[committed] libstdc++: Do not include <system_error> in concurrency headers

[Jonathan Wakely]

Tested x86_64-linux and powerpc64le-linux. Pushed to trunk.

-- >8 --

The <condition_variable>, <mutex>, and <shared_mutex> headers use
std::errc constants, but don't use std::system_error itself. They only
use the __throw_system_error(int) function, which is defined in
<bits/functexcept.h>.

By including the header for the errc constants instead of the whole of
<system_error> we avoid depending on the whole std::string definition.

libstdc++-v3/ChangeLog:

	* include/bits/std_mutex.h: Remove <system_error> include.
	* include/std/condition_variable: Add <bits/error_constants.h>
	include.
	* include/std/mutex: Likewise.
	* include/std/shared_mutex: Likewise.
---
 libstdc++-v3/include/bits/std_mutex.h       | 1 -
 libstdc++-v3/include/std/condition_variable | 3 ++-
 libstdc++-v3/include/std/mutex              | 2 +-
 libstdc++-v3/include/std/shared_mutex       | 1 +
 4 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/libstdc++-v3/include/bits/std_mutex.h b/libstdc++-v3/include/bits/std_mutex.h
index 68f5fb9ed65..bc515358d23 100644
--- a/libstdc++-v3/include/bits/std_mutex.h
+++ b/libstdc++-v3/include/bits/std_mutex.h
@@ -36,7 +36,6 @@
 # include <bits/c++0x_warning.h>
 #else
 
-#include <system_error>
 #include <bits/functexcept.h>
 #include <bits/gthr.h>
 
diff --git a/libstdc++-v3/include/std/condition_variable b/libstdc++-v3/include/std/condition_variable
index b885e1baa1b..f671fe4afe1 100644
--- a/libstdc++-v3/include/std/condition_variable
+++ b/libstdc++-v3/include/std/condition_variable
@@ -38,6 +38,7 @@
 #else
 
 #include <bits/chrono.h>
+#include <bits/error_constants.h>
 #include <bits/std_mutex.h>
 #include <bits/unique_lock.h>
 #include <bits/alloc_traits.h>
@@ -372,7 +373,7 @@ _GLIBCXX_BEGIN_INLINE_ABI_NAMESPACE(_V2)
         {
           return __p();
         }
- 
+
       std::stop_callback __cb(__stoken, [this] { notify_all(); });
       shared_ptr<mutex> __mutex = _M_mutex;
       while (!__p())
diff --git a/libstdc++-v3/include/std/mutex b/libstdc++-v3/include/std/mutex
index aca5f91e03c..4eedbe5038c 100644
--- a/libstdc++-v3/include/std/mutex
+++ b/libstdc++-v3/include/std/mutex
@@ -40,8 +40,8 @@
 #include <tuple>
 #include <exception>
 #include <type_traits>
-#include <system_error>
 #include <bits/chrono.h>
+#include <bits/error_constants.h>
 #include <bits/std_mutex.h>
 #include <bits/unique_lock.h>
 #if ! _GTHREAD_USE_MUTEX_TIMEDLOCK
diff --git a/libstdc++-v3/include/std/shared_mutex b/libstdc++-v3/include/std/shared_mutex
index 7b70697f178..57c3cc54d81 100644
--- a/libstdc++-v3/include/std/shared_mutex
+++ b/libstdc++-v3/include/std/shared_mutex
@@ -36,6 +36,7 @@
 #if __cplusplus >= 201402L
 
 #include <bits/chrono.h>
+#include <bits/error_constants.h>
 #include <bits/functexcept.h>
 #include <bits/move.h>        // move, __exchange
 #include <bits/std_mutex.h>   // defer_lock_t
-- 
2.39.0