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 f988342..6b2f964 100644 (file)
--- 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