[committed] libstdc++: Use init_priority attribute for Init object [PR 98108]

[Jonathan Wakely]

On 15/12/20 11:47 +0000, Jonathan Wakely wrote:
>This causes the global objects that run the <iostream> initialization
>code to be constructed earlier, which avoids some bugs in user code due
>to incorrectly relying on static initialization order.
>
>libstdc++-v3/ChangeLog:
>
>	PR libstdc++/98108
>	* include/std/iostream (__ioinit): Add init_priority attribute.
>

I've reverted this because it doesn't work on darwin, and isn't
required for correctness anyway.

Tested powerpc64le-linux. Committed to trunk.



>commit cf4ed3b41594b6935a337fe0aaf8149eadf88751
>Author: Jonathan Wakely <jwakely@redhat.com>
>Date:   Tue Dec 15 11:40:06 2020
>
>    libstdc++: Use init_priority attribute for Init object [PR 98108]
>
>    This causes the global objects that run the <iostream> initialization
>    code to be constructed earlier, which avoids some bugs in user code due
>    to incorrectly relying on static initialization order.
>
>    libstdc++-v3/ChangeLog:
>
>            PR libstdc++/98108
>            * include/std/iostream (__ioinit): Add init_priority attribute.
>
>diff --git a/libstdc++-v3/include/std/iostream b/libstdc++-v3/include/std/iostream
>index f988342b90a..6b2f964f688 100644
>--- a/libstdc++-v3/include/std/iostream
>+++ b/libstdc++-v3/include/std/iostream
>@@ -70,8 +70,16 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> #endif
>   //@}
>
>+#if __has_attribute(__init_priority__)
>+# define _GLIBCXX_INIT_PRIO(N) __attribute__((__init_priority__(N)))
>+#else
>+# define _GLIBCXX_INIT_PRIO(N)
>+#endif
>+
>   // For construction of filebuffers for cout, cin, cerr, clog et. al.
>-  static ios_base::Init __ioinit;
>+  static ios_base::Init __ioinit _GLIBCXX_INIT_PRIO(90);
>+
>+#undef _GLIBCXX_INIT_PRIO
>
> _GLIBCXX_END_NAMESPACE_VERSION
> } // namespace