[src/trunk]: src/usr.bin/make make(1): make :hash modifier more efficient

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

details:   https://anonhg.NetBSD.org/src/rev/9021fec05f69
branches:  trunk
changeset: 936736:9021fec05f69
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sun Aug 02 19:49:17 2020 +0000

description:
make(1): make :hash modifier more efficient

It's not necessary to allocate a 256-byte buffer just to store 9 bytes
in it, and to null-terminate it after writing every single byte to it.

diffstat:

 usr.bin/make/var.c |  18 +++++++++---------
 1 files changed, 9 insertions(+), 9 deletions(-)

diffs (47 lines):

diff -r d7e3951347e6 -r 9021fec05f69 usr.bin/make/var.c
--- a/usr.bin/make/var.c        Sun Aug 02 19:11:57 2020 +0000
+++ b/usr.bin/make/var.c        Sun Aug 02 19:49:17 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: var.c,v 1.404 2020/08/02 19:11:57 rillig Exp $ */
+/*     $NetBSD: var.c,v 1.405 2020/08/02 19:49:17 rillig Exp $ */
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
@@ -69,14 +69,14 @@
  */
 
 #ifndef MAKE_NATIVE
-static char rcsid[] = "$NetBSD: var.c,v 1.404 2020/08/02 19:11:57 rillig Exp $";
+static char rcsid[] = "$NetBSD: var.c,v 1.405 2020/08/02 19:49:17 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 1.404 2020/08/02 19:11:57 rillig Exp $");
+__RCSID("$NetBSD: var.c,v 1.405 2020/08/02 19:49:17 rillig Exp $");
 #endif
 #endif /* not lint */
 #endif
@@ -1815,14 +1815,14 @@
     h *= 0xc2b2ae35;
     h ^= h >> 16;
 
-    Buffer buf;
-    Buf_InitZ(&buf, 0);
-    for (len = 0; len < 8; ++len) {
-       Buf_AddByte(&buf, hexdigits[h & 15]);
+    char *buf = bmake_malloc(9);
+    size_t i;
+    for (i = 0; i < 8; i++) {
+       buf[i] = hexdigits[h & 0x0f];
        h >>= 4;
     }
-
-    return Buf_Destroy(&buf, FALSE);
+    buf[8] = '\0';
+    return buf;
 }
 
 static char *