From f64eb636677d714781b4543f111b1c9239328db6 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Thu, 28 Jul 2022 12:42:14 +0200 Subject: gimple, internal-fn: Add IFN_TRAP and use it for __builtin_unreachable [PR106099] __builtin_unreachable and __ubsan_handle_builtin_unreachable don't use vops, they are marked const/leaf/noreturn/nothrow/cold. But __builtin_trap uses vops, isn't const, just leaf/noreturn/nothrow/cold. This is I believe so that when users explicitly use __builtin_trap in their sources they get stores visible at the trap side. -fsanitize=unreachable -fsanitize-undefined-trap-on-error used to transform __builtin_unreachable to __builtin_trap even in the past, but the sanopt pass has TODO_update_ssa, so it worked fine. Now that gimple_build_builtin_unreachable can build a __builtin_trap call right away, we can run into problems that whenever we need it we would need to either manually or through TODO_update* ensure the vops being updated. Though, as it is originally __builtin_unreachable which is just implemented as trap, I think for this case it is fine to avoid vops. For this the patch introduces IFN_TRAP, which has ECF_* flags like __builtin_unreachable and is expanded as __builtin_trap. 2022-07-28 Jakub Jelinek PR tree-optimization/106099 * internal-fn.def (TRAP): New internal fn. * internal-fn.h (expand_TRAP): Declare. * internal-fn.cc (expand_TRAP): Define. * gimple.cc (gimple_build_builtin_unreachable): For BUILT_IN_TRAP, use internal fn rather than builtin. * gcc.dg/ubsan/pr106099.c: New test. --- gcc/internal-fn.def | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'gcc/internal-fn.def') diff --git a/gcc/internal-fn.def b/gcc/internal-fn.def index 7c398ba..7bf661c 100644 --- a/gcc/internal-fn.def +++ b/gcc/internal-fn.def @@ -456,6 +456,10 @@ DEF_INTERNAL_FN (SHUFFLEVECTOR, ECF_CONST | ECF_LEAF | ECF_NOTHROW, NULL) /* <=> optimization. */ DEF_INTERNAL_FN (SPACESHIP, ECF_CONST | ECF_LEAF | ECF_NOTHROW, NULL) +/* __builtin_trap created from/for __builtin_unreachable. */ +DEF_INTERNAL_FN (TRAP, ECF_CONST | ECF_LEAF | ECF_NORETURN + | ECF_NOTHROW | ECF_COLD, NULL) + #undef DEF_INTERNAL_INT_FN #undef DEF_INTERNAL_FLT_FN #undef DEF_INTERNAL_FLT_FLOATN_FN -- cgit v1.1