From: Dietmar Maurer <dietmar@proxmox.com>
Date: Sat, 15 Mar 2014 09:24:02 +0000 (+0100)
Subject: add compile time test for log struct size
X-Git-Url: https://git.proxmox.com/?p=pve-firewall.git;a=commitdiff_plain;h=5b06fd6c0e9ce50c58cfb32f6820d1ebce5858c4;ds=inline

add compile time test for log struct size

The STATIC_ASSERT macro declares an external function (which is never used).
The declaratin fails if the expression evaluates to false, because that
would result in a negative array bound.
---

diff --git a/src/pvefw-logger.c b/src/pvefw-logger.c
index 31218a2..3a069f1 100644
--- a/src/pvefw-logger.c
+++ b/src/pvefw-logger.c
@@ -73,7 +73,7 @@ Example:
 #define PIDFILE "/var/run/pvefw-logger.pid"
 
 #define LQ_LEN 512
-#define LE_MAX (512 - 16) // try to fit into 512 bytes
+#define LE_MAX (512 - 4) // try to fit into 512 bytes
 
 #define MAX_CHAIN_LEN 28
 
@@ -82,6 +82,11 @@ struct log_entry {
     char buf[LE_MAX];
 };
 
+#define STATIC_ASSERT(cond) \
+    extern void pve_static_assert(int test[(cond) ? 1 : -1])
+
+STATIC_ASSERT(sizeof(struct log_entry) == 512);
+
 int outfd = -1;
 
 gboolean terminate_threads = FALSE;