From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2122) id 134593860C3E; Tue, 26 Jan 2021 22:11:49 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 134593860C3E MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Jason Merrill To: gcc-cvs@gcc.gnu.org Subject: [gcc r11-6919] c++: Invisible refs are not restrict [PR97474] X-Act-Checkin: gcc X-Git-Author: Jason Merrill X-Git-Refname: refs/heads/master X-Git-Oldrev: a4dfd0f089af33f2af57bf422f9859405b9b4a16 X-Git-Newrev: 96253f069ead0736536de803b06a8053a85039a6 Message-Id: <20210126221149.134593860C3E@sourceware.org> Date: Tue, 26 Jan 2021 22:11:49 +0000 (GMT) X-BeenThere: gcc-cvs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 26 Jan 2021 22:11:49 -0000 https://gcc.gnu.org/g:96253f069ead0736536de803b06a8053a85039a6 commit r11-6919-g96253f069ead0736536de803b06a8053a85039a6 Author: Jason Merrill Date: Tue Jan 26 16:04:24 2021 -0500 c++: Invisible refs are not restrict [PR97474] In this testcase, we refer to the a parameter through a reference in its own member, which we asserted couldn't happen by marking the parameter as 'restrict'. This assumption could also be broken if the address escapes from the constructor. gcc/cp/ChangeLog: PR c++/97474 * call.c (type_passed_as): Don't mark invisiref restrict. gcc/testsuite/ChangeLog: PR c++/97474 * g++.dg/torture/pr97474.C: New test. Diff: --- gcc/cp/call.c | 6 +----- gcc/testsuite/g++.dg/torture/pr97474.C | 28 ++++++++++++++++++++++++++++ 2 files changed, 29 insertions(+), 5 deletions(-) diff --git a/gcc/cp/call.c b/gcc/cp/call.c index 5977582e279..87a7af12796 100644 --- a/gcc/cp/call.c +++ b/gcc/cp/call.c @@ -8263,11 +8263,7 @@ type_passed_as (tree type) { /* Pass classes with copy ctors by invisible reference. */ if (TREE_ADDRESSABLE (type)) - { - type = build_reference_type (type); - /* There are no other pointers to this temporary. */ - type = cp_build_qualified_type (type, TYPE_QUAL_RESTRICT); - } + type = build_reference_type (type); else if (targetm.calls.promote_prototypes (NULL_TREE) && INTEGRAL_TYPE_P (type) && COMPLETE_TYPE_P (type) diff --git a/gcc/testsuite/g++.dg/torture/pr97474.C b/gcc/testsuite/g++.dg/torture/pr97474.C new file mode 100644 index 00000000000..6ce117e43a5 --- /dev/null +++ b/gcc/testsuite/g++.dg/torture/pr97474.C @@ -0,0 +1,28 @@ +// PR c++/97474 +// { dg-do run } + +extern "C" int printf (const char *, ...); +extern "C" void abort (); + +struct A { + int a; + int& b; + + A(int x) : a(x), b(a) {} + A(const A& other) : a(other.a), b(a) {} + A() : a(0), b(a) {} +}; + +int foo(A a) { + a.a *= a.b; + return a.b; +} + + +int main() { + A a(3); + + int r = foo (a); + if (r != 9) + abort (); +}