From 958d42abdf1a1936d290aab126cebd6bb4a52361 Mon Sep 17 00:00:00 2001 From: Patrick Palka Date: Fri, 11 Dec 2020 09:40:58 -0500 Subject: [PATCH] c++: missing SFINAE with pointer subtraction [PR78173] This fixes a missed SFINAE when subtracting pointers to an incomplete type. gcc/cp/ChangeLog: PR c++/78173 * typeck.c (pointer_diff): Use complete_type_or_maybe_complain instead of complete_type_or_else. gcc/testsuite/ChangeLog: PR c++/78173 * g++.dg/cpp2a/concepts-pr78173.C: New test. --- gcc/cp/typeck.c | 2 +- gcc/testsuite/g++.dg/cpp2a/concepts-pr78173.C | 9 +++++++++ 2 files changed, 10 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-pr78173.C diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c index afbb8ef02e6..a6505814c53 100644 --- a/gcc/cp/typeck.c +++ b/gcc/cp/typeck.c @@ -5984,7 +5984,7 @@ pointer_diff (location_t loc, tree op0, tree op1, tree ptrtype, tree restype = ptrdiff_type_node; tree target_type = TREE_TYPE (ptrtype); - if (!complete_type_or_else (target_type, NULL_TREE)) + if (!complete_type_or_maybe_complain (target_type, NULL_TREE, complain)) return error_mark_node; if (VOID_TYPE_P (target_type)) diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-pr78173.C b/gcc/testsuite/g++.dg/cpp2a/concepts-pr78173.C new file mode 100644 index 00000000000..50f561abcce --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-pr78173.C @@ -0,0 +1,9 @@ +// PR c++/78173 +// { dg-do compile { target c++20 } } + +template +concept CanDifference = requires(T x, T y) { + x - y; +}; + +static_assert(!CanDifference); -- 2.30.2