Module Name: src
Committed By: rillig
Date: Sat Aug 1 13:35:13 UTC 2020
Modified Files:
src/usr.bin/make: var.c
src/usr.bin/make/unit-tests: sysv.mk
Log Message:
make(1): reduce the number of string comparisons in ${VAR:%.c=%.o}
There is only a single position in the word where the tail ".c" can
match, since it is implicitly anchored at the end. Therefore there's no
need to do several string comparisons.
To generate a diff of this commit:
cvs rdiff -u -r1.377 -r1.378 src/usr.bin/make/var.c
cvs rdiff -u -r1.11 -r1.12 src/usr.bin/make/unit-tests/sysv.mk
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/usr.bin/make/var.c
diff -u src/usr.bin/make/var.c:1.377 src/usr.bin/make/var.c:1.378
--- src/usr.bin/make/var.c:1.377 Sat Aug 1 13:16:29 2020
+++ src/usr.bin/make/var.c Sat Aug 1 13:35:13 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: var.c,v 1.377 2020/08/01 13:16:29 rillig Exp $ */
+/* $NetBSD: var.c,v 1.378 2020/08/01 13:35:13 rillig Exp $ */
/*
* Copyright (c) 1988, 1989, 1990, 1993
@@ -69,14 +69,14 @@
*/
#ifndef MAKE_NATIVE
-static char rcsid[] = "$NetBSD: var.c,v 1.377 2020/08/01 13:16:29 rillig Exp $";
+static char rcsid[] = "$NetBSD: var.c,v 1.378 2020/08/01 13:35:13 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 1.377 2020/08/01 13:16:29 rillig Exp $");
+__RCSID("$NetBSD: var.c,v 1.378 2020/08/01 13:35:13 rillig Exp $");
#endif
#endif /* not lint */
#endif
@@ -1205,19 +1205,18 @@ Str_SYSVMatch(const char *word, const ch
}
}
- const char *suffix = w;
+ /* Test whether the tail matches */
+ size_t w_len = strlen(w);
+ size_t p_len = strlen(p);
+ if (w_len < p_len)
+ return NULL;
- /* Find a matching tail */
- /* XXX: This loop should not be necessary since there is only one
- * possible position where strcmp could ever return 0. */
- do {
- if (strcmp(p, w) == 0) {
- *match_len = w - suffix;
- return suffix;
- }
- } while (*w++ != '\0');
+ const char *w_tail = w + w_len - p_len;
+ if (memcmp(p, w_tail, p_len) != 0)
+ return NULL;
- return NULL;
+ *match_len = w_tail - w;
+ return w;
}
Index: src/usr.bin/make/unit-tests/sysv.mk
diff -u src/usr.bin/make/unit-tests/sysv.mk:1.11 src/usr.bin/make/unit-tests/sysv.mk:1.12
--- src/usr.bin/make/unit-tests/sysv.mk:1.11 Sat Aug 1 12:47:56 2020
+++ src/usr.bin/make/unit-tests/sysv.mk Sat Aug 1 13:35:13 2020
@@ -1,4 +1,4 @@
-# $Id: sysv.mk,v 1.11 2020/08/01 12:47:56 rillig Exp $
+# $Id: sysv.mk,v 1.12 2020/08/01 13:35:13 rillig Exp $
all: foo fun sam bla words ampersand anchor-dollar
all: mismatch
@@ -87,8 +87,10 @@ EXPR.7= ${LIST:o%%e=X} # Only the first
EXP.7= one two # None of the words contains a literal '%'.
EXPR.8= ${LIST:%=%%}
EXP.8= one% two%
+EXPR.9= ${LIST:%nes=%xxx} # lhs is longer than the word "one"
+EXP.9= one two
-.for i in ${:U:range=8}
+.for i in ${:U:range=9}
.if ${EXPR.$i} != ${EXP.$i}
.warning test case $i expected "${EXP.$i}", got "${EXPR.$i}
.endif
