https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78324
--- Comment #1 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
Root cause is that the substring loc code isn't set up to cope with
-ftrack-macro-expansion=0, and attempts to handle this location:
../../src/gcc/testsuite/gcc.dg/tree-ssa/builtin-sprintf-2.c:95:1: note:
RNG (0, 0, 0, "%hhi", i)
^~~
as the location of the literal, rather than:
RNG (0, 0, 0, "%hhi", i)
^~~~
On re-parsing to locate substring locations, it attempts to parse the 'R' as a
raw string, and so this code within cpp_interpret_string_1 fires:
if (*p == 'R')
{
const uchar *prefix;
/* Skip over 'R"'. */
p += 2;
prefix = p;
while (*p != '(')
p++;
and the issue happens in the "while" loop, as it erroneously walks through this
memory:
(gdb) p strs.m_vec.m_vecdata[0]
$20 = {len = 3, text = 0xc9bcca0 "RNG"}
trying to find the open parenthesis.
It looks like the substring_loc code needs to handle non-default values of
-ftrack-macro-expansion; am continuing to investigate.
