Re: [PATCH v3 3/8] tools include: add dis-asm-compat.h to handle version differences

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Sun, Jul 31, 2022 at 06:38:29PM -0700, Andres Freund escreveu:
> binutils changed the signature of init_disassemble_info(), which now causes
> compilation failures for tools/{perf,bpf}, e.g. on debian unstable.
> Relevant binutils commit:
> https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=60a3da00bd5407f07
> 
> This commit introduces a wrapper for init_disassemble_info(), to avoid
> spreading #ifdef DISASM_INIT_STYLED to a bunch of places. Subsequent
> commits will use it to fix the build failures.
> 
> It likely is worth adding a wrapper for disassember(), to avoid the already
> existing DISASM_FOUR_ARGS_SIGNATURE ifdefery.
> 
> Cc: Alexei Starovoitov <ast@kernel.org>
> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
> Cc: Sedat Dilek <sedat.dilek@gmail.com>
> Cc: Quentin Monnet <quentin@isovalent.com>
> Cc: Ben Hutchings <benh@debian.org>
> Link: http://lore.kernel.org/lkml/20220622181918.ykrs5rsnmx3og4sv@alap3.anarazel.de
> Signed-off-by: Andres Freund <andres@anarazel.de>
> Signed-off-by: Ben Hutchings <benh@debian.org>

So, who is the author of this patch? Ben? b4 complained about it:

NOTE: some trailers ignored due to from/email mismatches:
    ! Trailer: Signed-off-by: Ben Hutchings <benh@debian.org>
     Msg From: Andres Freund <andres@anarazel.de>
NOTE: Rerun with -S to apply them anyway

If it is Ben, then we would need a:

From: Ben Hutchings <benh@debian.org>

At the beginning of the patch, right?

- Arnaldo

> ---
>  tools/include/tools/dis-asm-compat.h | 55 ++++++++++++++++++++++++++++
>  1 file changed, 55 insertions(+)
>  create mode 100644 tools/include/tools/dis-asm-compat.h
> 
> diff --git a/tools/include/tools/dis-asm-compat.h b/tools/include/tools/dis-asm-compat.h
> new file mode 100644
> index 000000000000..70f331e23ed3
> --- /dev/null
> +++ b/tools/include/tools/dis-asm-compat.h
> @@ -0,0 +1,55 @@
> +/* SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause */
> +#ifndef _TOOLS_DIS_ASM_COMPAT_H
> +#define _TOOLS_DIS_ASM_COMPAT_H
> +
> +#include <stdio.h>
> +#include <dis-asm.h>
> +
> +/* define types for older binutils version, to centralize ifdef'ery a bit */
> +#ifndef DISASM_INIT_STYLED
> +enum disassembler_style {DISASSEMBLER_STYLE_NOT_EMPTY};
> +typedef int (*fprintf_styled_ftype) (void *, enum disassembler_style, const char*, ...);
> +#endif
> +
> +/*
> + * Trivial fprintf wrapper to be used as the fprintf_styled_func argument to
> + * init_disassemble_info_compat() when normal fprintf suffices.
> + */
> +static inline int fprintf_styled(void *out,
> +				 enum disassembler_style style,
> +				 const char *fmt, ...)
> +{
> +	va_list args;
> +	int r;
> +
> +	(void)style;
> +
> +	va_start(args, fmt);
> +	r = vfprintf(out, fmt, args);
> +	va_end(args);
> +
> +	return r;
> +}
> +
> +/*
> + * Wrapper for init_disassemble_info() that hides version
> + * differences. Depending on binutils version and architecture either
> + * fprintf_func or fprintf_styled_func will be called.
> + */
> +static inline void init_disassemble_info_compat(struct disassemble_info *info,
> +						void *stream,
> +						fprintf_ftype unstyled_func,
> +						fprintf_styled_ftype styled_func)
> +{
> +#ifdef DISASM_INIT_STYLED
> +	init_disassemble_info(info, stream,
> +			      unstyled_func,
> +			      styled_func);
> +#else
> +	(void)styled_func;
> +	init_disassemble_info(info, stream,
> +			      unstyled_func);
> +#endif
> +}
> +
> +#endif /* _TOOLS_DIS_ASM_COMPAT_H */
> -- 
> 2.37.0.3.g30cc8d0f14

-- 

- Arnaldo