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, 39 insertions, 16 deletions

diff --git a/src/starter/parser/conf_parser.c b/src/starter/parser/conf_parser.c
index 6d1c54d20..66e0ae8e4 100644
--- a/src/starter/parser/conf_parser.c
+++ b/src/starter/parser/conf_parser.c
@@ -158,10 +158,13 @@ typedef struct {
 } dictionary_enumerator_t;
 
 METHOD(enumerator_t, dictionary_enumerate, bool,
-	dictionary_enumerator_t *this, char **key, char **value)
+	dictionary_enumerator_t *this, va_list args)
 {
 	setting_t *setting;
 	section_t *parent;
+	char **key, **value;
+
+	VA_ARGS_VGET(args, key, value);
 
 	while (TRUE)
 	{
@@ -221,7 +224,8 @@ METHOD(dictionary_t, dictionary_create_enumerator, enumerator_t*,
 
 	INIT(enumerator,
 		.public = {
-			.enumerate = (void*)_dictionary_enumerate,
+			.enumerate = enumerator_enumerate_default,
+			.venumerate = _dictionary_enumerate,
 			.destroy = _dictionary_enumerator_destroy,
 		},
 		.seen = hashtable_create(hashtable_hash_str, hashtable_equals_str, 8),
@@ -290,24 +294,43 @@ static dictionary_t *section_dictionary_create(private_conf_parser_t *parser,
 	return &this->public;
 }
 
-static bool conn_filter(void *unused, section_t **section, char **name)
+CALLBACK(conn_filter, bool,
+	void *unused, enumerator_t *orig, va_list args)
 {
-	if (streq((*section)->name, "%default"))
+	section_t *section;
+	char **name;
+
+	VA_ARGS_VGET(args, name);
+
+	while (orig->enumerate(orig, &section))
 	{
-		return FALSE;
+		if (!streq(section->name, "%default"))
+		{
+			*name = section->name;
+			return TRUE;
+		}
 	}
-	*name = (*section)->name;
-	return TRUE;
+	return FALSE;
 }
 
-static bool ca_filter(void *unused, void *key, char **name, section_t **section)
+CALLBACK(ca_filter, bool,
+	void *unused, enumerator_t *orig, va_list args)
 {
-	if (streq((*section)->name, "%default"))
+	void *key;
+	section_t *section;
+	char **name;
+
+	VA_ARGS_VGET(args, name);
+
+	while (orig->enumerate(orig, &key, &section))
 	{
-		return FALSE;
+		if (!streq(section->name, "%default"))
+		{
+			*name = section->name;
+			return TRUE;
+		}
 	}
-	*name = (*section)->name;
-	return TRUE;
+	return FALSE;
 }
 
 METHOD(conf_parser_t, get_sections, enumerator_t*,
@@ -317,12 +340,12 @@ METHOD(conf_parser_t, get_sections, enumerator_t*,
 	{
 		case CONF_PARSER_CONN:
 			return enumerator_create_filter(
-						array_create_enumerator(this->conns_order),
-						(void*)conn_filter, NULL, NULL);
+									array_create_enumerator(this->conns_order),
+									conn_filter, NULL, NULL);
 		case CONF_PARSER_CA:
 			return enumerator_create_filter(
-						this->cas->create_enumerator(this->cas),
-						(void*)ca_filter, NULL, NULL);
+									this->cas->create_enumerator(this->cas),
+									ca_filter, NULL, NULL);
 		case CONF_PARSER_CONFIG_SETUP:
 		default:
 			return enumerator_create_empty();