On 11/27/24 01:20, Stefano Garzarella wrote:
On Tue, Nov 26, 2024 at 01:17:34PM -0800, Pierrick Bouvier wrote:
This attribute is not recognized by clang.
An investigation has been performed to ensure this attribute has no
effect on layout of structures we use in QEMU [1], so it's safe to
remove now.
In the future, we'll forbid introducing new bitfields in packed struct.
Why?
I suggest reporting in this commit description what you wrote in the
following patch in the documentation (or a summary), because at first
glance I could not understand the correlation between removing
gcc_struct and bitfields in packed struct.
Thanks,
I'll mention the problem came explicitely from the bitfields.
[1]
https://lore.kernel.org/qemu-devel/[email protected]/
Signed-off-by: Pierrick Bouvier <[email protected]>
---
meson.build | 5 -----
include/qemu/compiler.h | 7 +------
scripts/cocci-macro-file.h | 6 +-----
subprojects/libvhost-user/libvhost-user.h | 6 +-----
4 files changed, 3 insertions(+), 21 deletions(-)
The patch LGTM.
Acked-by: Stefano Garzarella <[email protected]>
diff --git a/meson.build b/meson.build
index e0b880e4e13..fa6d24e1233 100644
--- a/meson.build
+++ b/meson.build
@@ -354,11 +354,6 @@ elif host_os == 'sunos'
qemu_common_flags += '-D__EXTENSIONS__'
elif host_os == 'haiku'
qemu_common_flags += ['-DB_USE_POSITIVE_POSIX_ERRORS', '-D_BSD_SOURCE',
'-fPIC']
-elif host_os == 'windows'
- if not compiler.compiles('struct x { int y; } __attribute__((gcc_struct));',
- args: '-Werror')
- error('Your compiler does not support __attribute__((gcc_struct)) - please
use GCC instead of Clang')
- endif
endif
# Choose instruction set (currently x86-only)
diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h
index c06954ccb41..d904408e5ed 100644
--- a/include/qemu/compiler.h
+++ b/include/qemu/compiler.h
@@ -22,12 +22,7 @@
#define QEMU_EXTERN_C extern
#endif
-#if defined(_WIN32) && (defined(__x86_64__) || defined(__i386__))
-# define QEMU_PACKED __attribute__((gcc_struct, packed))
-#else
-# define QEMU_PACKED __attribute__((packed))
-#endif
-
+#define QEMU_PACKED __attribute__((packed))
#define QEMU_ALIGNED(X) __attribute__((aligned(X)))
#ifndef glue
diff --git a/scripts/cocci-macro-file.h b/scripts/cocci-macro-file.h
index d247a5086e9..c64831d5408 100644
--- a/scripts/cocci-macro-file.h
+++ b/scripts/cocci-macro-file.h
@@ -23,11 +23,7 @@
#define G_GNUC_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
#define G_GNUC_NULL_TERMINATED __attribute__((sentinel))
-#if defined(_WIN32) && (defined(__x86_64__) || defined(__i386__))
-# define QEMU_PACKED __attribute__((gcc_struct, packed))
-#else
-# define QEMU_PACKED __attribute__((packed))
-#endif
+#define QEMU_PACKED __attribute__((packed))
#define cat(x,y) x ## y
#define cat2(x,y) cat(x,y)
diff --git a/subprojects/libvhost-user/libvhost-user.h
b/subprojects/libvhost-user/libvhost-user.h
index deb40e77b3f..2ffc58c11b1 100644
--- a/subprojects/libvhost-user/libvhost-user.h
+++ b/subprojects/libvhost-user/libvhost-user.h
@@ -186,11 +186,7 @@ typedef struct VhostUserShared {
unsigned char uuid[UUID_LEN];
} VhostUserShared;
-#if defined(_WIN32) && (defined(__x86_64__) || defined(__i386__))
-# define VU_PACKED __attribute__((gcc_struct, packed))
-#else
-# define VU_PACKED __attribute__((packed))
-#endif
+#define VU_PACKED __attribute__((packed))
typedef struct VhostUserMsg {
int request;
--
2.39.5
