[src/trunk]: src/usr.bin/make make(1): inline call to strchr in ValidShortVar...

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

details:   https://anonhg.NetBSD.org/src/rev/544843d9f1d1
branches:  trunk
changeset: 954903:544843d9f1d1
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sun Sep 13 08:11:40 2020 +0000

description:
make(1): inline call to strchr in ValidShortVarname

It's a pity that neither GCC 5 nor GCC 10 nor Clang 9 inline this code
themselves, even though it would be easy to do.

Clang 9 at least replaces strchr with memchr, but that is still too
complicated for a simple "is this character one of these" question.

For a repeated "if (varname != ...)" instead of the switch, GCC 10
generates really boring and inefficient code, even though it is easy to
see that the order of the comparisons doesn't matter.

diffstat:

 usr.bin/make/var.c |  18 +++++++++++++-----
 1 files changed, 13 insertions(+), 5 deletions(-)

diffs (45 lines):

diff -r 2753232a09a9 -r 544843d9f1d1 usr.bin/make/var.c
--- a/usr.bin/make/var.c        Sun Sep 13 07:42:20 2020 +0000
+++ b/usr.bin/make/var.c        Sun Sep 13 08:11:40 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: var.c,v 1.507 2020/09/13 07:42:20 rillig Exp $ */
+/*     $NetBSD: var.c,v 1.508 2020/09/13 08:11:40 rillig Exp $ */
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
@@ -69,14 +69,14 @@
  */
 
 #ifndef MAKE_NATIVE
-static char rcsid[] = "$NetBSD: var.c,v 1.507 2020/09/13 07:42:20 rillig Exp $";
+static char rcsid[] = "$NetBSD: var.c,v 1.508 2020/09/13 08:11:40 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 1.507 2020/09/13 07:42:20 rillig Exp $");
+__RCSID("$NetBSD: var.c,v 1.508 2020/09/13 08:11:40 rillig Exp $");
 #endif
 #endif /* not lint */
 #endif
@@ -3372,8 +3372,16 @@
 static Boolean
 ValidShortVarname(char varname, const char *start)
 {
-    if (varname != '\0' && strchr(")}:$", varname) == NULL)
-       return TRUE;
+    switch (varname) {
+    case '\0':
+    case ')':
+    case '}':
+    case ':':
+    case '$':
+       break;
+    default:
+        return TRUE;
+    }
 
     if (!DEBUG(LINT))
        return FALSE;