Re: Bug#950414: binutils-dev: failed to build linux perf (tools/perf) due to missing functions

[Romain Naour <romain.naour@smile.fr>]

Hi All,

Le 04/02/2020 à 16:35, Hagen Paul Pfeifer a écrit :
> * Matthias Klose | 2020-02-03 22:29:21 [+0100]:
> 
> [CCing Alan Modra, H.J. Lu, Nick Clifton & Arnaldo]
> 
> Ok, I tried to check what happens:
> 
> - Alan Modra modified the bfd_section_* macros (see commit fd3619828e94a)
>   upstream (https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=summary)
>   Or in other words: this patch removed/renamed the macros silently. This was
>   back in September last Year. No __attribute__ deprecation warning or other
>   information was given a priori to react.
> - This went mainline and was now taken by Debian Bullseye the last couple of
>   days. RedHat and other distributions will probably run in the same problems,
>   once they upgrade binutils.
> - Linux perf and other applications build on these functionality are now
>   doomed.

Binutils 2.34 broke also elf2flt tool:

https://github.com/uclinux-dev/elf2flt/blob/453398f917d167f8c308c8f997270c48ae8f8b12/elf2flt.c#L326

elf2flt is used in Buildroot build for armv7m (cortex-m4) and m68k-codefire.

https://gitlab.com/kubu93/toolchains-builder/-/jobs/423715926

Best regards,
Romain

> 
>> binutils doesn't have any comitment to a stable ABI/API for libopcodes and
>> libbfd.
> 
> Sure? They exposed bfd_get_section_flags and friends in bfd.h - it was not
> hidden somewhere in private header files nor was it guarded by any other
> measure. Correct me if I am wrong!
> 
> And: the functions/macros where used in the wild! They where helpful and
> serviceable to the broader audience - which is (sorry: "was" :-) great!
> 
> The following patch fixed the problem for me to build Linux perf again:
> 
> --- /usr/include/bfd.h	2020-02-04 15:24:36.746534674 +0000
> +++ /usr/include/bfd.new.h	2020-02-04 15:24:39.486542126 +0000
> @@ -1243,6 +1243,11 @@
>    return (sec->flags & SEC_IS_COMMON) != 0;
>  }
> 
> +#define bfd_get_section_flags(bfd, ptr) ((void) bfd, (ptr)->flags)
> +#define bfd_get_section_userdata(bfd, ptr) ((void) bfd, (ptr)->userdata)
> +#define bfd_get_section_vma(bfd, ptr) ((void) bfd, (ptr)->vma)
> +#define bfd_get_section_size(ptr) ((ptr)->size)
> +
> 
> 
> Note: for binutils ./bfd/bfd-in.h should be adjusted - sure.
> 
> Hagen Paul Pfeifer
> 
>>> It seems other people (kernel folks, Stephen) have the identical error as
>>> well: https://lkml.org/lkml/2020/1/30/1005
>>> Stephen: or is the bug fixed somewhere else? Do you have an workaround?a
>>
>> I don't have a work-around. If you rely on binutils internals, you really should
>> adjust to binutils upstream.