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[patch] Constructing std::shared_ptr from an empty std::unique_ptr
- From: Jonathan Wakely <jwakely at redhat dot com>
- To: libstdc++ at gcc dot gnu dot org, gcc-patches at gcc dot gnu dot org
- Date: Wed, 13 May 2015 17:43:03 +0100
- Subject: [patch] Constructing std::shared_ptr from an empty std::unique_ptr
- Authentication-results: sourceware.org; auth=none
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4383.html#2415
Voted in to the WP in Lenexa.
Tested powerpc64le-linux, committed to trunk.
commit 87937e036ae87944f7ac2b26d8ae17fe81525c4f
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Wed May 13 15:54:45 2015 +0100
* include/bits/shared_ptr_base.h (__shared_count(unique_ptr&&)): Check
for nullptr (LWG 2415).
* testsuite/20_util/shared_ptr/cons/unique_ptr_deleter.cc: Test
construction from empty unique_ptr.
* testsuite/20_util/shared_ptr/cons/43820_neg.cc: Adjust dg-error.
* testsuite/20_util/shared_ptr/cons/void_neg.cc: Likewise.
diff --git a/libstdc++-v3/include/bits/shared_ptr_base.h b/libstdc++-v3/include/bits/shared_ptr_base.h
index 8c3af12..081df87 100644
--- a/libstdc++-v3/include/bits/shared_ptr_base.h
+++ b/libstdc++-v3/include/bits/shared_ptr_base.h
@@ -632,6 +632,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
explicit
__shared_count(std::unique_ptr<_Tp, _Del>&& __r) : _M_pi(0)
{
+ // _GLIBCXX_RESOLVE_LIB_DEFECTS
+ // 2415. Inconsistency between unique_ptr and shared_ptr
+ if (__r.get() == nullptr)
+ return;
+
using _Ptr = typename unique_ptr<_Tp, _Del>::pointer;
using _Del2 = typename conditional<is_reference<_Del>::value,
reference_wrapper<typename remove_reference<_Del>::type>,
diff --git a/libstdc++-v3/testsuite/20_util/shared_ptr/cons/43820_neg.cc b/libstdc++-v3/testsuite/20_util/shared_ptr/cons/43820_neg.cc
index 97cc139..6255522 100644
--- a/libstdc++-v3/testsuite/20_util/shared_ptr/cons/43820_neg.cc
+++ b/libstdc++-v3/testsuite/20_util/shared_ptr/cons/43820_neg.cc
@@ -32,7 +32,7 @@ void test01()
{
X* px = 0;
std::shared_ptr<X> p1(px); // { dg-error "here" }
- // { dg-error "incomplete" "" { target *-*-* } 886 }
+ // { dg-error "incomplete" "" { target *-*-* } 891 }
std::shared_ptr<X> p9(ap()); // { dg-error "here" }
// { dg-error "incomplete" "" { target *-*-* } 307 }
diff --git a/libstdc++-v3/testsuite/20_util/shared_ptr/cons/unique_ptr_deleter.cc b/libstdc++-v3/testsuite/20_util/shared_ptr/cons/unique_ptr_deleter.cc
index 67bf577..e010977 100644
--- a/libstdc++-v3/testsuite/20_util/shared_ptr/cons/unique_ptr_deleter.cc
+++ b/libstdc++-v3/testsuite/20_util/shared_ptr/cons/unique_ptr_deleter.cc
@@ -34,7 +34,7 @@ int D::count = 0;
// 20.7.12.2.1 shared_ptr constructors [util.smartptr.shared.const]
// Construction from unique_ptr
-int
+void
test01()
{
bool test __attribute__((unused)) = true;
@@ -47,13 +47,25 @@ test01()
VERIFY( sp.use_count() == 1 );
}
VERIFY( D::count == 1 );
+}
- return 0;
+void
+test02()
+{
+ bool test __attribute__((unused)) = true;
+
+ D::count = 0;
+ std::unique_ptr<A, D> up;
+ {
+ std::shared_ptr<A> sp = std::move(up);
+ }
+ VERIFY( D::count == 0 ); // LWG 2415
}
int
main()
{
test01();
+ test02();
return 0;
}
diff --git a/libstdc++-v3/testsuite/20_util/shared_ptr/cons/void_neg.cc b/libstdc++-v3/testsuite/20_util/shared_ptr/cons/void_neg.cc
index 2afcd8b..3f6c4ae 100644
--- a/libstdc++-v3/testsuite/20_util/shared_ptr/cons/void_neg.cc
+++ b/libstdc++-v3/testsuite/20_util/shared_ptr/cons/void_neg.cc
@@ -25,5 +25,5 @@
void test01()
{
std::shared_ptr<void> p((void*)nullptr); // { dg-error "here" }
- // { dg-error "incomplete" "" { target *-*-* } 885 }
+ // { dg-error "incomplete" "" { target *-*-* } 890 }
}