60 lines
1.5 KiB
Go
60 lines
1.5 KiB
Go
package main
|
|
|
|
import (
|
|
"debug/elf"
|
|
"debug/gosym"
|
|
"fmt"
|
|
"log"
|
|
"math"
|
|
"os"
|
|
"runtime"
|
|
)
|
|
|
|
var bloop = -3.4
|
|
|
|
func main() {
|
|
fmt.Println("task 1: verify version")
|
|
fmt.Println(" program compiled with", runtime.Version())
|
|
|
|
fmt.Println("task 2: check for presence of variable and function")
|
|
// inspect ELF symbol table
|
|
f, err := elf.Open(os.Args[0])
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
defer f.Close()
|
|
symSection := f.Section(".gosymtab")
|
|
lineSection := f.Section(".gopclntab")
|
|
textSection := f.Section(".text")
|
|
if symSection == nil || lineSection == nil || textSection == nil {
|
|
log.Fatal("symbolic information not found")
|
|
}
|
|
symData, err := symSection.Data()
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
lineData, err := lineSection.Data()
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
table, err := gosym.NewTable(symData,
|
|
gosym.NewLineTable(lineData, textSection.Addr))
|
|
if err != nil {
|
|
log.Fatal(" ", err)
|
|
}
|
|
var foundBloop, foundFabs bool
|
|
for _, s := range table.Syms {
|
|
if s.Name == "main.bloop" {
|
|
foundBloop = true
|
|
fmt.Println(" bloop symbol table entry:", s)
|
|
} else if s.Name == "math.Abs" {
|
|
foundFabs = true
|
|
fmt.Println(" abs symbol table entry:", s)
|
|
}
|
|
}
|
|
if foundBloop && foundFabs {
|
|
fmt.Println(" bloop: ", bloop)
|
|
fmt.Println(" abs(bloop): ", math.Abs(bloop))
|
|
}
|
|
}
|