[Bug preprocessor/118860] [15 Regression] ICE Segfault with --param=file-cache-files= since r15-7431-g66af77cbed6c5b

[heiko at hexco dot de via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118860

Heiko Eißfeldt <heiko at hexco dot de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |heiko at hexco dot de

--- Comment #2 from Heiko Eißfeldt <heiko at hexco dot de> ---
$ g++ pr31078.C --param=file-cache-files=16 -Wunused
works

$ g++ pr31078.C --param=file-cache-files=17 -Wunused
does not

Looks like file_cache::tune() needs to reallocate when num_file_slots_ is
greater than the default
size_t file_cache::num_file_slots = 16;
used by the constructor

file_cache::file_cache ()
: m_file_slots (new file_cache_slot[num_file_slots])
{
  initialize_input_context (nullptr, false);
}