Author: pfg
Date: Tue May 24 03:08:32 2016
New Revision: 300555
URL: https://svnweb.freebsd.org/changeset/base/300555
Log:
sed: rewrite the main loop.
Rewrite the main loop of the "sed s/..." command, shortening it by ten
lines and simplifying it by removing the switch statement implementing
/g, /1, and /2 separately and repetitively.
This will be needed to bring a fix from OpenBSD later.
Obtained from: OpenBSD (schwarze CVS Rev. 1.18)
Modified:
stable/10/usr.bin/sed/process.c
Directory Properties:
stable/10/ (props changed)
Modified: stable/10/usr.bin/sed/process.c
==============================================================================
--- stable/10/usr.bin/sed/process.c Tue May 24 03:00:24 2016
(r300554)
+++ stable/10/usr.bin/sed/process.c Tue May 24 03:08:32 2016
(r300555)
@@ -369,7 +369,7 @@ substitute(struct s_command *cp)
{
SPACE tspace;
regex_t *re;
- regoff_t re_off, slen;
+ regoff_t slen;
int lastempty, n;
char *s;
@@ -390,61 +390,55 @@ substitute(struct s_command *cp)
n = cp->u.s->n;
lastempty = 1;
- switch (n) {
- case 0: /* Global */
- do {
- if (lastempty || match[0].rm_so != match[0].rm_eo) {
- /* Locate start of replaced string. */
- re_off = match[0].rm_so;
- /* Copy leading retained string. */
- cspace(&SS, s, re_off, APPEND);
- /* Add in regular expression. */
+ do {
+ /* Copy the leading retained string. */
+ if (n <= 1 && match[0].rm_so)
+ cspace(&SS, s, match[0].rm_so, APPEND);
+
+ /* Skip zero-length matches right after other matches. */
+ if (lastempty || match[0].rm_so ||
+ match[0].rm_so != match[0].rm_eo) {
+ if (n <= 1) {
+ /* Want this match: append replacement. */
regsub(&SS, s, cp->u.s->new);
- }
-
- /* Move past this match. */
- if (match[0].rm_so != match[0].rm_eo) {
- s += match[0].rm_eo;
- slen -= match[0].rm_eo;
- lastempty = 0;
+ if (n == 1)
+ n = -1;
} else {
- if (match[0].rm_so < slen)
- cspace(&SS, s + match[0].rm_so, 1,
- APPEND);
- s += match[0].rm_so + 1;
- slen -= match[0].rm_so + 1;
- lastempty = 1;
+ /* Want a later match: append original. */
+ if (match[0].rm_eo)
+ cspace(&SS, s, match[0].rm_eo, APPEND);
+ n--;
}
- } while (slen >= 0 && regexec_e(re, s, REG_NOTBOL, 0, slen));
- /* Copy trailing retained string. */
- if (slen > 0)
- cspace(&SS, s, slen, APPEND);
- break;
- default: /* Nth occurrence */
- while (--n) {
- if (match[0].rm_eo == match[0].rm_so)
- match[0].rm_eo = match[0].rm_so + 1;
- s += match[0].rm_eo;
- slen -= match[0].rm_eo;
- if (slen < 0)
- return (0);
- if (!regexec_e(re, s, REG_NOTBOL, 0, slen))
- return (0);
}
- /* FALLTHROUGH */
- case 1: /* 1st occurrence */
- /* Locate start of replaced string. */
- re_off = match[0].rm_so + (s - ps);
- /* Copy leading retained string. */
- cspace(&SS, ps, re_off, APPEND);
- /* Add in regular expression. */
- regsub(&SS, s, cp->u.s->new);
- /* Copy trailing retained string. */
+
+ /* Move past this match. */
s += match[0].rm_eo;
slen -= match[0].rm_eo;
+
+ /*
+ * After a zero-length match, advance one byte,
+ * and at the end of the line, terminate.
+ */
+ if (match[0].rm_so == match[0].rm_eo) {
+ if (*s == '\0' || *s == '\n')
+ slen = -1;
+ else
+ slen--;
+ if (*s != '\0')
+ cspace(&SS, s++, 1, APPEND);
+ lastempty = 1;
+ } else
+ lastempty = 0;
+
+ } while (n >= 0 && slen >= 0 && regexec_e(re, s, REG_NOTBOL, 0, slen));
+
+ /* Did not find the requested number of matches. */
+ if (n > 1)
+ return (0);
+
+ /* Copy the trailing retained string. */
+ if (slen > 0)
cspace(&SS, s, slen, APPEND);
- break;
- }
/*
* Swap the substitute space and the pattern space, and make sure
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