golang path 代码
文件路径：/src/cmd/internal/objabi/path.go
/ 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 objabi
import "strings"
/ PathToPrefix converts raw string to the prefix that will be used in the
/ symbol table. All control characters, space, '%' and '"', as well as
/ non-7-bit clean bytes turn into %xx. The period needs escaping only in the
/ last segment of the path, and it makes for happier users if we escape that as
/ little as possible.
func PathToPrefix(s string) string {
slash := strings.LastIndex(s, "/")
/ check for chars that need escaping
n := 0
for r := 0; r < len(s); r++ {
if c := s[r]; c <= ' ' || (c == '.' && r > slash) || c == '%' || c == '"' || c >= 0x7F {
n++
}
}
/ quick exit
if n == 0 {
return s
}
/ escape
const hex = "0123456789abcdef"
p := make([]byte, 0, len(s)+2*n)
for r := 0; r < len(s); r++ {
if c := s[r]; c <= ' ' || (c == '.' && r > slash) || c == '%' || c == '"' || c >= 0x7F {
p = append(p, '%', hex[c>>4], hex[c&0xF])
} else {
p = append(p, c)
}
}
return string(p)
}
/ IsRuntimePackagePath examines 'pkgpath' and returns TRUE if it
/ belongs to the collection of "runtime-related" packages, including
/ "runtime" itself, "reflect", "syscall", and the
/ "runtime/internal/*" packages. The compiler and/or assembler in
/ some cases need to be aware of when they are building such a
/ package, for example to enable features such as ABI selectors in
/ assembly sources.
/
/ Keep in sync with cmd/dist/build.go:IsRuntimePackagePath.
func IsRuntimePackagePath(pkgpath string) bool {
rval := false
switch pkgpath {
case "runtime":
rval = true
case "reflect":
rval = true
case "syscall":
rval = true
case "internal/bytealg":
rval = true
default:
rval = strings.HasPrefix(pkgpath, "runtime/internal")
}
return rval
}