[src/trunk]: src/usr.bin/make make(1): fix variable names in UnescapeBackslash

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

details:   https://anonhg.NetBSD.org/src/rev/d5c139b14a2f
branches:  trunk
changeset: 957961:d5c139b14a2f
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sat Dec 19 10:18:46 2020 +0000

description:
make(1): fix variable names in UnescapeBackslash

The previous variable names had been chosen at a time when compilers
didn't merge variables into the same registers.  Luckily, these times
are gone, and it's no longer necessary to use a variable for 2 or more
completely unrelated purposes.

diffstat:

 usr.bin/make/parse.c |  47 +++++++++++++++++++++++++----------------------
 1 files changed, 25 insertions(+), 22 deletions(-)

diffs (110 lines):

diff -r 2124f93edd8c -r d5c139b14a2f usr.bin/make/parse.c
--- a/usr.bin/make/parse.c      Sat Dec 19 09:02:32 2020 +0000
+++ b/usr.bin/make/parse.c      Sat Dec 19 10:18:46 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: parse.c,v 1.490 2020/12/19 00:27:34 rillig Exp $       */
+/*     $NetBSD: parse.c,v 1.491 2020/12/19 10:18:46 rillig Exp $       */
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
@@ -117,7 +117,7 @@
 #include "pathnames.h"
 
 /*     "@(#)parse.c    8.3 (Berkeley) 3/19/94" */
-MAKE_RCSID("$NetBSD: parse.c,v 1.490 2020/12/19 00:27:34 rillig Exp $");
+MAKE_RCSID("$NetBSD: parse.c,v 1.491 2020/12/19 10:18:46 rillig Exp $");
 
 /* types and constants */
 
@@ -2731,44 +2731,48 @@
        return TRUE;
 }
 
+/*
+ * Beginning at start, unescape '\#' to '#' and replace backslash-newline
+ * with a single space.
+ */
 static void
-UnescapeBackslash(char *escaped, char *const line)
+UnescapeBackslash(char *const line, char *start)
 {
-       char *tp, *ptr;
-
-       tp = ptr = escaped;
-       escaped = line;
+       char *src = start;
+       char *dst = start;
+       char *spaceStart = line;
+
        for (;;) {
-               char ch = *ptr++;
+               char ch = *src++;
                if (ch != '\\') {
                        if (ch == '\0')
                                break;
-                       *tp++ = ch;
+                       *dst++ = ch;
                        continue;
                }
 
-               ch = *ptr++;
+               ch = *src++;
                if (ch == '\0') {
                        /* Delete '\\' at end of buffer */
-                       tp--;
+                       dst--;
                        break;
                }
 
                /* Delete '\\' from before '#' on non-command lines */
                if (ch == '#' && line[0] != '\t') {
-                       *tp++ = ch;
+                       *dst++ = ch;
                        continue;
                }
 
                if (ch != '\n') {
                        /* Leave '\\' in buffer for later */
-                       *tp++ = '\\';
+                       *dst++ = '\\';
                        /*
                         * Make sure we don't delete an escaped ' ' from the
                         * line end.
                         */
-                       escaped = tp + 1;
-                       *tp++ = ch;
+                       spaceStart = dst + 1;
+                       *dst++ = ch;
                        continue;
                }
 
@@ -2776,15 +2780,14 @@
                 * Escaped '\n' -- replace following whitespace with a single
                 * ' '.
                 */
-               pp_skip_hspace(&ptr);
-               ch = ' ';
-               *tp++ = ch;
+               pp_skip_hspace(&src);
+               *dst++ = ' ';
        }
 
        /* Delete any trailing spaces - eg from empty continuations */
-       while (tp > escaped && ch_isspace(tp[-1]))
-               tp--;
-       *tp = '\0';
+       while (dst > spaceStart && ch_isspace(dst[-1]))
+               dst--;
+       *dst = '\0';
 }
 
 typedef enum GetLineMode {
@@ -2848,7 +2851,7 @@
                return line;
 
        /* Remove escapes from '\n' and '#' */
-       UnescapeBackslash(escaped, line);
+       UnescapeBackslash(line, escaped);
 
        return line;
 }