cmd/dist: diagnose lack of gcc earlier in build
Fixes #10731.
Change-Id: I105629b03fd3323c0a2ca5b6b0fd35ee92b7fd2e
Reviewed-on: https://go-review.googlesource.com/12146
Reviewed-by: Rob Pike <r@golang.org>
diff --git a/src/cmd/dist/build.go b/src/cmd/dist/build.go
index f557238..0616be8 100644
--- a/src/cmd/dist/build.go
+++ b/src/cmd/dist/build.go
@@ -9,6 +9,7 @@
"flag"
"fmt"
"os"
+ "os/exec"
"path/filepath"
"strings"
)
@@ -1022,6 +1023,7 @@
setup()
+ checkCC()
bootstrapBuildTools()
// For the main bootstrap, building for host os/arch.
@@ -1067,6 +1069,57 @@
}
}
+// Copied from go/build/build.go.
+// Cannot use go/build directly because cmd/dist for a new release
+// builds against an old release's go/build, which may be out of sync.
+var cgoEnabled = map[string]bool{
+ "darwin/386": true,
+ "darwin/amd64": true,
+ "darwin/arm": true,
+ "darwin/arm64": true,
+ "dragonfly/amd64": true,
+ "freebsd/386": true,
+ "freebsd/amd64": true,
+ "linux/386": true,
+ "linux/amd64": true,
+ "linux/arm": true,
+ "linux/arm64": true,
+ "linux/ppc64le": true,
+ "android/386": true,
+ "android/amd64": true,
+ "android/arm": true,
+ "netbsd/386": true,
+ "netbsd/amd64": true,
+ "netbsd/arm": true,
+ "openbsd/386": true,
+ "openbsd/amd64": true,
+ "solaris/amd64": true,
+ "windows/386": true,
+ "windows/amd64": true,
+}
+
+func needCC() bool {
+ switch os.Getenv("CGO_ENABLED") {
+ case "1":
+ return true
+ case "0":
+ return false
+ }
+ return cgoEnabled[gohostos+"/"+gohostarch]
+}
+
+func checkCC() {
+ if !needCC() {
+ return
+ }
+ if _, err := exec.Command(defaultcc, "--help").Output(); err != nil {
+ fatal("cannot invoke C compiler %q: %v\n\n"+
+ "Go needs a system C compiler for use with cgo.\n"+
+ "To set a C compiler, export CC=the-compiler.\n"+
+ "To disable cgo, export CGO_ENABLED=0.\n", defaultcc, err)
+ }
+}
+
func defaulttarg() string {
// xgetwd might return a path with symlinks fully resolved, and if
// there happens to be symlinks in goroot, then the hasprefix test
diff --git a/src/go/build/build.go b/src/go/build/build.go
index bd84c57..6496414 100644
--- a/src/go/build/build.go
+++ b/src/go/build/build.go
@@ -256,6 +256,7 @@
// if set, or else the compiled code's GOARCH, GOOS, and GOROOT.
var Default Context = defaultContext()
+// Also known to cmd/dist/build.go.
var cgoEnabled = map[string]bool{
"darwin/386": true,
"darwin/amd64": true,
