Re: [PATCH v2 3/4] gdbserver: Add powerpc fast tracepoint support.

[Marcin KoÅcielnicki <koriakin at 0x04 dot net>]

On 30/03/16 17:35, Ulrich Weigand wrote:
> Simon Marchi wrote:
>
> > Ahh, it seems like the ordering is important here.  If I include it before
> > <elf.h> (and everything that includes <elf.h>), it works.
>
> Hmm, it would probably be best to avoid mixing in-tree BFD headers and
> system headers this way.  I'd suggest to *not* include <elf.h> at all,
> but instead use:
>
> #include "elf/common.h"
> #include "elf/ppc64.h"
>
> Bye,
> Ulrich

That doesn't work either:

../../../gdb/gdbserver/linux-ppc-low.c: In function ‘is_elfv2_inferior’:
../../../gdb/gdbserver/linux-ppc-low.c:763:3: error: unknown type name 
‘Elf64_Ehdr’
   Elf64_Ehdr ehdr;
   ^
../../../gdb/gdbserver/linux-ppc-low.c:772:18: error: request for member 
‘e_ident’ in something not a structure or union
   if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG))
                  ^
../../../gdb/gdbserver/linux-ppc-low.c:772:28: error: ‘ELFMAG’ 
undeclared (first use in this function)
   if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG))
                            ^
../../../gdb/gdbserver/linux-ppc-low.c:772:28: note: each undeclared 
identifier is reported only once for each function it appears in
../../../gdb/gdbserver/linux-ppc-low.c:772:36: error: ‘SELFMAG’ 
undeclared (first use in this function)
   if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG))
                                    ^
../../../gdb/gdbserver/linux-ppc-low.c:775:15: error: request for member 
‘e_flags’ in something not a structure or union
   return (ehdr.e_flags & EF_PPC64_ABI) == 2;
               ^
../../../gdb/gdbserver/linux-ppc-low.c:776:1: error: control reaches end 
of non-void function [-Werror=return-type]
 }
 ^

There's no equivalent to ELFMAG in the BFD headers, and getting to 
e_flags requires more work too (you need elf/external.h and manually 
assemble the word from bytes).  Perhaps it'd be simpler to just define 
EF_PPC64_ABI manually if it's not defined?