From: Jonathan Wakely <jwakely@redhat.com>
To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org
Subject: [committed 2/5] libstdc++: Fix conversion to/from net::ip::address_v4::bytes_type
Date: Fri, 24 Feb 2023 14:28:05 +0000 [thread overview]
Message-ID: <20230224142808.714075-2-jwakely@redhat.com> (raw)
In-Reply-To: <20230224142808.714075-1-jwakely@redhat.com>
Tested x86_64-linux. Pushed to trunk.
-- >8 --
I messed up the endianness of the address_v4::bytes_type array, which
should always be in network byte order. We can just use bit_cast to
convert the _M_addr member to/from bytes_type.
libstdc++-v3/ChangeLog:
* include/experimental/internet (address_4(const bytes_type&)):
Use __builtin_bit_cast if available, otherwise convert to
network byte order.
(address_v4::to_bytes()): Likewise, but convert from network
byte order.
* testsuite/experimental/net/internet/address/v4/cons.cc: Fix
incorrect tests. Check for constexpr too.
* testsuite/experimental/net/internet/address/v4/creation.cc:
Likewise.
* testsuite/experimental/net/internet/address/v4/members.cc:
Check that bytes_type is a standard-layout type.
---
libstdc++-v3/include/experimental/internet | 20 ++++++++---
.../net/internet/address/v4/cons.cc | 33 ++++++++++++-------
.../net/internet/address/v4/creation.cc | 24 +++++++++++---
.../net/internet/address/v4/members.cc | 3 ++
4 files changed, 60 insertions(+), 20 deletions(-)
diff --git a/libstdc++-v3/include/experimental/internet b/libstdc++-v3/include/experimental/internet
index 08bd0db4bb2..3fd200251fa 100644
--- a/libstdc++-v3/include/experimental/internet
+++ b/libstdc++-v3/include/experimental/internet
@@ -198,7 +198,12 @@ namespace ip
constexpr
address_v4(const bytes_type& __b)
- : _M_addr((__b[0] << 24) | (__b[1] << 16) | (__b[2] << 8) | __b[3])
+#if __has_builtin(__builtin_bit_cast)
+ : _M_addr(__builtin_bit_cast(uint_type, __b))
+#else
+ : _M_addr(_S_hton_32((__b[0] << 24) | (__b[1] << 16)
+ | (__b[2] << 8) | __b[3]))
+#endif
{ }
explicit constexpr
@@ -227,12 +232,17 @@ namespace ip
constexpr bytes_type
to_bytes() const noexcept
{
+#if __has_builtin(__builtin_bit_cast)
+ return __builtin_bit_cast(bytes_type, _M_addr);
+#else
+ auto __host = to_uint();
return bytes_type{
- (_M_addr >> 24) & 0xFF,
- (_M_addr >> 16) & 0xFF,
- (_M_addr >> 8) & 0xFF,
- _M_addr & 0xFF
+ (__host >> 24) & 0xFF,
+ (__host >> 16) & 0xFF,
+ (__host >> 8) & 0xFF,
+ __host & 0xFF
};
+#endif
}
constexpr uint_type
diff --git a/libstdc++-v3/testsuite/experimental/net/internet/address/v4/cons.cc b/libstdc++-v3/testsuite/experimental/net/internet/address/v4/cons.cc
index 65f23642de4..af9fef2215e 100644
--- a/libstdc++-v3/testsuite/experimental/net/internet/address/v4/cons.cc
+++ b/libstdc++-v3/testsuite/experimental/net/internet/address/v4/cons.cc
@@ -24,41 +24,45 @@
using std::experimental::net::ip::address_v4;
-void
+#if __cplusplus < 202002L
+// Naughty, but operator== for std::array is not constexpr until C++20.
+constexpr bool
+operator==(const address_v4::bytes_type& lhs, const address_v4::bytes_type& rhs)
+{
+ return lhs[0] == rhs[0] && lhs[1] == rhs[1]
+ && lhs[2] == rhs[2] && lhs[3] == rhs[3];
+}
+#endif
+
+constexpr void
test01()
{
- bool test __attribute__((unused)) = false;
-
address_v4 a0;
VERIFY( a0.to_uint() == 0 );
VERIFY( a0.to_bytes() == address_v4::bytes_type{} );
}
-void
+constexpr void
test02()
{
- bool test __attribute__((unused)) = false;
-
address_v4 a0{ address_v4::bytes_type{} };
VERIFY( a0.to_uint() == 0 );
VERIFY( a0.to_bytes() == address_v4::bytes_type{} );
address_v4::bytes_type b1{ 1, 2, 3, 4 };
address_v4 a1{ b1 };
- VERIFY( a1.to_uint() == ntohl((1 << 24) | (2 << 16) | (3 << 8) | 4) );
+ VERIFY( a1.to_uint() == ((1 << 24) | (2 << 16) | (3 << 8) | 4) );
VERIFY( a1.to_bytes() == b1 );
}
-void
+constexpr void
test03()
{
- bool test __attribute__((unused)) = false;
-
address_v4 a0{ 0u };
VERIFY( a0.to_uint() == 0 );
VERIFY( a0.to_bytes() == address_v4::bytes_type{} );
- address_v4::uint_type u1 = ntohl((5 << 24) | (6 << 16) | (7 << 8) | 8);
+ address_v4::uint_type u1 = (5 << 24) | (6 << 16) | (7 << 8) | 8;
address_v4 a1{ u1 };
VERIFY( a1.to_uint() == u1 );
VERIFY( a1.to_bytes() == address_v4::bytes_type( 5, 6, 7, 8 ) );
@@ -70,4 +74,11 @@ main()
test01();
test02();
test03();
+
+ constexpr bool c = []{
+ test01();
+ test02();
+ test03();
+ return true;
+ };
}
diff --git a/libstdc++-v3/testsuite/experimental/net/internet/address/v4/creation.cc b/libstdc++-v3/testsuite/experimental/net/internet/address/v4/creation.cc
index 441c832bf54..84aebbb7adc 100644
--- a/libstdc++-v3/testsuite/experimental/net/internet/address/v4/creation.cc
+++ b/libstdc++-v3/testsuite/experimental/net/internet/address/v4/creation.cc
@@ -25,7 +25,17 @@
namespace net = std::experimental::net;
using net::ip::address_v4;
-void
+#if __cplusplus < 202002L
+// Naughty, but operator== for std::array is not constexpr until C++20.
+constexpr bool
+operator==(const address_v4::bytes_type& lhs, const address_v4::bytes_type& rhs)
+{
+ return lhs[0] == rhs[0] && lhs[1] == rhs[1]
+ && lhs[2] == rhs[2] && lhs[3] == rhs[3];
+}
+#endif
+
+constexpr void
test01()
{
auto a0 = make_address_v4( address_v4::bytes_type{} );
@@ -34,18 +44,18 @@ test01()
address_v4::bytes_type b1{ 1, 2, 3, 4 };
auto a1 = make_address_v4( b1 );
- VERIFY( a1.to_uint() == ntohl((1 << 24) | (2 << 16) | (3 << 8) | 4) );
+ VERIFY( a1.to_uint() == ((1 << 24) | (2 << 16) | (3 << 8) | 4) );
VERIFY( a1.to_bytes() == b1 );
}
-void
+constexpr void
test02()
{
auto a0 = net::ip::make_address_v4(0u);
VERIFY( a0.to_uint() == 0 );
VERIFY( a0.to_bytes() == address_v4::bytes_type{} );
- address_v4::uint_type u1 = ntohl((5 << 24) | (6 << 16) | (7 << 8) | 8);
+ address_v4::uint_type u1 = ((5 << 24) | (6 << 16) | (7 << 8) | 8);
auto a1 = net::ip::make_address_v4( u1 );
VERIFY( a1.to_uint() == u1 );
VERIFY( a1.to_bytes() == address_v4::bytes_type( 5, 6, 7, 8 ) );
@@ -84,4 +94,10 @@ main()
test01();
test02();
test03();
+
+ constexpr bool c = []{
+ test01();
+ test02();
+ return true;
+ };
}
diff --git a/libstdc++-v3/testsuite/experimental/net/internet/address/v4/members.cc b/libstdc++-v3/testsuite/experimental/net/internet/address/v4/members.cc
index c40a8103664..ac59405c599 100644
--- a/libstdc++-v3/testsuite/experimental/net/internet/address/v4/members.cc
+++ b/libstdc++-v3/testsuite/experimental/net/internet/address/v4/members.cc
@@ -26,6 +26,9 @@
using std::experimental::net::ip::address_v4;
+static_assert(std::is_standard_layout<address_v4::bytes_type>::value,
+ "net::ip::address_v4::bytes_type is a standard layout type");
+
constexpr bool
test01()
{
--
2.39.2
next prev parent reply other threads:[~2023-02-24 14:28 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-24 14:28 [committed 1/5] libstdc++: Optimize net::ip::address_v4::to_string() Jonathan Wakely
2023-02-24 14:28 ` Jonathan Wakely [this message]
2023-02-24 14:28 ` [committed 3/5] libstdc++: Fix members of net::ip::network_v4 Jonathan Wakely
2023-02-24 14:28 ` [committed 4/5] libstdc++: Make net::ip::basic_endpoint comparisons constexpr Jonathan Wakely
2023-02-24 14:28 ` [committed 5/5] libstdc++: Constrain net::executor constructors Jonathan Wakely
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