Re: [PATCH] Force array coercion in c_get_string

[Tom Tromey <tromey at adacore dot com>]

>>>>> "Pedro" == Pedro Alves <palves@redhat.com> writes:

>> The actual patch is somewhat more
>> complicated than you might think, because the caller can request more
>> array elements than the type allows.  This is normal when the type is
>> using the C struct hack.

Pedro> Which test exposes this issue?

>From py-value.exp:

  # Test fetching a string longer than its declared (in C) size.
  # PR 16286
  gdb_py_test_silent_cmd "python xstr = gdb.parse_and_eval('xstr')" "get xstr" 1
  gdb_test "python print(xstr\['text'\].string (length = xstr\['length'\]))" "x{100}" \
    "read string beyond declared size"

Pedro> I'm a bit confused here.  If we ever coerce an array and then read more
Pedro> elements than the type allows, won't we be reading garbage passed the
Pedro> coerced array elements?

In the case where we want to read past the array limit, c_get_string
will take the second branch, which does an explicit read_string.

Tom