Re: [dpdk-dev] [PATCH v2 1/7] eal: add wrappers for POSIX string functions

[Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>]

2021-02-23 09:45, Bruce Richardson:
> On Tue, Feb 23, 2021 at 01:57:50AM +0300, Dmitry Kozlyuk wrote:
> > 2021-02-22 14:26, Bruce Richardson:  
> > > As you say, though, the main issue will be whether we have instances in
> > > public header files or not. I would hope that no static inline functions in
> > > DPDK use any of the functions in question, but I'm not sure. Perhaps if
> > > there are instances in public headers those could be reworked to not use
> > > the problematic functions.  
> > 
> > No instances of strdup(), strncasecmp(), or strtok_r() in any DPDK headers.
> >   
> > > For any functions, such as strdup, which are not in a public header I would
> > > suggest the following as a possible start point, based off what was done
> > > for strlcpy.
> > > 
> > > * In DPDK (probably EAL), define an rte_strdup function for use as a
> > >   fallback.
> > > * Inside the meson build scripts, use "cc.has_function()" to check if the
> > >   regular strdup function is available. If not, then add "-DRTE_NO_STRDUP"
> > >   to the c_args for DPDK building
> > > * Inside our DPDK header (rte_string_fns.h in the strdup case), we can add
> > >   a conditional define such as:
> > >    #ifdef RTE_NO_STRDUP
> > >    #define strdup(s) rte_strdup(s)
> > >    #endif
> > > 
> > > Thoughts on this?  
> > 
> > Looks good to me, I can rework the patchset like so.
> > 
> > Policy considerations:
> > 1. The approach only applies to platform-agnostic functions, like str*().
> >    Functions like sleep() still belong to librte_eal.
> > 2. Deprecated functions, like index(3p), should be replaced
> >    with alternatives suggested by the standard.
> > 3. If a standard C11 alternative is available, it should be used.
> >    This mostly applies to types, like u_int32 -> uint32_t
> >    (it's even in DPDK coding style already, isn't it?).
> > 
> > A nit: RTE_NO_XXX -> RTE_HAS_XXX (for consistency with existing macros)?  
> 
> Sure, thanks.

There's a meson issue with `cc.has_function()`:
https://github.com/mesonbuild/meson/issues/5628

What if we just define RTE_INTERNAL for librte_eal/windows/include/rte_os.h
(and other public headers if need be) to distinguish the case when it's used
from within DPDK?