csv_from_object.go

// $ go mod init
// $ go mod tidy
// --
// It'll install the x86 ASM package.
// It traverses the directory for subdirectories and all the files.
// It determines the sections (it only decodes the executable section) and the assembly of each file into a CSV.

package main

import (
	"debug/elf"
	"encoding/csv"
	"fmt"
	"log"
	"os"
	"path/filepath"
	"strings"

	"golang.org/x/arch/x86/x86asm"
)

func main() {
	if len(os.Args) < 2 {
		fmt.Println("Usage: go run main.go <directory>")
		os.Exit(1)
	}

	dir := os.Args[1]

	csvFile, err := os.Create("disassembly.csv")
	if err != nil {
		log.Fatalf("Error creating CSV file: %v", err)
	}
	defer csvFile.Close()

	writer := csv.NewWriter(csvFile)
	defer writer.Flush()

	writer.Write([]string{"Filename", "Section", "Assembly"})

	err = filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		if !info.IsDir() && filepath.Ext(path) == ".o" { // Process only ELF files
			err = processELF(path, writer)
			if err != nil {
				return err
			}
		}
		return nil
	})
	if err != nil {
		log.Fatalf("Error walking directory: %v", err)
	}
}

func processELF(filename string, writer *csv.Writer) error {
	f, err := elf.Open(filename)
	if err != nil {
		return fmt.Errorf("error opening ELF file %s: %v", filename, err)
	}
	defer f.Close()

	var combinedAssemblyOutput string

	for _, section := range f.Sections {
		// check if the section is executable
		if section.Flags&elf.SHF_EXECINSTR != 0 {
			combinedAssemblyOutput += fmt.Sprintf("Section: %s\n", section.Name)

			data, err := section.Data()
			if err != nil {
				return fmt.Errorf("error reading section %s in %s: %v", section.Name, filename, err)
			}

			for i := 0; i < len(data); {
				inst, err := x86asm.Decode(data[i:], 64)
				if err != nil {
					return fmt.Errorf("error decoding instruction in %s: %v", filename, err)
				}
				combinedAssemblyOutput += fmt.Sprintf("%#x: %s\n", section.Addr+uint64(i), inst.String())
				i += inst.Len
			}

			combinedAssemblyOutput = strings.ReplaceAll(combinedAssemblyOutput, "\n", " ")
			writer.Write([]string{filename, section.Name, combinedAssemblyOutput})
		}
	}

	return nil
}