On Tue, Mar 08, 2022 at 12:57:20AM IST, Nick Desaulniers wrote:
> Also, please cc me and the llvm mailing list on all changes to
> include/linux/compiler-clang.h. I see now on lore there's further
> patches here than just this single patch I was cc'ed on.
>
Mea culpa, sorry about that.
> On Mon, Mar 7, 2022 at 11:25 AM Nick Desaulniers
> <ndesaulniers@xxxxxxxxxx> wrote:
> >
> > On Fri, Mar 4, 2022 at 2:47 PM Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx> wrote:
> > >
> > > From: Nathan Chancellor <nathan@xxxxxxxxxx>
> > >
> > > Add __diag macros similar to those in compiler-gcc.h, so that warnings
> > > that need to be adjusted for specific cases but not globally can be
> > > ignored when building with clang.
> > >
> > > Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
> > > Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> > > Cc: llvm@xxxxxxxxxxxxxxx
> > > Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
> > > [ Kartikeya: wrote commit message ]
> > > Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
> > > ---
> > > include/linux/compiler-clang.h | 22 ++++++++++++++++++++++
> > > 1 file changed, 22 insertions(+)
> > >
> > > diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h
> > > index 3c4de9b6c6e3..f1aa41d520bd 100644
> > > --- a/include/linux/compiler-clang.h
> > > +++ b/include/linux/compiler-clang.h
> >
> > The equivalent functionality for GCC has
> > 357 #ifndef __diag_GCC
> > 358 #define __diag_GCC(version, severity, string)
> > 359 #endif
> > in include/linux/compiler_types.h. Should this patch as well? (at
> > least #define __diag_clang`)?
> >
I left it out because there are no users for it, no code is doing
__diag_ignore(clang, ...), all of the current ones are hardcoding e.g.
__diag_ignore(GCC, 8, ...).
> > > @@ -68,3 +68,25 @@
> > >
> > > #define __nocfi __attribute__((__no_sanitize__("cfi")))
> > > #define __cficanonical __attribute__((__cfi_canonical_jump_table__))
> > > +
> > > +/*
> > > + * Turn individual warnings and errors on and off locally, depending
> > > + * on version.
> > > + */
> > > +#define __diag_clang(version, severity, s) \
> > > + __diag_clang_ ## version(__diag_clang_ ## severity s)
> > > +
> > > +/* Severity used in pragma directives */
> > > +#define __diag_clang_ignore ignored
> > > +#define __diag_clang_warn warning
> > > +#define __diag_clang_error error
> >
> > These severities match GCC. I wonder if rather than copy+pasting these
> > over, we could rework __diag_ignore, __diag_warn, and __diag_error to
> > not invoke a compiler-suffixed macro and rather pass the compiler
> > along (or make it implicit since we know CONFIG_CC_IS_CLANG vs
> > CONFIG_CC_IS_GCC)? We can probably land this than follow up on better
> > code-reuse between compilers for diagnostics.
> >
That was the idea with __diag_ignore_all in the next patch. FYI this series has
already been applied.
> > > +
> > > +#define __diag_str1(s) #s
> > > +#define __diag_str(s) __diag_str1(s)
> > > +#define __diag(s) _Pragma(__diag_str(clang diagnostic s))
> > > +
> > > +#if CONFIG_CLANG_VERSION >= 110000
> > > +#define __diag_clang_11(s) __diag(s)
> > > +#else
> > > +#define __diag_clang_11(s)
> > > +#endif
> > > --
> > > 2.35.1
> > >
> >
> >
> > --
> > Thanks,
> > ~Nick Desaulniers
>
>
>
> --
> Thanks,
> ~Nick Desaulniers
--
Kartikeya
