02/08/2021 15:48, Akhil Goyal:
> > 2021-08-02 12:45 (UTC+0000), Akhil Goyal:
> > > > 21/07/2021 21:55, Dmitry Kozlyuk:
> > > > > Windows headers define `s_addr`, `min`, and `max` as macros.
> > > > > If DPDK headers are included after Windows ones, DPDK structure
> > > > > definitions containing fields with these names get broken (example 1),
> > > > > as well as any usage of such fields (example 2). If DPDK headers
> > > > > undefined these macros, it could break consumer code (example 3).
> > > > > It is proposed to rename structure fields in DPDK, because Win32
> > headers
> > > > > are used more widely than DPDK, as a general-purpose platform
> > compared
> > > > > to domain-specific kit, and are harder to fix because of that.
> > > > > Exact new names are left for further discussion.
> > > > >
> > > > > Example 1:
> > > > >
> > > > > /* in DPDK public header included after windows.h */
> > > > > struct rte_type {
> > > > > int min; /* ERROR: `min` is a macro */
> > > > > };
> > > > >
> > > > > Example 2:
> > > > >
> > > > > #include <rte_ether.h>
> > > > > #include <winsock2.h>
> > > > > struct rte_ether_hdr eh;
> > > > > eh.s_addr.addr_bytes[0] = 0; /* ERROR: `addr_s` is a macro */
> > > > >
> > > > > Example 3:
> > > > >
> > > > > #include <winsock2.h>
> > > > > #include <rte_ether.h>
> > > > > struct in_addr addr;
> > > > > addr.s_addr = 0; /* ERROR: there is no `s_addr` field,
> > > > > and `s_addr` macro is undefined by DPDK.
> > > > > */
> > > > >
> > > > > Commit 6c068dbd9fea ("net: work around s_addr macro on Windows")
> > > > > modified definition of `struct rte_ether_hdr` to avoid the issue.
> > > > > However, the workaround assumes `#define s_addr S_addr.S_un`
> > > > > in Windows headers, which is not a part of official API.
> > > > > It also complicates the definition of `struct rte_ether_hdr`.
> > > > >
> > > > > Signed-off-by: Dmitry Kozlyuk <dmitry.kozl...@gmail.com>
> > > > > Acked-by: Khoa To <k...@microsoft.com>
[...]
> > > > Acked-by: Thomas Monjalon <tho...@monjalon.net>
> > > >
> > > Can we have a local variable named as min/max?
> > > If not, then I believe it is not a good idea.
> >
> > Yes, except for inline functions in public headers.
> > The only problematic one I know of is this (rte_lru_x86.h):
> >
> > static inline int
> > f_lru_pos(uint64_t lru_list)
> > {
> > __m128i lst = _mm_set_epi64x((uint64_t)-1, lru_list);
> > __m128i min = _mm_minpos_epu16(lst); /* <<< */
> > return _mm_extract_epi16(min, 1);
> > }
> >
> > Fixing it breaks neither API nor ABI, thus no explicit deprecation notice.
> OK,
> Acked-by: Akhil Goyal <gak...@marvell.com>
Applied, thanks.
