From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1734) id 2013C3858D28; Sat, 4 Mar 2023 17:43:45 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 2013C3858D28 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1677951825; bh=kmx5L1qTj90gxyyWsD9gr5wz0W1kKX7McAfiRGXX68c=; h=From:To:Subject:Date:From; b=jpnDSK5bb82iBOr/ydFKbQ8eMBcnrPv1IzXbALLS50RsDxbn7HA9bZi7vldS5bLTI Nyh9LEMEHgPOG44KeLRJC0qX9mp9Olk4Ow9YmCqNDbs3HgOmFWanlY3sma9XJdamV/ QUPa2NfRm8Naq5LbhkVc9sLeBqNzuCkJzSVYnBvM= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Marek Polacek To: gcc-cvs@gcc.gnu.org Subject: [gcc r12-9215] c++: ICE with constexpr variable template [PR107938] X-Act-Checkin: gcc X-Git-Author: Marek Polacek X-Git-Refname: refs/heads/releases/gcc-12 X-Git-Oldrev: aa1f923af4d8cb5f5735d39f667f61aa7c900b5e X-Git-Newrev: 445082ff3cb7f9d30021adf338e9ab6038c3e412 Message-Id: <20230304174345.2013C3858D28@sourceware.org> Date: Sat, 4 Mar 2023 17:43:45 +0000 (GMT) List-Id: https://gcc.gnu.org/g:445082ff3cb7f9d30021adf338e9ab6038c3e412 commit r12-9215-g445082ff3cb7f9d30021adf338e9ab6038c3e412 Author: Marek Polacek Date: Thu Feb 23 17:54:47 2023 -0500 c++: ICE with constexpr variable template [PR107938] Since r11-557, cp_finish_decl can call check_initializer even in a template for a constexpr initializer. That ultimately leads to convert_for_assignment and check_address_or_pointer_of_packed_member, where we crash, because it doesn't expect that the CALL_EXPR is a function object. Q has a constexpr operator(), but since we're in a template, q(0) is a CALL_EXPR whose CALL_EXPR_FN is just a VAR_DECL; it hasn't been converted to Q::operator(&q, 0) yet. I propose to robustify check_address_or_pointer_of_packed_member. var-templ74.C has an XFAIL, subject to 107939. I noticed that our -Waddress-of-packed-member tests weren't testing member functions, added thus. (I was tempted to check FUNCTION_POINTER_TYPE_P but that doesn't include METHOD_TYPE.) PR c++/107938 gcc/c-family/ChangeLog: * c-warn.cc (check_address_or_pointer_of_packed_member): Check POINTER_TYPE_P. gcc/testsuite/ChangeLog: * g++.dg/cpp1y/var-templ73.C: New test. * g++.dg/cpp1y/var-templ74.C: New test. * g++.dg/warn/Waddress-of-packed-member3.C: New test. (cherry picked from commit ea718febab2a1f6e58806738abf70f1c73c6a308) Diff: --- gcc/c-family/c-warn.cc | 4 ++++ gcc/testsuite/g++.dg/cpp1y/var-templ73.C | 12 +++++++++++ gcc/testsuite/g++.dg/cpp1y/var-templ74.C | 19 ++++++++++++++++++ .../g++.dg/warn/Waddress-of-packed-member3.C | 23 ++++++++++++++++++++++ 4 files changed, 58 insertions(+) diff --git a/gcc/c-family/c-warn.cc b/gcc/c-family/c-warn.cc index 0ad0034180b..0791ba1647a 100644 --- a/gcc/c-family/c-warn.cc +++ b/gcc/c-family/c-warn.cc @@ -2986,6 +2986,10 @@ check_address_or_pointer_of_packed_member (tree type, tree rhs) if (rhs == NULL_TREE) return NULL_TREE; rhs = TREE_TYPE (rhs); /* Pointer type. */ + /* We could be called while processing a template and RHS could be + a functor. In that case it's a class, not a pointer. */ + if (!POINTER_TYPE_P (rhs)) + return NULL_TREE; rhs = TREE_TYPE (rhs); /* Function type. */ rhstype = TREE_TYPE (rhs); if (!rhstype || !POINTER_TYPE_P (rhstype)) diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ73.C b/gcc/testsuite/g++.dg/cpp1y/var-templ73.C new file mode 100644 index 00000000000..b76babcfa81 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1y/var-templ73.C @@ -0,0 +1,12 @@ +// PR c++/107938 +// { dg-do compile { target c++14 } } + +struct Q { + int n; + constexpr const Q* operator()(int) const { return this; } +}; + +constexpr Q q{}; + +template +constexpr const Q* p = q(0); diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ74.C b/gcc/testsuite/g++.dg/cpp1y/var-templ74.C new file mode 100644 index 00000000000..4e2e800a6eb --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1y/var-templ74.C @@ -0,0 +1,19 @@ +// PR c++/107938 +// { dg-do compile { target c++14 } } + +struct Q { + int n; + constexpr const Q* operator()(int) const { return this; } +}; + +extern const Q q; + +template +constexpr const Q* p = q(0); // { dg-bogus "not usable" "PR107939" { xfail *-*-* } } + +void +g () +{ + constexpr const Q* p2 = q(0); + constexpr auto x = p<0>; +} diff --git a/gcc/testsuite/g++.dg/warn/Waddress-of-packed-member3.C b/gcc/testsuite/g++.dg/warn/Waddress-of-packed-member3.C new file mode 100644 index 00000000000..aeffb969c01 --- /dev/null +++ b/gcc/testsuite/g++.dg/warn/Waddress-of-packed-member3.C @@ -0,0 +1,23 @@ +// { dg-do compile { target { ! default_packed } } } +// Test that -Waddress-of-packed-member works with member functions. + +struct S { + char c; +} __attribute__((packed)); + +struct X { + S* memfn (); + static S* smemfn (); +} x; + +S *foo (); + +S** +f () +{ + S **s; + s = reinterpret_cast(foo ()); // { dg-warning "converting a packed" } + s = reinterpret_cast(x.memfn ()); // { dg-warning "converting a packed" } + s = reinterpret_cast(X::smemfn ()); // { dg-warning "converting a packed" } + return s; +}