ref: 3c58fa90c8fd063c7ccb00a85a7e238ae2788a73
dir: /jslex.c/
#include "js.h" #include "jslex.h" #include "jsstate.h" #include "jsutf.h" #define nelem(a) (sizeof (a) / sizeof (a)[0]) static const char *tokenstring[] = { "(end-of-file)", "'\\x01'", "'\\x02'", "'\\x03'", "'\\x04'", "'\\x05'", "'\\x06'", "'\\x07'", "'\\x08'", "'\\x09'", "'\\x0A'", "'\\x0B'", "'\\x0C'", "'\\x0D'", "'\\x0E'", "'\\x0F'", "'\\x10'", "'\\x11'", "'\\x12'", "'\\x13'", "'\\x14'", "'\\x15'", "'\\x16'", "'\\x17'", "'\\x18'", "'\\x19'", "'\\x1A'", "'\\x1B'", "'\\x1C'", "'\\x1D'", "'\\x1E'", "'\\x1F'", "' '", "'!'", "'\"'", "'#'", "'$'", "'%'", "'&'", "'\\''", "'('", "')'", "'*'", "'+'", "','", "'-'", "'.'", "'/'", "'0'", "'1'", "'2'", "'3'", "'4'", "'5'", "'6'", "'7'", "'8'", "'9'", "':'", "';'", "'<'", "'='", "'>'", "'?'", "'@'", "'A'", "'B'", "'C'", "'D'", "'E'", "'F'", "'G'", "'H'", "'I'", "'J'", "'K'", "'L'", "'M'", "'N'", "'O'", "'P'", "'Q'", "'R'", "'S'", "'T'", "'U'", "'V'", "'W'", "'X'", "'Y'", "'Z'", "'['", "'\'", "']'", "'^'", "'_'", "'`'", "'a'", "'b'", "'c'", "'d'", "'e'", "'f'", "'g'", "'h'", "'i'", "'j'", "'k'", "'l'", "'m'", "'n'", "'o'", "'p'", "'q'", "'r'", "'s'", "'t'", "'u'", "'v'", "'w'", "'x'", "'y'", "'z'", "'{'", "'|'", "'}'", "'~'", "'\\x7F'", 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, "(identifier)", "(number)", "(string)", "(regexp)", "'<='", "'>='", "'=='", "'!='", "'==='", "'!=='", "'<<'", "'>>'", "'>>>'", "'&&'", "'||'", "'+='", "'-='", "'*='", "'/='", "'%='", "'<<='", "'>>='", "'>>>='", "'&='", "'|='", "'^='", "'++'", "'--'", "'break'", "'case'", "'catch'", "'continue'", "'debugger'", "'default'", "'delete'", "'do'", "'else'", "'false'", "'finally'", "'for'", "'function'", "'if'", "'in'", "'instanceof'", "'new'", "'null'", "'return'", "'switch'", "'this'", "'throw'", "'true'", "'try'", "'typeof'", "'var'", "'void'", "'while'", "'with'", }; const char *jsP_tokenstring(int token) { if (token >= 0 && token < nelem(tokenstring)) if (tokenstring[token]) return tokenstring[token]; return "<unknown>"; } static const char *keywords[] = { "break", "case", "catch", "continue", "debugger", "default", "delete", "do", "else", "false", "finally", "for", "function", "if", "in", "instanceof", "new", "null", "return", "switch", "this", "throw", "true", "try", "typeof", "var", "void", "while", "with", }; static inline int findword(const char *s, const char **list, int num) { int l = 0; int r = num - 1; while (l <= r) { int m = (l + r) >> 1; int c = strcmp(s, list[m]); if (c < 0) r = m - 1; else if (c > 0) l = m + 1; else return m; } return -1; } static inline int findkeyword(js_State *J, const char *s) { int i = findword(s, keywords, nelem(keywords)); if (i >= 0) { J->text = keywords[i]; return TK_BREAK + i; /* first keyword + i */ } J->text = js_intern(J, s); return TK_IDENTIFIER; } static inline int iswhite(int c) { return c == 0x9 || c == 0xB || c == 0xC || c == 0x20 || c == 0xA0 || c == 0xFEFF; } static inline int isnewline(c) { return c == 0xA || c == 0xD || c == 0x2028 || c == 0x2029; } static inline int isidentifierstart(int c) { return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '$' || c == '_' || isalpharune(c); } static inline int isidentifierpart(int c) { return (c >= '0' && c <= '9') || isidentifierstart(c); } static inline int isdec(int c) { return (c >= '0' && c <= '9'); } static inline int ishex(int c) { return (c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F'); } static inline int tohex(int c) { if (c >= '0' && c <= '9') return c - '0'; if (c >= 'a' && c <= 'f') return c - 'a' + 0xA; if (c >= 'A' && c <= 'F') return c - 'A' + 0xA; return 0; } #define PEEK (J->lexchar) #define NEXT() next(J) #define ACCEPT(x) (PEEK == x ? (NEXT(), 1) : 0) #define EXPECT(x) (ACCEPT(x) || (jsP_error(J, "expected '%c'", x), 0)) static void next(js_State *J) { Rune c; J->source += chartorune(&c, J->source); /* consume CR LF as one unit */ if (c == '\r' && PEEK == '\n') ++J->source; if (isnewline(c)) { J->line++; c = '\n'; } J->lexchar = c; } static void unescape(js_State *J) { if (ACCEPT('\\')) { if (ACCEPT('u')) { int x = 0; if (!ishex(PEEK)) goto error; x |= tohex(PEEK) << 12; NEXT(); if (!ishex(PEEK)) goto error; x |= tohex(PEEK) << 8; NEXT(); if (!ishex(PEEK)) goto error; x |= tohex(PEEK) << 4; NEXT(); if (!ishex(PEEK)) goto error; x |= tohex(PEEK); J->lexchar = x; return; } error: jsP_error(J, "unexpected escape sequence"); } } static void textinit(js_State *J) { if (!J->buf.text) { J->buf.cap = 4096; J->buf.text = malloc(J->buf.cap); } J->buf.len = 0; } static inline void textpush(js_State *J, Rune c) { int n = runelen(c); if (J->buf.len + n > J->buf.cap) { J->buf.cap = J->buf.cap * 2; J->buf.text = realloc(J->buf.text, J->buf.cap); } J->buf.len += runetochar(J->buf.text + J->buf.len, &c); } static inline char *textend(js_State *J) { textpush(J, 0); return J->buf.text; } static inline void lexlinecomment(js_State *J) { while (PEEK && PEEK != '\n') NEXT(); } static inline int lexcomment(js_State *J) { /* already consumed initial '/' '*' sequence */ while (PEEK != 0) { if (ACCEPT('*')) { while (ACCEPT('*')) NEXT(); if (ACCEPT('/')) return 0; } NEXT(); } return -1; } static inline double lexhex(js_State *J) { double n = 0; if (!ishex(PEEK)) return jsP_error(J, "malformed hexadecimal number"); while (ishex(PEEK)) { n = n * 16 + tohex(PEEK); NEXT(); } return n; } static inline double lexinteger(js_State *J) { double n = 0; if (!isdec(PEEK)) return jsP_error(J, "malformed number"); while (isdec(PEEK)) { n = n * 10 + (PEEK - '0'); NEXT(); } return n; } static inline double lexfraction(js_State *J) { double n = 0; double d = 1; while (isdec(PEEK)) { n = n * 10 + (PEEK - '0'); d = d * 10; NEXT(); } return n / d; } static inline double lexexponent(js_State *J) { double sign; if (ACCEPT('e') || ACCEPT('E')) { if (ACCEPT('-')) sign = -1; else if (ACCEPT('+')) sign = 1; else sign = 1; return sign * lexinteger(J); } return 0; } static inline int lexnumber(js_State *J) { double n; if (ACCEPT('0')) { if (ACCEPT('x') || ACCEPT('X')) { J->number = lexhex(J); return TK_NUMBER; } if (isdec(PEEK)) return jsP_error(J, "number with leading zero"); n = 0; if (ACCEPT('.')) n += lexfraction(J); n *= pow(10, lexexponent(J)); } else if (ACCEPT('.')) { if (!isdec(PEEK)) return '.'; n = lexfraction(J); n *= pow(10, lexexponent(J)); } else { n = lexinteger(J); if (ACCEPT('.')) n += lexfraction(J); n *= pow(10, lexexponent(J)); } if (isidentifierstart(PEEK)) return jsP_error(J, "number with letter suffix"); J->number = n; return TK_NUMBER; } static inline int lexescape(js_State *J) { int x = 0; /* already consumed '\' */ if (ACCEPT('\n')) return 0; switch (PEEK) { case 'u': NEXT(); if (!ishex(PEEK)) return 1; else { x |= tohex(PEEK) << 12; NEXT(); } if (!ishex(PEEK)) return 1; else { x |= tohex(PEEK) << 8; NEXT(); } if (!ishex(PEEK)) return 1; else { x |= tohex(PEEK) << 4; NEXT(); } if (!ishex(PEEK)) return 1; else { x |= tohex(PEEK); NEXT(); } textpush(J, x); break; case 'x': NEXT(); if (!ishex(PEEK)) return 1; else { x |= tohex(PEEK) << 4; NEXT(); } if (!ishex(PEEK)) return 1; else { x |= tohex(PEEK); NEXT(); } textpush(J, x); break; case '0': textpush(J, 0); NEXT(); break; case '\\': textpush(J, '\\'); NEXT(); break; case '\'': textpush(J, '\''); NEXT(); break; case '"': textpush(J, '"'); NEXT(); break; case 'b': textpush(J, '\b'); NEXT(); break; case 'f': textpush(J, '\f'); NEXT(); break; case 'n': textpush(J, '\n'); NEXT(); break; case 'r': textpush(J, '\r'); NEXT(); break; case 't': textpush(J, '\t'); NEXT(); break; case 'v': textpush(J, '\v'); NEXT(); break; default: textpush(J, PEEK); NEXT(); break; } return 0; } static inline int lexstring(js_State *J) { const char *s; int q = PEEK; NEXT(); textinit(J); while (PEEK != q) { if (PEEK == 0 || PEEK == '\n') return jsP_error(J, "string not terminated"); if (ACCEPT('\\')) { if (lexescape(J)) return jsP_error(J, "malformed escape sequence"); } else { textpush(J, PEEK); NEXT(); } } EXPECT(q); s = textend(J); J->text = js_intern(J, s); return TK_STRING; } /* the ugliest language wart ever... */ static int isregexpcontext(int last) { switch (last) { case ']': case ')': case '}': case TK_IDENTIFIER: case TK_NUMBER: case TK_STRING: case TK_FALSE: case TK_NULL: case TK_THIS: case TK_TRUE: return 0; default: return 1; } } static int lexregexp(js_State *J) { const char *s; int g, m, i; int c; /* already consumed initial '/' */ textinit(J); /* regexp body */ while (PEEK != '/') { if (PEEK == 0 || PEEK == '\n') { return jsP_error(J, "regular expression not terminated"); } else if (ACCEPT('\\')) { textpush(J, '\\'); if (PEEK == 0 || PEEK == '\n') return jsP_error(J, "regular expression not terminated"); textpush(J, PEEK); NEXT(); } else { textpush(J, PEEK); NEXT(); } } EXPECT('/'); s = textend(J); /* regexp flags */ g = i = m = 0; c = PEEK; while (isidentifierpart(PEEK)) { if (ACCEPT('g')) ++g; else if (ACCEPT('i')) ++i; else if (ACCEPT('m')) ++m; else return jsP_error(J, "illegal flag in regular expression: %c", PEEK); } if (g > 1 || i > 1 || m > 1) return jsP_error(J, "duplicated flag in regular expression"); J->text = js_intern(J, s); J->number = 0; if (g) J->number += JS_REGEXP_G; if (i) J->number += JS_REGEXP_I; if (m) J->number += JS_REGEXP_M; return TK_REGEXP; } /* simple "return [no Line Terminator here] ..." contexts */ static inline int isnlthcontext(int last) { switch (last) { case TK_BREAK: case TK_CONTINUE: case TK_RETURN: case TK_THROW: return 1; default: return 0; } } static int lex(js_State *J) { J->newline = 0; while (1) { J->lexline = J->line; /* save location of beginning of token */ while (iswhite(PEEK)) NEXT(); if (ACCEPT('\n')) { J->newline = 1; if (isnlthcontext(J->lasttoken)) return ';'; continue; } if (ACCEPT('/')) { if (ACCEPT('/')) { lexlinecomment(J); continue; } else if (ACCEPT('*')) { if (lexcomment(J)) return jsP_error(J, "multi-line comment not terminated"); continue; } else if (isregexpcontext(J->lasttoken)) { return lexregexp(J); } else if (ACCEPT('=')) { return TK_DIV_ASS; } else { return '/'; } } if (PEEK >= '0' && PEEK <= '9') { return lexnumber(J); } switch (PEEK) { case '(': NEXT(); return '('; case ')': NEXT(); return ')'; case ',': NEXT(); return ','; case ':': NEXT(); return ':'; case ';': NEXT(); return ';'; case '?': NEXT(); return '?'; case '[': NEXT(); return '['; case ']': NEXT(); return ']'; case '{': NEXT(); return '{'; case '}': NEXT(); return '}'; case '~': NEXT(); return '~'; case '\'': case '"': return lexstring(J); case '.': return lexnumber(J); case '<': NEXT(); if (ACCEPT('<')) { if (ACCEPT('=')) return TK_SHL_ASS; return TK_SHL; } if (ACCEPT('=')) return TK_LE; return '<'; case '>': NEXT(); if (ACCEPT('>')) { if (ACCEPT('>')) { if (ACCEPT('=')) return TK_USHR_ASS; return TK_USHR; } if (ACCEPT('=')) return TK_SHR_ASS; return TK_SHR; } if (ACCEPT('=')) return TK_GE; return '>'; case '=': NEXT(); if (ACCEPT('=')) { if (ACCEPT('=')) return TK_STRICTEQ; return TK_EQ; } return '='; case '!': NEXT(); if (ACCEPT('=')) { if (ACCEPT('=')) return TK_STRICTNE; return TK_NE; } return '!'; case '+': NEXT(); if (ACCEPT('+')) return TK_INC; if (ACCEPT('=')) return TK_ADD_ASS; return '+'; case '-': NEXT(); if (ACCEPT('-')) return TK_DEC; if (ACCEPT('=')) return TK_SUB_ASS; return '-'; case '*': NEXT(); if (ACCEPT('=')) return TK_MUL_ASS; return '*'; case '%': NEXT(); if (ACCEPT('=')) return TK_MOD_ASS; return '%'; case '&': NEXT(); if (ACCEPT('&')) return TK_AND; if (ACCEPT('=')) return TK_AND_ASS; return '&'; case '|': NEXT(); if (ACCEPT('|')) return TK_OR; if (ACCEPT('=')) return TK_OR_ASS; return '|'; case '^': NEXT(); if (ACCEPT('=')) return TK_XOR_ASS; return '^'; case 0: return 0; /* EOF */ } /* Handle \uXXXX escapes in identifiers */ unescape(J); if (isidentifierstart(PEEK)) { textinit(J); textpush(J, PEEK); NEXT(); unescape(J); while (isidentifierpart(PEEK)) { textpush(J, PEEK); NEXT(); unescape(J); } textend(J); return findkeyword(J, J->buf.text); } if (PEEK >= 0x20 && PEEK <= 0x7E) return jsP_error(J, "unexpected character: '%c'", PEEK); return jsP_error(J, "unexpected character: \\u%04X", PEEK); } } void jsP_initlex(js_State *J, const char *filename, const char *source) { J->filename = filename; J->source = source; J->line = 1; J->lasttoken = 0; next(J); /* load first lookahead character */ } int jsP_lex(js_State *J) { return J->lasttoken = lex(J); }