How to get the symbol name for a memory address in GDB?

For instance, I know that 0x46767f0 belongs to an NSString*, is there any way I can find out what NSString it is to help me find some bugs I'm after?

Solution 1:

I believe you're looking for:

info symbol <addresss>

Print the name of a symbol which is stored at the address addr. If no symbol is stored exactly at addr, GDB prints the nearest symbol and an offset from it.

Example:

(gdb) info symbol 0x400225
_start + 5 in section .text of /tmp/a.out

(gdb) info symbol 0x2aaaac2811cf
__read_nocancel + 6 in section .text of /usr/lib64/libc.so.6

You can read more about it here.

Solution 2:

gdb> list *0xAABBCCDD

That tells you the filename and line number.

Solution 3:

If it is a stack variable, there is no way that I am aware to do it. Otherwise, try p/a <pointer symbol or address> and it will print the symbol name (or offset to the nearest symbol name).