From: Tobias Brunner <tobias@strongswan.org>
Date: Thu, 19 May 2022 09:10:07 +0000 (+0200)
Subject: object: Fix CALLBACK macros with GCC 12
X-Git-Tag: 5.9.7dr2~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=993ea3282571b993ec2c631def5b6f3303b6d2f5;p=thirdparty%2Fstrongswan.git

object: Fix CALLBACK macros with GCC 12

GCC 12 produces weird code when a callback is called directly (e.g.
parse_bool() via parse_option() in vici_config.c).  Instead of the actual
pointer, it explicitly passes 0 as first argument, which likely causes
a segmentation fault.  It doesn't happen when called indirectly via
function pointer that has void* as first argument, which this patch
kinda replicates for direct calls to avoid the issue.

Closes strongswan/strongswan#1053
---

diff --git a/src/libstrongswan/utils/utils/object.h b/src/libstrongswan/utils/utils/object.h
index 174ea812a1..da580c01af 100644
--- a/src/libstrongswan/utils/utils/object.h
+++ b/src/libstrongswan/utils/utils/object.h
@@ -120,7 +120,7 @@
 #define CALLBACK(name, ret, param1, ...) \
 	static ret _cb_##name(union {void *_generic; param1;} \
 	__attribute__((transparent_union)), ##__VA_ARGS__); \
-	static typeof(_cb_##name) *name = (typeof(_cb_##name)*)_cb_##name; \
+	static ret (*name)(void*, ##__VA_ARGS__) = _cb_##name; \
 	static ret _cb_##name(param1, ##__VA_ARGS__)
 
 /**
@@ -131,7 +131,7 @@
 	__attribute__((transparent_union)), \
 	union {void *_generic; param2;} \
 	__attribute__((transparent_union)), ##__VA_ARGS__); \
-	static typeof(_cb_##name) *name = (typeof(_cb_##name)*)_cb_##name; \
+	static ret (*name)(void*, void*, ##__VA_ARGS__) = _cb_##name; \
 	static ret _cb_##name(param1, param2, ##__VA_ARGS__)
 
 #endif /** OBJECT_H_ @} */