Add two Apple-compatible block introspection functions.

blocks_runtime.m

@@ -39,12 +39,17 @@
 static void *_HeapBlockByRef = (void*)1;
 
 
+PUBLIC _Bool _Block_has_signature(id b)
+{
+	const struct Block_layout *block = (struct Block_layout*)b;
+	return ((NULL != block) && (block->flags & BLOCK_HAS_SIGNATURE));
+}
 /**
  * Returns the Objective-C type encoding for the block.
  */
-PUBLIC const char *block_getType_np(const void *b)
+PUBLIC const char * _Block_signature(id b)
 {
-	const struct Block_layout *block = b;
+	const struct Block_layout *block = (struct Block_layout*)b;
 	if ((NULL == block) || !(block->flags & BLOCK_HAS_SIGNATURE))
 	{
 		return NULL;
@@ -55,6 +60,10 @@ PUBLIC const char *block_getType_np(const void *b)
 	}
 	return block->descriptor->encoding;
 }
+PUBLIC const char *block_getType_np(const void *b)
+{
+	return _Block_signature(b);
+}
 
 static int increment24(int *ref)
 {

objc/blocks_runtime.h

@@ -16,6 +16,13 @@
 PUBLIC BLOCKS_EXPORT void *_Block_copy(const void *);
 PUBLIC BLOCKS_EXPORT void _Block_release(const void *);
 PUBLIC BLOCKS_EXPORT const char *block_getType_np(const void *b) OBJC_NONPORTABLE;
+#ifdef __OBJC__
+PUBLIC BLOCKS_EXPORT _Bool _Block_has_signature(id);
+PUBLIC BLOCKS_EXPORT const char * _Block_signature(id);
+#else
+PUBLIC BLOCKS_EXPORT _Bool _Block_has_signature(void *);
+PUBLIC BLOCKS_EXPORT const char * _Block_signature(void *);
+#endif
 
 #define Block_copy(x) ((__typeof(x))_Block_copy((const void *)(x)))
 #define Block_release(x) _Block_release((const void *)(x))