var gentab = []struct {
	pkg  string // Relative to $GOROOT/src
	file string
	gen  func(dir, file string)
}{
	{"go/build", "zcgo.go", mkzcgo},
	{"cmd/go/internal/cfg", "zdefaultcc.go", mkzdefaultcc},
	{"runtime/internal/sys", "zversion.go", mkzversion},
	{"time/tzdata", "zzipdata.go", mktzdata},
}

// installed maps from a dir name (as given to install) to a chan

		"bin/**",
		"pkg/**",

		// Generated during cmd/dist. See ../dist/build.go:/gentab.
		"src/cmd/go/internal/cfg/zdefaultcc.go",
		"src/go/build/zcgo.go",
		"src/runtime/internal/sys/zversion.go",
		"src/time/tzdata/zzipdata.go",

		// Generated during cmd/dist by bootstrapBuildTools.
		"src/cmd/cgo/zdefaultcc.go",
		"src/cmd/internal/objabi/zbootstrap.go",
		"src/internal/buildcfg/zbootstrap.go",

	return err
}

// GccCmd returns a gcc command line prefix
// defaultCC is defined in zdefaultcc.go, written by cmd/dist.
func (b *Builder) GccCmd(incdir, workdir string) []string {
	return b.compilerCmd(b.ccExe(), incdir, workdir)
}

// GxxCmd returns a g++ command line prefix
// defaultCXX is defined in zdefaultcc.go, written by cmd/dist.
func (b *Builder) GxxCmd(incdir, workdir string) []string {

}

// checkGCCBaseCmd returns the start of the compiler command line.
// It uses $CC if set, or else $GCC, or else the compiler recorded
// during the initial build as defaultCC.
// defaultCC is defined in zdefaultcc.go, written by cmd/dist.
//
// The compiler command line is split into arguments on whitespace. Quotes
// are understood, so arguments may contain whitespace.
//