gcc: Add support for Apple's Block extension

Block objects [1] are a C-level syntactic and runtime feature. They
are similar to standard C functions, but in addition to executable
code they may also contain variable bindings to automatic (stack)
or managed (heap) memory. A block can therefore maintain a set of
state (data) that it can use to impact behavior when executed.

This port is based on Apple's GCC 5646 with some bugfixes from
Apple GCC 5666.3. It has some small differences with the support
in clang, which remains the recommended compiler.

Perhaps the most notable difference is that in GCC that __block
is not actually a keyword, but a macro. There will be workaround
for this issue in a near future. Other issues can be consulted in
the clang documentation [2]

For better compatiblity with Apple's GCC and llvm-gcc some related
fixes and features from Apple have been included. Support for the
non-standard nested functions in GCC is now off by default.

No effort was made to update the ObjC support since FreeBSD doesn't
carry ObjC in the base system, but some of the code crept in and
was more difficult to remove than to adjust.

Reference:
[1]
https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/Blocks/Articles/00_Introduction.html
[2]
http://clang.llvm.org/compatibility.html#block-variable-initialization

Obtained from:	Apple GCC 4.2
MFC after:	3 weeks

1 files changed, 2 insertions, 0 deletions

diff --git a/contrib/gcc/cgraph.h b/contrib/gcc/cgraph.h
index dccf3ff..1e208de 100644
--- a/contrib/gcc/cgraph.h
+++ b/contrib/gcc/cgraph.h
@@ -302,6 +302,8 @@ struct cgraph_node *cgraph_master_clone (struct cgraph_node *);
 void cgraph_add_new_function (tree);
 
 /* In cgraphunit.c  */
+/* APPLE LOCAL radar 6305545 */
+void lower_if_nested_functions (tree);
 bool cgraph_assemble_pending_functions (void);
 bool cgraph_varpool_assemble_pending_decls (void);
 void cgraph_finalize_function (tree, bool);