From 18396541e4793382a989a23f41f5deb347610234 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Fri, 28 Feb 2020 17:35:32 +0100 Subject: [PATCH] c++: Further tweak for P1937R2 - const{expr,eval} inconsistencies Seems I've missed one thing, as the first hunk in https://github.com/cplusplus/draft/commit/c8e68ed202b4a9260616bcee8a9768b5dca4bbca changes the wording so that only potentially-evaluated id-expressions that denote immediate functions must appear only in the specified contexts. That IMO means that in unevaluated contexts there aren't such restrictions anymore, so I think in unevaluated contexts one should be able to take the address of an immediate function. 2020-02-28 Jakub Jelinek P1937R2 - Fixing inconsistencies between const{expr,eval} functions * typeck.c (cp_build_addr_expr_1): Allow taking address of immediate functions in unevaluated contexts. * g++.dg/cpp2a/consteval3.C: Change dg-error about taking address of immediate function in unevaluated contexts into dg-bogus. * g++.dg/cpp2a/consteval16.C: New test. --- gcc/cp/ChangeLog | 6 ++++++ gcc/cp/typeck.c | 1 + gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/g++.dg/cpp2a/consteval16.C | 7 +++++++ gcc/testsuite/g++.dg/cpp2a/consteval3.C | 4 ++-- 5 files changed, 21 insertions(+), 2 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp2a/consteval16.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 22fe8036f18..4dc30e0a321 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,9 @@ +2020-02-28 Jakub Jelinek + + P1937R2 - Fixing inconsistencies between const{expr,eval} functions + * typeck.c (cp_build_addr_expr_1): Allow taking address of immediate + functions in unevaluated contexts. + 2020-02-27 Nathan Sidwell PR c++/93933 diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c index 2a3243f3e81..8e3188a415d 100644 --- a/gcc/cp/typeck.c +++ b/gcc/cp/typeck.c @@ -6332,6 +6332,7 @@ cp_build_addr_expr_1 (tree arg, bool strict_lvalue, tsubst_flags_t complain) tree stripped_arg = tree_strip_any_location_wrapper (arg); if (TREE_CODE (stripped_arg) == FUNCTION_DECL && DECL_IMMEDIATE_FUNCTION_P (stripped_arg) + && cp_unevaluated_operand == 0 && (current_function_decl == NULL_TREE || !DECL_IMMEDIATE_FUNCTION_P (current_function_decl))) { diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index cde33ee5015..3727ae255fe 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,5 +1,10 @@ 2020-02-28 Jakub Jelinek + P1937R2 - Fixing inconsistencies between const{expr,eval} functions + * g++.dg/cpp2a/consteval3.C: Change dg-error about taking address of + immediate function in unevaluated contexts into dg-bogus. + * g++.dg/cpp2a/consteval16.C: New test. + PR middle-end/92152 * g++.dg/torture/pr92152.C (size_t): Use decltype (sizeof (0)) instead of hardcoding unsigned long. diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval16.C b/gcc/testsuite/g++.dg/cpp2a/consteval16.C new file mode 100644 index 00000000000..9b43de8b5fa --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/consteval16.C @@ -0,0 +1,7 @@ +// { dg-do compile } +// { dg-options "-std=c++2a" } + +consteval int foo () { return 0; } +int bar (int (*) ()); +auto sz = sizeof (bar (foo)); // { dg-bogus "taking address of an immediate function" } +decltype (bar (foo)) baz; // { dg-bogus "taking address of an immediate function" } diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval3.C b/gcc/testsuite/g++.dg/cpp2a/consteval3.C index edd3a7310b2..9fb1f1a0b12 100644 --- a/gcc/testsuite/g++.dg/cpp2a/consteval3.C +++ b/gcc/testsuite/g++.dg/cpp2a/consteval3.C @@ -31,8 +31,8 @@ consteval consteval int f11 () { return 0; } // { dg-error "duplicate 'consteval struct U { consteval ~U () {} }; // { dg-error "a destructor cannot be 'consteval'" } struct V { consteval int v = 5; }; // { dg-error "non-static data member 'v' declared 'consteval'" } struct W { consteval static int w; }; // { dg-error "static data member 'w' declared 'consteval'" } -int i = sizeof (&f6); // { dg-error "taking address of an immediate function 'consteval int f6\\(int\\)'" } -using j = decltype (&f6); // { dg-error "taking address of an immediate function 'consteval int f6\\(int\\)'" } +int i = sizeof (&f6); // { dg-bogus "taking address of an immediate function 'consteval int f6\\(int\\)'" } +using j = decltype (&f6); // { dg-bogus "taking address of an immediate function 'consteval int f6\\(int\\)'" } int k = sizeof (f6 (d)); // { dg-bogus "the value of 'd' is not usable in a constant expression" } using l = decltype (f6 (d)); // { dg-bogus "the value of 'd' is not usable in a constant expression" } bool m = noexcept (f6 (d)); // { dg-bogus "the value of 'd' is not usable in a constant expression" } -- 2.30.2