[src/trunk]: src/usr.bin/make make(1): clean up code for subexpressions in th...

[rillig <rillig%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/b1b61352a272
branches:  trunk
changeset: 936960:b1b61352a272
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sun Aug 09 15:07:13 2020 +0000

description:
make(1): clean up code for subexpressions in the :C modifier

An ampersand in the replacement string can never produce an
out-of-bounds error or an undefined-subexpression error.  This makes the
error message simpler since it only needs to cover the case of a single
digit.

diffstat:

 usr.bin/make/var.c |  46 ++++++++++++++++++++++------------------------
 1 files changed, 22 insertions(+), 24 deletions(-)

diffs (82 lines):

diff -r 4583fee3afb8 -r b1b61352a272 usr.bin/make/var.c
--- a/usr.bin/make/var.c        Sun Aug 09 15:03:25 2020 +0000
+++ b/usr.bin/make/var.c        Sun Aug 09 15:07:13 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: var.c,v 1.444 2020/08/09 14:30:35 rillig Exp $ */
+/*     $NetBSD: var.c,v 1.445 2020/08/09 15:07:13 rillig Exp $ */
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
@@ -69,14 +69,14 @@
  */
 
 #ifndef MAKE_NATIVE
-static char rcsid[] = "$NetBSD: var.c,v 1.444 2020/08/09 14:30:35 rillig Exp $";
+static char rcsid[] = "$NetBSD: var.c,v 1.445 2020/08/09 15:07:13 rillig Exp $";
 #else
 #include <sys/cdefs.h>
 #ifndef lint
 #if 0
 static char sccsid[] = "@(#)var.c      8.3 (Berkeley) 3/19/94";
 #else
-__RCSID("$NetBSD: var.c,v 1.444 2020/08/09 14:30:35 rillig Exp $");
+__RCSID("$NetBSD: var.c,v 1.445 2020/08/09 15:07:13 rillig Exp $");
 #endif
 #endif /* not lint */
 #endif
@@ -1384,36 +1384,34 @@
            if (*rp == '\\' && (rp[1] == '&' || rp[1] == '\\')) {
                SepBuf_AddBytes(buf, rp + 1, 1);
                rp++;
-           } else if (*rp == '&' ||
-                      (*rp == '\\' && isdigit((unsigned char)rp[1]))) {
-               int n;
-               char errstr[3];
-
-               if (*rp == '&') {
-                   n = 0;
-                   errstr[0] = '&';
-                   errstr[1] = '\0';
-               } else {
-                   n = rp[1] - '0';
-                   errstr[0] = '\\';
-                   errstr[1] = rp[1];
-                   errstr[2] = '\0';
-                   rp++;
-               }
+               continue;
+           }
+
+           if (*rp == '&') {
+               SepBuf_AddBytesBetween(buf, wp + m[0].rm_so, wp + m[0].rm_eo);
+               continue;
+           }
+
+           if (*rp != '\\' || !isdigit((unsigned char)rp[1])) {
+               SepBuf_AddBytes(buf, rp, 1);
+               continue;
+           }
+
+           {                   /* \0 to \9 backreference */
+               int n = rp[1] - '0';
+               rp++;
 
                if (n >= args->nsub) {
-                   Error("No subexpression %s", errstr);
+                   Error("No subexpression \\%d", n);
                } else if (m[n].rm_so == -1 && m[n].rm_eo == -1) {
-                   Error("No match for subexpression %s", errstr);
+                   Error("No match for subexpression \\%d", n);
                } else {
                    SepBuf_AddBytesBetween(buf, wp + m[n].rm_so,
                                           wp + m[n].rm_eo);
                }
-
-           } else {
-               SepBuf_AddBytes(buf, rp, 1);
            }
        }
+
        wp += m[0].rm_eo;
        if (args->pflags & VARP_SUB_GLOBAL) {
            flags |= REG_NOTBOL;