freebsd-dev/usr.bin/sed/compile.c
Warner Losh fbbd9655e5 Renumber copyright clause 4
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by:	Jan Schaumann <jschauma@stevens.edu>
Pull Request:	https://github.com/freebsd/freebsd/pull/96
2017-02-28 23:42:47 +00:00

953 lines
22 KiB
C

/*-
* 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>
__FBSDID("$FreeBSD$");
#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 <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;
}
}
}
/*
* 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)
{
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 ((d = compile_ccl(&p, d)) == NULL)
errx(1, "%lu: %s: unbalanced brackets ([])", linenum, fname);
continue;
} else if (*p == '\\' && p[1] == '[') {
*d++ = *p++;
} else if (*p == '\\' && p[1] == c)
p++;
else if (*p == '\\' && p[1] == 'n') {
*d++ = '\n';
p += 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;
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;
}
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, 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 if (*p == '&' || *p == '\\')
*sp++ = '\\';
} 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);
}
}
}