gcc/libgo/go/runtime/debug/mod.go
2020-08-01 11:21:40 -07:00

116 lines
2.5 KiB
Go

// Copyright 2018 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 debug
import (
"strings"
_ "unsafe" // for go:linkname
)
// exported from runtime
func modinfo() string
// ReadBuildInfo returns the build information embedded
// in the running binary. The information is available only
// in binaries built with module support.
func ReadBuildInfo() (info *BuildInfo, ok bool) {
return readBuildInfo(modinfo())
}
// BuildInfo represents the build information read from
// the running binary.
type BuildInfo struct {
Path string // The main package path
Main Module // The module containing the main package
Deps []*Module // Module dependencies
}
// Module represents a module.
type Module struct {
Path string // module path
Version string // module version
Sum string // checksum
Replace *Module // replaced by this module
}
func readBuildInfo(data string) (*BuildInfo, bool) {
if len(data) < 32 {
return nil, false
}
data = data[16 : len(data)-16]
const (
pathLine = "path\t"
modLine = "mod\t"
depLine = "dep\t"
repLine = "=>\t"
)
readEntryFirstLine := func(elem []string) (Module, bool) {
if len(elem) != 2 && len(elem) != 3 {
return Module{}, false
}
sum := ""
if len(elem) == 3 {
sum = elem[2]
}
return Module{
Path: elem[0],
Version: elem[1],
Sum: sum,
}, true
}
var (
info = &BuildInfo{}
last *Module
line string
ok bool
)
// Reverse of cmd/go/internal/modload.PackageBuildInfo
for len(data) > 0 {
i := strings.IndexByte(data, '\n')
if i < 0 {
break
}
line, data = data[:i], data[i+1:]
switch {
case strings.HasPrefix(line, pathLine):
elem := line[len(pathLine):]
info.Path = elem
case strings.HasPrefix(line, modLine):
elem := strings.Split(line[len(modLine):], "\t")
last = &info.Main
*last, ok = readEntryFirstLine(elem)
if !ok {
return nil, false
}
case strings.HasPrefix(line, depLine):
elem := strings.Split(line[len(depLine):], "\t")
last = new(Module)
info.Deps = append(info.Deps, last)
*last, ok = readEntryFirstLine(elem)
if !ok {
return nil, false
}
case strings.HasPrefix(line, repLine):
elem := strings.Split(line[len(repLine):], "\t")
if len(elem) != 3 {
return nil, false
}
if last == nil {
return nil, false
}
last.Replace = &Module{
Path: elem[0],
Version: elem[1],
Sum: elem[2],
}
last = nil
}
}
return info, true
}