[PATCH] Makefile: Fix grep warning

[Andrew Jones]

On Thu, Aug 10, 2023 at 01:46:19PM +0200, Andreas Schwab wrote:
> On Aug 10 2023, Andrew Jones wrote:
> 
> > On Thu, Aug 10, 2023 at 01:32:49PM +0200, Andreas Schwab wrote:
> >> On Aug 10 2023, Andrew Jones wrote:
> >> 
> >> > grep (at least my version, grep-3.8-3.fc38.x86_64) warns with
> >> > "grep: warning: stray \ before -". Fix the warning by making
> >> > the command line input to grep less ambiguous.
> >> >
> >> > Signed-off-by: Andrew Jones <ajones at ventanamicro.com>
> >> > ---
> >> >  Makefile | 2 +-
> >> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >> >
> >> > diff --git a/Makefile b/Makefile
> >> > index 730dbd910e51..03768a51f710 100644
> >> > --- a/Makefile
> >> > +++ b/Makefile
> >> > @@ -168,7 +168,7 @@ endif
> >> >  OPENSBI_LD_PIE := $(shell $(CC) $(CLANG_TARGET) $(RELAX_FLAG) $(USE_LD_FLAG) -fPIE -nostdlib -Wl,-pie -x c /dev/null -o /dev/null >/dev/null 2>&1 && echo y || echo n)
> >> >  
> >> >  # Check whether the compiler supports -m(no-)save-restore
> >> > -CC_SUPPORT_SAVE_RESTORE := $(shell $(CC) $(CLANG_TARGET) $(RELAX_FLAG) -nostdlib -mno-save-restore -x c /dev/null -o /dev/null 2>&1 | grep "\-save\-restore" >/dev/null && echo n || echo y)
> >> > +CC_SUPPORT_SAVE_RESTORE := $(shell $(CC) $(CLANG_TARGET) $(RELAX_FLAG) -nostdlib -mno-save-restore -x c /dev/null -o /dev/null 2>&1 | grep -- "-save-restore" >/dev/null && echo n || echo y)
> >> 
> >> Please use grep -e ... instead.
> >
> > Sure, but I'd like to put a justification in the commit message, something
> > like, Use -e, as opposed to --, because...
> 
> It's portable.

Hmm, shellcheck doesn't complain,

 shellcheck -s sh <(echo "echo foo | grep -- foo")

but maybe the concern is that plopping the "grep -- foo" string into
random shells may not always work, since a random shell could assume
the -- is for itself to interpret, rather than for grep?

Anyway, v2 coming up, but without a justification for -e vs. --, since
it's not clear to me.

Thanks,
drew