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, 9 insertions, 8 deletions

diff --git a/src/libcharon/daemon.c b/src/libcharon/daemon.c
index 8daea783f..7c9f83d12 100644
--- a/src/libcharon/daemon.c
+++ b/src/libcharon/daemon.c
@@ -282,13 +282,14 @@ static void logger_entry_unregister_destroy(logger_entry_t *this)
 	logger_entry_destroy(this);
 }
 
-/**
- * Match a logger entry by target and whether it is a file or syslog logger
- */
-static bool logger_entry_match(logger_entry_t *this, char *target,
-							   logger_type_t *type)
+CALLBACK(logger_entry_match, bool,
+	logger_entry_t *this, va_list args)
 {
-	return this->type == *type && streq(this->target, target);
+	logger_type_t type;
+	char *target;
+
+	VA_ARGS_VGET(args, target, type);
+	return this->type == type && streq(this->target, target);
 }
 
 /**
@@ -350,8 +351,8 @@ static logger_entry_t *get_logger_entry(char *target, logger_type_t type,
 {
 	logger_entry_t *entry;
 
-	if (existing->find_first(existing, (void*)logger_entry_match,
-							(void**)&entry, target, &type) != SUCCESS)
+	if (!existing->find_first(existing, logger_entry_match, (void**)&entry,
+							  target, type))
 	{
 		INIT(entry,
 			.target = strdup(target),