return pkgMap
}

var nopkg = &Pkg{
	Syms: make(map[string]*Sym),
}

func (pkg *Pkg) Lookup(name string) *Sym {
	s, _ := pkg.LookupOK(name)
	return s
}

// LookupOK looks up name in pkg and reports whether it previously existed.
func (pkg *Pkg) LookupOK(name string) (s *Sym, existed bool) {
	// TODO(gri) remove this check in favor of specialized lookup
	if pkg == nil {
		pkg = nopkg
	}

	// except for the types package, which is protected separately.
	// Reusing funcsymsmu to also cover this package lookup
	// avoids a general, broader, expensive package lookup mutex.
	funcsymsmu.Lock()
	sf, existed := s.Pkg.LookupOK(ir.FuncSymName(s))
	if !existed {
		funcsyms = append(funcsyms, n)
	}
	funcsymsmu.Unlock()

	return sf.Linksym()
}

func GlobalLinksym(n *ir.Name) *obj.LSym {