Module Name: src
Committed By: rillig
Date: Sat Aug 22 21:12:29 UTC 2020
Modified Files:
src/usr.bin/make: parse.c
src/usr.bin/make/unit-tests: varname-empty.mk
Log Message:
make(1): fix undefined behavior when assigning to variable ""
Using a programming language with built-in array bounds checks would
have prevented this bug, and many others as well.
To generate a diff of this commit:
cvs rdiff -u -r1.258 -r1.259 src/usr.bin/make/parse.c
cvs rdiff -u -r1.3 -r1.4 src/usr.bin/make/unit-tests/varname-empty.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/parse.c
diff -u src/usr.bin/make/parse.c:1.258 src/usr.bin/make/parse.c:1.259
--- src/usr.bin/make/parse.c:1.258 Sat Aug 22 17:34:25 2020
+++ src/usr.bin/make/parse.c Sat Aug 22 21:12:29 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: parse.c,v 1.258 2020/08/22 17:34:25 rillig Exp $ */
+/* $NetBSD: parse.c,v 1.259 2020/08/22 21:12:29 rillig Exp $ */
/*
* Copyright (c) 1988, 1989, 1990, 1993
@@ -69,14 +69,14 @@
*/
#ifndef MAKE_NATIVE
-static char rcsid[] = "$NetBSD: parse.c,v 1.258 2020/08/22 17:34:25 rillig Exp $";
+static char rcsid[] = "$NetBSD: parse.c,v 1.259 2020/08/22 21:12:29 rillig Exp $";
#else
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)parse.c 8.3 (Berkeley) 3/19/94";
#else
-__RCSID("$NetBSD: parse.c,v 1.258 2020/08/22 17:34:25 rillig Exp $");
+__RCSID("$NetBSD: parse.c,v 1.259 2020/08/22 21:12:29 rillig Exp $");
#endif
#endif /* not lint */
#endif
@@ -1876,7 +1876,7 @@ Parse_DoVar(char *line, GNode *ctxt)
* XXX Rather than counting () and {} we should look for $ and
* then expand the variable.
*/
- for (depth = 0, cp = line + 1; depth > 0 || *cp != '='; cp++) {
+ for (depth = 0, cp = line; depth > 0 || *cp != '='; cp++) {
if (*cp == '(' || *cp == '{') {
depth++;
continue;
Index: src/usr.bin/make/unit-tests/varname-empty.mk
diff -u src/usr.bin/make/unit-tests/varname-empty.mk:1.3 src/usr.bin/make/unit-tests/varname-empty.mk:1.4
--- src/usr.bin/make/unit-tests/varname-empty.mk:1.3 Sat Aug 22 21:02:56 2020
+++ src/usr.bin/make/unit-tests/varname-empty.mk Sat Aug 22 21:12:29 2020
@@ -1,4 +1,4 @@
-# $NetBSD: varname-empty.mk,v 1.3 2020/08/22 21:02:56 rillig Exp $
+# $NetBSD: varname-empty.mk,v 1.4 2020/08/22 21:12:29 rillig Exp $
#
# Tests for the special variable with the empty name.
#
@@ -9,7 +9,7 @@
# Until 2020-08-22 it was possible to assign a value to the variable with
# the empty name, leading to all kinds of unexpected effects.
?= default
-#= assigned # XXX: probably undefined behavior
+= assigned # undefined behavior until 2020-08-22
+= appended
:= subst
!= echo 'value'
