From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 96887 invoked by alias); 18 Sep 2018 15:26:07 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 96877 invoked by uid 89); 18 Sep 2018 15:26:06 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-26.9 required=5.0 tests=BAYES_00,GIT_PATCH_0,GIT_PATCH_1,GIT_PATCH_2,GIT_PATCH_3,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy= X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 18 Sep 2018 15:26:02 +0000 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D94D330832EE for ; Tue, 18 Sep 2018 15:26:00 +0000 (UTC) Received: from redhat.com (dhcp-17-157.bos.redhat.com [10.18.17.157]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 2C2934DA8D; Tue, 18 Sep 2018 15:26:00 +0000 (UTC) Date: Tue, 18 Sep 2018 15:37:00 -0000 From: Marek Polacek To: Jason Merrill Cc: GCC Patches , Jakub Jelinek Subject: Re: C++ PATCH to implement P1064R0, Virtual Function Calls in Constant Expressions (v4) Message-ID: <20180918152558.GP16755@redhat.com> References: <20180914171950.GE5587@redhat.com> <20180914204521.GJ5587@redhat.com> <20180917213938.GL5587@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-SW-Source: 2018-09/txt/msg00996.txt.bz2 On Mon, Sep 17, 2018 at 11:28:06PM -0400, Jason Merrill wrote: > On Mon, Sep 17, 2018 at 5:39 PM, Marek Polacek wrote: > > On Fri, Sep 14, 2018 at 04:45:22PM -0400, Marek Polacek wrote: > >> On Fri, Sep 14, 2018 at 04:30:46PM -0400, Jason Merrill wrote: > >> > On Fri, Sep 14, 2018 at 1:19 PM, Marek Polacek wrote: > >> > > This patch implements another bit of C++20, virtual calls in constant > >> > > expression: > >> > > > >> > > The basic idea is that since in a constant expression we know the dynamic > >> > > type (to detect invalid code etc.), the restriction that prohibits virtual > >> > > calls is unnecessary. > >> > > > >> > > Handling virtual function calls turned out to be fairly easy (as anticipated); > >> > > I simply let the constexpr machinery figure out the dynamic type and then > >> > > OBJ_TYPE_REF_TOKEN gives us the index into the virtual function table. That > >> > > way we get the function decl we're interested in, and cxx_eval_call_expression > >> > > takes it from there. > >> > > > >> > > But handling pointer-to-virtual-member-functions doesn't work like that. > >> > > get_member_function_from_ptrfunc creates a COND_EXPR which looks like > >> > > if (pf.__pfn & 1) // is it a virtual function? > >> > > // yes, find the pointer in the vtable > >> > > else > >> > > // no, just return the pointer > >> > > so ideally we want to evaluate the then-branch. Eventually it'll evaluate it > >> > > to something like _ZTV2X2[2], but the vtable isn't constexpr so we'd end up > >> > > with "not a constant expression" error. > >> > > >> > Then let's mark the vtable as constexpr, there's no reason for it not to be. > > > > Done. But then I had to add indexes to the vtable's ctor (because find_array_ctor_elt > > expects it), which broke an assert in gimple_get_virt_method_for_vtable. But I > > don't need the array_ref hack anymore! > > > Also, I had to set DECL_DECLARED_CONSTEXPR_P after maybe_commonize_var, > > otherwise we run into the sorry in that function with -fno-weak... > > Hmm, we shouldn't give that sorry for DECL_ARTIFICIAL variables. > > Looking more closely, it seems that the call to maybe_commonize_var > from initialize_artificial_var did nothing before this change, since > the vtable is DECL_ARTIFICIAL, so it didn't pass the condition at the > top. I suppose we should extend the !DECL_ARTIFICIAL check in > maybe_commonize_var to the inline variable case as well. Done. And then I could move setting DECL_DECLARED_CONSTEXPR_P to initialize_artificial_var, which is where I think it belongs. > >> Ok, unfortunately it wasn't as easy as merely marking it DECL_DECLARED_CONSTEXPR_P > >> in initialize_artificial_var because then I saw "used in its own initializer" > >> error. Which I don't know why, but now that I know you agree with this direction > >> I can dig deeper. > >> > >> > > Since the vtable initializer is > >> > > a compile-time constant, I thought we could make it work by a hack as the one > >> > > in cxx_eval_array_reference. We'll then let cxx_eval_call_expression do its > >> > > job and everything is hunky-dory. > >> > > > >> > > Except when it isn't: I noticed that the presence of _vptr doesn't make the > >> > > class non-empty, and when cxx_eval_constant_expression saw a decl with an empty > >> > > class type, it just evaluated it to { }. But such a class still had gotten an > >> > > initializer that looks like {.D.2082 = {._vptr.X2 = &_ZTV2X2 + 16}}. So > >> > > replacing it with { } will lose the proper initializer whereupon we fail. > >> > > The check I've added to cxx_eval_constant_expression won't win any beauty > >> > > contests but unfortunately EMPTY_CONSTRUCTOR_P doesn't work there. > >> > > >> > Perhaps we should check !TYPE_POLYMORPHIC_P as well as > >> > is_really_empty_class. Perhaps there should be a predicate for that, > >> > say, is_really_nearly_empty_class... > > > > For now I've only added the !TYPE_POLYMORPHIC_P check, which works just fine. > > > > Bootstrapped/regtested on x86_64-linux, ok for trunk? > > > > 2018-09-17 Marek Polacek > > > > P1064R0 - Allowing Virtual Function Calls in Constant Expressions > > * call.c (build_over_call): Add FIXME. > > * class.c (initialize_vtable): Mark the vtable as constexpr. > > (build_vtbl_initializer): Build vtable's constructor with indexes. > > * constexpr.c (cxx_eval_constant_expression): Don't ignore _vptr's > > initializer. Handle OBJ_TYPE_REF. > > (potential_constant_expression_1): Handle OBJ_TYPE_REF. > > * decl.c (grokdeclarator): Change error to pedwarn. Only warn when > > pedantic and not C++2a. > > > > * gimple-fold.c (gimple_get_virt_method_for_vtable): Remove assert. > > > > * g++.dg/cpp0x/constexpr-virtual5.C: Adjust dg-error. > > * g++.dg/cpp2a/constexpr-virtual1.C: New test. > > * g++.dg/cpp2a/constexpr-virtual2.C: New test. > > * g++.dg/cpp2a/constexpr-virtual3.C: New test. > > * g++.dg/cpp2a/constexpr-virtual4.C: New test. > > * g++.dg/cpp2a/constexpr-virtual5.C: New test. > > * g++.dg/cpp2a/constexpr-virtual6.C: New test. > > * g++.dg/cpp2a/constexpr-virtual7.C: New test. > > * g++.dg/cpp2a/constexpr-virtual8.C: New test. > > * g++.dg/cpp2a/constexpr-virtual9.C: New test. > > * g++.dg/diagnostic/virtual-constexpr.C: Skip for C++2a. Use > > -pedantic-errors. Adjust dg-error. > > > > diff --git gcc/cp/call.c gcc/cp/call.c > > index 69503ca7920..6c70874af40 100644 > > --- gcc/cp/call.c > > +++ gcc/cp/call.c > > @@ -8401,7 +8401,8 @@ build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain) > > > > if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0 > > /* Don't mess with virtual lookup in instantiate_non_dependent_expr; > > - virtual functions can't be constexpr. */ > > + virtual functions can't be constexpr. FIXME Actually, no longer > > + true in C++2a. */ > > && !in_template_function ()) > > I notice that removing the in_template_function check doesn't break > template/virtual4.C nowadays. Does it break anything else? It doesn't seem to! So, removed. > > + /* The C++ FE now produces indexed fields but we can index the array > > + directly. */ > > if (access_index < CONSTRUCTOR_NELTS (init)) > > { > > fn = CONSTRUCTOR_ELT (init, access_index)->value; > > - gcc_checking_assert (!CONSTRUCTOR_ELT (init, access_index)->index); > > Rather than remove this assert, let's fix it to check that the ->index > matches access_index. Done. Bootstrapped/regtested on ppc64le-linux, additionally tested dg.exp with GXX_TESTSUITE_STDS=98,11,14,17,2a on x86_64-linux, ok for trunk? 2018-09-18 Marek Polacek P1064R0 - Allowing Virtual Function Calls in Constant Expressions * call.c (build_over_call): No longer check if we're outside a template function. * class.c (build_vtbl_initializer): Build vtable's constructor with indexes. * constexpr.c (cxx_eval_constant_expression): Don't ignore _vptr's initializer. Handle OBJ_TYPE_REF. (potential_constant_expression_1): Handle OBJ_TYPE_REF. * decl.c (maybe_commonize_var): Bail out for any DECL_ARTIFICIAL. (initialize_artificial_var): Mark the variable as constexpr. (grokdeclarator): Change error to pedwarn. Only warn when pedantic and not C++2a. * gimple-fold.c (gimple_get_virt_method_for_vtable): Adjust assert. * g++.dg/cpp0x/constexpr-virtual5.C: Adjust dg-error. * g++.dg/cpp2a/constexpr-virtual1.C: New test. * g++.dg/cpp2a/constexpr-virtual2.C: New test. * g++.dg/cpp2a/constexpr-virtual3.C: New test. * g++.dg/cpp2a/constexpr-virtual4.C: New test. * g++.dg/cpp2a/constexpr-virtual5.C: New test. * g++.dg/cpp2a/constexpr-virtual6.C: New test. * g++.dg/cpp2a/constexpr-virtual7.C: New test. * g++.dg/cpp2a/constexpr-virtual8.C: New test. * g++.dg/cpp2a/constexpr-virtual9.C: New test. * g++.dg/diagnostic/virtual-constexpr.C: Skip for C++2a. Use -pedantic-errors. Adjust dg-error. diff --git gcc/cp/call.c gcc/cp/call.c index 69503ca7920..ddf0ed044a0 100644 --- gcc/cp/call.c +++ gcc/cp/call.c @@ -8399,10 +8399,7 @@ build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain) && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL) maybe_warn_class_memaccess (input_location, fn, args); - if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0 - /* Don't mess with virtual lookup in instantiate_non_dependent_expr; - virtual functions can't be constexpr. */ - && !in_template_function ()) + if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0) { tree t; tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (argarray[0])), diff --git gcc/cp/class.c gcc/cp/class.c index e950a7423f7..b9cde037337 100644 --- gcc/cp/class.c +++ gcc/cp/class.c @@ -9266,6 +9266,7 @@ build_vtbl_initializer (tree binfo, tree vcall_index; tree fn, fn_original; tree init = NULL_TREE; + tree idx = build_int_cst (size_type_node, jx++); fn = BV_FN (v); fn_original = fn; @@ -9369,7 +9370,7 @@ build_vtbl_initializer (tree binfo, int i; if (init == size_zero_node) for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i) - CONSTRUCTOR_APPEND_ELT (*inits, NULL_TREE, init); + CONSTRUCTOR_APPEND_ELT (*inits, idx, init); else for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i) { @@ -9377,11 +9378,11 @@ build_vtbl_initializer (tree binfo, fn, build_int_cst (NULL_TREE, i)); TREE_CONSTANT (fdesc) = 1; - CONSTRUCTOR_APPEND_ELT (*inits, NULL_TREE, fdesc); + CONSTRUCTOR_APPEND_ELT (*inits, idx, fdesc); } } else - CONSTRUCTOR_APPEND_ELT (*inits, NULL_TREE, init); + CONSTRUCTOR_APPEND_ELT (*inits, idx, init); } } diff --git gcc/cp/constexpr.c gcc/cp/constexpr.c index 88c73787961..aa33319875f 100644 --- gcc/cp/constexpr.c +++ gcc/cp/constexpr.c @@ -4209,7 +4209,11 @@ cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t, CONST_DECL for aggregate constants. */ if (lval) return t; + /* is_really_empty_class doesn't take into account _vptr, so initializing + otherwise empty class with { } would overwrite the initializer that + initialize_vtable created for us. */ if (COMPLETE_TYPE_P (TREE_TYPE (t)) + && !TYPE_POLYMORPHIC_P (TREE_TYPE (t)) && is_really_empty_class (TREE_TYPE (t))) { /* If the class is empty, we aren't actually loading anything. */ @@ -4778,7 +4782,6 @@ cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t, case MODOP_EXPR: /* GCC internal stuff. */ case VA_ARG_EXPR: - case OBJ_TYPE_REF: case NON_DEPENDENT_EXPR: case BASELINK: case OFFSET_REF: @@ -4788,6 +4791,34 @@ cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t, *non_constant_p = true; break; + case OBJ_TYPE_REF: + { + /* Virtual function call. Let the constexpr machinery figure out + the dynamic type. */ + int token = tree_to_shwi (OBJ_TYPE_REF_TOKEN (t)); + tree obj = OBJ_TYPE_REF_OBJECT (t); + obj = cxx_eval_constant_expression (ctx, obj, lval, non_constant_p, + overflow_p); + /* We expect something in the form of &x.D.2103.D.2094; get x. */ + if (TREE_CODE (obj) != ADDR_EXPR) + { + if (!ctx->quiet) + error_at (cp_expr_loc_or_loc (t, input_location), + "expression %qE is not a constant expression", t); + *non_constant_p = true; + return t; + } + obj = TREE_OPERAND (obj, 0); + while (handled_component_p (obj)) + obj = TREE_OPERAND (obj, 0); + tree objtype = TREE_TYPE (obj); + /* Find the function decl in the virtual functions list. TOKEN is + the DECL_VINDEX that says which function we're looking for. */ + tree virtuals = BINFO_VIRTUALS (TYPE_BINFO (objtype)); + r = TREE_VALUE (chain_index (token, virtuals)); + break; + } + case PLACEHOLDER_EXPR: /* Use of the value or address of the current object. */ if (tree ctor = lookup_placeholder (ctx, lval, TREE_TYPE (t))) @@ -5871,7 +5902,6 @@ potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now, case OACC_UPDATE: /* GCC internal stuff. */ case VA_ARG_EXPR: - case OBJ_TYPE_REF: case TRANSACTION_EXPR: case ASM_EXPR: case AT_ENCODE_EXPR: @@ -5880,6 +5910,14 @@ potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now, error_at (loc, "expression %qE is not a constant expression", t); return false; + case OBJ_TYPE_REF: + if (cxx_dialect >= cxx2a) + /* In C++2a virtual calls can be constexpr, don't give up yet. */ + return true; + else if (flags & tf_error) + error_at (loc, "virtual functions cannot be constexpr before C++2a"); + return false; + case TYPEID_EXPR: /* -- a typeid expression whose operand is of polymorphic class type; */ diff --git gcc/cp/decl.c gcc/cp/decl.c index 50b60e89df5..827c1720335 100644 --- gcc/cp/decl.c +++ gcc/cp/decl.c @@ -5583,11 +5583,13 @@ layout_var_decl (tree decl) void maybe_commonize_var (tree decl) { + /* Don't mess with __FUNCTION__ and similar. */ + if (DECL_ARTIFICIAL (decl)) + return; + /* Static data in a function with comdat linkage also has comdat linkage. */ if ((TREE_STATIC (decl) - /* Don't mess with __FUNCTION__. */ - && ! DECL_ARTIFICIAL (decl) && DECL_FUNCTION_SCOPE_P (decl) && vague_linkage_p (DECL_CONTEXT (decl))) || (TREE_PUBLIC (decl) && DECL_INLINE_VAR_P (decl))) @@ -6774,6 +6776,10 @@ initialize_artificial_var (tree decl, vec *v) gcc_assert (TREE_CODE (init) == CONSTRUCTOR); DECL_INITIAL (decl) = init; DECL_INITIALIZED_P (decl) = 1; + /* Mark the decl as constexpr so that we can access its content + at compile time. */ + DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl) = true; + DECL_DECLARED_CONSTEXPR_P (decl) = true; determine_visibility (decl); layout_var_decl (decl); maybe_commonize_var (decl); @@ -10854,12 +10860,13 @@ grokdeclarator (const cp_declarator *declarator, storage_class = sc_none; staticp = 0; } - if (constexpr_p) + if (constexpr_p && cxx_dialect < cxx2a) { gcc_rich_location richloc (declspecs->locations[ds_virtual]); richloc.add_range (declspecs->locations[ds_constexpr]); - error_at (&richloc, "member %qD cannot be declared both % " - "and %", dname); + pedwarn (&richloc, OPT_Wpedantic, "member %qD can be declared both " + "% and % only in -std=c++2a or " + "-std=gnu++2a", dname); } } friendp = decl_spec_seq_has_spec_p (declspecs, ds_friend); diff --git gcc/gimple-fold.c gcc/gimple-fold.c index 362ab59e9c0..1e84722d22d 100644 --- gcc/gimple-fold.c +++ gcc/gimple-fold.c @@ -6988,12 +6988,13 @@ gimple_get_virt_method_for_vtable (HOST_WIDE_INT token, access_index = offset / BITS_PER_UNIT / elt_size; gcc_checking_assert (offset % (elt_size * BITS_PER_UNIT) == 0); - /* This code makes an assumption that there are no - indexed fileds produced by C++ FE, so we can directly index the array. */ + /* The C++ FE can now produce indexed fields, and we check if the indexes + match. */ if (access_index < CONSTRUCTOR_NELTS (init)) { fn = CONSTRUCTOR_ELT (init, access_index)->value; - gcc_checking_assert (!CONSTRUCTOR_ELT (init, access_index)->index); + tree idx = CONSTRUCTOR_ELT (init, access_index)->index; + gcc_checking_assert (!idx || tree_to_uhwi (idx) == access_index); STRIP_NOPS (fn); } else diff --git gcc/testsuite/g++.dg/cpp0x/constexpr-virtual5.C gcc/testsuite/g++.dg/cpp0x/constexpr-virtual5.C index 2465f9d9b4f..5f9ab4d9c28 100644 --- gcc/testsuite/g++.dg/cpp0x/constexpr-virtual5.C +++ gcc/testsuite/g++.dg/cpp0x/constexpr-virtual5.C @@ -2,5 +2,5 @@ // { dg-do compile { target c++11 } } struct S { - constexpr virtual int f() { return 1; } // { dg-error "13:member .f. cannot be declared both .virtual. and .constexpr." } + constexpr virtual int f() { return 1; } // { dg-error "13:member .f. can be declared both .virtual. and .constexpr." "" { target c++17_down } } }; diff --git gcc/testsuite/g++.dg/cpp2a/constexpr-virtual1.C gcc/testsuite/g++.dg/cpp2a/constexpr-virtual1.C index e69de29bb2d..fcf8cac6417 100644 --- gcc/testsuite/g++.dg/cpp2a/constexpr-virtual1.C +++ gcc/testsuite/g++.dg/cpp2a/constexpr-virtual1.C @@ -0,0 +1,8 @@ +// P1064R0 +// { dg-do compile { target c++11 } } +// { dg-options "-pedantic-errors" } + +struct X +{ + constexpr virtual int f() { return 0; } // { dg-error "member .f. can be declared both .virtual. and .constexpr. only" "" { target c++17_down } } +}; diff --git gcc/testsuite/g++.dg/cpp2a/constexpr-virtual2.C gcc/testsuite/g++.dg/cpp2a/constexpr-virtual2.C index e69de29bb2d..9d82c5c59ac 100644 --- gcc/testsuite/g++.dg/cpp2a/constexpr-virtual2.C +++ gcc/testsuite/g++.dg/cpp2a/constexpr-virtual2.C @@ -0,0 +1,49 @@ +// P1064R0 +// { dg-do compile } +// { dg-options "-std=c++2a" } + +struct X1 +{ + virtual int f() const = 0; +}; + +struct X2: public X1 +{ + constexpr virtual int f() const { return 2; } +}; + +struct X3: public X2 +{ + virtual int f() const { return 3; } +}; + +struct X4: public X3 +{ + constexpr virtual int f() const { return 4; } +}; + +constexpr int (X1::*pf)() const = &X1::f; + +constexpr X2 x2; +static_assert(x2.f() == 2); +static_assert((x2.*pf)() == 2); + +constexpr X1 const& r2 = x2; +static_assert(r2.f() == 2); +static_assert((r2.*pf)() == 2); + +constexpr X1 const* p2 = &x2; +static_assert(p2->f() == 2); +static_assert((p2->*pf)() == 2); + +constexpr X4 x4; +static_assert(x4.f() == 4); +static_assert((x4.*pf)() == 4); + +constexpr X1 const& r4 = x4; +static_assert(r4.f() == 4); +static_assert((r4.*pf)() == 4); + +constexpr X1 const* p4 = &x4; +static_assert(p4->f() == 4); +static_assert((p4->*pf)() == 4); diff --git gcc/testsuite/g++.dg/cpp2a/constexpr-virtual3.C gcc/testsuite/g++.dg/cpp2a/constexpr-virtual3.C index e69de29bb2d..d71422fc4d0 100644 --- gcc/testsuite/g++.dg/cpp2a/constexpr-virtual3.C +++ gcc/testsuite/g++.dg/cpp2a/constexpr-virtual3.C @@ -0,0 +1,52 @@ +// P1064R0 +// { dg-do compile } +// { dg-options "-std=c++2a" } + +struct X1 +{ + virtual int f() const = 0; +}; + +struct X2: public X1 +{ + int i2 = 42; + constexpr virtual int f() const { return 2; } +}; + +struct X3: public X2 +{ + int i3 = 42; + virtual int f() const { return 3; } +}; + +struct X4: public X3 +{ + int i4 = 42; + constexpr virtual int f() const { return 4; } +}; + +constexpr int (X1::*pf)() const = &X1::f; + +constexpr X2 x2; +static_assert(x2.f() == 2); +static_assert((x2.*pf)() == 2); + +constexpr X1 const& r2 = x2; +static_assert(r2.f() == 2); +static_assert((r2.*pf)() == 2); + +constexpr X1 const* p2 = &x2; +static_assert(p2->f() == 2); +static_assert((p2->*pf)() == 2); + +constexpr X4 x4; +static_assert(x4.f() == 4); +static_assert((x4.*pf)() == 4); + +constexpr X1 const& r4 = x4; +static_assert(r4.f() == 4); +static_assert((r4.*pf)() == 4); + +constexpr X1 const* p4 = &x4; +static_assert(p4->f() == 4); +static_assert((p4->*pf)() == 4); diff --git gcc/testsuite/g++.dg/cpp2a/constexpr-virtual4.C gcc/testsuite/g++.dg/cpp2a/constexpr-virtual4.C index e69de29bb2d..2038bebc6d1 100644 --- gcc/testsuite/g++.dg/cpp2a/constexpr-virtual4.C +++ gcc/testsuite/g++.dg/cpp2a/constexpr-virtual4.C @@ -0,0 +1,57 @@ +// P1064R0 +// { dg-do compile } +// { dg-options "-std=c++2a" } + +struct X1 +{ + virtual int f1() const = 0; + virtual int f2() const = 0; + virtual int f3() const = 0; +}; + +struct X2: public X1 +{ + constexpr virtual int f1() const { return 21; } + constexpr virtual int f2() const { return 22; } + constexpr virtual int f3() const { return 23; } +}; + +struct X3: public X2 +{ + virtual int f1() const { return 31; } + virtual int f2() const { return 32; } + virtual int f3() const { return 33; } +}; + +struct X4: public X3 +{ + constexpr virtual int f1() const { return 41; } + constexpr virtual int f2() const { return 42; } + constexpr virtual int f3() const { return 43; } +}; + +constexpr int (X1::*pf)() const = &X1::f2; + +constexpr X2 x2; +static_assert(x2.f2() == 22); +static_assert((x2.*pf)() == 22); + +constexpr X1 const& r2 = x2; +static_assert(r2.f2() == 22); +static_assert((r2.*pf)() == 22); + +constexpr X1 const* p2 = &x2; +static_assert(p2->f2() == 22); +static_assert((p2->*pf)() == 22); + +constexpr X4 x4; +static_assert(x4.f2() == 42); +static_assert((x4.*pf)() == 42); + +constexpr X1 const& r4 = x4; +static_assert(r4.f2() == 42); +static_assert((r4.*pf)() == 42); + +constexpr X1 const* p4 = &x4; +static_assert(p4->f2() == 42); +static_assert((p4->*pf)() == 42); diff --git gcc/testsuite/g++.dg/cpp2a/constexpr-virtual5.C gcc/testsuite/g++.dg/cpp2a/constexpr-virtual5.C index e69de29bb2d..6d27990a8b6 100644 --- gcc/testsuite/g++.dg/cpp2a/constexpr-virtual5.C +++ gcc/testsuite/g++.dg/cpp2a/constexpr-virtual5.C @@ -0,0 +1,60 @@ +// P1064R0 +// { dg-do compile } +// { dg-options "-std=c++2a" } + +struct X1 +{ + virtual int f1() const = 0; + virtual int f2() const = 0; + virtual int f3() const = 0; +}; + +struct X2: public X1 +{ + int i2 = 42; + constexpr virtual int f1() const { return 21; } + constexpr virtual int f2() const { return 22; } + constexpr virtual int f3() const { return 23; } +}; + +struct X3: public X2 +{ + int i3 = 42; + virtual int f1() const { return 31; } + virtual int f2() const { return 32; } + virtual int f3() const { return 33; } +}; + +struct X4: public X3 +{ + int i4 = 42; + constexpr virtual int f1() const { return 41; } + constexpr virtual int f2() const { return 42; } + constexpr virtual int f3() const { return 43; } +}; + +constexpr int (X1::*pf)() const = &X1::f2; + +constexpr X2 x2; +static_assert(x2.f2() == 22); +static_assert((x2.*pf)() == 22); + +constexpr X1 const& r2 = x2; +static_assert(r2.f2() == 22); +static_assert((r2.*pf)() == 22); + +constexpr X1 const* p2 = &x2; +static_assert(p2->f2() == 22); +static_assert((p2->*pf)() == 22); + +constexpr X4 x4; +static_assert(x4.f2() == 42); +static_assert((x4.*pf)() == 42); + +constexpr X1 const& r4 = x4; +static_assert(r4.f2() == 42); +static_assert((r4.*pf)() == 42); + +constexpr X1 const* p4 = &x4; +static_assert(p4->f2() == 42); +static_assert((p4->*pf)() == 42); diff --git gcc/testsuite/g++.dg/cpp2a/constexpr-virtual6.C gcc/testsuite/g++.dg/cpp2a/constexpr-virtual6.C index e69de29bb2d..ece5e703c32 100644 --- gcc/testsuite/g++.dg/cpp2a/constexpr-virtual6.C +++ gcc/testsuite/g++.dg/cpp2a/constexpr-virtual6.C @@ -0,0 +1,25 @@ +// P1064R0 +// { dg-do compile } +// { dg-options "-std=c++2a" } + +struct X1 +{ + constexpr virtual X1 const *f() const { return this; } +}; + +struct Y +{ + int m = 0; +}; + +struct X2: public Y, public X1 +{ + constexpr virtual X2 const *f() const { return this; } +}; + +constexpr X1 x1; +static_assert(x1.f() == &x1); + +constexpr X2 x2; +constexpr X1 const& r2 = x2; +static_assert(r2.f() == &r2); diff --git gcc/testsuite/g++.dg/cpp2a/constexpr-virtual7.C gcc/testsuite/g++.dg/cpp2a/constexpr-virtual7.C index e69de29bb2d..b0f499608ef 100644 --- gcc/testsuite/g++.dg/cpp2a/constexpr-virtual7.C +++ gcc/testsuite/g++.dg/cpp2a/constexpr-virtual7.C @@ -0,0 +1,87 @@ +// P1064R0 +// { dg-do compile } +// { dg-options "-std=c++2a" } + +struct X1 +{ + virtual int f() const = 0; +}; + +struct X2: public X1 +{ + constexpr virtual int f() const { return 2; } +}; + +struct X3: public X2 +{ + virtual int f() const { return 3; } +}; + +struct X4: public X3 +{ + constexpr virtual int f() const { return 4; } +}; + +constexpr int (X1::*pf)() const = &X1::f; + +constexpr X2 x2; + +struct S +{ + int i, j; + constexpr S() : i(x2.f()), j((x2.*pf)()) { } +}; + +static_assert(S().i == 2); +static_assert(S().j == 2); + +constexpr X1 const& r2 = x2; + +struct S2 +{ + int i, j; + constexpr S2() : i(r2.f()), j((r2.*pf)()) { } +}; + +static_assert(S2().i == 2); +static_assert(S2().j == 2); + +constexpr X1 const* p2 = &x2; +struct S3 +{ + int i, j; + constexpr S3() : i(p2->f()), j((p2->*pf)()) { } +}; + +static_assert(S3().i == 2); +static_assert(S3().j == 2); + +constexpr X4 x4; +struct S4 +{ + int i, j; + constexpr S4() : i(x4.f()), j((x4.*pf)()) { } +}; + +static_assert(S4().i == 4); +static_assert(S4().j == 4); + +constexpr X1 const& r4 = x4; +struct S5 +{ + int i, j; + constexpr S5() : i(r4.f()), j((r4.*pf)()) { } +}; + +static_assert(S5().i == 4); +static_assert(S5().j == 4); + +constexpr X1 const* p4 = &x4; +struct S6 +{ + int i, j; + constexpr S6() : i(p4->f()), j((p4->*pf)()) { } +}; + +static_assert(S6().i == 4); +static_assert(S6().j == 4); diff --git gcc/testsuite/g++.dg/cpp2a/constexpr-virtual8.C gcc/testsuite/g++.dg/cpp2a/constexpr-virtual8.C index e69de29bb2d..4a7cc972a91 100644 --- gcc/testsuite/g++.dg/cpp2a/constexpr-virtual8.C +++ gcc/testsuite/g++.dg/cpp2a/constexpr-virtual8.C @@ -0,0 +1,50 @@ +// P1064R0 +// { dg-do compile } +// { dg-options "-std=c++2a" } + +template +struct X1 +{ + virtual T f() const = 0; +}; + +struct X2: public X1 +{ + constexpr virtual int f() const { return 2; } +}; + +struct X3: public X2 +{ + virtual int f() const { return 3; } +}; + +struct X4: public X3 +{ + constexpr virtual int f() const { return 4; } +}; + +constexpr int (X1::*pf)() const = &X1::f; + +constexpr X2 x2; +static_assert(x2.f() == 2); +static_assert((x2.*pf)() == 2); + +constexpr X1 const& r2 = x2; +static_assert(r2.f() == 2); +static_assert((r2.*pf)() == 2); + +constexpr X1 const* p2 = &x2; +static_assert(p2->f() == 2); +static_assert((p2->*pf)() == 2); + +constexpr X4 x4; +static_assert(x4.f() == 4); +static_assert((x4.*pf)() == 4); + +constexpr X1 const& r4 = x4; +static_assert(r4.f() == 4); +static_assert((r4.*pf)() == 4); + +constexpr X1 const* p4 = &x4; +static_assert(p4->f() == 4); +static_assert((p4->*pf)() == 4); diff --git gcc/testsuite/g++.dg/cpp2a/constexpr-virtual9.C gcc/testsuite/g++.dg/cpp2a/constexpr-virtual9.C index e69de29bb2d..3a12adc2659 100644 --- gcc/testsuite/g++.dg/cpp2a/constexpr-virtual9.C +++ gcc/testsuite/g++.dg/cpp2a/constexpr-virtual9.C @@ -0,0 +1,83 @@ +// P1064R0 +// { dg-do compile } +// { dg-options "-std=c++2a" } + +struct X1 +{ + virtual int f() const = 0; + virtual int f(int) const = 0; + virtual int f(int, int) const = 0; +}; + +struct X2: public X1 +{ + constexpr virtual int f() const { return 2; } + constexpr virtual int f(int) const { return 12; } + constexpr virtual int f(int, int) const { return 22; } +}; + +struct X3: public X2 +{ + virtual int f() const { return 3; } + virtual int f(int) const { return 13; } + virtual int f(int, int) const { return 23; } +}; + +struct X4: public X3 +{ + constexpr virtual int f() const { return 4; } + constexpr virtual int f(int) const { return 14; } + constexpr virtual int f(int, int) const { return 24; } +}; + +constexpr int (X1::*pf)() const = &X1::f; +constexpr int (X1::*pf1)(int) const = &X1::f; +constexpr int (X1::*pf2)(int, int) const = &X1::f; + +constexpr X2 x2; +static_assert(x2.f() == 2); +static_assert((x2.*pf)() == 2); +static_assert(x2.f(1) == 12); +static_assert((x2.*pf1)(1) == 12); +static_assert(x2.f(1, 2) == 22); +static_assert((x2.*pf2)(1, 2) == 22); + +constexpr X1 const& r2 = x2; +static_assert(r2.f() == 2); +static_assert((r2.*pf)() == 2); +static_assert(r2.f(1) == 12); +static_assert((r2.*pf1)(1) == 12); +static_assert(r2.f(1, 2) == 22); +static_assert((r2.*pf2)(1, 2) == 22); + +constexpr X1 const* p2 = &x2; +static_assert(p2->f() == 2); +static_assert((p2->*pf)() == 2); +static_assert(p2->f(1) == 12); +static_assert((p2->*pf1)(1) == 12); +static_assert(p2->f(1, 2) == 22); +static_assert((p2->*pf2)(1, 2) == 22); + +constexpr X4 x4; +static_assert(x4.f() == 4); +static_assert((x4.*pf)() == 4); +static_assert(x4.f(1) == 14); +static_assert((x4.*pf1)(1) == 14); +static_assert(x4.f(1, 2) == 24); +static_assert((x4.*pf2)(1, 2) == 24); + +constexpr X1 const& r4 = x4; +static_assert(r4.f() == 4); +static_assert((r4.*pf)() == 4); +static_assert(r4.f(1) == 14); +static_assert((r4.*pf1)(1) == 14); +static_assert(r4.f(1, 2) == 24); +static_assert((r4.*pf2)(1, 2) == 24); + +constexpr X1 const* p4 = &x4; +static_assert(p4->f() == 4); +static_assert((p4->*pf)() == 4); +static_assert(p4->f(1) == 14); +static_assert((p4->*pf1)(1) == 14); +static_assert(p4->f(1, 2) == 24); +static_assert((p4->*pf2)(1, 2) == 24); diff --git gcc/testsuite/g++.dg/diagnostic/virtual-constexpr.C gcc/testsuite/g++.dg/diagnostic/virtual-constexpr.C index 2c83236cae9..9223c692737 100644 --- gcc/testsuite/g++.dg/diagnostic/virtual-constexpr.C +++ gcc/testsuite/g++.dg/diagnostic/virtual-constexpr.C @@ -1,14 +1,15 @@ -// { dg-options "-fdiagnostics-show-caret" } +// { dg-options "-fdiagnostics-show-caret -pedantic-errors" } // { dg-do compile { target c++11 } } +// { dg-skip-if "virtual constexpr" { *-*-* } { "-std=gnu++2a" } { "" } } struct S { - virtual constexpr void foo(); // { dg-error "3:member .foo. cannot be declared both .virtual. and .constexpr." } + virtual constexpr void foo(); // { dg-error "3:member .foo. can be declared both .virtual. and .constexpr." } /* { dg-begin-multiline-output "" } virtual constexpr void foo(); ^~~~~~~ ~~~~~~~~~ { dg-end-multiline-output "" } */ - constexpr virtual void bar(); // { dg-error "13:member .bar. cannot be declared both .virtual. and .constexpr." } + constexpr virtual void bar(); // { dg-error "13:member .bar. can be declared both .virtual. and .constexpr." } /* { dg-begin-multiline-output "" } constexpr virtual void bar(); ~~~~~~~~~ ^~~~~~~