What does "= save" mean in gdb

Question

after this tutorial about C and gdb . This is certainly a useful tutorial, but they started with examples like this:

(gdb) print a
$1 = {1, 2, 3}
(gdb) ptype a
type = int [3]

and then suddenly began to display this sequence

= preserve do
  :escaped
    (gdb) x/4xb a + 1
    0x7fff5fbff570: 0x02  0x00  0x00  0x00

in his examples, without explaining what it was. I can not understand or recreate it. A google search for "gdb preserve do" points to the same site. I can continue to follow without him, but I'm curious, what is this = preserve do?

Answer 1

without explaining what it is

This is a mistake in their HTML formatting (markup) and has nothing to do with GDB.