From b3dc6c07e27f4bab5dfe4b4055af9a74e230d2a3 Mon Sep 17 00:00:00 2001
From: "David E. O'Brien" <obrien@FreeBSD.org>
Date: Thu, 31 May 2012 00:36:56 +0000
Subject: [PATCH] Add "-V '${VAR}'" variable expansion from Portable Berkeley
 Make.

Submitted by:	Simon Gerraty <sjg@juniper.net>
---
 usr.bin/make/make.1 |  5 +++++
 usr.bin/make/var.c  | 14 +++++++++-----
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/usr.bin/make/make.1 b/usr.bin/make/make.1
index fc91f3c95f7d..d15428b55454 100644
--- a/usr.bin/make/make.1
+++ b/usr.bin/make/make.1
@@ -320,6 +320,11 @@ Do not build any targets.
 Multiple instances of this option may be specified;
 the variables will be printed one per line,
 with a blank line for each null or undefined variable.
+If
+.Ar variable
+contains a
+.Sq Ic $
+then the value will be expanded before printing.
 .It Fl v
 Be extra verbose.
 Print any extra information.
diff --git a/usr.bin/make/var.c b/usr.bin/make/var.c
index 341ee79b16b6..477c4a906bce 100644
--- a/usr.bin/make/var.c
+++ b/usr.bin/make/var.c
@@ -2593,7 +2593,7 @@ void
 Var_Print(Lst *vlist, Boolean expandVars)
 {
 	LstNode		*n;
-	const char	*name;
+	char		*name;
 
 	LST_FOREACH(n, vlist) {
 		name = Lst_Datum(n);
@@ -2601,13 +2601,17 @@ Var_Print(Lst *vlist, Boolean expandVars)
 			char *value;
 			char *v;
 
-			v = emalloc(strlen(name) + 1 + 3);
-			sprintf(v, "${%s}", name);
-
+			if (*name == '$') {
+				v = name;
+			} else {
+				v = emalloc(strlen(name) + 1 + 3);
+				sprintf(v, "${%s}", name);
+			}
 			value = Buf_Peel(Var_Subst(v, VAR_GLOBAL, FALSE));
 			printf("%s\n", value);
 
-			free(v);
+			if (v != name)
+				free(v);
 			free(value);
 		} else {
 			const char *value = Var_Value(name, VAR_GLOBAL);