On Wed, May 16, 2018 at 1:37 PM, Marek Polacek <pola...@redhat.com> wrote:
> On Wed, May 16, 2018 at 11:35:56AM -0400, Jason Merrill wrote:
>> On Wed, May 16, 2018 at 11:15 AM, Marek Polacek <pola...@redhat.com> wrote:
>> > This PR has been on my mind for quite some time but I've not found a
>> > solution
>> > that I'd like. Maybe one of you can think of something better.
>> >
>> > The problem in this test is that in C++11, .eh optimizes out the catch,
>> > so the exception is never caught. That is because lower_catch doesn't
>> > think that the region may throw (eh_region_may_contain_throw). That's
>> > so because P::P () is marked as TREE_NOTHROW, which is wrong, because
>> > it calls X::X() which calls init() with throw. TREE_NOTHROW is set in
>> > finish_function:
>> >
>> > /* If this function can't throw any exceptions, remember that. */
>> > if (!processing_template_decl
>> > && !cp_function_chain->can_throw
>> > && !flag_non_call_exceptions
>> > && !decl_replaceable_p (fndecl))
>> > TREE_NOTHROW (fndecl) = 1;
>> >
>> > P::P() should have been marked as can_throw in set_flags_from_callee, but
>> > when
>> > processing X::X() cfun is null, so we can't set it. P::P() is created only
>> > later via implicitly_declare_fn.
>>
>> This should be handled by bot_manip (under break_out_target_exprs,
>> under get_nsdmi), but it seems that it currently only calls
>> set_flags_from_callee for CALL_EXPR, not for AGGR_INIT_EXPR as we have
>> in this case.
>
> Ah, nice! So, this tweaks set_flags_from_callee to also work for
> AGGR_INIT_EXPRs.
>
> Bootstrapped/regtested on x86_64-linux, ok for trunk?
>
> 2018-05-16 Marek Polacek <pola...@redhat.com>
>
> PR c++/85363
> * call.c (set_flags_from_callee): Handle AGGR_INIT_EXPRs too.
> * tree.c (bot_manip): Call set_flags_from_callee for
> AGGR_INIT_EXPRs too.
>
> * g++.dg/cpp0x/initlist-throw1.C: New test.
> * g++.dg/cpp0x/initlist-throw2.C: New test.
>
> diff --git gcc/cp/call.c gcc/cp/call.c
> index 09a3618b007..11b40747932 100644
> --- gcc/cp/call.c
> +++ gcc/cp/call.c
> @@ -319,16 +319,23 @@ build_call_n (tree function, int n, ...)
> void
> set_flags_from_callee (tree call)
> {
> - bool nothrow;
> - tree decl = get_callee_fndecl (call);
> + /* Handle both CALL_EXPRs and AGGR_INIT_EXPRs. */
> + tree decl = cp_get_callee_fndecl_nofold (call);
>
> /* We check both the decl and the type; a function may be known not to
> throw without being declared throw(). */
> - nothrow = decl && TREE_NOTHROW (decl);
> - if (CALL_EXPR_FN (call))
> - nothrow |= TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (call))));
> - else if (internal_fn_flags (CALL_EXPR_IFN (call)) & ECF_NOTHROW)
> - nothrow = true;
> + bool nothrow = decl && TREE_NOTHROW (decl);
> + if (TREE_CODE (call) == CALL_EXPR)
> + {
> + if (CALL_EXPR_FN (call))
> + nothrow
> + |= TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (call))));
> + else if (internal_fn_flags (CALL_EXPR_IFN (call)) & ECF_NOTHROW)
> + nothrow = true;
> + }
> + else if (AGGR_INIT_EXPR_FN (call))
> + nothrow
> + |= TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (AGGR_INIT_EXPR_FN (call))));
You should be able to avoid duplication here by using cp_get_callee
rather than *_FN.
Jason
