Module Name: src
Committed By: rillig
Date: Sun Sep 13 07:42:20 UTC 2020
Modified Files:
src/usr.bin/make: var.c
src/usr.bin/make/unit-tests: varmod.exp varmod.mk
Log Message:
make(1): in lint mode, complain about erroneous $$
Since 2008-12-21, make has silently ignored strange variable names in
constructs like '$$', '$}', '$' followed by nothing. Ignoring these
bugs in makefiles instead of reporting them is not a good idea.
To improve the situation, make complains about these errors now, but
only in lint mode (-dL). This preserves existing behavior while still
allowing to validate existing makefiles that they don't depend on this
bug.
If the test phase goes well, these error messages may be enabled
unconditionally.
https://mail-index.netbsd.org/pkgsrc-users/2020/09/12/msg032229.html
To generate a diff of this commit:
cvs rdiff -u -r1.506 -r1.507 src/usr.bin/make/var.c
cvs rdiff -u -r1.1 -r1.2 src/usr.bin/make/unit-tests/varmod.exp
cvs rdiff -u -r1.2 -r1.3 src/usr.bin/make/unit-tests/varmod.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:1.506 src/usr.bin/make/var.c:1.507
--- src/usr.bin/make/var.c:1.506 Sun Sep 13 05:55:39 2020
+++ src/usr.bin/make/var.c Sun Sep 13 07:42:20 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: var.c,v 1.506 2020/09/13 05:55:39 rillig Exp $ */
+/* $NetBSD: var.c,v 1.507 2020/09/13 07:42:20 rillig Exp $ */
/*
* Copyright (c) 1988, 1989, 1990, 1993
@@ -69,14 +69,14 @@
*/
#ifndef MAKE_NATIVE
-static char rcsid[] = "$NetBSD: var.c,v 1.506 2020/09/13 05:55:39 rillig Exp $";
+static char rcsid[] = "$NetBSD: var.c,v 1.507 2020/09/13 07:42:20 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 1.506 2020/09/13 05:55:39 rillig Exp $");
+__RCSID("$NetBSD: var.c,v 1.507 2020/09/13 07:42:20 rillig Exp $");
#endif
#endif /* not lint */
#endif
@@ -3369,6 +3369,27 @@ ParseVarname(const char **pp, char start
return Buf_Destroy(&buf, FALSE);
}
+static Boolean
+ValidShortVarname(char varname, const char *start)
+{
+ if (varname != '\0' && strchr(")}:$", varname) == NULL)
+ return TRUE;
+
+ if (!DEBUG(LINT))
+ return FALSE;
+
+ if (varname == '$')
+ Parse_Error(PARSE_FATAL,
+ "To escape a dollar, use \\$, not $$, at \"%s\"", start);
+ else if (varname == '\0')
+ Parse_Error(PARSE_FATAL, "Dollar followed by nothing");
+ else
+ Parse_Error(PARSE_FATAL,
+ "Invalid variable name '%c', at \"%s\"", varname, start);
+
+ return FALSE;
+}
+
/*-
*-----------------------------------------------------------------------
* Var_Parse --
@@ -3454,8 +3475,7 @@ Var_Parse(const char **pp, GNode *ctxt,
* value if it exists.
*/
- /* Error out some really stupid names */
- if (startc == '\0' || strchr(")}:$", startc)) {
+ if (!ValidShortVarname(startc, start)) {
(*pp)++;
return var_Error;
}
@@ -3572,7 +3592,7 @@ Var_Parse(const char **pp, GNode *ctxt,
* return.
*/
nstr = Buf_GetAll(&v->val, NULL);
- if (strchr(nstr, '$') != NULL && (eflags & VARE_WANTRES) != 0) {
+ if (strchr(nstr, '$') != NULL && (eflags & VARE_WANTRES)) {
nstr = Var_Subst(nstr, ctxt, eflags);
*freePtr = nstr;
}
Index: src/usr.bin/make/unit-tests/varmod.exp
diff -u src/usr.bin/make/unit-tests/varmod.exp:1.1 src/usr.bin/make/unit-tests/varmod.exp:1.2
--- src/usr.bin/make/unit-tests/varmod.exp:1.1 Sun Aug 16 12:07:51 2020
+++ src/usr.bin/make/unit-tests/varmod.exp Sun Sep 13 07:42:20 2020
@@ -1 +1,6 @@
-exit status 0
+make: "varmod.mk" line 42: To escape a dollar, use \$, not $$, at "$$:L} != """
+make: "varmod.mk" line 42: Invalid variable name ':', at "$:L} != """
+make: "varmod.mk" line 47: Dollar followed by nothing
+make: Fatal errors encountered -- cannot continue
+make: stopped in unit-tests
+exit status 1
Index: src/usr.bin/make/unit-tests/varmod.mk
diff -u src/usr.bin/make/unit-tests/varmod.mk:1.2 src/usr.bin/make/unit-tests/varmod.mk:1.3
--- src/usr.bin/make/unit-tests/varmod.mk:1.2 Sun Aug 16 14:25:16 2020
+++ src/usr.bin/make/unit-tests/varmod.mk Sun Sep 13 07:42:20 2020
@@ -1,8 +1,51 @@
-# $NetBSD: varmod.mk,v 1.2 2020/08/16 14:25:16 rillig Exp $
+# $NetBSD: varmod.mk,v 1.3 2020/09/13 07:42:20 rillig Exp $
#
# Tests for variable modifiers, such as :Q, :S,from,to or :Ufallback.
-# TODO: Implementation
+DOLLAR1= $$
+DOLLAR2= ${:U\$}
-all:
- @:;
+# To get a single '$' sign in the value of a variable expression, it has to
+# be written as '$$' in a literal variable value.
+#
+# See Var_Parse, where it calls Var_Subst.
+.if ${DOLLAR1} != "\$"
+. error
+.endif
+
+# Another way to get a single '$' sign is to use the :U modifier. In the
+# argument of that modifier, a '$' is escaped using the backslash instead.
+#
+# See Var_Parse, where it calls Var_Subst.
+.if ${DOLLAR2} != "\$"
+. error
+.endif
+
+# It is also possible to use the :U modifier directly in the expression.
+#
+# See Var_Parse, where it calls Var_Subst.
+.if ${:U\$} != "\$"
+. error
+.endif
+
+# XXX: As of 2020-09-13, it is not possible to use '$$' in a variable name
+# to mean a single '$'. This contradicts the manual page, which says that
+# '$' can be escaped as '$$'.
+.if ${$$:L} != ""
+. error
+.endif
+
+# In lint mode, make prints helpful error messages.
+# For compatibility, make does not print these error messages in normal mode.
+# Should it?
+.MAKEFLAGS: -dL
+.if ${$$:L} != ""
+. error
+.endif
+
+# A '$' followed by nothing is an error as well.
+.if ${:Uword:@word@${word}$@} != "word"
+. error
+.endif
+
+all: # nothing
