Merge branch 'variadic-enumerators'

This adds several changes to enumerator_t and linked_list_t to improve
portability.  In particular to Apple's ARM64 iOS platform, whose calling
convention for variadic and regular functions are different.  This means
that assigning a non-variadic function to a variadic function pointer,
as we did with our enumerator_t::enumerate() implementations and several
callbacks, will result in crashes as the called function will access the
arguments differently than the caller provided them.

To avoid this issue the enumerator_t interface is now fully variadic.
A new mandatory method is added, venumerate(), that takes a va_list with
the arguments provided while enumerating.  enumerate() is replaced with
a generic implementation that prepares a va_list and calls the
enumerator's venumerate() implementation.  As this allows passing the
arguments of one enumerator to another it avoids the five pointer hack
used by enumerator_create_nested() and enumerator_create_cleaner().
To simplify the implementation of venumerate() a helper macro is provided
that assigns values from a given va_list to local variables.

The signature of the callback passed to enumerator_create_filter() has
also changed significantly.  It's now required to enumerate over the
original enumerator in the callback as this avoids the previous in/out
pointer hack. The arguments to the outer enumerator are provided in a
va_list.

Similar changes to avoid such five pointer hacks affect the signatures
of the callbacks for linked_list_t's invoke_function() and find_first()
methods.  For the latter the return type also changed from status_t to
bool, which is important as SUCCESS is defined as 0, so checks for ==
SUCCESS will now fail.

1 files changed, 15 insertions, 10 deletions

diff --git a/src/libsimaka/simaka_message.c b/src/libsimaka/simaka_message.c
index 234d7ef2a..6827c1795 100644
--- a/src/libsimaka/simaka_message.c
+++ b/src/libsimaka/simaka_message.c
@@ -222,17 +222,22 @@ METHOD(simaka_message_t, get_type, eap_type_t,
 	return this->hdr->type;
 }
 
-/**
- * convert attr_t to type and data enumeration
- */
-static bool attr_enum_filter(void *null, attr_t **in, simaka_attribute_t *type,
-							 void *dummy, chunk_t *data)
+CALLBACK(attr_enum_filter, bool,
+	void *null, enumerator_t *orig, va_list args)
 {
-	attr_t *attr = *in;
+	attr_t *attr;
+	simaka_attribute_t *type;
+	chunk_t *data;
 
-	*type = attr->type;
-	*data = chunk_create(attr->data, attr->len);
-	return TRUE;
+	VA_ARGS_VGET(args, type, data);
+
+	if (orig->enumerate(orig, &attr))
+	{
+		*type = attr->type;
+		*data = chunk_create(attr->data, attr->len);
+		return TRUE;
+	}
+	return FALSE;
 }
 
 METHOD(simaka_message_t, create_attribute_enumerator, enumerator_t*,
@@ -240,7 +245,7 @@ METHOD(simaka_message_t, create_attribute_enumerator, enumerator_t*,
 {
 	return enumerator_create_filter(
 						this->attributes->create_enumerator(this->attributes),
-						(void*)attr_enum_filter, NULL, NULL);
+						attr_enum_filter, NULL, NULL);
 }
 
 METHOD(simaka_message_t, add_attribute, void,