[Bug sanitizer/64289] New: ICE with -fsanitize=float-cast-overflow

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64289

            Bug ID: 64289
           Summary: ICE with -fsanitize=float-cast-overflow
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: sanitizer
          Assignee: jakub at gcc dot gnu.org
          Reporter: jakub at gcc dot gnu.org
                CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
                    jakub at gcc dot gnu.org, kcc at gcc dot gnu.org,
                    mpolacek at gcc dot gnu.org

/* { dg-do compile } */
/* { dg-options "-fsanitize=float-cast-overflow" } */

int
foo (int a)
{
  return (int) (0 ? 0 : a ? a : 0.5);
}

ICEs when compiled as C, because save_expr must not be used until c_fully_fold.
Unfortunately as convert.c is shared by all FEs, it can't call c_save_expr
instead.  So, either we'd need to turn it into a langhook, or we need a
workaround in c-convert.c like we've done already for the other save_expr in
convert.c case.