在Go1.11中,添加了Dwarf调试符号的运行时类型信息,您可以使用此地址获得运行时类型。DW_AT_go_runtime_type。 gort 您可以查看更多内容。
package main
import (
"debug/dwarf"
"fmt"
"log"
"os"
"reflect"
"runtime"
"unsafe"
"github.com/go-delve/delve/pkg/dwarf/godwarf"
"github.com/go-delve/delve/pkg/proc"
)
func main() {
path, err := os.Executable()
if err != nil {
log.Fatalln(err)
}
bi := proc.NewBinaryInfo(runtime.GOOS, runtime.GOARCH)
err = bi.LoadBinaryInfo(path, 0, nil)
if err != nil {
log.Fatalln(err)
}
mds, err := loadModuleData(bi, new(localMemory))
if err != nil {
log.Fatalln(err)
}
types, err := bi.Types()
if err != nil {
log.Fatalln(err)
}
for _, name := range types {
dwarfType, err := findType(bi, name)
if err != nil {
continue
}
typeAddr, err := dwarfToRuntimeType(bi, mds, dwarfType, name)
if err != nil {
continue
}
typ := reflect.TypeOf(*(*interface{})(unsafe.Pointer(&typeAddr)))
log.Printf("load type name:%s type:%s\n", name, typ)
}
}
// delve counterpart to runtime.moduledata
type moduleData struct {
text, etext uint64
types, etypes uint64
typemapVar *proc.Variable
}
//go:linkname findType github.com/go-delve/delve/pkg/proc.(*BinaryInfo).findType
func findType(bi *proc.BinaryInfo, name string) (godwarf.Type, error)
//go:linkname loadModuleData github.com/go-delve/delve/pkg/proc.loadModuleData
func loadModuleData(bi *proc.BinaryInfo, mem proc.MemoryReadWriter) ([]moduleData, error)
//go:linkname imageToModuleData github.com/go-delve/delve/pkg/proc.(*BinaryInfo).imageToModuleData
func imageToModuleData(bi *proc.BinaryInfo, image *proc.Image, mds []moduleData) *moduleData
type localMemory int
func (mem *localMemory) ReadMemory(data []byte, addr uint64) (int, error) {
buf := *(*[]byte)(unsafe.Pointer(&reflect.SliceHeader{Data: uintptr(addr), Len: len(data), Cap: len(data)}))
copy(data, buf)
return len(data), nil
}
func (mem *localMemory) WriteMemory(addr uint64, data []byte) (int, error) {
return 0, fmt.Errorf("not support")
}
func dwarfToRuntimeType(bi *proc.BinaryInfo, mds []moduleData, typ godwarf.Type, name string) (typeAddr uint64, err error) {
if typ.Common().Index >= len(bi.Images) {
return 0, fmt.Errorf("could not find image for type %s", name)
}
img := bi.Images[typ.Common().Index]
rdr := img.DwarfReader()
rdr.Seek(typ.Common().Offset)
e, err := rdr.Next()
if err != nil {
return 0, fmt.Errorf("could not find dwarf entry for type:%s err:%s", name, err)
}
entryName, ok := e.Val(dwarf.AttrName).(string)
if !ok || entryName != name {
return 0, fmt.Errorf("could not find name for type:%s entry:%s", name, entryName)
}
off, ok := e.Val(godwarf.AttrGoRuntimeType).(uint64)
if !ok || off == 0 {
return 0, fmt.Errorf("could not find runtime type for type:%s", name)
}
md := imageToModuleData(bi, img, mds)
if md == nil {
return 0, fmt.Errorf("could not find module data for type %s", name)
}
typeAddr = md.types + off
if typeAddr < md.types || typeAddr >= md.etypes {
return off, nil
}
return typeAddr, nil
}
init()
中注册函数的代码。 - THUNDERGROOVEgo test
并让库发现所有类型,实例化它们,然后调用它们。所有这些都在一个进程执行中完成。这是一个非常棘手的问题。 - Michael Whatcott