From: Jason Merrill <jason@redhat.com>
To: Jakub Jelinek <jakub@redhat.com>
Cc: gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] c++: Fix up handling of non-dependent subscript with static operator[] [PR108437]
Date: Thu, 19 Jan 2023 13:09:04 -0500 [thread overview]
Message-ID: <f2161222-66a5-3b0f-6df6-9e87d31d6805@redhat.com> (raw)
In-Reply-To: <Y8kEy10R0C8zeVC5@tucnak>
On 1/19/23 03:52, Jakub Jelinek wrote:
> Hi!
>
> As the following testcases shows, when adding static operator[]
> support I've missed that the 2 build_min_non_dep_op_overload functions
> need to be adjusted. The first one we only use for the single index
> case, but as cp_tree_code_length (ARRAY_REF) is 2, we were running
> into an assertion there which compared nargs and expected_nargs.
> For ARRAY_REF, the operator[] is either a non-static member or newly
> static member, never out of class and for the static member case
> if user uses single index the operator[] needs to have a single
> argument as well, but the function is called with 2 - the object
> it is invoked on and the index.
This should be in a comment for the new special handling of ARRAY_REF.
OK with that change.
> We need to evaluate side-effects
> of the object and use just a single argument in the call - the index.
> The other build_min_non_dep_op_overload overload has been added
> solely for ARRAY_REF - CALL_EXPR is the other operator that accepts
> variable number of operands but that one goes through different
> routines. There we asserted it is a METHOD_TYPE, so again
> we shouldn't assert that but handle the case when it is not one
> by making sure object's side-effects are evaluated if needed and
> passing all the index arguments to the static operator[].
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
>
> 2023-01-19 Jakub Jelinek <jakub@redhat.com>
>
> PR c++/108437
> * cp-tree.h (keep_unused_object_arg): Declare.
> * call.cc (keep_unused_object_arg): No longer static.
> * tree.cc (build_min_non_dep_op_overload): Handle ARRAY_REF
> with overload being static member function.
>
> * g++.dg/cpp23/subscript12.C: New test.
> * g++.dg/cpp23/subscript13.C: New test.
>
> --- gcc/cp/cp-tree.h.jj 2023-01-16 11:52:16.067734300 +0100
> +++ gcc/cp/cp-tree.h 2023-01-18 16:47:55.258697839 +0100
> @@ -6599,6 +6599,7 @@ inline tree build_new_op (const op_locat
> return build_new_op (loc, code, flags, arg1, arg2, NULL_TREE, NULL_TREE,
> NULL, complain);
> }
> +extern tree keep_unused_object_arg (tree, tree, tree);
> extern tree build_op_call (tree, vec<tree, va_gc> **,
> tsubst_flags_t);
> extern tree build_op_subscript (const op_location_t &, tree,
> --- gcc/cp/call.cc.jj 2023-01-16 11:52:16.059734418 +0100
> +++ gcc/cp/call.cc 2023-01-18 16:48:02.966586328 +0100
> @@ -5187,7 +5187,7 @@ build_operator_new_call (tree fnname, ve
> or static operator(), in which cases the source expression
> would be `obj[...]' or `obj(...)'. */
>
> -static tree
> +tree
> keep_unused_object_arg (tree result, tree obj, tree fn)
> {
> if (result == NULL_TREE
> --- gcc/cp/tree.cc.jj 2023-01-16 11:52:16.093733917 +0100
> +++ gcc/cp/tree.cc 2023-01-18 17:01:08.937242864 +0100
> @@ -3693,14 +3693,14 @@ build_min_non_dep_op_overload (enum tree
> {
> va_list p;
> int nargs, expected_nargs;
> - tree fn, call;
> + tree fn, call, obj = NULL_TREE;
>
> non_dep = extract_call_expr (non_dep);
>
> nargs = call_expr_nargs (non_dep);
>
> expected_nargs = cp_tree_code_length (op);
> - if (TREE_CODE (TREE_TYPE (overload)) == METHOD_TYPE)
> + if (TREE_CODE (TREE_TYPE (overload)) == METHOD_TYPE || op == ARRAY_REF)
> expected_nargs -= 1;
> if ((op == POSTINCREMENT_EXPR
> || op == POSTDECREMENT_EXPR)
> @@ -3715,6 +3715,8 @@ build_min_non_dep_op_overload (enum tree
> if (TREE_CODE (TREE_TYPE (overload)) == FUNCTION_TYPE)
> {
> fn = overload;
> + if (op == ARRAY_REF)
> + obj = va_arg (p, tree);
> for (int i = 0; i < nargs; i++)
> {
> tree arg = va_arg (p, tree);
> @@ -3746,6 +3748,8 @@ build_min_non_dep_op_overload (enum tree
> CALL_EXPR_ORDERED_ARGS (call_expr) = CALL_EXPR_ORDERED_ARGS (non_dep);
> CALL_EXPR_REVERSE_ARGS (call_expr) = CALL_EXPR_REVERSE_ARGS (non_dep);
>
> + if (obj)
> + return keep_unused_object_arg (call, obj, overload);
> return call;
> }
>
> @@ -3759,11 +3763,15 @@ build_min_non_dep_op_overload (tree non_
> non_dep = extract_call_expr (non_dep);
>
> unsigned int nargs = call_expr_nargs (non_dep);
> - gcc_assert (TREE_CODE (TREE_TYPE (overload)) == METHOD_TYPE);
> - tree binfo = TYPE_BINFO (TREE_TYPE (object));
> - tree method = build_baselink (binfo, binfo, overload, NULL_TREE);
> - tree fn = build_min (COMPONENT_REF, TREE_TYPE (overload),
> - object, method, NULL_TREE);
> + tree fn = overload;
> + if (TREE_CODE (TREE_TYPE (overload)) == METHOD_TYPE)
> + {
> + tree binfo = TYPE_BINFO (TREE_TYPE (object));
> + tree method = build_baselink (binfo, binfo, overload, NULL_TREE);
> + fn = build_min (COMPONENT_REF, TREE_TYPE (overload),
> + object, method, NULL_TREE);
> + object = NULL_TREE;
> + }
> gcc_assert (vec_safe_length (args) == nargs);
>
> tree call = build_min_non_dep_call_vec (non_dep, fn, args);
> @@ -3774,6 +3782,8 @@ build_min_non_dep_op_overload (tree non_
> CALL_EXPR_ORDERED_ARGS (call_expr) = CALL_EXPR_ORDERED_ARGS (non_dep);
> CALL_EXPR_REVERSE_ARGS (call_expr) = CALL_EXPR_REVERSE_ARGS (non_dep);
>
> + if (object)
> + return keep_unused_object_arg (call, object, overload);
> return call;
> }
>
> --- gcc/testsuite/g++.dg/cpp23/subscript12.C.jj 2023-01-18 17:15:04.963153521 +0100
> +++ gcc/testsuite/g++.dg/cpp23/subscript12.C 2023-01-18 17:14:40.816503156 +0100
> @@ -0,0 +1,34 @@
> +// PR c++/108437
> +// { dg-do run { target c++23 } }
> +
> +struct S { static int &operator[] (int x) { static int a[2]; return a[x]; } };
> +struct U { static int &operator[] (int x, int y, int z) { static int a[2]; return a[x + y + z]; } };
> +struct V { static int &operator[] () { static int a; return a; } };
> +
> +template <class T, class W, class X> void
> +foo ()
> +{
> + S s;
> + s[0]++;
> + T t;
> + t[0]++;
> + U u;
> + u[0, 0, 0]++;
> + V v;
> + v[]++;
> + W w;
> + w[0, 0, 0]++;
> + X x;
> + x[]++;
> +}
> +
> +int
> +main ()
> +{
> + S::operator[] (0) = 1;
> + U::operator[] (0, 0, 0) = 2;
> + V::operator[] () = 3;
> + foo <S, U, V> ();
> + if (S::operator[] (0) != 3 || U::operator[] (0, 0, 0) != 4 || V::operator[] () != 5)
> + __builtin_abort ();
> +}
> --- gcc/testsuite/g++.dg/cpp23/subscript13.C.jj 2023-01-18 17:15:08.110107955 +0100
> +++ gcc/testsuite/g++.dg/cpp23/subscript13.C 2023-01-18 17:14:55.833285718 +0100
> @@ -0,0 +1,43 @@
> +// PR c++/108437
> +// { dg-do run { target c++23 } }
> +
> +struct S { static int &operator[] (int x) { static int a[2]; return a[x]; } };
> +struct U { static int &operator[] (int x, int y, int z) { static int a[2]; return a[x + y + z]; } };
> +struct V { static int &operator[] () { static int a; return a; } };
> +int cnt;
> +
> +template <typename T>
> +T &
> +bar (T &x)
> +{
> + ++cnt;
> + return x;
> +}
> +
> +template <class T, class W, class X> void
> +foo ()
> +{
> + S s;
> + bar (s)[0]++;
> + T t;
> + bar (t)[0]++;
> + U u;
> + bar (u)[0, 0, 0]++;
> + V v;
> + bar (v)[]++;
> + W w;
> + bar (w)[0, 0, 0]++;
> + X x;
> + bar (x)[]++;
> +}
> +
> +int
> +main ()
> +{
> + S::operator[] (0) = 1;
> + U::operator[] (0, 0, 0) = 2;
> + V::operator[] () = 3;
> + foo <S, U, V> ();
> + if (S::operator[] (0) != 3 || U::operator[] (0, 0, 0) != 4 || V::operator[] () != 5 || cnt != 6)
> + __builtin_abort ();
> +}
>
> Jakub
>
prev parent reply other threads:[~2023-01-19 18:09 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-19 8:52 Jakub Jelinek
2023-01-19 18:09 ` Jason Merrill [this message]
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