[Bug preprocessor/96935] ICE in subspan, at input.h:69

[jan.smets at nokia dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96935

--- Comment #3 from Jan Smets <jan.smets at nokia dot com> ---
A bisect resulted in this commit :

commit 0d48e8779c6a9ac88f5efd1b4a2d40f43ef75faf
Author: David Malcolm <dmalcolm@redhat.com>
Date:   Fri Oct 5 19:02:17 2018 +0000

    Support string locations for C++ in -Wformat (PR c++/56856)

    -Wformat in the C++ FE doesn't work as well as it could:
    (a) it doesn't report precise locations within the string literal, and
    (b) it doesn't underline arguments for those arguments
!CAN_HAVE_LOCATION_P,
    despite having location wrapper nodes.



Your suggestion doesn't trigger it for me.
I'v  built GCC with -g -O0 , but the standard provided backtrace didn't include
function call arguments.

A printf confirms your suspicion about start.column == 0 
 => start.column=0 literal_length=1