On Thu, Oct 17, 2019 at 6:22 PM Jakub Jelinek <ja...@redhat.com> wrote:
>
> On Wed, Oct 16, 2019 at 04:36:07PM -0400, Jason Merrill wrote:
> > > As for CLEANUP_STMT, I've tried it (the second patch), but it didn't
> > > change
> > > anything, the diagnostics was still
> > > constexpr-dtor3.C:16:23: in ‘constexpr’ expansion of ‘f4()’
> > > constexpr-dtor3.C:16:24: in ‘constexpr’ expansion of ‘(&
> > > w13)->W7::~W7()’
> > > constexpr-dtor3.C:5:34: error: inline assembly is not a constant
> > > expression
> > > 5 | constexpr ~W7 () { if (w == 5) asm (""); w = 3; } // {
> > > dg-error "inline assembly is not a constant expression" }
> > > | ^~~
> > > constexpr-dtor3.C:5:34: note: only unevaluated inline assembly is allowed
> > > in a ‘constexpr’ function in C++2a
> > > as without that change.
> >
> > That's because the patch changes EXPR_LOCATION for evaluation of the
> > CLEANUP_BODY, but it should be for evaluation of CLEANUP_EXPR instead.
>
> Indeed, that works too. Bootstrapped/regtested on x86_64-linux and
> i686-linux, ok for trunk?
OK, thanks.
> 2019-10-18 Jakub Jelinek <ja...@redhat.com>
>
> * constexpr.c (cxx_eval_constant_expression) <case CLEANUP_STMT>:
> Temporarily change input_location to CLEANUP_STMT location.
>
> * g++.dg/cpp2a/constexpr-dtor3.C: Expect in 'constexpr' expansion of
> message on the line with variable declaration.
> * g++.dg/ext/constexpr-attr-cleanup1.C: Likewise.
>
> --- gcc/cp/constexpr.c.jj 2019-10-17 00:15:50.126726231 +0200
> +++ gcc/cp/constexpr.c 2019-10-17 11:21:34.400062565 +0200
> @@ -4984,14 +4984,20 @@ cxx_eval_constant_expression (const cons
> non_constant_p, overflow_p,
> jump_target);
> if (!CLEANUP_EH_ONLY (t) && !*non_constant_p)
> - /* Also evaluate the cleanup. If we weren't skipping at the
> - start of the CLEANUP_BODY, change jump_target temporarily
> - to &initial_jump_target, so that even a return or break or
> - continue in the body doesn't skip the cleanup. */
> - cxx_eval_constant_expression (ctx, CLEANUP_EXPR (t), true,
> - non_constant_p, overflow_p,
> - jump_target ? &initial_jump_target
> - : NULL);
> + {
> + location_t loc = input_location;
> + if (EXPR_HAS_LOCATION (t))
> + input_location = EXPR_LOCATION (t);
> + /* Also evaluate the cleanup. If we weren't skipping at the
> + start of the CLEANUP_BODY, change jump_target temporarily
> + to &initial_jump_target, so that even a return or break or
> + continue in the body doesn't skip the cleanup. */
> + cxx_eval_constant_expression (ctx, CLEANUP_EXPR (t), true,
> + non_constant_p, overflow_p,
> + jump_target ? &initial_jump_target
> + : NULL);
> + input_location = loc;
> + }
> }
> break;
>
> --- gcc/testsuite/g++.dg/cpp2a/constexpr-dtor3.C.jj 2019-10-17
> 00:15:49.425736657 +0200
> +++ gcc/testsuite/g++.dg/cpp2a/constexpr-dtor3.C 2019-10-17
> 11:20:13.977290046 +0200
> @@ -149,7 +149,7 @@ constexpr int x3 = f3 ();
> constexpr int
> f4 ()
> {
> - W7 w13 = 5;
> + W7 w13 = 5; // { dg-message "in 'constexpr' expansion of"
> }
> return 0;
> }
>
> --- gcc/testsuite/g++.dg/ext/constexpr-attr-cleanup1.C.jj 2019-10-03
> 00:32:15.604526950 +0200
> +++ gcc/testsuite/g++.dg/ext/constexpr-attr-cleanup1.C 2019-10-18
> 00:18:50.248166117 +0200
> @@ -15,7 +15,7 @@ cleanup2 (int *x)
> constexpr bool
> foo ()
> {
> - int a __attribute__((cleanup (cleanup))) = 1;
> + int a __attribute__((cleanup (cleanup))) = 1; // { dg-message "in
> 'constexpr' expansion of" }
> return true;
> }
>
>
>
> Jakub
