Hello,
In yacc the dup_line() function malloc()'ed a buffer and copied
a line into it. The copied line includes \n.
Allocate-and-copy can be done by strndup() in one hit.
I ran this on i386 with awk/awkgram.y and rcs/date.y and didn't
see any difference in y.tab.c compared to the system's yacc.
- Michael
Index: reader.c
===================================================================
RCS file: /cvs/src/usr.bin/yacc/reader.c,v
retrieving revision 1.34
diff -u -p -u -r1.34 reader.c
--- reader.c 25 May 2017 20:11:03 -0000 1.34
+++ reader.c 3 Nov 2017 07:48:08 -0000
@@ -171,21 +171,17 @@ get_line(void)
char *
dup_line(void)
{
- char *p, *s, *t;
+ char *p, *end;
+ size_t len;
if (line == NULL)
- return (0);
- s = line;
- while (*s != '\n')
- ++s;
- p = malloc(s - line + 1);
+ return (NULL);
+ end = strchr(line, '\n');
+ assert(end != NULL);
+ len = end - line + 1;
+ p = strndup(line, len);
if (p == NULL)
no_space();
-
- s = line;
- t = p;
- while ((*t++ = *s++) != '\n')
- continue;
return (p);
}
