From 16158c96496b537194111526d25e19f268d613b6 Mon Sep 17 00:00:00 2001
From: Jonathan Wakely <jwakely@redhat.com>
Date: Thu, 22 Jul 2021 14:48:27 +0100
Subject: [PATCH] libstdc++: Remove unnecessary uses of <utility>

The <algorithm> header includes <utility>, with a comment referring to
UK-300, a National Body comment on the C++11 draft. That comment
proposed to move std::swap to <utility> and then require <algorithm> to
include <utility>. The comment was rejected, so we do not need to
implement the suggestion. For backwards compatibility with C++03 we do
want <algorithm> to define std::swap, but it does so anyway via
<bits/move.h>. We don't need the whole of <utility> to do that.

A few other headers that need std::swap can include <bits/move.h> to
get it, instead of <utility>.

There are several headers that include <utility> to get std::pair, but
they can use <bits/stl_pair.h> to get it without also including the
rel_ops namespace and other contents of <utility>.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/std/algorithm: Do not include <utility>.
	* include/std/functional: Likewise.
	* include/std/regex: Include <bits/stl_pair.h> instead of
	<utility>.
	* include/debug/map.h: Likewise.
	* include/debug/multimap.h: Likewise.
	* include/debug/multiset.h: Likewise.
	* include/debug/set.h: Likewise.
	* include/debug/vector: Likewise.
	* include/bits/fs_path.h: Likewise.
	* include/bits/unique_ptr.h: Do not include <utility>.
	* include/experimental/any: Likewise.
	* include/experimental/executor: Likewise.
	* include/experimental/memory: Likewise.
	* include/experimental/optional: Likewise.
	* include/experimental/socket: Use __exchange instead
	of std::exchange.
	* src/filesystem/ops-common.h: Likewise.
	* testsuite/20_util/default_delete/48631_neg.cc: Adjust expected
	errors to not use a hardcoded line number.
	* testsuite/20_util/default_delete/void_neg.cc: Likewise.
	* testsuite/20_util/specialized_algorithms/uninitialized_copy/constrained.cc:
	Include <utility> for std::as_const.
	* testsuite/20_util/specialized_algorithms/uninitialized_default_construct/constrained.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/uninitialized_move/constrained.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/uninitialized_value_construct/constrained.cc:
	Likewise.
	* testsuite/23_containers/vector/cons/destructible_debug_neg.cc:
	Adjust dg-error line number.
---
 libstdc++-v3/include/bits/fs_path.h                    |  2 +-
 libstdc++-v3/include/bits/unique_ptr.h                 |  1 -
 libstdc++-v3/include/debug/map.h                       |  2 +-
 libstdc++-v3/include/debug/multimap.h                  |  2 +-
 libstdc++-v3/include/debug/multiset.h                  |  2 +-
 libstdc++-v3/include/debug/set.h                       |  2 +-
 libstdc++-v3/include/debug/vector                      |  1 -
 libstdc++-v3/include/experimental/any                  |  2 +-
 libstdc++-v3/include/experimental/executor             |  1 -
 libstdc++-v3/include/experimental/memory               |  1 -
 libstdc++-v3/include/experimental/optional             |  2 +-
 libstdc++-v3/include/experimental/socket               | 10 +++++-----
 libstdc++-v3/include/std/algorithm                     |  1 -
 libstdc++-v3/include/std/functional                    |  1 -
 libstdc++-v3/include/std/regex                         |  2 +-
 libstdc++-v3/src/filesystem/ops-common.h               |  3 ++-
 .../testsuite/20_util/default_delete/48631_neg.cc      |  2 +-
 .../testsuite/20_util/default_delete/void_neg.cc       |  2 +-
 .../uninitialized_copy/constrained.cc                  |  1 +
 .../uninitialized_default_construct/constrained.cc     |  1 +
 .../uninitialized_move/constrained.cc                  |  1 +
 .../uninitialized_value_construct/constrained.cc       |  1 +
 .../vector/cons/destructible_debug_neg.cc              |  2 +-
 23 files changed, 22 insertions(+), 23 deletions(-)

diff --git a/libstdc++-v3/include/bits/fs_path.h b/libstdc++-v3/include/bits/fs_path.h
index 4fcd1def92f..3151af1e901 100644
--- a/libstdc++-v3/include/bits/fs_path.h
+++ b/libstdc++-v3/include/bits/fs_path.h
@@ -32,7 +32,6 @@
 
 #if __cplusplus >= 201703L
 
-#include <utility>
 #include <type_traits>
 #include <locale>
 #include <iosfwd>
@@ -41,6 +40,7 @@
 #include <string_view>
 #include <system_error>
 #include <bits/stl_algobase.h>
+#include <bits/stl_pair.h>
 #include <bits/locale_conv.h>
 #include <ext/concurrence.h>
 #include <bits/shared_ptr.h>
diff --git a/libstdc++-v3/include/bits/unique_ptr.h b/libstdc++-v3/include/bits/unique_ptr.h
index 0a0667a7608..2d8b9ed3fae 100644
--- a/libstdc++-v3/include/bits/unique_ptr.h
+++ b/libstdc++-v3/include/bits/unique_ptr.h
@@ -33,7 +33,6 @@
 #include <bits/c++config.h>
 #include <debug/assertions.h>
 #include <type_traits>
-#include <utility>
 #include <tuple>
 #include <bits/stl_function.h>
 #include <bits/functional_hash.h>
diff --git a/libstdc++-v3/include/debug/map.h b/libstdc++-v3/include/debug/map.h
index ab34b2affd9..c0153d09abe 100644
--- a/libstdc++-v3/include/debug/map.h
+++ b/libstdc++-v3/include/debug/map.h
@@ -32,7 +32,7 @@
 #include <debug/safe_sequence.h>
 #include <debug/safe_container.h>
 #include <debug/safe_iterator.h>
-#include <utility>
+#include <bits/stl_pair.h>
 
 namespace std _GLIBCXX_VISIBILITY(default)
 {
diff --git a/libstdc++-v3/include/debug/multimap.h b/libstdc++-v3/include/debug/multimap.h
index 96a44f4725f..94929344a9d 100644
--- a/libstdc++-v3/include/debug/multimap.h
+++ b/libstdc++-v3/include/debug/multimap.h
@@ -32,7 +32,7 @@
 #include <debug/safe_sequence.h>
 #include <debug/safe_container.h>
 #include <debug/safe_iterator.h>
-#include <utility>
+#include <bits/stl_pair.h>
 
 namespace std _GLIBCXX_VISIBILITY(default)
 {
diff --git a/libstdc++-v3/include/debug/multiset.h b/libstdc++-v3/include/debug/multiset.h
index 0e76c5ff332..bb68d8c8f18 100644
--- a/libstdc++-v3/include/debug/multiset.h
+++ b/libstdc++-v3/include/debug/multiset.h
@@ -32,7 +32,7 @@
 #include <debug/safe_sequence.h>
 #include <debug/safe_container.h>
 #include <debug/safe_iterator.h>
-#include <utility>
+#include <bits/stl_pair.h>
 
 namespace std _GLIBCXX_VISIBILITY(default)
 {
diff --git a/libstdc++-v3/include/debug/set.h b/libstdc++-v3/include/debug/set.h
index c579de7426d..cdf35ea5396 100644
--- a/libstdc++-v3/include/debug/set.h
+++ b/libstdc++-v3/include/debug/set.h
@@ -32,7 +32,7 @@
 #include <debug/safe_sequence.h>
 #include <debug/safe_container.h>
 #include <debug/safe_iterator.h>
-#include <utility>
+#include <bits/stl_pair.h>
 
 namespace std _GLIBCXX_VISIBILITY(default)
 {
diff --git a/libstdc++-v3/include/debug/vector b/libstdc++-v3/include/debug/vector
index 987bba17c2b..79ccf527dd6 100644
--- a/libstdc++-v3/include/debug/vector
+++ b/libstdc++-v3/include/debug/vector
@@ -37,7 +37,6 @@ namespace std _GLIBCXX_VISIBILITY(default) { namespace __debug {
 } } // namespace std::__debug
 
 #include <vector>
-#include <utility>
 #include <debug/safe_sequence.h>
 #include <debug/safe_container.h>
 #include <debug/safe_iterator.h>
diff --git a/libstdc++-v3/include/experimental/any b/libstdc++-v3/include/experimental/any
index 3bb3e8c4a0a..7d18f267e8b 100644
--- a/libstdc++-v3/include/experimental/any
+++ b/libstdc++-v3/include/experimental/any
@@ -36,8 +36,8 @@
 
 #include <typeinfo>
 #include <new>
-#include <utility>
 #include <type_traits>
+#include <bits/move.h>
 #include <experimental/bits/lfts_config.h>
 
 namespace std _GLIBCXX_VISIBILITY(default)
diff --git a/libstdc++-v3/include/experimental/executor b/libstdc++-v3/include/experimental/executor
index c670f2739b6..4322a7f5caf 100644
--- a/libstdc++-v3/include/experimental/executor
+++ b/libstdc++-v3/include/experimental/executor
@@ -43,7 +43,6 @@
 #include <thread>
 #include <tuple>
 #include <unordered_map>
-#include <utility>
 #include <experimental/netfwd>
 #include <bits/unique_ptr.h>
 #include <experimental/bits/net.h>
diff --git a/libstdc++-v3/include/experimental/memory b/libstdc++-v3/include/experimental/memory
index a74b2402f7a..a89a5ecfa84 100644
--- a/libstdc++-v3/include/experimental/memory
+++ b/libstdc++-v3/include/experimental/memory
@@ -40,7 +40,6 @@
 
 #include <memory>
 #include <type_traits>
-#include <utility>
 #include <experimental/bits/shared_ptr.h>
 #include <bits/functional_hash.h>
 
diff --git a/libstdc++-v3/include/experimental/optional b/libstdc++-v3/include/experimental/optional
index ae2418f0500..431d23631cf 100644
--- a/libstdc++-v3/include/experimental/optional
+++ b/libstdc++-v3/include/experimental/optional
@@ -32,7 +32,6 @@
 
 #if __cplusplus >= 201402L
 
-#include <utility>
 #include <type_traits>
 #include <stdexcept>
 #include <new>
@@ -40,6 +39,7 @@
 #include <bits/functexcept.h>
 #include <bits/functional_hash.h>
 #include <bits/enable_special_members.h>
+#include <bits/move.h>
 #include <experimental/bits/lfts_config.h>
 
 namespace std _GLIBCXX_VISIBILITY(default)
diff --git a/libstdc++-v3/include/experimental/socket b/libstdc++-v3/include/experimental/socket
index 9db4a245ccf..6d1c114254a 100644
--- a/libstdc++-v3/include/experimental/socket
+++ b/libstdc++-v3/include/experimental/socket
@@ -429,16 +429,16 @@ inline namespace v1
 
     __socket_impl(__socket_impl&& __rhs)
     : _M_ctx(__rhs._M_ctx),
-      _M_sockfd(std::exchange(__rhs._M_sockfd, -1)),
-      _M_bits(std::exchange(__rhs._M_bits, {}))
+      _M_sockfd(std::__exchange(__rhs._M_sockfd, -1)),
+      _M_bits(std::__exchange(__rhs._M_bits, {}))
     { }
 
     __socket_impl&
     operator=(__socket_impl&& __rhs)
     {
       _M_ctx = __rhs._M_ctx;
-      _M_sockfd = std::exchange(__rhs._M_sockfd, -1);
-      _M_bits = std::exchange(__rhs._M_bits, {});
+      _M_sockfd = std::__exchange(__rhs._M_sockfd, -1);
+      _M_bits = std::__exchange(__rhs._M_bits, {});
       return *this;
     }
 
@@ -615,7 +615,7 @@ inline namespace v1
       {
 	__glibcxx_assert(is_open());
 	cancel(__ec);
-	return std::exchange(_M_sockfd, -1);
+	return std::__exchange(_M_sockfd, -1);
       }
 
       template<typename _SettableSocketOption>
diff --git a/libstdc++-v3/include/std/algorithm b/libstdc++-v3/include/std/algorithm
index 9ce4aa8423d..c9df7eae1ff 100644
--- a/libstdc++-v3/include/std/algorithm
+++ b/libstdc++-v3/include/std/algorithm
@@ -57,7 +57,6 @@
 
 #pragma GCC system_header
 
-#include <utility> // UK-300.
 #include <bits/stl_algobase.h>
 #include <bits/stl_algo.h>
 #if __cplusplus > 201703L
diff --git a/libstdc++-v3/include/std/functional b/libstdc++-v3/include/std/functional
index f61f2ac8cfd..131e6629341 100644
--- a/libstdc++-v3/include/std/functional
+++ b/libstdc++-v3/include/std/functional
@@ -61,7 +61,6 @@
 # include <unordered_map>
 # include <vector>
 # include <array>
-# include <utility>
 # include <bits/stl_algo.h>
 #endif
 #if __cplusplus > 201703L
diff --git a/libstdc++-v3/include/std/regex b/libstdc++-v3/include/std/regex
index cd33f26af0d..e623a6ed498 100644
--- a/libstdc++-v3/include/std/regex
+++ b/libstdc++-v3/include/std/regex
@@ -47,7 +47,6 @@
 #include <stack>
 #include <stdexcept>
 #include <string>
-#include <utility>
 #include <vector>
 #include <map>
 #include <cstring>
@@ -55,6 +54,7 @@
 #include <ext/aligned_buffer.h>
 #include <ext/numeric_traits.h>
 #include <bits/std_function.h>
+#include <bits/stl_pair.h>
 #include <bits/regex_constants.h>
 #include <bits/regex_error.h>
 #include <bits/regex_automaton.h>
diff --git a/libstdc++-v3/src/filesystem/ops-common.h b/libstdc++-v3/src/filesystem/ops-common.h
index 529d4e09016..43311e6c38f 100644
--- a/libstdc++-v3/src/filesystem/ops-common.h
+++ b/libstdc++-v3/src/filesystem/ops-common.h
@@ -26,6 +26,7 @@
 #define _GLIBCXX_OPS_COMMON_H 1
 
 #include <chrono>
+#include <bits/move.h> // std::__exchange
 
 #ifdef _GLIBCXX_HAVE_UNISTD_H
 # include <unistd.h>
@@ -407,7 +408,7 @@ _GLIBCXX_BEGIN_NAMESPACE_FILESYSTEM
 
     struct CloseFD {
       ~CloseFD() { if (fd != -1) posix::close(fd); }
-      bool close() { return posix::close(std::exchange(fd, -1)) == 0; }
+      bool close() { return posix::close(std::__exchange(fd, -1)) == 0; }
       int fd;
     };
 
diff --git a/libstdc++-v3/testsuite/20_util/default_delete/48631_neg.cc b/libstdc++-v3/testsuite/20_util/default_delete/48631_neg.cc
index 5de981665d9..3e80b73603e 100644
--- a/libstdc++-v3/testsuite/20_util/default_delete/48631_neg.cc
+++ b/libstdc++-v3/testsuite/20_util/default_delete/48631_neg.cc
@@ -26,4 +26,4 @@ struct D : B { };
 D d;
 std::default_delete<B[]> db;
 typedef decltype(db(&d)) type; // { dg-error "no match" }
-// { dg-error "no type" "" { target *-*-* } 116 }
+// { dg-prune-output "no type named 'type' in 'struct std::enable_if" }
diff --git a/libstdc++-v3/testsuite/20_util/default_delete/void_neg.cc b/libstdc++-v3/testsuite/20_util/default_delete/void_neg.cc
index 217c39b5eb4..ac4eabc5341 100644
--- a/libstdc++-v3/testsuite/20_util/default_delete/void_neg.cc
+++ b/libstdc++-v3/testsuite/20_util/default_delete/void_neg.cc
@@ -25,5 +25,5 @@ void test01()
 {
   std::default_delete<void> d;
   d(nullptr);   // { dg-error "here" }
-  // { dg-error "incomplete" "" { target *-*-* } 81 }
+  // { dg-error "delete pointer to incomplete type" "" { target *-*-* } 0 }
 }
diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/constrained.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/constrained.cc
index ac9128e6a00..7946effcf3a 100644
--- a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/constrained.cc
+++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/constrained.cc
@@ -25,6 +25,7 @@
 #include <span>
 #include <string>
 #include <vector>
+#include <utility>
 
 #include <testsuite_hooks.h>
 #include <testsuite_iterators.h>
diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_default_construct/constrained.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_default_construct/constrained.cc
index 05824c021a8..7267738a4af 100644
--- a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_default_construct/constrained.cc
+++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_default_construct/constrained.cc
@@ -25,6 +25,7 @@
 #include <span>
 #include <string>
 #include <vector>
+#include <utility>
 
 #include <testsuite_hooks.h>
 #include <testsuite_iterators.h>
diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_move/constrained.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_move/constrained.cc
index cc8cf0beef8..8759d042bb6 100644
--- a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_move/constrained.cc
+++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_move/constrained.cc
@@ -25,6 +25,7 @@
 #include <span>
 #include <string>
 #include <vector>
+#include <utility>
 
 #include <testsuite_hooks.h>
 #include <testsuite_iterators.h>
diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_value_construct/constrained.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_value_construct/constrained.cc
index efcf138dd5f..164d9ca667b 100644
--- a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_value_construct/constrained.cc
+++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_value_construct/constrained.cc
@@ -25,6 +25,7 @@
 #include <span>
 #include <string>
 #include <vector>
+#include <utility>
 
 #include <testsuite_hooks.h>
 #include <testsuite_iterators.h>
diff --git a/libstdc++-v3/testsuite/23_containers/vector/cons/destructible_debug_neg.cc b/libstdc++-v3/testsuite/23_containers/vector/cons/destructible_debug_neg.cc
index 2283d99b260..b85199e693f 100644
--- a/libstdc++-v3/testsuite/23_containers/vector/cons/destructible_debug_neg.cc
+++ b/libstdc++-v3/testsuite/23_containers/vector/cons/destructible_debug_neg.cc
@@ -46,7 +46,7 @@ test02()
 // { dg-error "value type is destructible" "" { target *-*-* } 0 }
 
 // In Debug Mode the "required from here" errors come from <debug/vector>
-// { dg-error "required from here" "" { target *-*-* } 173 }
+// { dg-error "required from here" "" { target *-*-* } 172 }
 
 // Needed because of PR c++/92193
 // { dg-prune-output "deleted function" }