From 5c32c38bf19b24f0aadd78012d17ff5caa82151e Mon Sep 17 00:00:00 2001
From: Matt Madison <matt@madison.systems>
Date: Sat, 17 Feb 2018 05:24:20 -0800
Subject: [PATCH] allow GOTOOLDIR to be overridden in the environment

to allow for split host/target build roots

Upstream-Status: Inappropriate [OE specific]

Signed-off-by: Matt Madison <matt@madison.systems>

---
 src/cmd/dist/build.go          | 4 +++-
 src/cmd/go/internal/cfg/cfg.go | 7 +++++--
 2 files changed, 8 insertions(+), 3 deletions(-)

Index: go/src/cmd/dist/build.go
===================================================================
--- go.orig/src/cmd/dist/build.go
+++ go/src/cmd/dist/build.go
@@ -228,7 +228,9 @@ func xinit() {
 	workdir = xworkdir()
 	xatexit(rmworkdir)
 
-	tooldir = pathf("%s/pkg/tool/%s_%s", goroot, gohostos, gohostarch)
+	if tooldir = os.Getenv("GOTOOLDIR"); tooldir == "" {
+		tooldir = pathf("%s/pkg/tool/%s_%s", goroot, gohostos, gohostarch)
+	}
 }
 
 // compilerEnv returns a map from "goos/goarch" to the
Index: go/src/cmd/go/internal/cfg/cfg.go
===================================================================
--- go.orig/src/cmd/go/internal/cfg/cfg.go
+++ go/src/cmd/go/internal/cfg/cfg.go
@@ -116,7 +116,11 @@ func init() {
 		// variables. This matches the initialization of ToolDir in
 		// go/build, except for using GOROOT rather than
 		// runtime.GOROOT.
-		build.ToolDir = filepath.Join(GOROOT, "pkg/tool/"+runtime.GOOS+"_"+runtime.GOARCH)
+		if s := os.Getenv("GOTOOLDIR"); s != "" {
+			build.ToolDir = filepath.Clean(s)
+		} else {
+			build.ToolDir = filepath.Join(GOROOT, "pkg/tool/"+runtime.GOOS+"_"+runtime.GOARCH)
+		}
 	}
 }