Re: [patch] Only do shrink_to_fit() when exceptions enabled

[Jonathan Wakely]

On 17/09/15 15:56 +0100, Jonathan Wakely wrote:

When exceptions are disabled a failed allocation while trying to
shrink_to_fit() will abort the program. Since shrink_to_fit() is a
non-binding request we should just ignore it rather than risk taking
down the whole process.

Tested powerpc64le-linux, committed to trunk.


Also committed to gcc-5-branch.



commit 13cf19282acf42a52d5eacd2c293a944bd3e5ebe
Author: Jonathan Wakely 
Date:   Thu Sep 17 00:07:33 2015 +0100

   Only do shrink_to_fit() when exceptions enabled
   
   	* include/bits/allocator.h (__shrink_to_fit_aux::_S_do_it):

Do nothing if exceptions are disabled.
* include/bits/basic_string.h (basic_string::shrink_to_fit): Likewise.

diff --git a/libstdc++-v3/include/bits/allocator.h 
b/libstdc++-v3/include/bits/allocator.h
index 6fd3214..0131521 100644
--- a/libstdc++-v3/include/bits/allocator.h
+++ b/libstdc++-v3/include/bits/allocator.h
@@ -209,15 +209,19 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
  static bool
  _S_do_it(_Tp& __c) noexcept
  {
-   __try
+#if __cpp_exceptions
+   try
  {
_Tp(__make_move_if_noexcept_iterator(__c.begin()),
__make_move_if_noexcept_iterator(__c.end()),
__c.get_allocator()).swap(__c);
return true;
  }
-   __catch(...)
+   catch(...)
  { return false; }
+#else
+   return false;
+#endif
  }
};
#endif
diff --git a/libstdc++-v3/include/bits/basic_string.h 
b/libstdc++-v3/include/bits/basic_string.h
index e6e7bb5..b5e7e36 100644
--- a/libstdc++-v3/include/bits/basic_string.h
+++ b/libstdc++-v3/include/bits/basic_string.h
@@ -833,13 +833,15 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
  void
  shrink_to_fit() noexcept
  {
+#if __cpp_exceptions
if (capacity() > size())
  {
-   __try
+   try
  { reserve(0); }
-   __catch(...)
+   catch(...)
  { }
  }
+#endif
  }
#endif

@@ -3282,12 +3284,14 @@ _GLIBCXX_END_NAMESPACE_CXX11
  void
  shrink_to_fit() _GLIBCXX_NOEXCEPT
  {
+#if __cpp_exceptions
if (capacity() > size())
  {
-   __try
+   try
  { reserve(0); }
-   __catch(...)
+   catch(...)
  { }
+#endif
  }
  }
#endif

Re: [patch] Only do shrink_to_fit() when exceptions enabled

[Jonathan Wakely]

Oops.

Bootstrapped with --disable-libstdcxx-dual-abi on x86_64-linux,
committed to trunk.

commit 9b9d9e3a5921f9a5225b466ce9d07b42b72f54dd
Author: Jonathan Wakely 
Date:   Mon Sep 21 11:58:41 2015 +0100

Fix bootstrap error introduced in r227870

	PR libstdc++/67647
	* include/bits/basic_string.h [!_GLIBCXX_USE_CXX11_ABI]
	(basic_string::shrink_to_fit): Fix #endif placement.

diff --git a/libstdc++-v3/include/bits/basic_string.h b/libstdc++-v3/include/bits/basic_string.h
index b5e7e36..c1689af 100644
--- a/libstdc++-v3/include/bits/basic_string.h
+++ b/libstdc++-v3/include/bits/basic_string.h
@@ -3291,8 +3291,8 @@ _GLIBCXX_END_NAMESPACE_CXX11
 	  { reserve(0); }
 	catch(...)
 	  { }
-#endif
 	  }
+#endif
   }
 #endif
 

[patch] Only do shrink_to_fit() when exceptions enabled

[Jonathan Wakely]

When exceptions are disabled a failed allocation while trying to
shrink_to_fit() will abort the program. Since shrink_to_fit() is a
non-binding request we should just ignore it rather than risk taking
down the whole process.

Tested powerpc64le-linux, committed to trunk.


commit 13cf19282acf42a52d5eacd2c293a944bd3e5ebe
Author: Jonathan Wakely 
Date:   Thu Sep 17 00:07:33 2015 +0100

Only do shrink_to_fit() when exceptions enabled

	* include/bits/allocator.h (__shrink_to_fit_aux::_S_do_it):
	Do nothing if exceptions are disabled.
	* include/bits/basic_string.h (basic_string::shrink_to_fit): Likewise.

diff --git a/libstdc++-v3/include/bits/allocator.h b/libstdc++-v3/include/bits/allocator.h
index 6fd3214..0131521 100644
--- a/libstdc++-v3/include/bits/allocator.h
+++ b/libstdc++-v3/include/bits/allocator.h
@@ -209,15 +209,19 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   static bool
   _S_do_it(_Tp& __c) noexcept
   {
-	__try
+#if __cpp_exceptions
+	try
 	  {
 	_Tp(__make_move_if_noexcept_iterator(__c.begin()),
 		__make_move_if_noexcept_iterator(__c.end()),
 		__c.get_allocator()).swap(__c);
 	return true;
 	  }
-	__catch(...)
+	catch(...)
 	  { return false; }
+#else
+	return false;
+#endif
   }
 };
 #endif
diff --git a/libstdc++-v3/include/bits/basic_string.h b/libstdc++-v3/include/bits/basic_string.h
index e6e7bb5..b5e7e36 100644
--- a/libstdc++-v3/include/bits/basic_string.h
+++ b/libstdc++-v3/include/bits/basic_string.h
@@ -833,13 +833,15 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
   void
   shrink_to_fit() noexcept
   {
+#if __cpp_exceptions
 	if (capacity() > size())
 	  {
-	__try
+	try
 	  { reserve(0); }
-	__catch(...)
+	catch(...)
 	  { }
 	  }
+#endif
   }
 #endif
 
@@ -3282,12 +3284,14 @@ _GLIBCXX_END_NAMESPACE_CXX11
   void
   shrink_to_fit() _GLIBCXX_NOEXCEPT
   {
+#if __cpp_exceptions
 	if (capacity() > size())
 	  {
-	__try
+	try
 	  { reserve(0); }
-	__catch(...)
+	catch(...)
 	  { }
+#endif
 	  }
   }
 #endif