diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE
index 21bf5f28f22..b73c3e1d88a 100644
--- a/gcc/go/gofrontend/MERGE
+++ b/gcc/go/gofrontend/MERGE
@@ -1,4 +1,4 @@
-6d1d558109b5f5e53b31cc3325485dbb9f06d430
+a790c5fec06ced726c7f0f597186883ce61d0a45
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
diff --git a/libgo/go/cmd/go/alldocs.go b/libgo/go/cmd/go/alldocs.go
index 3d5dd2b3972..f946bf6105f 100644
--- a/libgo/go/cmd/go/alldocs.go
+++ b/libgo/go/cmd/go/alldocs.go
@@ -1143,6 +1143,9 @@
 // 		Defined by Git. A colon-separated list of schemes that are allowed to be used
 // 		with git fetch/clone. If set, any scheme not explicitly mentioned will be
 // 		considered insecure by 'go get'.
+//	GCCGOTOOLDIR
+//		If set, where to find gccgo tools, such as cgo.
+//		The default is based on how gccgo was configured.
 //
 //
 // Import path syntax
diff --git a/libgo/go/cmd/go/help.go b/libgo/go/cmd/go/help.go
index 0c663ad463f..6b7422c95c6 100644
--- a/libgo/go/cmd/go/help.go
+++ b/libgo/go/cmd/go/help.go
@@ -508,6 +508,9 @@ Special-purpose environment variables:
 		Defined by Git. A colon-separated list of schemes that are allowed to be used
 		with git fetch/clone. If set, any scheme not explicitly mentioned will be
 		considered insecure by 'go get'.
+	GCCGOTOOLDIR
+		If set, where to find gccgo tools, such as cgo.
+		The default is based on how gccgo was configured.
 	`,
 }
 
diff --git a/libgo/go/go/build/build.go b/libgo/go/go/build/build.go
index 4e1b29fecd9..cce5d482ada 100644
--- a/libgo/go/go/build/build.go
+++ b/libgo/go/go/build/build.go
@@ -1549,7 +1549,7 @@ func init() {
 
 func getToolDir() string {
 	if runtime.Compiler == "gccgo" {
-		return runtime.GCCGOTOOLDIR
+		return envOr("GCCGOTOOLDIR", runtime.GCCGOTOOLDIR)
 	} else {
 		return filepath.Join(runtime.GOROOT(), "pkg/tool/"+runtime.GOOS+"_"+runtime.GOARCH)
 	}