Question

Given the following code sippet:

1:    int main(int argc, char **argv) {
2:       int i;
3:    
4:       i = i + 1;
5:    
6:       ...
7:    
8:    }

When you set a breakpoint on line 2: in the above code and start debugging in GDB the execution actually stops on line 4:. This is the correct behavior of course BUT is it possible to query GDB for the correct stop point number before debugging… right after the creation of the breakpoint.

Answer 1

(gdb) b 2
Breakpoint 1 at 0x400547: file main.cpp, line 2.

This is what info b shows:

(gdb) info b $bpnum
Num     Type           Disp Enb Address            What
1       breakpoint     keep y   0x0000000000400547 in main(int, char**) at main.cpp:2

and you need to do this for address in the column “Address”:

(gdb) info line *0x0000000000400547
Line 4 of "main.cpp" starts at address 0x400547 <main(int, char**)+11> and ends at 0x400550 <main(int, char**)+20>.

As you can see the real breakpoint on “Line 4 of main.cpp”