ref: a4b082e87a11db4311b8b84224abfdb9dbad297a
dir: /cc1/lex.c/
static char sccsid[] = "@(#) ./cc1/lex.c"; #include <assert.h> #include <ctype.h> #include <errno.h> #include <limits.h> #include <setjmp.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <cstd.h> #include "../inc/scc.h" #include "cc1.h" int yytoken; struct yystype yylval; char yytext[STRINGSIZ+3]; unsigned short yylen; int lexmode = CCMODE; unsigned lineno; char filenam[FILENAME_MAX]; int namespace = NS_IDEN; static int safe; Input *input; void ilex(void) { static struct keyword keys[] = { {"auto", SCLASS, AUTO}, {"break", BREAK, BREAK}, {"_Bool", TYPE, BOOL}, {"__builtin_va_list", TYPE, VA_LIST}, {"case", CASE, CASE}, {"char", TYPE, CHAR}, {"const", TQUALIFIER, CONST}, {"continue", CONTINUE, CONTINUE}, {"default", DEFAULT, DEFAULT}, {"do", DO, DO}, {"double", TYPE, DOUBLE}, {"else", ELSE, ELSE}, {"enum", TYPE, ENUM}, {"extern", SCLASS, EXTERN}, {"float", TYPE, FLOAT}, {"for", FOR, FOR}, {"goto", GOTO, GOTO}, {"if", IF, IF}, {"inline", TQUALIFIER, INLINE}, {"int", TYPE, INT}, {"long", TYPE, LONG}, {"register", SCLASS, REGISTER}, {"restrict", TQUALIFIER, RESTRICT}, {"return", RETURN, RETURN}, {"short", TYPE, SHORT}, {"signed", TYPE, SIGNED}, {"sizeof", SIZEOF, SIZEOF}, {"static", SCLASS, STATIC}, {"struct", TYPE, STRUCT}, {"switch", SWITCH, SWITCH}, {"typedef", SCLASS, TYPEDEF}, {"union", TYPE, UNION}, {"unsigned", TYPE, UNSIGNED}, {"void", TYPE, VOID}, {"volatile", TQUALIFIER, VOLATILE}, {"while", WHILE, WHILE}, {NULL, 0, 0}, }; keywords(keys, NS_KEYWORD); } int setloc(char *fname, unsigned line) { size_t len; if ((len = strlen(fname)) >= FILENAME_MAX) die("file name too long: '%s'", fname); memmove(filenam, fname, len); filenam[len] = '\0'; free(input->filenam); input->filenam = xstrdup(fname); lineno = input->lineno = line; return 1; } int addinput(char *fname, Symbol *hide, char *buffer) { FILE *fp; char *extp; unsigned flags; int infileln; Input *newip, *curip = input; if (hide) { /* this is a macro expansion */ fp = NULL; if (hide->hide == UCHAR_MAX) die("Too many macro expansions"); ++hide->hide; flags = IMACRO; } else if (fname) { /* a new file */ if ((fp = fopen(fname, "r")) == NULL) return 0; flags = IFILE; if (curip && onlyheader) { infileln = strlen(infile); if (extp = strrchr(infile, '.')) infileln -= strlen(extp); printf("%.*s.o: %s %s\n", infileln, infile, infile, fname); } } else { /* reading from stdin */ fp = stdin; fname = "<stdin>"; flags = ISTDIN; } newip = xmalloc(sizeof(*newip)); if (!buffer) { buffer = xmalloc(INPUTSIZ); buffer[0] = '\0'; } if (curip) curip->lineno = lineno; newip->p = newip->begin = newip->line = buffer; newip->filenam = NULL; newip->lineno = 0; newip->next = curip; newip->fp = fp; newip->hide = hide; newip->flags = flags; input = newip; return setloc(fname, (curip) ? curip->lineno : newip->lineno); } void delinput(void) { Input *ip = input; Symbol *hide = ip->hide; switch (ip->flags & ITYPE) { case IFILE: if (fclose(ip->fp)) die("error: failed to read from input file '%s'", ip->filenam); break; case IMACRO: assert(hide->hide == 1); --hide->hide; break; } input = ip->next; free(ip->filenam); free(ip->line); if (input) { lineno = input->lineno; strcpy(filenam, input->filenam); } } static void newline(void) { if (++lineno == 0) die("error: input file '%s' too long", filenam); } /* * Read the next character from the input file, counting number of lines * and joining lines escaped with \ */ static int readchar(void) { FILE *fp = input->fp; int c; repeat: switch (c = getc(fp)) { case '\\': if ((c = getc(fp)) == '\n') { newline(); goto repeat; } ungetc(c, fp); c = '\\'; break; case '\n': newline(); break; default: if (!isprint(c) && !ispunct(c)) warn("invalid input character. The shame of UB is yours"); break; } return c; } /* * discard a C comment. This function is only called from readline * because it is impossible to have a comment in a macro, because * comments are always discarded before processing any cpp directive */ static void comment(int type) { int c; repeat: while ((c = readchar()) != EOF && c != type) /* nothing */; if (c == EOF) { errorp("unterminated comment"); return; } if (type == '*' && (c = readchar()) != '/') goto repeat; } /* * readline is used to read a full logic line from a file. * It discards comments and check that the line fits in * the input buffer */ static int readline(void) { char *bp, *lim; int c, peekc = 0; if (feof(input->fp)) { input->flags |= IEOF; return 0; } *input->line = '\0'; lim = &input->line[INPUTSIZ-1]; for (bp = input->line; bp < lim-1; *bp++ = c) { c = (peekc) ? peekc : readchar(); peekc = 0; if (c == '\n' || c == EOF) break; if (c != '/') continue; /* check for /* or // */ peekc = readchar(); if (peekc != '*' && peekc != '/') continue; comment((peekc == '/') ? '\n' : '*'); peekc = 0; c = ' '; } input->begin = input->p = input->line; if (bp == lim-1) { errorp("line too long"); --bp; } *bp++ = '\n'; *bp = '\0'; return 1; } /* * moreinput gets more bytes to be passed to the lexer. * It can take more bytes from macro expansions or * directly reading from files. When a cpp directive * is processed the line is discarded because it must not * be passed to the lexer */ static int moreinput(void) { int wasexpand = 0; repeat: if (!input) return 0; if (*input->p == '\0') { if ((input->flags&ITYPE) == IMACRO) { wasexpand = 1; input->flags |= IEOF; } if (input->flags & IEOF) { delinput(); goto repeat; } if (!readline() || cpp()) { *input->p = '\0'; goto repeat; } } if (onlycpp && !wasexpand) ppragmaln(); return 1; } static void tok2str(void) { if ((yylen = input->p - input->begin) > INTIDENTSIZ) error("token too big"); memcpy(yytext, input->begin, yylen); yytext[yylen] = '\0'; input->begin = input->p; } static Symbol * readint(char *s, int base, int sign, Symbol *sym) { Type *tp = sym->type; struct limits *lim; TUINT u, val, max; int c; lim = getlimits(tp); max = lim->max.i; if (*s == '0') ++s; if (toupper(*s) == 'X') ++s; for (u = 0; isxdigit(c = *s++); u = u*base + val) { static char letters[] = "0123456789ABCDEF"; val = strchr(letters, toupper(c)) - letters; repeat: if (u <= max/base && u*base <= max - val) continue; if (tp->prop & TSIGNED) { if (tp == inttype) tp = (base==10) ? longtype : uinttype; else if (tp == longtype) tp = (base==10) ? llongtype : ulongtype; else goto overflow; } else { if (tp == uinttype) tp = (sign==UNSIGNED) ? ulongtype : longtype; else if (tp == ulongtype) tp = (sign==UNSIGNED) ? ullongtype : llongtype; else goto overflow; } sym->type = tp; lim = getlimits(tp); max = lim->max.i; goto repeat; } if (tp->prop & TSIGNED) sym->u.i = u; else sym->u.u = u; return sym; overflow: errorp("overflow in integer constant"); return sym; } static int integer(char *s, int base) { Type *tp; Symbol *sym; unsigned size, sign; for (size = sign = 0; ; ++input->p) { switch (toupper(*input->p)) { case 'L': if (size == LLONG) goto wrong_type; size = (size == LONG) ? LLONG : LONG; continue; case 'U': if (sign == UNSIGNED) goto wrong_type; sign = UNSIGNED; continue; default: goto convert; wrong_type: error("invalid suffix in integer constant"); } } convert: tp = ctype(INT, sign, size); sym = newsym(NS_IDEN, NULL); sym->type = tp; sym->flags |= SCONSTANT; yylval.sym = readint(s, base, sign, sym); return CONSTANT; } static char * digits(int base) { char *p; int c; for (p = input->p; c = *p; ++p) { switch (base) { case 8: if (!strchr("01234567", c)) goto end; break; case 10: if (!isdigit(c)) goto end; break; case 16: if (!isxdigit(c)) goto end; break; } } end: input->p = p; tok2str(); return yytext; } static int number(void) { int base; if (*input->p != '0') { base = 10; } else { if (toupper(*++input->p) == 'X') { ++input->p; base = 16; } else { base = 8; } } return integer(digits(base), base); } static int escape(void) { int c, base; switch (*++input->p) { case 'a': return '\a'; case 'f': return '\f'; case 'n': return '\n'; case 'r': return '\r'; case 't': return '\t'; case 'v': return '\v'; case '"': return '"'; case '\'': return '\''; case '\\': return '\\'; case '\?': return '\?'; case 'u': /* * FIXME: universal constants are not correctly handled */ if (!isdigit(*++input->p)) warn("incorrect digit for numerical character constant"); base = 10; break; case 'x': if (!isxdigit(*++input->p)) warn("\\x used with no following hex digits"); base = 16; break; case '0': if (!strchr("01234567", *++input->p)) warn("\\0 used with no following octal digits"); base = 8; break; default: warn("unknown escape sequence"); return ' '; } errno = 0; c = strtoul(input->p, &input->p, base); if (errno || c > 255) warn("character constant out of range"); --input->p; return c; } static int character(void) { int c; Symbol *sym; if ((c = *++input->p) == '\\') c = escape(); else c = *input->p; ++input->p; if (*input->p != '\'') errorp("invalid character constant"); else ++input->p; sym = newsym(NS_IDEN, NULL); sym->u.i = c; sym->type = inttype; yylval.sym = sym; tok2str(); return CONSTANT; } static int string(void) { char *bp = yytext; int c; *bp++ = '"'; for (++input->p; (c = *input->p) != '"'; ++input->p) { if (c == '\0') { errorp("missing terminating '\"' character"); break; } if (c == '\\') c = escape(); if (bp == &yytext[STRINGSIZ+1]) { /* TODO: proper error handling here */ error("string too long"); } *bp++ = c; } input->begin = ++input->p; *bp = '\0'; yylen = bp - yytext + 1; yylval.sym = newstring(yytext+1, yylen-1); *bp++ = '"'; *bp = '\0'; return STRING; } static int iden(void) { Symbol *sym; char *p, *begin; begin = input->p; for (p = begin; isalnum(*p) || *p == '_'; ++p) /* nothing */; input->p = p; tok2str(); if ((sym = lookup(NS_CPP, yytext, NOALLOC)) != NULL) { if (!disexpand && !sym->hide && expand(begin, sym)) return next(); } sym = lookup(namespace, yytext, ALLOC); yylval.sym = sym; if (sym->flags & SCONSTANT) return CONSTANT; if (sym->token != IDEN) yylval.token = sym->u.token; return sym->token; } static int follow(int expect, int ifyes, int ifno) { if (*input->p++ == expect) return ifyes; --input->p; return ifno; } static int minus(void) { switch (*input->p++) { case '-': return DEC; case '>': return INDIR; case '=': return SUB_EQ; default: --input->p; return '-'; } } static int plus(void) { switch (*input->p++) { case '+': return INC; case '=': return ADD_EQ; default: --input->p; return '+'; } } static int relational(int op, int equal, int shift, int assig) { int c; if ((c = *input->p++) == '=') return equal; if (c == op) return follow('=', assig, shift); --input->p; return op; } static int logic(int op, int equal, int logic) { int c; if ((c = *input->p++) == '=') return equal; if (c == op) return logic; --input->p; return op; } static int dot(void) { int c; if ((c = *input->p) != '.') return '.'; if ((c = *++input->p) != '.') error("incorrect token '..'"); ++input->p; return ELLIPSIS; } static int operator(void) { int t; switch (t = *input->p++) { case '<': t = relational('<', LE, SHL, SHL_EQ); break; case '>': t = relational('>', GE, SHR, SHR_EQ); break; case '&': t = logic('&', AND_EQ, AND); break; case '|': t = logic('|', OR_EQ, OR); break; case '=': t = follow('=', EQ, '='); break; case '^': t = follow('=', XOR_EQ, '^'); break; case '*': t = follow('=', MUL_EQ, '*'); break; case '/': t = follow('=', DIV_EQ, '/'); break; case '!': t = follow('=', NE, '!'); break; case '#': t = follow('#', '$', '#'); break; case '-': t = minus(); break; case '+': t = plus(); break; case '.': t = dot(); break; } tok2str(); return t; } /* TODO: Ensure that namespace is NS_IDEN after a recovery */ /* * skip all the spaces until the next token. When we are in * CPPMODE \n is not considered a whitespace */ static int skipspaces(void) { int c; for (;;) { switch (c = *input->p) { case '\n': if (lexmode == CPPMODE) goto return_byte; ++input->p; case '\0': if (!moreinput()) return EOF; break; case ' ': case '\t': case '\v': case '\r': case '\f': ++input->p; break; default: goto return_byte; } } return_byte: input->begin = input->p; return c; } int next(void) { int c; if ((c = skipspaces()) == EOF) yytoken = EOFTOK; else if (isalpha(c) || c == '_') yytoken = iden(); else if (isdigit(c)) yytoken = number(); else if (c == '"') yytoken = string(); else if (c == '\'') yytoken = character(); else yytoken = operator(); if (yytoken == EOF) { strcpy(yytext, "<EOF>"); if (cppctx) errorp("#endif expected"); } DBG("TOKEN %s", yytext); return yytoken; } void expect(int tok) { if (yytoken != tok) { if (isgraph(tok)) errorp("expected '%c' before '%s'", tok, yytext); else errorp("unexpected '%s'", yytext); } else { next(); } } int ahead(void) { skipspaces(); return *input->begin; } void setsafe(int type) { safe = type; } void discard(void) { extern jmp_buf recover; int c; input->begin = input->p; for (c = yytoken; ; c = *input->begin++) { switch (safe) { case END_COMP: if (c == '}') goto jump; goto semicolon; case END_COND: if (c == ')') goto jump; break; case END_LDECL: if (c == ',') goto jump; case END_DECL: semicolon: if (c == ';') goto jump; break; } if (c == '\0' && !moreinput()) exit(1); } jump: yytoken = c; longjmp(recover, 1); }