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 <jwak...@redhat.com>
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<T, true>::_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