[v6,02/30] eal/include: add new packing macros
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Commit Message
MSVC struct packing is not compatible with GCC. Add macro
__rte_packed_begin which can be used to push existing pack value
and set packing to 1-byte. Add macro __rte_packed_end to restore
the pack value prior to the push.
Macro __rte_packed_end is deliberately utilized to trigger a
MSVC compiler warning if no existing packing has been pushed allowing
easy identification of locations where the __rte_packed_begin is
missing.
Macro __rte_packed will be removed in a subsequent patch.
Signed-off-by: Andre Muezerie <andremue@linux.microsoft.com>
---
lib/eal/include/rte_common.h | 11 +++++++++++
1 file changed, 11 insertions(+)
Comments
On Tue, Nov 26, 2024 at 04:52:13PM -0800, Andre Muezerie wrote:
> MSVC struct packing is not compatible with GCC. Add macro
> __rte_packed_begin which can be used to push existing pack value
> and set packing to 1-byte. Add macro __rte_packed_end to restore
> the pack value prior to the push.
>
> Macro __rte_packed_end is deliberately utilized to trigger a
> MSVC compiler warning if no existing packing has been pushed allowing
> easy identification of locations where the __rte_packed_begin is
> missing.
>
> Macro __rte_packed will be removed in a subsequent patch.
>
> Signed-off-by: Andre Muezerie <andremue@linux.microsoft.com>
> ---
Acked-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
@@ -108,6 +108,17 @@ typedef uint16_t unaligned_uint16_t;
#define __rte_packed __attribute__((__packed__))
#endif
+/**
+ * Force a structure to be packed
+ */
+#ifdef RTE_TOOLCHAIN_MSVC
+#define __rte_packed_begin __pragma(pack(push, 1))
+#define __rte_packed_end __pragma(pack(pop))
+#else
+#define __rte_packed_begin
+#define __rte_packed_end __attribute__((__packed__))
+#endif
+
/**
* Macro to mark a type that is not subject to type-based aliasing rules
*/