Re: [dpdk-dev] [PATCH v4 1/7] eal: introduce portable format attribute

[Bruce Richardson <bruce.richardson@intel.com>]

On Mon, Mar 16, 2020 at 10:54:09AM +0000, Bruce Richardson wrote:
> On Sun, Mar 15, 2020 at 09:36:11AM +0100, Thomas Monjalon wrote:
> > 14/03/2020 00:38, Dmitry Kozlyuk:
> > > > I suggest this change (I can send a patch fixing the issue in other .h files):
> > > >
> > > > +/*
> > > > + * RTE_TOOLCHAIN_GCC is true if the target is built with GCC,
> > > > + * while a host application (like pmdinfogen) may have another compiler.
> > > > + * RTE_CC_IS_GNU is true if the file is compiled with GCC,
> > > > + * no matter it is a target or host application.
> > > > + */
> > > > +#if defined __GNUC__ && !defined __clang__ && !defined __INTEL_COMPILER
> > > > +#define RTE_CC_IS_GNU
> > > > +#endif
> > > > +
> > > > +#ifdef RTE_CC_IS_GNU
> > > > -/** Define GCC_VERSION **/
> > > > -#ifdef RTE_TOOLCHAIN_GCC
> > > >  #define GCC_VERSION (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + \
> > > >                 __GNUC_PATCHLEVEL__)
> > > >  #endif
> > > > @@ -96,7 +105,7 @@ typedef uint16_t unaligned_uint16_t;
> > > >   * even if the underlying stdio implementation is ANSI-compliant,
> > > >   * so this must be overridden.
> > > >   */
> > > > -#if defined(RTE_TOOLCHAIN_GCC)
> > > > +#ifdef RTE_CC_IS_GNU
> > > >  #define __rte_format_printf(format_index, first_arg) \
> > > >         __attribute__((format(gnu_printf, format_index, first_arg)))
> > > >  #else
> > > 
> > > The code you propose LGTM itself. If you think it's a better solution than
> > > the one proposed below, I see no problem going with it.
> > > 
> > > What I wonder is whether pmdinfogen should include the problematic code in the
> > > first place. The errors come from declarations in rte_debug.h, but pmdinfogen
> > > really can't use them, because definitions are compiled for different
> > > machine. Pmdinfogen pulls rte_debug.h via rte_pci.h, which is only needed for
> > > struct rte_pci_id. Shouldn't we instead break this bogus dependency chain by
> > > moving struct rte_pci_id to a separate header?
> > 
> > Splitting headers to avoid EAL dependency looks to be a bad precedent to me.
> > 
> 
> Rather than splitting, we can still fix this by breaking the dependency by
> just not having rte_debug.h included in rte_pci.h. From what I see, there
> is no need for that include to be there, and DPDK pretty much compiles fine
> with it removed - the only other change I had to make was add an extra
> include into mlx5_common.h to compensate for it not getting pulled in via
> rte_pci.h.
> 

And by adding rte_interrupts.h to drivers/bus/ifpga/rte_bus_ifpga.h we can
remove the following headers from rte_pci.h also:

stdio.h
errno.h
stdint.h
rte_interrupts.h

This means that we go from 9 includes in the file (including rte_debug.h) to
just 4.

Regards,
/Bruce