Re: [PATCH 4/8] riscv: ensure RISC-V C model definitions are passed to static analyzers

[Palmer Dabbelt]

On Thu, 17 Oct 2019 21:39:29 PDT (-0700), Paul Walmsley wrote:
> On Fri, 18 Oct 2019, Luc Van Oostenryck wrote:
>
> > On Thu, Oct 17, 2019 at 05:49:25PM -0700, Paul Walmsley wrote:
> > > Static analysis tools such as sparse don't set the RISC-V C model
> > > preprocessor directives such as "__riscv_cmodel_medany", set by the C
> > > compilers.  This causes the static analyzers to evaluate different
> > > preprocessor paths than C compilers would.  Fix this by defining the
> > > appropriate C model macros in the static analyzer command lines.
> > >
> > > Signed-off-by: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
> > > ---
> > >  arch/riscv/Makefile | 2 ++
> > >  1 file changed, 2 insertions(+)
> > >
> > > diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
> > > index f5e914210245..0247a90bd4d8 100644
> > > --- a/arch/riscv/Makefile
> > > +++ b/arch/riscv/Makefile
> > > @@ -47,9 +47,11 @@ KBUILD_CFLAGS += -DCONFIG_PAGE_OFFSET=$(CONFIG_PAGE_OFFSET)
> > >
> > >  ifeq ($(CONFIG_CMODEL_MEDLOW),y)
> > >  	KBUILD_CFLAGS += -mcmodel=medlow
> > > +	CHECKFLAGS += -D__riscv_cmodel_medlow
> > >  endif
> > >  ifeq ($(CONFIG_CMODEL_MEDANY),y)
> > >  	KBUILD_CFLAGS += -mcmodel=medany
> > > +	CHECKFLAGS += -D__riscv_cmodel_medany
> >
> > I can teach sparse about this in the following days.
>
> That would be great.  Would you be willing to follow up with me via E-mail
> or mailing list post when it's fixed?  If so, then in the meantime, I'll
> just drop this patch.

It's probably worth going through all our argument-dependent builtin 
definitions at the same time.  They're generated by riscv_cpu_cpp_builtins(): 
https://github.com/gcc-mirror/gcc/blob/master/gcc/config/riscv/riscv-c.c#L35 .

> - Paul
>
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