[src/trunk]: src/usr.bin/make Avoid calling brk_string() and hence Var_Export...

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

details:   https://anonhg.NetBSD.org/src/rev/fc272afaaeaa
branches:  trunk
changeset: 341964:fc272afaaeaa
user:      sjg <sjg%NetBSD.org@localhost>
date:      Tue Dec 01 07:26:08 2015 +0000

description:
Avoid calling brk_string() and hence Var_Export1() on
empty strings.

diffstat:

 usr.bin/make/var.c |  70 ++++++++++++++++++++++++++++-------------------------
 1 files changed, 37 insertions(+), 33 deletions(-)

diffs (110 lines):

diff -r 70b16f9c3e92 -r fc272afaaeaa usr.bin/make/var.c
--- a/usr.bin/make/var.c        Tue Dec 01 02:21:17 2015 +0000
+++ b/usr.bin/make/var.c        Tue Dec 01 07:26:08 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: var.c,v 1.199 2015/10/20 21:30:57 sjg Exp $    */
+/*     $NetBSD: var.c,v 1.200 2015/12/01 07:26:08 sjg Exp $    */
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
@@ -69,14 +69,14 @@
  */
 
 #ifndef MAKE_NATIVE
-static char rcsid[] = "$NetBSD: var.c,v 1.199 2015/10/20 21:30:57 sjg Exp $";
+static char rcsid[] = "$NetBSD: var.c,v 1.200 2015/12/01 07:26:08 sjg 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 1.199 2015/10/20 21:30:57 sjg Exp $");
+__RCSID("$NetBSD: var.c,v 1.200 2015/12/01 07:26:08 sjg Exp $");
 #endif
 #endif /* not lint */
 #endif
@@ -702,13 +702,15 @@
        int i;
 
        val = Var_Subst(NULL, tmp, VAR_GLOBAL, FALSE, TRUE);
-       av = brk_string(val, &ac, FALSE, &as);
-       for (i = 0; i < ac; i++) {
-           Var_Export1(av[i], 0);
+       if (*val) {
+           av = brk_string(val, &ac, FALSE, &as);
+           for (i = 0; i < ac; i++) {
+               Var_Export1(av[i], 0);
+           }
+           free(as);
+           free(av);
        }
        free(val);
-       free(as);
-       free(av);
     }
 }
 
@@ -740,35 +742,37 @@
        track = VAR_EXPORT_PARENT;
     }
     val = Var_Subst(NULL, str, VAR_GLOBAL, FALSE, TRUE);
-    av = brk_string(val, &ac, FALSE, &as);
-    for (i = 0; i < ac; i++) {
-       name = av[i];
-       if (!name[1]) {
-           /*
-            * A single char.
-            * If it is one of the vars that should only appear in
-            * local context, skip it, else we can get Var_Subst
-            * into a loop.
-            */
-           switch (name[0]) {
-           case '@':
-           case '%':
-           case '*':
-           case '!':
-               continue;
+    if (*val) {
+       av = brk_string(val, &ac, FALSE, &as);
+       for (i = 0; i < ac; i++) {
+           name = av[i];
+           if (!name[1]) {
+               /*
+                * A single char.
+                * If it is one of the vars that should only appear in
+                * local context, skip it, else we can get Var_Subst
+                * into a loop.
+                */
+               switch (name[0]) {
+               case '@':
+               case '%':
+               case '*':
+               case '!':
+                   continue;
+               }
+           }
+           if (Var_Export1(name, track)) {
+               if (VAR_EXPORTED_ALL != var_exportedVars)
+                   var_exportedVars = VAR_EXPORTED_YES;
+               if (isExport && track) {
+                   Var_Append(MAKE_EXPORTED, name, VAR_GLOBAL);
+               }
            }
        }
-       if (Var_Export1(name, track)) {
-           if (VAR_EXPORTED_ALL != var_exportedVars)
-               var_exportedVars = VAR_EXPORTED_YES;
-           if (isExport && track) {
-               Var_Append(MAKE_EXPORTED, name, VAR_GLOBAL);
-           }
-       }
+       free(as);
+       free(av);
     }
     free(val);
-    free(as);
-    free(av);
 }