/
pkg.go
70 lines (59 loc) · 1.46 KB
/
pkg.go
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// Copyright 2017 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package types
import "cmd/internal/obj"
type Pkg struct {
Name string // package name, e.g. "sys"
Path string // string literal used in import statement, e.g. "runtime/internal/sys"
Pathsym *obj.LSym
Prefix string // escaped path for use in symbol table
Imported bool // export data of this package was parsed
Direct bool // imported directly
Syms map[string]*Sym
}
var Nopkg = &Pkg{
Syms: make(map[string]*Sym),
}
func (pkg *Pkg) Lookup(name string) *Sym {
s, _ := pkg.LookupOK(name)
return s
}
var InitSyms []*Sym
// LookupOK looks up name in pkg and reports whether it previously existed.
func (pkg *Pkg) LookupOK(name string) (s *Sym, existed bool) {
if pkg == nil {
pkg = Nopkg
}
if s := pkg.Syms[name]; s != nil {
return s, true
}
s = &Sym{
Name: name,
Pkg: pkg,
}
if name == "init" {
InitSyms = append(InitSyms, s)
}
pkg.Syms[name] = s
return s, false
}
func (pkg *Pkg) LookupBytes(name []byte) *Sym {
if pkg == nil {
pkg = Nopkg
}
if s := pkg.Syms[string(name)]; s != nil {
return s
}
str := InternString(name)
return pkg.Lookup(str)
}
var internedStrings = map[string]string{}
func InternString(b []byte) string {
s, ok := internedStrings[string(b)] // string(b) here doesn't allocate
if !ok {
s = string(b)
internedStrings[s] = s
}
return s
}