Re: [RFC/PATCH] arm64: Rename macro arguments to silence sparse

[Luc Van Oostenryck]

On Mon, Feb 06, 2017 at 05:08:17PM -0800, Stephen Boyd wrote:
> On 02/06/2017 05:01 PM, Stephen Boyd wrote:
> > When I compile files with sparse, I get these sorts of warnings:
> >
> > arch/arm64/include/asm/lse.h:14:28: warning: Unknown escape 'l'
> > arch/arm64/include/asm/lse.h:14:37: warning: Unknown escape 'l'
> > arch/arm64/include/asm/alternative.h:172:28: warning: Unknown escape 'o'
> >
> > This is because sparse is trying to tokenize these files and sees
> > a line like this:
> >
> >  alternative_insn "\llsc", "\lse", ARM64_HAS_LSE_ATOMICS
> >
> > It gets past alternative_insn part and then sees the start of a
> > string with the double quote character. So sparse starts to parse
> > the string (eat_string() in the sparse code) but the string has
> > an escape character '\' in it. Sparse sees the escape character,
> > so it checks to see if it's an escape sequence, but '\l' isn't.
> > This causes sparse to spit out this warning of an unknown escape
> > sequence 'l'.
> >
> > In reality, sparse isn't going to use these macros anyway because
> > this whole thing is inside an __ASSEMBLER__ ifdef.

Yes, annoying. Conversion of escaped characters is supposed to be
done just after preprocessing. It's definitively a bug.

Luc