gistfile1.txt

package main

import (
	"debug/dwarf"
	"debug/elf"
	"fmt"
	"io"
	"log"
	"os"
)

func main() {

	elfFile, err := elf.Open(os.Args[1])
	if err != nil {
		log.Fatal(err)
	}

	dwarfData, err := elfFile.DWARF()
	if err != nil {
		log.Fatal(err)
	}

	entryReader := dwarfData.Reader()
	typeReader := dwarfData.Reader()

	readingAFunction := false
	for {
		// Read all entries in sequence
		entry, err := entryReader.Next()
		if err == io.EOF {
			// We've reached the end of DWARF entries
			break
		}
		if entryIsEmpty(entry) {
			readingAFunction = false
		}

		// Check if this entry is a function
		if entry.Tag == dwarf.TagSubprogram {
			// Go through fields
			for _, field := range entry.Field {
				if field.Attr == dwarf.AttrName {
					fmt.Printf("%s\n", field.Val.(string))
					readingAFunction = true
				}
			}
		}

		if !(readingAFunction && entry.Tag == dwarf.TagFormalParameter) {
			continue
		}

		var (
			name     string
			typeName string
		)

		for _, field := range entry.Field {

			if field.Attr == dwarf.AttrName {
				name = field.Val.(string)
			}

			if field.Attr == dwarf.AttrType {
				typeReader.Seek(field.Val.(dwarf.Offset))
				typeEntry, err := typeReader.Next()
				if err != nil {
					log.Fatal(err)
				}

				for i := range typeEntry.Field {
					if typeEntry.Field[i].Attr == dwarf.AttrName {
						typeName = typeEntry.Field[i].Val.(string)
					}
				}
			}
		}

		fmt.Printf("\t%s %s\n", name, typeName)
	}

}

// Can use `Children` field, but there's also always a NULL/empty entry at the end of entry trees.
func entryIsEmpty(e *dwarf.Entry) bool {
	return e.Children == false &&
		len(e.Field) == 0 &&
		e.Offset == 0 &&
		e.Tag == dwarf.Tag(0)
}