On Fri, Jan 03, 2025 at 11:24:02AM -0800, Stephen Hemminger wrote:
> On Fri, 3 Jan 2025 07:36:48 -0800
> Andre Muezerie <andre...@linux.microsoft.com> wrote:
>
> > From: Andre Muezerie <andre...@linux.microsoft.com>
> > To: andre...@linux.microsoft.com
> > Cc: dev@dpdk.org, step...@networkplumber.org
> > Subject: [PATCH v11 0/3] add diagnostics macros to make code portable
> > Date: Fri, 3 Jan 2025 07:36:48 -0800
> > X-Mailer: git-send-email 1.8.3.1
> >
> > It was a common pattern to have "GCC diagnostic ignored" pragmas
> > sprinkled over the code and only activate these pragmas for certain
> > compilers (gcc and clang). Clang supports GCC's pragma for
> > compatibility with existing source code, so #pragma GCC diagnostic
> > and #pragma clang diagnostic are synonyms for Clang
> > (https://clang.llvm.org/docs/UsersManual.html).
> >
> > Now that effort is being made to make the code compatible with MSVC
> > these expressions would become more complex. It makes sense to hide
> > this complexity behind macros. This makes maintenance easier as these
> > macros are defined in a single place. As a plus the code becomes
> > more readable as well.
>
> Since 90% of these cases are about removing const from a pointer,
> maybe it would be better to have a macro that did that?
>
> Would not work for base driver code which is pretending to be platform
> independent.
Most of the warnings I've seen were about dropping the volatile qualifier, like
the one below:
../drivers/net/i40e/i40e_rxtx_vec_sse.c:42:32: warning: cast from 'volatile
struct i40e_32byte_rx_desc::(unnamed at
../drivers/net/i40e/base/i40e_type.h:803:2) *' to
'__attribute__((__vector_size__(2 * sizeof(long long)))) long long *' drops
volatile qualifier [-Wcast-qual]
42 | _mm_store_si128((__m128i
*)&rxdp[i].read,
| ^
To make sure I understood your suggestion correctly, you're proposing to
replace this
__rte_diagnostic_push
__rte_diagnostic_ignored_wcast_qual
_mm_store_si128((__m128i *)&rxdp[i].read, dma_addr0);
__rte_diagnostic_pop
with something like this?
_mm_store_si128(RTE_IGNORE_CAST_QUAL((__m128i *)&rxdp[i].read),
dma_addr0);
This could be done, and I think it does look better, despite the slight line
length increase.
