[Spice-devel] [PATCH] mingw32: specify packing alignment to 1 byte, to override -mms-bitfield

[Marc-André Lureau]

From: Marc-André Lureau <marcandre.lureau at redhat.com>

Ex: G_STRUCT_OFFSET(SpiceLinkReply, num_channel_caps) is 172 bytes
when compiled with -mms-bitfield, and 170 bytes without.

GLib/Gtk are compiled with -mms-bitfield, and it is necessary to
compile with the same option for compatibility. The pack pragma
for MINGW32 corrects the structure alignement.

We could use the pack pragma for GNUC unconditionally, that could help
to ensure struct binary compatibility between different compiled
flavours.
---
 spice/end-packed.h   |    4 +---
 spice/start-packed.h |    4 ++++
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/spice/end-packed.h b/spice/end-packed.h
index e191737..1acea18 100644
--- a/spice/end-packed.h
+++ b/spice/end-packed.h
@@ -33,8 +33,6 @@
 
 #undef SPICE_ATTR_PACKED
 
-#ifndef __GNUC__
-
+#if defined(__MINGW32__) || !defined(__GNUC__)
 #pragma pack(pop)
-
 #endif
diff --git a/spice/start-packed.h b/spice/start-packed.h
index 78ec7c7..ab3fa98 100644
--- a/spice/start-packed.h
+++ b/spice/start-packed.h
@@ -49,6 +49,10 @@
 
 #define SPICE_ATTR_PACKED __attribute__ ((__packed__))
 
+#ifdef __MINGW32__
+#pragma pack(push,1)
+#endif
+
 #else
 
 #pragma pack(push)
-- 
1.7.3.4