Re: [RFA] Avoid ubsan complaint in BFD

[John Darrington <john at darrington dot wattle dot id dot au>]

My personal opinion is that if tools don't understand the standard(s)
properly, then it's bad form to pander to them just for the sake of
shutting them up.

I remember in years gone by people used to religiously write
if (x != NULL)
  free (x);

As well as needlessly increasting the line count it meant that coverage
analysis would complain about untrialled branches.  It got to be silly.

Just my $0.02

On Fri, Jul 20, 2018 at 09:52:41AM -0600, Tom Tromey wrote:
     I built gdb with ubsan and ran the test suite.
     
     One complaint was due to bfd_get_elf_phdrs passing NULL to memcpy.
     This patch avoids the complaint.
     
     bfd/ChangeLog
     2018-07-20  Tom Tromey  <tom@tromey.com>
     
     	* elf.c (bfd_get_elf_phdrs): Don't call memcpy with size 0.
     ---
      bfd/ChangeLog | 4 ++++
      bfd/elf.c     | 5 +++--
      2 files changed, 7 insertions(+), 2 deletions(-)
     
     diff --git a/bfd/elf.c b/bfd/elf.c
     index 874629dc859..f72182788f9 100644
     --- a/bfd/elf.c
     +++ b/bfd/elf.c
     @@ -11629,8 +11629,9 @@ bfd_get_elf_phdrs (bfd *abfd, void *phdrs)
          }
      
        num_phdrs = elf_elfheader (abfd)->e_phnum;
     -  memcpy (phdrs, elf_tdata (abfd)->phdr,
     -	  num_phdrs * sizeof (Elf_Internal_Phdr));
     +  if (num_phdrs != 0)
     +    memcpy (phdrs, elf_tdata (abfd)->phdr,
     +	    num_phdrs * sizeof (Elf_Internal_Phdr));
      
        return num_phdrs;
      }
     -- 
     2.13.6

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