[Qemu-devel] [PATCH v2 1/2] cpu: Provide a proper prototype for target_words_bigendian() in a header

[Thomas Huth]

We've got three places already that provide a prototype for this
function in a .c file - that's ugly. Let's provide a proper prototype
in a header instead, with a proper description why this function should
not be used in most cases.

Signed-off-by: Thomas Huth <address@hidden>
---
 NB: I've tried to replace the "utterly broken" comment with something
 better, as suggested by Laszlo... not sure whether I've really got the
 message right here, so feel free to provide some better wording if you
 like!

 exec.c             |  5 -----
 hw/virtio/virtio.c |  1 -
 include/qom/cpu.h  | 11 +++++++++++
 qom/cpu.c          |  1 -
 4 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/exec.c b/exec.c
index d0821e6..5d99ef5 100644
--- a/exec.c
+++ b/exec.c
@@ -3906,11 +3906,6 @@ int qemu_target_page_bits_min(void)
 }
 #endif
 
-/*
- * A helper function for the _utterly broken_ virtio device model to find out 
if
- * it's running on a big endian machine. Don't do this at home kids!
- */
-bool target_words_bigendian(void);
 bool target_words_bigendian(void)
 {
 #if defined(TARGET_WORDS_BIGENDIAN)
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 94f5c8e..4e61944 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -1169,7 +1169,6 @@ int virtio_set_status(VirtIODevice *vdev, uint8_t val)
     return 0;
 }
 
-bool target_words_bigendian(void);
 static enum virtio_device_endian virtio_default_endian(void)
 {
     if (target_words_bigendian()) {
diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index dc130cd..6d35c37 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -1085,6 +1085,17 @@ void cpu_exec_initfn(CPUState *cpu);
 void cpu_exec_realizefn(CPUState *cpu, Error **errp);
 void cpu_exec_unrealizefn(CPUState *cpu);
 
+/**
+ * target_words_bigendian:
+ * Returns true if the (default) endianness of the target is big endian,
+ * false otherwise. Note that in target-specifc code, you can use
+ * TARGET_WORDS_BIGENDIAN directly instead. On the other hand, common
+ * code should normally never need to know about the endianness of the
+ * target, so please do *not* use this function unless you know very well
+ * what you are doing!
+ */
+bool target_words_bigendian(void);
+
 #ifdef NEED_CPU_H
 
 #ifdef CONFIG_SOFTMMU
diff --git a/qom/cpu.c b/qom/cpu.c
index 92599f3..f774654 100644
--- a/qom/cpu.c
+++ b/qom/cpu.c
@@ -194,7 +194,6 @@ static bool cpu_common_debug_check_watchpoint(CPUState 
*cpu, CPUWatchpoint *wp)
     return true;
 }
 
-bool target_words_bigendian(void);
 static bool cpu_common_virtio_is_big_endian(CPUState *cpu)
 {
     return target_words_bigendian();
-- 
1.8.3.1