The address where filename has been loaded is missing [GDB]

Question

I have following sample code ``` #include<stdio.h> int main() { int num1, num2; printf("Enter two numbers
"); scanf("%d",&num1); scanf("%d",&num2); int i; for(i = 0; i < num2; i++) num1 = num1 + num1; printf("Result is %d 
",num1); return 0; } ``` I compiled this code with -g option to gcc. ``` gcc -g file.c ``` Generate separate symbol file ``` objcopy --only-keep-debug a.out a.out.sym ``` Strip the symbols from a.out ``` strip -s a.out ``` Load this a.out in gdb ``` gdb a.out ``` gdb says "no debug information found" fine. Then I use add-symbol-file command in gdb ``` (gdb) add-symbol-file a.out.debug [Enter] The address where a.out.debug has been loaded is missing ``` - I want to know how to find this address? - Is there any command or trick to find it? - This address is representing WHAT? I know gdb has an other command symbol-file but it overwrites the previous loaded symbols. So I have to use this command to add many symbol files in gdb. my system is 64bit running ubuntu LTS 1…

Accepted Answer

objcopy --only-keep-debug a.out a.out.sym

If you want GDB to load the a.out.sym automatically, follow the steps outlined here (note in particular that you need to do the "add `.gnu_debuglink`" step).

This address is representing WHAT

The address GDB wants is the location of `.text` section of the binary. To find it, use `readelf -WS a.out`. E.g.

```
$ readelf -WS /bin/date
There are 28 section headers, starting at offset 0xe350:

Section Headers:
  [Nr] Name              Type            Address          Off    Size   ES Flg Lk Inf Al
  [ 0]                   NULL            0000000000000000 000000 000000 00      0   0  0
  [ 1] .interp           PROGBITS        0000000000400238 000238 00001c 00   A  0   0  1
...
  [13] .text             PROGBITS        0000000000401900 001900 0077f8 00  AX  0   0 16
```

Here, you want to give GDB `0x401900` as the load address.

The address where filename has been loaded is missing [GDB]

Solution

Problem