gas misbehavior in binutils-2.16.1 for sh4 target and --enable-shared

gas misbehavior in binutils-2.16.1 for sh4 target and --enable-shared

[Mike Frysinger]

while debugging a gcc issue, i noticed that `file` was giving me varying 
results; turns out that it was due to configuring binutils-2.16.1 with 
--enable-shared.  binutils-2.15 works as expected, so i'm inclined to think it 
a bug :).  the other quirky thing is readelf shows different Flags in the ELF 
header ...

using vanilla binutils-2.16.1 and binutils-2.15 on an amd64 host, i ran:
./configure --target=sh4-linux --enable-shared
make
touch test.s
./gas/as-new test.s -o test.o
file test.o
./binutils/readelf -h test.o | grep Flags

binutils-2.16.1 with --enabled-shared:
test.o: ELF 32-bit LSB relocatable, Hitachi SH, version 1 (SYSV), not stripped
Flags: 0x19, unknown ISA

binutils-2.16.1 without --enabled-shared:
binutils-2.15 with --enabled-shared:
test.o: ELF 32-bit LSB relocatable, Hitachi SH, version 1 MathCoPro/FPU/MAU 
Required (SYSV), not stripped
Flags: 0x1, sh1

running through strace shows that the correct libbfd.so is being loaded, 
libbfd-2.16.1.so from ./bfd/.libs/x86_64/libbfd-2.16.1.so ... so what 
gives ? :)

for reference, i tested a few different versions ... 2.15.92.0.2 and 
2.16.91.0.3 also have this odd behavior ...
-mike

Re: gas misbehavior in binutils-2.16.1 for sh4 target and --enable-shared

[Kaz Kojima]

Mike Frysinger <vapier@gentoo.org> wrote:
> binutils-2.16.1 with --enabled-shared:
> test.o: ELF 32-bit LSB relocatable, Hitachi SH, version 1 (SYSV), not stripped
> Flags: 0x19, unknown ISA

It's caused by an off-by-one error.  Thanks for catching it.
sh_elf_get_flags_from_mach looks up a value in a table starting with
the wrong index.  I've committed the attached patch.  

Regards,
	kaz
--
2005-08-25  Kaz Kojima  <kkojima@rr.iij4u.or.jp>

	* elf32-sh.c (sh_elf_get_flags_from_mach): Fix off-by-one error.

--- ORIG/src/bfd/elf32-sh.c	2005-08-25 11:59:27.000000000 +0900
+++ LOCAL/src/bfd/elf32-sh.c	2005-08-25 12:05:33.000000000 +0900
@@ -6655,7 +6655,7 @@ sh_elf_set_mach_from_flags (bfd *abfd)
 int
 sh_elf_get_flags_from_mach (unsigned long mach)
 {
-  int i = ARRAY_SIZE (sh_ef_bfd_table);
+  int i = ARRAY_SIZE (sh_ef_bfd_table) - 1;
   
   for (; i>0; i--)
     if (sh_ef_bfd_table[i] == mach)

Re: gas misbehavior in binutils-2.16.1 for sh4 target and --enable-shared

[Alan Modra]

On Thu, Aug 25, 2005 at 02:13:29PM +0900, Kaz Kojima wrote:
> +  int i = ARRAY_SIZE (sh_ef_bfd_table) - 1;
>    
>    for (; i>0; i--)
>      if (sh_ef_bfd_table[i] == mach)

Do you want to check sh_ef_bfd_table[0]?

-- 
Alan Modra
IBM OzLabs - Linux Technology Centre

Re: gas misbehavior in binutils-2.16.1 for sh4 target and --enable-shared

[Kaz Kojima]

Alan Modra <amodra@bigpond.net.au> wrote:
>> +  int i = ARRAY_SIZE (sh_ef_bfd_table) - 1;
>>    
>>    for (; i>0; i--)
>>      if (sh_ef_bfd_table[i] == mach)
> 
> Do you want to check sh_ef_bfd_table[0]?

Ah, I also thought so.  sh_ef_bfd_table[0] is set to EF_SH_UNKNOWN
which is 0 for backwards compatibility.  So I think that this is
intentional.

Regards,
	kaz

Re: gas misbehavior in binutils-2.16.1 for sh4 target and --enable-shared

[Mike Frysinger]

On Thursday 25 August 2005 01:13 am, Kaz Kojima wrote:
> Mike Frysinger <vapier@gentoo.org> wrote:
> > binutils-2.16.1 with --enabled-shared:
> > test.o: ELF 32-bit LSB relocatable, Hitachi SH, version 1 (SYSV), not
> > stripped Flags: 0x19, unknown ISA
>
> It's caused by an off-by-one error.  Thanks for catching it.
> sh_elf_get_flags_from_mach looks up a value in a table starting with
> the wrong index.  I've committed the attached patch.

yep, that certainly did the trick, thanks
-mike