define gdb symbol

sample.c

https://stackoverflow.com/questions/7272558/can-we-define-a-new-data-type-in-a-gdb-session

// sample.c
#include "sample.h"
struct sample foo;

gcc -g -c sample.c

(gdb) add-symbol-file sample.o 0
add symbol table from file "sample.o" at
    .text_addr = 0x0

(gdb) p (struct sample *)0x7fffffffd6b0
$1 = (struct sample *) 0x7fffffffd6b0
(gdb) p *$1
$2 = {i = 42, less = 0x7fffffffd6b0, more = 0x7fffffffd6b0}