In the case of value-initializing an object of class type T,
[dcl.init.general]/8 says:
- if T has either no default constructor ([class.default.ctor]) or
a default constructor that is user-provided or deleted, then the
object is default-initialized;
- otherwise, the object is zero-initialized and ... if T has a
non-trivial default constructor, the object is default-initialized;
But when determining whether to first zero-initialize the object,
expand_aggr_init_1 incorrectly looks for _any_ user provided
constructor, not just for a user-provided _default_ constructor. This
causes us to incorrectly skip the zero-initialization step when the
class type has a trivial default constructor alongside another
user-defined constructor.
It seems the predicate type_has_non_user_provided_default_constructor
accurately captures the above rule for when to first perform a
zero-initialization during value-initialization, so this patch corrects
the check in expand_aggr_init_1 using this predicate instead.
Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
trunk?
PR c++/65816
gcc/cp/ChangeLog:
* init.c (expand_aggr_init_1): Check
type_has_non_user_provided_default_constructor instead of
type_has_user_provided_constructor.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/constexpr-delegating3.C: New test.
* g++.dg/cpp0x/dc10.C: New test.
* g++.dg/cpp0x/initlist-base4.C: New test.
* g++.dg/cpp2a/constexpr-init22.C: New test.
libstdc++-v3/ChangeLog:
* testsuite/23_containers/deque/allocator/default_init.cc,
testsuite/23_containers/forward_list/allocator/default_init.cc,
testsuite/23_containers/list/allocator/default_init.cc,
testsuite/23_containers/map/allocator/default_init.cc,
testsuite/23_containers/set/allocator/default_init.cc,
testsuite/23_containers/vector/allocator/default_init.cc,
testsuite/23_containers/vector/bool/allocator/default_init.cc:
Remove xfail.
---
gcc/cp/init.c | 4 +--
.../g++.dg/cpp0x/constexpr-delegating3.C | 10 +++++++
gcc/testsuite/g++.dg/cpp0x/dc10.C | 19 ++++++++++++++
gcc/testsuite/g++.dg/cpp0x/initlist-base4.C | 26 +++++++++++++++++++
gcc/testsuite/g++.dg/cpp2a/constexpr-init22.C | 14 ++++++++++
.../deque/allocator/default_init.cc | 1 -
.../forward_list/allocator/default_init.cc | 1 -
.../list/allocator/default_init.cc | 1 -
.../map/allocator/default_init.cc | 1 -
.../set/allocator/default_init.cc | 1 -
.../vector/allocator/default_init.cc | 1 -
.../vector/bool/allocator/default_init.cc | 1 -
12 files changed, 71 insertions(+), 9 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp0x/constexpr-delegating3.C
create mode 100644 gcc/testsuite/g++.dg/cpp0x/dc10.C
create mode 100644 gcc/testsuite/g++.dg/cpp0x/initlist-base4.C
create mode 100644 gcc/testsuite/g++.dg/cpp2a/constexpr-init22.C
diff --git a/gcc/cp/init.c b/gcc/cp/init.c
index a85f4d50750..7aba5c60b32 100644
--- a/gcc/cp/init.c
+++ b/gcc/cp/init.c
@@ -2078,9 +2078,9 @@ expand_aggr_init_1 (tree binfo, tree true_exp, tree exp,
tree init, int flags,
that's value-initialization. */
if (init == void_type_node)
{
- /* If the type has data but no user-provided ctor, we need to zero
+ /* If the type has data but no user-provided default ctor, we need to
zero
out the object. */
- if (!type_has_user_provided_constructor (type)
+ if (type_has_non_user_provided_default_constructor (type)
&& !is_really_empty_class (type, /*ignore_vptr*/true))
{
tree field_size = NULL_TREE;
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-delegating3.C
b/gcc/testsuite/g++.dg/cpp0x/constexpr-delegating3.C
new file mode 100644
index 00000000000..2263ec89488
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-delegating3.C
@@ -0,0 +1,10 @@
+// PR c++/65816
+// { dg-do compile { target c++11 } }
+
+struct test {
+ int m;
+ test() = default;
+ constexpr test(int) : test() {}
+};
+
+static_assert(test(0).m == 0, "");
diff --git a/gcc/testsuite/g++.dg/cpp0x/dc10.C
b/gcc/testsuite/g++.dg/cpp0x/dc10.C
new file mode 100644
index 00000000000..c008a1703e8
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/dc10.C
@@ -0,0 +1,19 @@
+// PR c++/65816
+// { dg-do run { target c++11 } }
+
+void* operator new(decltype(sizeof(int)), void* ptr) { return ptr; }
+
+struct test {
+ int i;
+ test() = default;
+ test(int) : test() {}
+};
+
+int main() {
+ alignas(test) unsigned char space[sizeof(test)];
+ for (auto& c : space) c = 0xff;
+
+ auto ptr = ::new(&space) test(42);
+ int& i = static_cast<test&>(*ptr).i;
+ if (i != 0) __builtin_abort();
+}
diff --git a/gcc/testsuite/g++.dg/cpp0x/initlist-base4.C
b/gcc/testsuite/g++.dg/cpp0x/initlist-base4.C
new file mode 100644
index 00000000000..4a02af92799
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/initlist-base4.C
@@ -0,0 +1,26 @@
+// PR c++/65816
+// { dg-do run { target c++11 } }
+
+void* operator new(decltype(sizeof(int)), void* ptr) { return ptr; }
+
+struct item { int i; };
+
+struct collector : item {
+ int j;
+ collector() = default;
+ collector(int) {}
+};
+
+struct tuple : collector {
+ tuple() : collector() {}
+};
+
+int main() {
+ alignas(tuple) unsigned char space[sizeof(tuple)];
+ for (auto& c : space) c = 0xff;
+
+ auto ptr = ::new(&space) tuple;
+ int& i = static_cast<tuple&>(*ptr).i;
+ int& j = static_cast<tuple&>(*ptr).j;
+ if (i != 0 || j != 0) __builtin_abort();
+}
diff --git a/gcc/testsuite/g++.dg/cpp2a/constexpr-init22.C
b/gcc/testsuite/g++.dg/cpp2a/constexpr-init22.C
new file mode 100644
index 00000000000..50e4a95dbda
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/constexpr-init22.C
@@ -0,0 +1,14 @@
+// PR c++/65816
+// { dg-do compile { target c++20 } }
+
+struct X {
+ int i;
+ X() = default;
+ constexpr X(int) { }
+};
+
+struct Y : X {
+ constexpr Y() : X() { }
+};
+
+static_assert(Y().i == 0);
diff --git
a/libstdc++-v3/testsuite/23_containers/deque/allocator/default_init.cc
b/libstdc++-v3/testsuite/23_containers/deque/allocator/default_init.cc
index f51cc5b49b9..9428206f2ef 100644
--- a/libstdc++-v3/testsuite/23_containers/deque/allocator/default_init.cc
+++ b/libstdc++-v3/testsuite/23_containers/deque/allocator/default_init.cc
@@ -17,7 +17,6 @@
// { dg-do run { target c++11 } }
// { dg-options "-O0" }
-// { dg-xfail-run-if "PR c++/65816" { *-*-* } }
#include <deque>
#include <testsuite_hooks.h>
diff --git
a/libstdc++-v3/testsuite/23_containers/forward_list/allocator/default_init.cc
b/libstdc++-v3/testsuite/23_containers/forward_list/allocator/default_init.cc
index a60192641d4..4298fa5ffa5 100644
---
a/libstdc++-v3/testsuite/23_containers/forward_list/allocator/default_init.cc
+++
b/libstdc++-v3/testsuite/23_containers/forward_list/allocator/default_init.cc
@@ -17,7 +17,6 @@
// { dg-do run { target c++11 } }
// { dg-options "-O0" }
-// { dg-xfail-run-if "PR c++/65816" { *-*-* } }
#include <forward_list>
#include <testsuite_hooks.h>
diff --git
a/libstdc++-v3/testsuite/23_containers/list/allocator/default_init.cc
b/libstdc++-v3/testsuite/23_containers/list/allocator/default_init.cc
index 62bfd78df18..03d8cfc89e8 100644
--- a/libstdc++-v3/testsuite/23_containers/list/allocator/default_init.cc
+++ b/libstdc++-v3/testsuite/23_containers/list/allocator/default_init.cc
@@ -17,7 +17,6 @@
// { dg-do run { target c++11 } }
// { dg-options "-O0" }
-// { dg-xfail-run-if "PR c++/65816" { *-*-* } }
#include <list>
#include <testsuite_hooks.h>
diff --git a/libstdc++-v3/testsuite/23_containers/map/allocator/default_init.cc
b/libstdc++-v3/testsuite/23_containers/map/allocator/default_init.cc
index bc9027703fc..6e3f36d60a4 100644
--- a/libstdc++-v3/testsuite/23_containers/map/allocator/default_init.cc
+++ b/libstdc++-v3/testsuite/23_containers/map/allocator/default_init.cc
@@ -17,7 +17,6 @@
// { dg-do run { target c++11 } }
// { dg-options "-O0" }
-// { dg-xfail-run-if "PR c++/65816" { *-*-* } }
#include <map>
#include <testsuite_hooks.h>
diff --git a/libstdc++-v3/testsuite/23_containers/set/allocator/default_init.cc
b/libstdc++-v3/testsuite/23_containers/set/allocator/default_init.cc
index 8a99b491c25..b031cb81504 100644
--- a/libstdc++-v3/testsuite/23_containers/set/allocator/default_init.cc
+++ b/libstdc++-v3/testsuite/23_containers/set/allocator/default_init.cc
@@ -17,7 +17,6 @@
// { dg-do run { target c++11 } }
// { dg-options "-O0" }
-// { dg-xfail-run-if "PR c++/65816" { *-*-* } }
#include <set>
#include <testsuite_hooks.h>
diff --git
a/libstdc++-v3/testsuite/23_containers/vector/allocator/default_init.cc
b/libstdc++-v3/testsuite/23_containers/vector/allocator/default_init.cc
index c16d3b046e4..4673db71b6c 100644
--- a/libstdc++-v3/testsuite/23_containers/vector/allocator/default_init.cc
+++ b/libstdc++-v3/testsuite/23_containers/vector/allocator/default_init.cc
@@ -17,7 +17,6 @@
// { dg-do run { target c++11 } }
// { dg-options "-O0" }
-// { dg-xfail-run-if "PR c++/65816" { *-*-* } }
#include <vector>
#include <testsuite_hooks.h>
diff --git
a/libstdc++-v3/testsuite/23_containers/vector/bool/allocator/default_init.cc
b/libstdc++-v3/testsuite/23_containers/vector/bool/allocator/default_init.cc
index 4111e3ac3eb..61cc7859d74 100644
--- a/libstdc++-v3/testsuite/23_containers/vector/bool/allocator/default_init.cc
+++ b/libstdc++-v3/testsuite/23_containers/vector/bool/allocator/default_init.cc
@@ -17,7 +17,6 @@
// { dg-do run { target c++11 } }
// { dg-options "-O0" }
-// { dg-xfail-run-if "PR c++/65816" { *-*-* } }
#include <vector>
#include <testsuite_hooks.h>
--
2.32.0.rc2
