Add a new file, HACKING, in order to collect recurring
issues with submitted patches.
Start with preprocessor rules, adapted from libvirt HACKING.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
--- /dev/null
+1. Preprocessor
+
+For variadic macros, stick with this C99-like syntax:
+
+#define DPRINTF(fmt, ...) \
+ do { printf("IRQ: " fmt, ## __VA_ARGS__); } while (0)