MFC r260311, r260831:

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 __block is not
actually a keyword, but a macro. There may be workaround for this
issue in the 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.

References:
[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

1 files changed, 15 insertions, 1 deletions

diff --git a/contrib/gcc/cgraphunit.c b/contrib/gcc/cgraphunit.c
index cc8b98f..6beb42e 100644
--- a/contrib/gcc/cgraphunit.c
+++ b/contrib/gcc/cgraphunit.c
@@ -458,6 +458,19 @@ cgraph_lower_function (struct cgraph_node *node)
   node->lowered = true;
 }
 
+/* APPLE LOCAL begin radar 6305545 */
+/** lower_if_nested_functions - This routine is called from cplus side only.
+    Its purpose is to lower block helper (or any other nested function)
+    which may have been nested in a constructor or destructor. We have to
+    do this because structors are cloned and are not lowered themselves (which
+    is the only way to lower the nested functions). */
+void 
+lower_if_nested_functions (tree decl)
+{
+    lower_nested_functions (decl, true);
+}
+/* APPLE LOCAL end radar 6305545 */
+
 /* DECL has been parsed.  Take it, queue it, compile it at the whim of the
    logic in effect.  If NESTED is true, then our caller cannot stand to have
    the garbage collector run at the moment.  We would need to either create
@@ -476,7 +489,8 @@ cgraph_finalize_function (tree decl, bool nested)
   node->local.finalized = true;
   node->lowered = DECL_STRUCT_FUNCTION (decl)->cfg != NULL;
   if (node->nested)
-    lower_nested_functions (decl);
+    /* APPLE LOCAL radar 6305545 */
+    lower_nested_functions (decl, false);
   gcc_assert (!node->nested);
 
   /* If not unit at a time, then we need to create the call graph