221 
    222   static bool IsEqualityOp(Value op) {
    223     return op == EQ || op == EQ_STRICT;
    224   }
    225 
    226   static Value NegateCompareOp(Value op) {
    227     ASSERT(IsCompareOp(op));
    228     switch (op) {
    229       case EQ: return NE;
    230       case NE: return EQ;
    231       case EQ_STRICT: return NE_STRICT;
    232       case LT: return GTE;
    233       case GT: return LTE;
    234       case LTE: return GT;
    235       case GTE: return LT;
    236       default:
    237         return op;
    238     }
    239   }
    240 
    241   static Value InvertCompareOp(Value op) {
    242     ASSERT(IsCompareOp(op));
    243     switch (op) {
    244       case EQ: return NE;
    245       case NE: return EQ;
    246       case EQ_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         return op;
    253     }
    254   }
    255 
    256   static bool IsBitOp(Value op) {
    257     return (BIT_OR <= op && op <= SHR) || op == BIT_NOT;
    258   }
    259 
    260   static bool IsUnaryOp(Value op) {
    261     return (NOT <= op && op <= VOID) || op == ADD || op == SUB;
    262   }
    263 
    264   static bool IsCountOp(Value op) {
    265     return op == INC || op == DEC;
    266   }
    267 
    268   static bool IsShiftOp(Value op) {
    269     return (SHL <= op) && (op <= SHR);
    270   }
    271 
    272   // Returns a string corresponding to the JS token string
    273   // (.e., "<" for the token LT) or NULL if the token doesn't
    274   // have a (unique) string (e.g. an IDENTIFIER).
    275   static const char* String(Value tok) {
    276     ASSERT(tok < NUM_TOKENS);  // tok is unsigned.
    277     return string_[tok];
    278   }
    279 
    280   // Returns the precedence > 0 for binary and compare
    281   // operators; returns 0 otherwise.
    282   static int Precedence(Value tok) {
    283     ASSERT(tok < NUM_TOKENS);  // tok is unsigned.
    284     return precedence_[tok];
    285   }
    286 
    287  private:
    288   static const char* const name_[NUM_TOKENS];
    289   static const char* const string_[NUM_TOKENS];
    290   static const int8_t precedence_[NUM_TOKENS];
    291   static const char token_type[NUM_TOKENS];
    292 };
    293 
    294 } }  // namespace v8::internal
    295 
    296 #endif  // V8_TOKEN_H_
    297