ref: 7681aff4af1f56f6a0ed6a9451cc632f14bffbdd
dir: /cc1/lex.c/
#include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <ctype.h> #include <sizes.h> #include <cc.h> #include "cc1.h" static FILE *yyin; const char *filename; unsigned linenum; uint8_t yytoken; struct yystype yylval; char yytext[IDENTSIZ + 1]; static uint8_t integer(char *s, char base) { static Type *tp; static Symbol *sym; static char ch, size, sign; static long v; size = sign = 0; type: switch (ch = toupper(getc(yyin))) { case 'L': if (size == LONG + LONG) goto wrong_type; size += LONG; goto type; case 'U': if (sign == UNSIGNED) goto wrong_type; goto type; default: ungetc(ch, yyin); tp = ctype(INT, sign, size); break; wrong_type: error("invalid suffix in integer constant"); } sym = install("", NS_IDEN); sym->type = tp; v = strtol(yytext, NULL, base); if (tp == inttype) sym->u.i = v; yylval.sym = sym; return CONSTANT; } static uint8_t number(void) { register char ch, *bp; static char base; if ((ch = getc(yyin)) == '0') { if (toupper(ch = getc(yyin)) == 'X') { base = 16; } else { base = 8; ungetc(ch, yyin); } } else { base = 10; ungetc(ch, yyin); } for (bp = yytext ; bp < &yytext[IDENTSIZ]; *bp++ = ch) { ch = getc(yyin); switch (base) { case 8: if (ch >= '7') goto end; /* passthru */ case 10: if (!isdigit(ch)) goto end; break; case 16: if (!isxdigit(ch)) goto end; break; } } end: if (bp == &yytext[IDENTSIZ]) error("identifier too long %s", yytext); *bp = '\0'; ungetc(ch, yyin); return integer(yytext, base); } static char * escape(char *s) { char c; repeat: switch (getc(yyin)) { case '\\': c = '\''; break; case 'a': c = '\a'; break; case 'f': c = '\f'; break; case 'n': c = '\n'; break; case 'r': c = '\r'; break; case 't': c = '\t'; break; case 'v': c = '\v'; break; case '\'': c = '\\'; break; case '"': c ='"'; break; case '?': c = '?'; break; case 'x': /* TODO: */ case '0': /* TODO: */ case 'u': /* TODO: */ case '\n': ++linenum; if ((c = getc(yyin)) == '\\') goto repeat; break; default: warn(1, "unknown escape sequence"); return s; } *s = c; return ++s; } static uint8_t character(void) { static char c; register Symbol *sym; getc(yyin); /* discard the initial ' */ c = getc(yyin); if (c == '\\') escape(&c); if (getc(yyin) != '\'') error("invalid character constant"); sym = install("", NS_IDEN); sym->u.i = c; sym->type = inttype; yylval.sym = sym; return CONSTANT; } static uint8_t string(void) { static char buf[STRINGSIZ+1]; register char *bp; register int c; static Symbol *sym; getc(yyin); /* discard the initial " */ for (bp = buf; bp < &buf[STRINGSIZ]; ) { switch (c = getc(yyin)) { case EOF: error("found EOF while parsing"); case '"': goto end_string; case '\\': bp = escape(bp); break; default: *bp++ = c; } } end_string: if (bp == &buf[IDENTSIZ]) error("string too long"); *bp = '\0'; sym = install("", NS_IDEN); sym->u.s = xstrdup(buf); sym->type = mktype(chartype, PTR, 0); yylval.sym = sym; return STRING; } static uint8_t iden(void) { register char *bp; register int c; register Symbol *sym; for (bp = yytext; bp < &yytext[IDENTSIZ]; *bp++ = c) { if (!isalnum(c = getc(yyin)) && c != '_') break; } if (bp == &yytext[IDENTSIZ]) error("identifier too long %s", yytext); *bp = '\0'; ungetc(c, yyin); sym = yylval.sym = lookup(yytext, NS_IDEN); if (!sym || sym->token == IDEN) return IDEN; yylval.token = sym->u.token; return sym->token; } static uint8_t follow(int expect, int ifyes, int ifno) { register int c = getc(yyin); if (c == expect) { yytext[1] = c; yytext[2] = 0; return ifyes; } ungetc(c, yyin); return ifno; } static uint8_t minus(void) { register int c = getc(yyin); yytext[1] = c; yytext[2] = '\0'; switch (c) { case '-': return DEC; case '>': return INDIR; case '=': return SUB_EQ; default: yytext[1] = '\0'; ungetc(c, yyin); return '-'; } } static uint8_t plus(void) { register int c = getc(yyin); yytext[1] = c; yytext[2] = '\0'; switch (c) { case '+': return INC; case '=': return ADD_EQ; default: yytext[1] = '\0'; ungetc(c, yyin); return '+'; } } static uint8_t relational(uint8_t op, uint8_t equal, uint8_t shift, uint8_t assig) { register int c = getc(yyin); yytext[1] = c; yytext[2] = '\0'; if (c == '=') return equal; if (c == op) return follow('=', assig, shift); ungetc(c, yyin); yytext[1] = '\0'; return op; } static uint8_t logic(uint8_t op, uint8_t equal, uint8_t logic) { register int c = getc(yyin); yytext[1] = c; yytext[2] = '\0'; if (c == '=') return equal; if (c == op) return logic; ungetc(c, yyin); yytext[1] = '\0'; return op; } static uint8_t dot(void) { int c; if ((c = getc(yyin)) != '.') { ungetc(c, yyin); return '.'; } else if ((c = getc(yyin)) != '.') { error("incorrect token '%s'", yytext); } else { yytext[2] = yytext[1] = '.'; yytext[3] = '\0'; return ELLIPSIS; } } static uint8_t operator(void) { register uint8_t c = getc(yyin); yytext[0] = c; yytext[1] = '\0'; switch (c) { case '<': return relational('<', LE, SHL, SHL_EQ); case '>': return relational('>', GE, SHR, SHR_EQ); case '&': return logic('&', AND_EQ, AND); case '|': return logic('|', OR_EQ, OR); case '=': return follow('=', EQ, '='); case '^': return follow('=', XOR_EQ, '^'); case '*': return follow('=', MUL_EQ, '*'); case '/': return follow('=', DIV_EQ, '/'); case '!': return follow('=', NE, '!'); case '-': return minus(); case '+': return plus(); case '.': return dot(); default: return c; } } static int skipspaces(void) { register int c; while (isspace(c = getc(yyin))) { if (c == '\n') ++linenum; } return c; } uint8_t next(void) { register int c; ungetc(c = skipspaces(), yyin); if (isalpha(c) || c == '_') { yytoken = iden(); } else if (isdigit(c)) { yytoken = number(); } else if (c == '"') { yytoken = string(); } else if (c == '\'') { yytoken = character(); } else if (c == EOF) { strcpy(yytext, "EOF"); yytoken = EOFTOK; } else { yytoken = operator(); } return yytoken; } void expect(register uint8_t tok) { if (yytoken != tok) unexpected(); next(); } uint8_t ahead(void) { register int c; ungetc(c = skipspaces(), yyin); return c; } void open_file(register const char *file) { if (yyin != NULL) fclose(yyin); if (file == NULL) { yyin = stdin; filename = "(stdin)"; } else { if ((yyin = fopen(file, "r")) == NULL) die("file '%s' not found", file); filename = file; } linenum = 1; }