In libobjc/:

2011-10-09  Nicola Pero  <nicola.pero@meta-innovation.com>

	PR libobjc/49883
	* init.c (__objc_exec_class): Work around a bug in clang's code
	generation.  Clang sets the class->info field to values different
	from 0x1 or 0x2 (the only allowed values in the traditional GNU
	Objective-C runtime ABI) to store some additional information, but
	this breaks backwards compatibility.  Wipe out all the bits in the
	fields other than the first two upon loading a class.

2011-10-09  Nicola Pero  <nicola.pero@meta-innovation.com>
	
	* class.c (objc_lookup_class): Added back for compatibility with
	clang which seems to emit calls to it.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@179721 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 9 insertions, 0 deletions

diff --git a/libobjc/init.c b/libobjc/init.c
index d4475b3b787..23ba41ba128 100644
--- a/libobjc/init.c
+++ b/libobjc/init.c
@@ -643,6 +643,15 @@ __objc_exec_class (struct objc_module *module)
       assert (CLS_ISMETA (class->class_pointer));
       DEBUG_PRINTF (" installing class '%s'\n", class->name);
 
+      /* Workaround for a bug in clang: Clang may set flags other than
+	 _CLS_CLASS and _CLS_META even when compiling for the
+	 traditional ABI (version 8), confusing our runtime.  Try to
+	 wipe these flags out.  */
+      if (CLS_ISCLASS (class))
+	__CLS_INFO (class) = _CLS_CLASS;
+      else
+	__CLS_INFO (class) = _CLS_META;
+
       /* Initialize the subclass list to be NULL.  In some cases it
 	 isn't and this crashes the program.  */
       class->subclass_list = NULL;