4.4BSD/usr/src/usr.bin/sed/compile.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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*/
#ifndef lint
static char sccsid[] = "@(#)compile.c 8.1 (Berkeley) 6/6/93";
#endif /* not lint */
#include <sys/types.h>
#include <sys/stat.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <regex.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.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 __P((char *, struct s_addr *));
static char *compile_delimited __P((char *, char *));
static char *compile_flags __P((char *, struct s_subst *));
static char *compile_re __P((char *, regex_t **));
static char *compile_subst __P((char *, struct s_subst *));
static char *compile_text __P((void));
static char *compile_tr __P((char *, char **));
static struct s_command
**compile_stream __P((char *, struct s_command **, char *));
static char *duptoeol __P((char *, char *));
static void enterlabel __P((struct s_command *));
static struct s_command
*findlabel __P((char *));
static void fixuplabel __P((struct s_command *, struct s_command *));
static void uselabel __P((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},
{'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()
{
*compile_stream(NULL, &prog, NULL) = NULL;
fixuplabel(prog, NULL);
uselabel();
appends = xmalloc(sizeof(struct s_appends) * appendnum);
match = xmalloc((maxnsub + 1) * sizeof(regmatch_t));
}
#define EATSPACE() do { \
if (p) \
while (*p && isascii(*p) && isspace(*p)) \
p++; \
} while (0)
static struct s_command **
compile_stream(terminator, link, p)
char *terminator;
struct s_command **link;
register char *p;
{
static char lbuf[_POSIX2_LINE_MAX + 1]; /* To save stack */
struct s_command *cmd, *cmd2;
struct s_format *fp;
int naddr; /* Number of addresses */
if (p != NULL)
goto semicolon;
for (;;) {
if ((p = cu_fgets(lbuf, sizeof(lbuf))) == NULL) {
if (terminator != NULL)
err(COMPILE, "unexpected EOF (pending }'s)");
return (link);
}
semicolon: EATSPACE();
if (p && (*p == '#' || *p == '\0'))
continue;
if (*p == '}') {
if (terminator == NULL)
err(COMPILE, "unexpected }");
return (link);
}
*link = cmd = xmalloc(sizeof(struct s_command));
link = &cmd->next;
cmd->nonsel = cmd->inrange = 0;
/* First parse the addresses */
naddr = 0;
cmd->a1 = cmd->a2 = NULL;
/* Valid characters to start an address */
#define addrchar(c) (strchr("0123456789/\\$", (c)))
if (addrchar(*p)) {
naddr++;
cmd->a1 = xmalloc(sizeof(struct s_addr));
p = compile_addr(p, cmd->a1);
EATSPACE(); /* EXTENSION */
if (*p == ',') {
naddr++;
p++;
EATSPACE(); /* EXTENSION */
cmd->a2 = xmalloc(sizeof(struct s_addr));
p = compile_addr(p, cmd->a2);
}
}
nonsel: /* Now parse the command */
EATSPACE();
if (!*p)
err(COMPILE, "command expected");
cmd->code = *p;
for (fp = cmd_fmts; fp->code; fp++)
if (fp->code == *p)
break;
if (!fp->code)
err(COMPILE, "invalid command code %c", *p);
if (naddr > fp->naddr)
err(COMPILE,
"command %c expects up to %d address(es), found %d", *p, fp->naddr, naddr);
switch (fp->args) {
case NONSEL: /* ! */
cmd->nonsel = ! cmd->nonsel;
p++;
goto nonsel;
case GROUP: /* { */
p++;
EATSPACE();
if (!*p)
p = NULL;
cmd2 = xmalloc(sizeof(struct s_command));
cmd2->code = '}';
*compile_stream("}", &cmd->u.c, p) = cmd2;
cmd->next = cmd2;
link = &cmd2->next;
break;
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)
err(COMPILE,
"extra characters at the end of %c command", cmd->code);
break;
case TEXT: /* a c i */
p++;
EATSPACE();
if (*p != '\\')
err(COMPILE,
"command %c expects \\ followed by text", cmd->code);
p++;
EATSPACE();
if (*p)
err(COMPILE,
"extra characters after \\ at the end of %c command", cmd->code);
cmd->t = compile_text();
break;
case COMMENT: /* \0 # */
break;
case WFILE: /* w */
p++;
EATSPACE();
if (*p == '\0')
err(COMPILE, "filename expected");
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(FATAL, "%s: %s\n", p, strerror(errno));
break;
case RFILE: /* r */
p++;
EATSPACE();
if (*p == '\0')
err(COMPILE, "filename expected");
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)
err(COMPILE, "empty label");
enterlabel(cmd);
break;
case SUBST: /* s */
p++;
if (*p == '\0' || *p == '\\')
err(COMPILE,
"substitute pattern can not be delimited by newline or backslash");
cmd->u.s = xmalloc(sizeof(struct s_subst));
p = compile_re(p, &cmd->u.s->re);
if (p == NULL)
err(COMPILE, "unterminated substitute pattern");
--p;
p = compile_subst(p, cmd->u.s);
p = compile_flags(p, cmd->u.s);
EATSPACE();
if (*p == ';') {
p++;
link = &cmd->next;
goto semicolon;
}
break;
case TR: /* y */
p++;
p = compile_tr(p, (char **)&cmd->u.y);
EATSPACE();
if (*p == ';') {
p++;
link = &cmd->next;
goto semicolon;
}
if (*p)
err(COMPILE,
"extra text at the end of a transform command");
break;
}
}
}
/*
* Get a delimited string. P points to the delimeter 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(p, d)
char *p, *d;
{
char c;
c = *p++;
if (c == '\0')
return (NULL);
else if (c == '\\')
err(COMPILE, "\\ can not be used as a string delimiter");
else if (c == '\n')
err(COMPILE, "newline can not be used as a string delimiter");
while (*p) {
if (*p == '\\' && p[1] == c)
p++;
else if (*p == '\\' && p[1] == 'n') {
*d++ = '\n';
p += 2;
continue;
} else if (*p == '\\' && p[1] == '\\')
*d++ = *p++;
else if (*p == c) {
*d = '\0';
return (p + 1);
}
*d++ = *p++;
}
return (NULL);
}
/*
* Get a regular expression. P points to the delimiter of the regular
* expression; repp points to the address of a regexp pointer. 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 regular expression. The regexp
* pointer is set to the compiled regular expression.
* Cflags are passed to regcomp.
*/
static char *
compile_re(p, repp)
char *p;
regex_t **repp;
{
int eval;
char re[_POSIX2_LINE_MAX + 1];
p = compile_delimited(p, re);
if (p && strlen(re) == 0) {
*repp = NULL;
return (p);
}
*repp = xmalloc(sizeof(regex_t));
if (p && (eval = regcomp(*repp, re, 0)) != 0)
err(COMPILE, "RE error: %s", strregerror(eval, *repp));
if (maxnsub < (*repp)->re_nsub)
maxnsub = (*repp)->re_nsub;
return (p);
}
/*
* 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(p, s)
char *p;
struct s_subst *s;
{
static char lbuf[_POSIX2_LINE_MAX + 1];
int asize, ref, size;
char c, *text, *op, *sp;
c = *p++; /* Terminator character */
if (c == '\0')
return (NULL);
s->maxbref = 0;
s->linenum = linenum;
asize = 2 * _POSIX2_LINE_MAX + 1;
text = xmalloc(asize);
size = 0;
do {
op = sp = text + size;
for (; *p; p++) {
if (*p == '\\') {
p++;
if (strchr("123456789", *p) != NULL) {
*sp++ = '\\';
ref = *p - '0';
if (s->re != NULL &&
ref > s->re->re_nsub)
err(COMPILE,
"\\%c not defined in the RE", *p);
if (s->maxbref < ref)
s->maxbref = ref;
} else if (*p == '&' || *p == '\\')
*sp++ = '\\';
} else if (*p == c) {
p++;
*sp++ = '\0';
size += sp - op;
s->new = xrealloc(text, size);
return (p);
} else if (*p == '\n') {
err(COMPILE,
"unescaped newline inside substitute pattern");
/* NOTREACHED */
}
*sp++ = *p;
}
size += sp - op;
if (asize - size < _POSIX2_LINE_MAX + 1) {
asize *= 2;
text = xmalloc(asize);
}
} while (cu_fgets(p = lbuf, sizeof(lbuf)));
err(COMPILE, "unterminated substitute in regular expression");
/* NOTREACHED */
}
/*
* Compile the flags of the s command
*/
static char *
compile_flags(p, s)
char *p;
struct s_subst *s;
{
int gn; /* True if we have seen g or n */
char wfile[_POSIX2_LINE_MAX + 1], *q;
s->n = 1; /* Default */
s->p = 0;
s->wfile = NULL;
s->wfd = -1;
for (gn = 0;;) {
EATSPACE(); /* EXTENSION */
switch (*p) {
case 'g':
if (gn)
err(COMPILE,
"more than one number or 'g' in substitute flags");
gn = 1;
s->n = 0;
break;
case '\0':
case '\n':
case ';':
return (p);
case 'p':
s->p = 1;
break;
case '1': case '2': case '3':
case '4': case '5': case '6':
case '7': case '8': case '9':
if (gn)
err(COMPILE,
"more than one number or 'g' in substitute flags");
gn = 1;
/* XXX Check for overflow */
s->n = (int)strtol(p, &p, 10);
break;
case 'w':
p++;
#ifdef HISTORIC_PRACTICE
if (*p != ' ') {
err(WARNING, "space missing before w wfile");
return (p);
}
#endif
EATSPACE();
q = wfile;
while (*p) {
if (*p == '\n')
break;
*q++ = *p++;
}
*q = '\0';
if (q == wfile)
err(COMPILE, "no wfile specified");
s->wfile = strdup(wfile);
if (!aflag && (s->wfd = open(wfile,
O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
DEFFILEMODE)) == -1)
err(FATAL, "%s: %s\n", wfile, strerror(errno));
return (p);
default:
err(COMPILE,
"bad flag in substitute command: '%c'", *p);
break;
}
p++;
}
}
/*
* Compile a translation set of strings into a lookup table.
*/
static char *
compile_tr(p, transtab)
char *p;
char **transtab;
{
int i;
char *lt, *op, *np;
char old[_POSIX2_LINE_MAX + 1];
char new[_POSIX2_LINE_MAX + 1];
if (*p == '\0' || *p == '\\')
err(COMPILE,
"transform pattern can not be delimited by newline or backslash");
p = compile_delimited(p, old);
if (p == NULL) {
err(COMPILE, "unterminated transform source string");
return (NULL);
}
p = compile_delimited(--p, new);
if (p == NULL) {
err(COMPILE, "unterminated transform target string");
return (NULL);
}
EATSPACE();
if (strlen(new) != strlen(old)) {
err(COMPILE, "transform strings are not the same length");
return (NULL);
}
/* We assume characters are 8 bits */
lt = xmalloc(UCHAR_MAX);
for (i = 0; i <= UCHAR_MAX; i++)
lt[i] = (char)i;
for (op = old, np = new; *op; op++, np++)
lt[(u_char)*op] = *np;
*transtab = lt;
return (p);
}
/*
* Compile the text following an a or i command.
*/
static char *
compile_text()
{
int asize, size;
char *text, *p, *op, *s;
char lbuf[_POSIX2_LINE_MAX + 1];
asize = 2 * _POSIX2_LINE_MAX + 1;
text = xmalloc(asize);
size = 0;
while (cu_fgets(lbuf, sizeof(lbuf))) {
op = s = text + size;
p = lbuf;
EATSPACE();
for (; *p; p++) {
if (*p == '\\')
p++;
*s++ = *p;
}
size += s - op;
if (p[-2] != '\\') {
*s = '\0';
break;
}
if (asize - size < _POSIX2_LINE_MAX + 1) {
asize *= 2;
text = xmalloc(asize);
}
}
return (xrealloc(text, size + 1));
}
/*
* 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(p, a)
char *p;
struct s_addr *a;
{
char *end;
switch (*p) {
case '\\': /* Context address */
++p;
/* FALLTHROUGH */
case '/': /* Context address */
p = compile_re(p, &a->u.r);
if (p == NULL)
err(COMPILE, "unterminated regular expression");
a->type = AT_RE;
return (p);
case '$': /* Last line */
a->type = AT_LAST;
return (p + 1);
/* Line number */
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
a->type = AT_LINE;
a->u.l = strtol(p, &end, 10);
return (end);
default:
err(COMPILE, "expected context address");
return (NULL);
}
}
/*
* duptoeol --
* Return a copy of all the characters up to \n or \0.
*/
static char *
duptoeol(s, ctype)
register char *s;
char *ctype;
{
size_t len;
int ws;
char *start;
ws = 0;
for (start = s; *s != '\0' && *s != '\n'; ++s)
ws = isspace(*s);
*s = '\0';
if (ws)
err(WARNING, "whitespace after %s", ctype);
len = s - start + 1;
return (memmove(xmalloc(len), 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(cp, end)
struct s_command *cp, *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)
err(COMPILE2, "undefined label '%s'", 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(cp)
struct s_command *cp;
{
register struct labhash **lhp, *lh;
register u_char *p;
register 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)
err(COMPILE2, "duplicate label '%s'", cp->t);
lh = xmalloc(sizeof *lh);
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(name)
char *name;
{
register struct labhash *lh;
register u_char *p;
register 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()
{
register struct labhash *lh, *next;
register int i;
for (i = 0; i < LHSZ; i++) {
for (lh = labels[i]; lh != NULL; lh = next) {
next = lh->lh_next;
if (!lh->lh_ref)
err(WARNING, "unused label '%s'",
lh->lh_cmd->t);
free(lh);
}
}
}