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From:   Namhyung Kim <namhyung@kernel.org>
Date:   Thu, 11 Feb 2021 18:14:03 +0900
Message-ID: <CAM9d7civ8h5uh6_uMj9zKBkeRaCxr_UvA0inEiR8EmgHHxRtGQ@mail.gmail.com>
Subject: Re: [PATCH] perf: Use (long) for iterator for bfd symbols
To:     Dmitry Safonov <dima@arista.com>
Cc:     linux-kernel <linux-kernel@vger.kernel.org>,
        Dmitry Safonov <0x7f454c46@gmail.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Ingo Molnar <mingo@redhat.com>,
        Jacek Caban <jacek@codeweavers.com>,
        Jiri Olsa <jolsa@redhat.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Remi Bernon <rbernon@codeweavers.com>
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Hello,

On Tue, Feb 9, 2021 at 11:51 PM Dmitry Safonov <dima@arista.com> wrote:
>
> GCC (GCC) 8.4.0 20200304 fails to build perf with:
> : util/symbol.c: In function 'dso__load_bfd_symbols':
> : util/symbol.c:1626:16: error: comparison of integer expressions of different signednes
> :   for (i = 0; i < symbols_count; ++i) {
> :                 ^
> : util/symbol.c:1632:16: error: comparison of integer expressions of different signednes
> :    while (i + 1 < symbols_count &&
> :                 ^
> : util/symbol.c:1637:13: error: comparison of integer expressions of different signednes
> :    if (i + 1 < symbols_count &&
> :              ^
> : cc1: all warnings being treated as errors
>
> It's unlikely that the symtable will be that big, but the fix is
> oneliner and as perf has CORE_CFLAGS += -Wextra, which makes build to
> fail together with CORE_CFLAGS += -Werror
>
> Fixes: eac9a4342e54 ("perf symbols: Try reading the symbol table with libbfd")
> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
> Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Jacek Caban <jacek@codeweavers.com>
> Cc: Jiri Olsa <jolsa@redhat.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Remi Bernon <rbernon@codeweavers.com>
> Signed-off-by: Dmitry Safonov <dima@arista.com>

Acked-by: Namhyung Kim <namhyung@kernel.org>

Thanks,
Namhyung


> ---
>  tools/perf/util/symbol.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
> index 64a039cbba1b..1645fb4ec9ed 100644
> --- a/tools/perf/util/symbol.c
> +++ b/tools/perf/util/symbol.c
> @@ -1561,12 +1561,11 @@ static int bfd2elf_binding(asymbol *symbol)
>  int dso__load_bfd_symbols(struct dso *dso, const char *debugfile)
>  {
>         int err = -1;
> -       long symbols_size, symbols_count;
> +       long symbols_size, symbols_count, i;
>         asection *section;
>         asymbol **symbols, *sym;
>         struct symbol *symbol;
>         bfd *abfd;
> -       u_int i;
>         u64 start, len;
>
>         abfd = bfd_openr(dso->long_name, NULL);
> --
> 2.30.0
>