It was not obvious to me why "qemu/osdep.h" must be the first #include.
This documents the rationale and the overall #include order.
Cc: Fam Zheng <f...@redhat.com>
Cc: Markus Armbruster <arm...@redhat.com>
Cc: Eric Blake <ebl...@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
---
HACKING | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/HACKING b/HACKING
index 20a9101..ced1236 100644
--- a/HACKING
+++ b/HACKING
@@ -1,10 +1,25 @@
1. Preprocessor
+1.1. Variadic macros
+
For variadic macros, stick with this C99-like syntax:
#define DPRINTF(fmt, ...) \
do { printf("IRQ: " fmt, ## __VA_ARGS__); } while (0)
+1.2. Include directives
+
+Order include directives as follows:
+
+#include "qemu/osdep.h" /* Always first... */
+#include <...> /* then system headers... */
+#include "..." /* and finally QEMU headers. */
+
+The "qemu/osdep.h" header contains preprocessor macros that affect the behavior
+of core system headers like <stdint.h>. It must be the first include so that
+core system headers included by external libraries get the preprocessor macros
+that QEMU depends on.
+
2. C types
It should be common sense to use the right type, but we have collected
--
2.7.4
