/*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1992 Diomidis Spinellis. * Copyright (c) 1992, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Diomidis Spinellis of Imperial College, University of London. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <sys/cdefs.h> #ifndef lint static const char sccsid[] = "@(#)compile.c 8.1 (Berkeley) 6/6/93"; #endif #include <sys/types.h> #include <sys/stat.h> #include <ctype.h> #include <err.h> #include <errno.h> #include <fcntl.h> #include <limits.h> #include <regex.h> #include <stdbool.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <wchar.h> #include "defs.h" #include "extern.h" #define LHSZ 128 #define LHMASK (LHSZ - 1) static struct labhash { struct labhash *lh_next; u_int lh_hash; struct s_command *lh_cmd; int lh_ref; } *labels[LHSZ]; static char *compile_addr(char *, struct s_addr *); static char *compile_ccl(char **, char *); static char *compile_delimited(char *, char *, int); static char *compile_flags(char *, struct s_subst *); static regex_t *compile_re(char *, int); static char *compile_subst(char *, struct s_subst *); static char *compile_text(void); static char *compile_tr(char *, struct s_tr **); static struct s_command **compile_stream(struct s_command **); static char *duptoeol(char *, const char *); static void enterlabel(struct s_command *); static struct s_command *findlabel(char *); static void fixuplabel(struct s_command *, struct s_command *); static void uselabel(void); /* * Command specification. This is used to drive the command parser. */ struct s_format { char code; /* Command code */ int naddr; /* Number of address args */ enum e_args args; /* Argument type */ }; static struct s_format cmd_fmts[] = { {'{', 2, GROUP}, {'}', 0, ENDGROUP}, {'a', 1, TEXT}, {'b', 2, BRANCH}, {'c', 2, TEXT}, {'d', 2, EMPTY}, {'D', 2, EMPTY}, {'g', 2, EMPTY}, {'G', 2, EMPTY}, {'h', 2, EMPTY}, {'H', 2, EMPTY}, {'i', 1, TEXT}, {'l', 2, EMPTY}, {'n', 2, EMPTY}, {'N', 2, EMPTY}, {'p', 2, EMPTY}, {'P', 2, EMPTY}, {'q', 1, EMPTY}, {'r', 1, RFILE}, {'s', 2, SUBST}, {'t', 2, BRANCH}, {'w', 2, WFILE}, {'x', 2, EMPTY}, {'y', 2, TR}, {'!', 2, NONSEL}, {':', 0, LABEL}, {'#', 0, COMMENT}, {'=', 1, EMPTY}, {'\0', 0, COMMENT}, }; /* The compiled program. */ struct s_command *prog; /* * Compile the program into prog. * Initialise appends. */ void compile(void) { *compile_stream(&prog) = NULL; fixuplabel(prog, NULL); uselabel(); if (appendnum == 0) appends = NULL; else if ((appends = malloc(sizeof(struct s_appends) * appendnum)) == NULL) err(1, "malloc"); if ((match = malloc((maxnsub + 1) * sizeof(regmatch_t))) == NULL) err(1, "malloc"); } #define EATSPACE() do { \ if (p) \ while (*p && isspace((unsigned char)*p)) \ p++; \ } while (0) static struct s_command ** compile_stream(struct s_command **link) { char *p; static char lbuf[_POSIX2_LINE_MAX + 1]; /* To save stack */ struct s_command *cmd, *cmd2, *stack; struct s_format *fp; char re[_POSIX2_LINE_MAX + 1]; int naddr; /* Number of addresses */ stack = NULL; for (;;) { if ((p = cu_fgets(lbuf, sizeof(lbuf), NULL)) == NULL) { if (stack != NULL) errx(1, "%lu: %s: unexpected EOF (pending }'s)", linenum, fname); return (link); } semicolon: EATSPACE(); if (p) { if (*p == '#' || *p == '\0') continue; else if (*p == ';') { p++; goto semicolon; } } if ((*link = cmd = malloc(sizeof(struct s_command))) == NULL) err(1, "malloc"); link = &cmd->next; cmd->startline = cmd->nonsel = 0; /* First parse the addresses */ naddr = 0; /* Valid characters to start an address */ #define addrchar(c) (strchr("0123456789/\\$", (c))) if (addrchar(*p)) { naddr++; if ((cmd->a1 = malloc(sizeof(struct s_addr))) == NULL) err(1, "malloc"); p = compile_addr(p, cmd->a1); EATSPACE(); /* EXTENSION */ if (*p == ',') { p++; EATSPACE(); /* EXTENSION */ naddr++; if ((cmd->a2 = malloc(sizeof(struct s_addr))) == NULL) err(1, "malloc"); p = compile_addr(p, cmd->a2); EATSPACE(); } else cmd->a2 = NULL; } else cmd->a1 = cmd->a2 = NULL; nonsel: /* Now parse the command */ if (!*p) errx(1, "%lu: %s: command expected", linenum, fname); cmd->code = *p; for (fp = cmd_fmts; fp->code; fp++) if (fp->code == *p) break; if (!fp->code) errx(1, "%lu: %s: invalid command code %c", linenum, fname, *p); if (naddr > fp->naddr) errx(1, "%lu: %s: command %c expects up to %d address(es), found %d", linenum, fname, *p, fp->naddr, naddr); switch (fp->args) { case NONSEL: /* ! */ p++; EATSPACE(); cmd->nonsel = 1; goto nonsel; case GROUP: /* { */ p++; EATSPACE(); cmd->next = stack; stack = cmd; link = &cmd->u.c; if (*p) goto semicolon; break; case ENDGROUP: /* * Short-circuit command processing, since end of * group is really just a noop. */ cmd->nonsel = 1; if (stack == NULL) errx(1, "%lu: %s: unexpected }", linenum, fname); cmd2 = stack; stack = cmd2->next; cmd2->next = cmd; /*FALLTHROUGH*/ case EMPTY: /* d D g G h H l n N p P q x = \0 */ p++; EATSPACE(); if (*p == ';') { p++; link = &cmd->next; goto semicolon; } if (*p) errx(1, "%lu: %s: extra characters at the end of %c command", linenum, fname, cmd->code); break; case TEXT: /* a c i */ p++; EATSPACE(); if (*p != '\\') errx(1, "%lu: %s: command %c expects \\ followed by text", linenum, fname, cmd->code); p++; EATSPACE(); if (*p) errx(1, "%lu: %s: extra characters after \\ at the end of %c command", linenum, fname, cmd->code); cmd->t = compile_text(); break; case COMMENT: /* \0 # */ break; case WFILE: /* w */ p++; EATSPACE(); if (*p == '\0') errx(1, "%lu: %s: filename expected", linenum, fname); cmd->t = duptoeol(p, "w command"); if (aflag) cmd->u.fd = -1; else if ((cmd->u.fd = open(p, O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1) err(1, "%s", p); break; case RFILE: /* r */ p++; EATSPACE(); if (*p == '\0') errx(1, "%lu: %s: filename expected", linenum, fname); else cmd->t = duptoeol(p, "read command"); break; case BRANCH: /* b t */ p++; EATSPACE(); if (*p == '\0') cmd->t = NULL; else cmd->t = duptoeol(p, "branch"); break; case LABEL: /* : */ p++; EATSPACE(); cmd->t = duptoeol(p, "label"); if (strlen(p) == 0) errx(1, "%lu: %s: empty label", linenum, fname); enterlabel(cmd); break; case SUBST: /* s */ p++; if (*p == '\0' || *p == '\\') errx(1, "%lu: %s: substitute pattern can not be delimited by newline or backslash", linenum, fname); if ((cmd->u.s = calloc(1, sizeof(struct s_subst))) == NULL) err(1, "malloc"); p = compile_delimited(p, re, 0); if (p == NULL) errx(1, "%lu: %s: unterminated substitute pattern", linenum, fname); /* Compile RE with no case sensitivity temporarily */ if (*re == '\0') cmd->u.s->re = NULL; else cmd->u.s->re = compile_re(re, 0); --p; p = compile_subst(p, cmd->u.s); p = compile_flags(p, cmd->u.s); /* Recompile RE with case sensitivity from "I" flag if any */ if (*re == '\0') cmd->u.s->re = NULL; else cmd->u.s->re = compile_re(re, cmd->u.s->icase); EATSPACE(); if (*p == ';') { p++; link = &cmd->next; goto semicolon; } break; case TR: /* y */ p++; p = compile_tr(p, &cmd->u.y); EATSPACE(); if (*p == ';') { p++; link = &cmd->next; goto semicolon; } if (*p) errx(1, "%lu: %s: extra text at the end of a transform command", linenum, fname); break; } } } static int hex2char(const char *in, char *out, int len) { long ord; char *endptr, hexbuf[3]; hexbuf[0] = in[0]; hexbuf[1] = len > 1 ? in[1] : '\0'; hexbuf[2] = '\0'; errno = 0; ord = strtol(hexbuf, &endptr, 16); if (*endptr != '\0' || errno != 0) return (ERANGE); *out = (char)ord; return (0); } static bool hexdigit(char c) { int lc; lc = tolower(c); return isdigit(lc) || (lc >= 'a' && lc <= 'f'); } static bool dohex(const char *in, char *out, int *len) { int tmplen; if (!hexdigit(in[0])) return (false); tmplen = 1; if (hexdigit(in[1])) ++tmplen; if (hex2char(in, out, tmplen) == 0) { *len = tmplen; return (true); } return (false); } /* * Get a delimited string. P points to the delimiter of the string; d points * to a buffer area. Newline and delimiter escapes are processed; other * escapes are ignored. * * Returns a pointer to the first character after the final delimiter or NULL * in the case of a non-terminated string. The character array d is filled * with the processed string. */ static char * compile_delimited(char *p, char *d, int is_tr) { int hexlen; char c; c = *p++; if (c == '\0') return (NULL); else if (c == '\\') errx(1, "%lu: %s: \\ can not be used as a string delimiter", linenum, fname); else if (c == '\n') errx(1, "%lu: %s: newline can not be used as a string delimiter", linenum, fname); while (*p) { if (*p == '[' && *p != c) { if (!is_tr) { if ((d = compile_ccl(&p, d)) == NULL) { errx(1, "%lu: %s: unbalanced brackets ([])", linenum, fname); } continue; } } else if (*p == '\\' && p[1] == '[') { if (is_tr) p++; else *d++ = *p++; } else if (*p == '\\' && p[1] == c) { p++; } else if (*p == '\\' && (p[1] == 'n' || p[1] == 'r' || p[1] == 't')) { switch (p[1]) { case 'n': *d++ = '\n'; break; case 'r': *d++ = '\r'; break; case 't': *d++ = '\t'; break; } p += 2; continue; } else if (*p == '\\' && p[1] == 'x') { if (dohex(&p[2], d, &hexlen)) { ++d; p += hexlen + 2; continue; } } else if (*p == '\\' && p[1] == '\\') { if (is_tr) p++; else *d++ = *p++; } else if (*p == c) { *d = '\0'; return (p + 1); } *d++ = *p++; } return (NULL); } /* compile_ccl: expand a POSIX character class */ static char * compile_ccl(char **sp, char *t) { int c, d, hexlen; char *s = *sp; *t++ = *s++; if (*s == '^') *t++ = *s++; if (*s == ']') *t++ = *s++; for (; *s && (*t = *s) != ']'; s++, t++) { if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '=')) { *++t = *++s, t++, s++; for (c = *s; (*t = *s) != ']' || c != d; s++, t++) if ((c = *s) == '\0') return NULL; } else if (*s == '\\') { switch (s[1]) { case 'n': *t = '\n'; s++; break; case 'r': *t = '\r'; s++; break; case 't': *t = '\t'; s++; break; case 'x': if (dohex(&s[2], t, &hexlen)) s += hexlen + 1; break; } } } return (*s == ']') ? *sp = ++s, ++t : NULL; } /* * Compiles the regular expression in RE and returns a pointer to the compiled * regular expression. * Cflags are passed to regcomp. */ static regex_t * compile_re(char *re, int case_insensitive) { regex_t *rep; int eval, flags; flags = rflags; if (case_insensitive) flags |= REG_ICASE; if ((rep = malloc(sizeof(regex_t))) == NULL) err(1, "malloc"); if ((eval = regcomp(rep, re, flags)) != 0) errx(1, "%lu: %s: RE error: %s", linenum, fname, strregerror(eval, rep)); if (maxnsub < rep->re_nsub) maxnsub = rep->re_nsub; return (rep); } /* * Compile the substitution string of a regular expression and set res to * point to a saved copy of it. Nsub is the number of parenthesized regular * expressions. */ static char * compile_subst(char *p, struct s_subst *s) { static char lbuf[_POSIX2_LINE_MAX + 1]; int asize, hexlen, size; u_char ref; char c, *text, *op, *sp; int more = 1, sawesc = 0; c = *p++; /* Terminator character */ if (c == '\0') return (NULL); s->maxbref = 0; s->linenum = linenum; asize = 2 * _POSIX2_LINE_MAX + 1; if ((text = malloc(asize)) == NULL) err(1, "malloc"); size = 0; do { op = sp = text + size; for (; *p; p++) { if (*p == '\\' || sawesc) { /* * If this is a continuation from the last * buffer, we won't have a character to * skip over. */ if (sawesc) sawesc = 0; else p++; if (*p == '\0') { /* * This escaped character is continued * in the next part of the line. Note * this fact, then cause the loop to * exit w/ normal EOL case and reenter * above with the new buffer. */ sawesc = 1; p--; continue; } else if (strchr("123456789", *p) != NULL) { *sp++ = '\\'; ref = *p - '0'; if (s->re != NULL && ref > s->re->re_nsub) errx(1, "%lu: %s: \\%c not defined in the RE", linenum, fname, *p); if (s->maxbref < ref) s->maxbref = ref; } else { switch (*p) { case '&': case '\\': *sp++ = '\\'; break; case 'n': *p = '\n'; break; case 'r': *p = '\r'; break; case 't': *p = '\t'; break; case 'x': #define ADVANCE_N(s, n) \ do { \ char *adv = (s); \ while (*(adv + (n) - 1) != '\0') { \ *adv = *(adv + (n)); \ ++adv; \ } \ *adv = '\0'; \ } while (0); if (dohex(&p[1], p, &hexlen)) { ADVANCE_N(p + 1, hexlen); } break; } } } else if (*p == c) { if (*++p == '\0' && more) { if (cu_fgets(lbuf, sizeof(lbuf), &more)) p = lbuf; } *sp++ = '\0'; size += sp - op; if ((s->new = realloc(text, size)) == NULL) err(1, "realloc"); return (p); } else if (*p == '\n') { errx(1, "%lu: %s: unescaped newline inside substitute pattern", linenum, fname); /* NOTREACHED */ } *sp++ = *p; } size += sp - op; if (asize - size < _POSIX2_LINE_MAX + 1) { asize *= 2; if ((text = realloc(text, asize)) == NULL) err(1, "realloc"); } } while (cu_fgets(p = lbuf, sizeof(lbuf), &more) != NULL); errx(1, "%lu: %s: unterminated substitute in regular expression", linenum, fname); /* NOTREACHED */ } /* * Compile the flags of the s command */ static char * compile_flags(char *p, struct s_subst *s) { int gn; /* True if we have seen g or n */ unsigned long nval; char wfile[_POSIX2_LINE_MAX + 1], *q, *eq; s->n = 1; /* Default */ s->p = 0; s->wfile = NULL; s->wfd = -1; s->icase = 0; for (gn = 0;;) { EATSPACE(); /* EXTENSION */ switch (*p) { case 'g': if (gn) errx(1, "%lu: %s: more than one number or 'g' in substitute flags", linenum, fname); gn = 1; s->n = 0; break; case '\0': case '\n': case ';': return (p); case 'p': s->p = 1; break; case 'i': case 'I': s->icase = 1; break; case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': if (gn) errx(1, "%lu: %s: more than one number or 'g' in substitute flags", linenum, fname); gn = 1; errno = 0; nval = strtol(p, &p, 10); if (errno == ERANGE || nval > INT_MAX) errx(1, "%lu: %s: overflow in the 'N' substitute flag", linenum, fname); s->n = nval; p--; break; case 'w': p++; #ifdef HISTORIC_PRACTICE if (*p != ' ') { warnx("%lu: %s: space missing before w wfile", linenum, fname); return (p); } #endif EATSPACE(); q = wfile; eq = wfile + sizeof(wfile) - 1; while (*p) { if (*p == '\n') break; if (q >= eq) err(1, "wfile too long"); *q++ = *p++; } *q = '\0'; if (q == wfile) errx(1, "%lu: %s: no wfile specified", linenum, fname); s->wfile = strdup(wfile); if (!aflag && (s->wfd = open(wfile, O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1) err(1, "%s", wfile); return (p); default: errx(1, "%lu: %s: bad flag in substitute command: '%c'", linenum, fname, *p); break; } p++; } } /* * Compile a translation set of strings into a lookup table. */ static char * compile_tr(char *p, struct s_tr **py) { struct s_tr *y; int i; const char *op, *np; char old[_POSIX2_LINE_MAX + 1]; char new[_POSIX2_LINE_MAX + 1]; size_t oclen, oldlen, nclen, newlen; mbstate_t mbs1, mbs2; if ((*py = y = malloc(sizeof(*y))) == NULL) err(1, NULL); y->multis = NULL; y->nmultis = 0; if (*p == '\0' || *p == '\\') errx(1, "%lu: %s: transform pattern can not be delimited by newline or backslash", linenum, fname); p = compile_delimited(p, old, 1); if (p == NULL) errx(1, "%lu: %s: unterminated transform source string", linenum, fname); p = compile_delimited(p - 1, new, 1); if (p == NULL) errx(1, "%lu: %s: unterminated transform target string", linenum, fname); EATSPACE(); op = old; oldlen = mbsrtowcs(NULL, &op, 0, NULL); if (oldlen == (size_t)-1) err(1, NULL); np = new; newlen = mbsrtowcs(NULL, &np, 0, NULL); if (newlen == (size_t)-1) err(1, NULL); if (newlen != oldlen) errx(1, "%lu: %s: transform strings are not the same length", linenum, fname); if (MB_CUR_MAX == 1) { /* * The single-byte encoding case is easy: generate a * lookup table. */ for (i = 0; i <= UCHAR_MAX; i++) y->bytetab[i] = (char)i; for (; *op; op++, np++) y->bytetab[(u_char)*op] = *np; } else { /* * Multi-byte encoding case: generate a lookup table as * above, but only for single-byte characters. The first * bytes of multi-byte characters have their lookup table * entries set to 0, which causes do_tr() to search through * an auxiliary vector of multi-byte mappings. */ memset(&mbs1, 0, sizeof(mbs1)); memset(&mbs2, 0, sizeof(mbs2)); for (i = 0; i <= UCHAR_MAX; i++) y->bytetab[i] = (btowc(i) != WEOF) ? i : 0; while (*op != '\0') { oclen = mbrlen(op, MB_LEN_MAX, &mbs1); if (oclen == (size_t)-1 || oclen == (size_t)-2) errc(1, EILSEQ, NULL); nclen = mbrlen(np, MB_LEN_MAX, &mbs2); if (nclen == (size_t)-1 || nclen == (size_t)-2) errc(1, EILSEQ, NULL); if (oclen == 1 && nclen == 1) y->bytetab[(u_char)*op] = *np; else { y->bytetab[(u_char)*op] = 0; y->multis = realloc(y->multis, (y->nmultis + 1) * sizeof(*y->multis)); if (y->multis == NULL) err(1, NULL); i = y->nmultis++; y->multis[i].fromlen = oclen; memcpy(y->multis[i].from, op, oclen); y->multis[i].tolen = nclen; memcpy(y->multis[i].to, np, nclen); } op += oclen; np += nclen; } } return (p); } /* * Compile the text following an a, c, or i command. */ static char * compile_text(void) { int asize, esc_nl, size; char *text, *p, *op, *s; char lbuf[_POSIX2_LINE_MAX + 1]; asize = 2 * _POSIX2_LINE_MAX + 1; if ((text = malloc(asize)) == NULL) err(1, "malloc"); size = 0; while (cu_fgets(lbuf, sizeof(lbuf), NULL) != NULL) { op = s = text + size; p = lbuf; #ifdef LEGACY_BSDSED_COMPAT EATSPACE(); #endif for (esc_nl = 0; *p != '\0'; p++) { if (*p == '\\' && p[1] != '\0' && *++p == '\n') esc_nl = 1; *s++ = *p; } size += s - op; if (!esc_nl) { *s = '\0'; break; } if (asize - size < _POSIX2_LINE_MAX + 1) { asize *= 2; if ((text = realloc(text, asize)) == NULL) err(1, "realloc"); } } text[size] = '\0'; if ((p = realloc(text, size + 1)) == NULL) err(1, "realloc"); return (p); } /* * Get an address and return a pointer to the first character after * it. Fill the structure pointed to according to the address. */ static char * compile_addr(char *p, struct s_addr *a) { char *end, re[_POSIX2_LINE_MAX + 1]; int icase; icase = 0; a->type = 0; switch (*p) { case '\\': /* Context address */ ++p; /* FALLTHROUGH */ case '/': /* Context address */ p = compile_delimited(p, re, 0); if (p == NULL) errx(1, "%lu: %s: unterminated regular expression", linenum, fname); /* Check for case insensitive regexp flag */ if (*p == 'I') { icase = 1; p++; } if (*re == '\0') a->u.r = NULL; else a->u.r = compile_re(re, icase); a->type = AT_RE; return (p); case '$': /* Last line */ a->type = AT_LAST; return (p + 1); case '+': /* Relative line number */ a->type = AT_RELLINE; p++; /* FALLTHROUGH */ /* Line number */ case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': if (a->type == 0) a->type = AT_LINE; a->u.l = strtol(p, &end, 10); return (end); default: errx(1, "%lu: %s: expected context address", linenum, fname); return (NULL); } } /* * duptoeol -- * Return a copy of all the characters up to \n or \0. */ static char * duptoeol(char *s, const char *ctype) { size_t len; int ws; char *p, *start; ws = 0; for (start = s; *s != '\0' && *s != '\n'; ++s) ws = isspace((unsigned char)*s); *s = '\0'; if (ws) warnx("%lu: %s: whitespace after %s", linenum, fname, ctype); len = s - start + 1; if ((p = malloc(len)) == NULL) err(1, "malloc"); return (memmove(p, start, len)); } /* * Convert goto label names to addresses, and count a and r commands, in * the given subset of the script. Free the memory used by labels in b * and t commands (but not by :). * * TODO: Remove } nodes */ static void fixuplabel(struct s_command *cp, struct s_command *end) { for (; cp != end; cp = cp->next) switch (cp->code) { case 'a': case 'r': appendnum++; break; case 'b': case 't': /* Resolve branch target. */ if (cp->t == NULL) { cp->u.c = NULL; break; } if ((cp->u.c = findlabel(cp->t)) == NULL) errx(1, "%lu: %s: undefined label '%s'", linenum, fname, cp->t); free(cp->t); break; case '{': /* Do interior commands. */ fixuplabel(cp->u.c, cp->next); break; } } /* * Associate the given command label for later lookup. */ static void enterlabel(struct s_command *cp) { struct labhash **lhp, *lh; u_char *p; u_int h, c; for (h = 0, p = (u_char *)cp->t; (c = *p) != 0; p++) h = (h << 5) + h + c; lhp = &labels[h & LHMASK]; for (lh = *lhp; lh != NULL; lh = lh->lh_next) if (lh->lh_hash == h && strcmp(cp->t, lh->lh_cmd->t) == 0) errx(1, "%lu: %s: duplicate label '%s'", linenum, fname, cp->t); if ((lh = malloc(sizeof *lh)) == NULL) err(1, "malloc"); lh->lh_next = *lhp; lh->lh_hash = h; lh->lh_cmd = cp; lh->lh_ref = 0; *lhp = lh; } /* * Find the label contained in the command l in the command linked * list cp. L is excluded from the search. Return NULL if not found. */ static struct s_command * findlabel(char *name) { struct labhash *lh; u_char *p; u_int h, c; for (h = 0, p = (u_char *)name; (c = *p) != 0; p++) h = (h << 5) + h + c; for (lh = labels[h & LHMASK]; lh != NULL; lh = lh->lh_next) { if (lh->lh_hash == h && strcmp(name, lh->lh_cmd->t) == 0) { lh->lh_ref = 1; return (lh->lh_cmd); } } return (NULL); } /* * Warn about any unused labels. As a side effect, release the label hash * table space. */ static void uselabel(void) { struct labhash *lh, *next; int i; for (i = 0; i < LHSZ; i++) { for (lh = labels[i]; lh != NULL; lh = next) { next = lh->lh_next; if (!lh->lh_ref) warnx("%lu: %s: unused label '%s'", linenum, fname, lh->lh_cmd->t); free(lh); } } }