From 0e665f256b4ac8c5f78713ebd4e9378fd4ecf5a8 Mon Sep 17 00:00:00 2001 From: Patrick Palka Date: Tue, 21 Apr 2020 18:41:02 -0400 Subject: [PATCH] c++: Constrained inherited constructor template [PR94549] A comment in satisfy_declaration_constraints says /* For inherited constructors, consider the original declaration; it has the correct template information attached. */ d = strip_inheriting_ctors (d); but it looks like this comment is wrong when the inherited constructor is for an instantiation of a constructor template. In that case, DECL_TEMPLATE_INFO is correct and DECL_INHERITED_CTOR points to the constructor template of the base class rather than to the particular instantiation of the constructor template (and so the DECL_TI_ARGS of the DECL_INHERITED_CTOR are in their dependent form). So doing strip_inheriting_ctors in this case then eventually leads to satisfy_associated_constraints returning true regardless of the constraints themselves, due to the passed in 'args' being dependent. An inherited constructor seems to have a non-empty DECL_TEMPLATE_INFO only when it's for an instantiation of a constructor template, so this patch fixes this issue by checking for empty DECL_TEMPLATE_INFO before calling strip_inheriting_ctors. There is another unguarded call to strip_inheriting_ctors in get_normalized_constraints_from_decl, but this one seems to be safe to do unconditionally because the rest of that function doesn't need/look at the DECL_TI_ARGS of the decl. gcc/cp/ChangeLog: PR c++/94549 * constraint.cc (satisfy_declaration_constraints): Don't strip the inherited constructor if it already has template information. gcc/testsuite/ChangeLog: PR c++/94549 * g++.dg/concepts/inherit-ctor3.C: Adjust expected diagnostics. * g++.dg/cpp2a/concepts-inherit-ctor4.C: New test. * g++.dg/cpp2a/concepts-inherit-ctor8.C: New test. --- gcc/cp/ChangeLog | 4 ++++ gcc/cp/constraint.cc | 7 ++++--- gcc/testsuite/ChangeLog | 7 +++++++ gcc/testsuite/g++.dg/concepts/inherit-ctor3.C | 4 ++-- .../g++.dg/cpp2a/concepts-inherit-ctor4.C | 4 ++-- .../g++.dg/cpp2a/concepts-inherit-ctor8.C | 20 +++++++++++++++++++ 6 files changed, 39 insertions(+), 7 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-inherit-ctor8.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 372fd08d1f9..67b571c4408 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,5 +1,9 @@ 2020-04-21 Patrick Palka + PR c++/94549 + * constraint.cc (satisfy_declaration_constraints): Don't strip the + inherited constructor if it already has template information. + PR c++/94597 * pt.c (any_template_parm_r) : New case. If this is a conversion operator, visit its TREE_TYPE. diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc index e5308414879..d56ec101cd9 100644 --- a/gcc/cp/constraint.cc +++ b/gcc/cp/constraint.cc @@ -2737,9 +2737,10 @@ satisfy_declaration_constraints (tree t, subst_info info) { gcc_assert (DECL_P (t)); - /* For inherited constructors, consider the original declaration; - it has the correct template information attached. */ - if (flag_new_inheriting_ctors) + if (!DECL_TEMPLATE_INFO (t)) + /* For inherited constructors without template information, consider + the original declaration; it has the correct template information + attached. */ t = strip_inheriting_ctors (t); /* Update the declaration for diagnostics. */ diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 0d6714743fb..87d99b1e22b 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,10 @@ +2020-04-21 Patrick Palka + + PR c++/94549 + * g++.dg/concepts/inherit-ctor3.C: Adjust expected diagnostics. + * g++.dg/cpp2a/concepts-inherit-ctor4.C: New test. + * g++.dg/cpp2a/concepts-inherit-ctor8.C: New test. + 2020-04-21 Jonathan Wakely PR c++/94149 diff --git a/gcc/testsuite/g++.dg/concepts/inherit-ctor3.C b/gcc/testsuite/g++.dg/concepts/inherit-ctor3.C index abfe96e8240..6b7a7a43910 100644 --- a/gcc/testsuite/g++.dg/concepts/inherit-ctor3.C +++ b/gcc/testsuite/g++.dg/concepts/inherit-ctor3.C @@ -12,12 +12,12 @@ template template struct S2 : S1 { // { dg-error "no matching function" } - using S1::S1; // { dg-error "no matching function" } + using S1::S1; }; struct X { } x; int main() { - S2 s1(0); // { dg-error "use of deleted function" } + S2 s1(0); // { dg-error "no matching function" } S2 s2; // { dg-error "use of deleted function" } } diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-inherit-ctor4.C b/gcc/testsuite/g++.dg/cpp2a/concepts-inherit-ctor4.C index 75190eb3413..34eaf22c26c 100644 --- a/gcc/testsuite/g++.dg/cpp2a/concepts-inherit-ctor4.C +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-inherit-ctor4.C @@ -10,9 +10,9 @@ template template struct S2 : S1 { - using S1::S1; // { dg-error "no matching function" } + using S1::S1; }; int main() { - S2 s(0); // { dg-error "use of deleted function" } + S2 s(0); // { dg-error "no matching function" } } diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-inherit-ctor8.C b/gcc/testsuite/g++.dg/cpp2a/concepts-inherit-ctor8.C new file mode 100644 index 00000000000..5b571e32318 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-inherit-ctor8.C @@ -0,0 +1,20 @@ +// PR c++/94549 +// { dg-do compile { target concepts } } + +struct base { + template + requires false + base(type); + + template + requires true + base(type); +}; + +struct derived : base { + using base::base; +}; + +void foo() { + derived{'G'}; +} -- 2.30.2