Subversion Repositories openrisc

/* BFD support for the ns32k architecture.

   Copyright 1990, 1991, 1994, 1995, 1998, 1999, 2000, 2001, 2002, 2003,

   2004, 2005, 2007 Free Software Foundation, Inc.

   Almost totally rewritten by Ian Dall from initial work

   by Andrew Cagney.

   This file is part of BFD, the Binary File Descriptor library.

   This program is free software; you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3 of the License, or

   (at your option) any later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program; if not, write to the Free Software

   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,

   MA 02110-1301, USA.  */

#include "sysdep.h"

#include "bfd.h"

#include "libbfd.h"

#include "ns32k.h"

#define N(machine, printable, d, next)  \

{  32, 32, 8, bfd_arch_ns32k, machine, "ns32k",printable,3,d,bfd_default_compatible,bfd_default_scan, next, }

static const bfd_arch_info_type arch_info_struct[] =

{

  N(32532,"ns32k:32532",TRUE, 0), /* The word ns32k will match this too.  */

};

const bfd_arch_info_type bfd_ns32k_arch =

  N(32032,"ns32k:32032",FALSE, &arch_info_struct[0]);

static bfd_reloc_status_type do_ns32k_reloc

  PARAMS ((bfd *, arelent *, struct bfd_symbol *, PTR, asection *,

           bfd *, char **,

           bfd_vma (*) (bfd_byte *, int),

           void (*) (bfd_vma, bfd_byte *, int)));

bfd_vma

_bfd_ns32k_get_displacement (buffer, size)

     bfd_byte *buffer;

     int size;

{

  bfd_signed_vma value;

  switch (size)

    {

    case 1:

      value = ((*buffer & 0x7f) ^ 0x40) - 0x40;

      break;

    case 2:

      value = ((*buffer++ & 0x3f) ^ 0x20) - 0x20;

      value = (value << 8) | (0xff & *buffer);

      break;

    case 4:

      value = ((*buffer++ & 0x3f) ^ 0x20) - 0x20;

      value = (value << 8) | (0xff & *buffer++);

      value = (value << 8) | (0xff & *buffer++);

      value = (value << 8) | (0xff & *buffer);

      break;

    default:

      abort ();

      return 0;

    }

  return value;

}

void

_bfd_ns32k_put_displacement (value, buffer, size)

     bfd_vma value;

     bfd_byte *buffer;

     int size;

{

  switch (size)

    {

    case 1:

      value &= 0x7f;

      *buffer++ = value;

      break;

    case 2:

      value &= 0x3fff;

      value |= 0x8000;

      *buffer++ = (value >> 8);

      *buffer++ = value;

      break;

    case 4:

      value |= (bfd_vma) 0xc0000000;

      *buffer++ = (value >> 24);

      *buffer++ = (value >> 16);

      *buffer++ = (value >> 8);

      *buffer++ = value;

      break;

  }

  return;

}

bfd_vma

_bfd_ns32k_get_immediate (buffer, size)

     bfd_byte *buffer;

     int size;

{

  bfd_vma value = 0;

  switch (size)

    {

    case 4:

      value = (value << 8) | (*buffer++ & 0xff);

      value = (value << 8) | (*buffer++ & 0xff);

    case 2:

      value = (value << 8) | (*buffer++ & 0xff);

    case 1:

      value = (value << 8) | (*buffer++ & 0xff);

      break;

    default:

      abort ();

    }

  return value;

}

void

_bfd_ns32k_put_immediate (value, buffer, size)

     bfd_vma value;

     bfd_byte *buffer;

     int size;

{

  buffer += size - 1;

  switch (size)

    {

    case 4:

      *buffer-- = (value & 0xff); value >>= 8;

      *buffer-- = (value & 0xff); value >>= 8;

    case 2:

      *buffer-- = (value & 0xff); value >>= 8;

    case 1:

      *buffer-- = (value & 0xff); value >>= 8;

    }

}

/* This is just like the standard perform_relocation except we

   use get_data and put_data which know about the ns32k storage

   methods.  This is probably a lot more complicated than it

   needs to be!  */

static bfd_reloc_status_type

do_ns32k_reloc (abfd, reloc_entry, symbol, data, input_section, output_bfd,

                error_message, get_data, put_data)

     bfd *abfd;

     arelent *reloc_entry;

     struct bfd_symbol *symbol;

     PTR data;

     asection *input_section;

     bfd *output_bfd;

     char **error_message ATTRIBUTE_UNUSED;

     bfd_vma (*get_data) PARAMS ((bfd_byte *, int));

     void (*put_data) PARAMS ((bfd_vma, bfd_byte *, int));

{

  int overflow = 0;

  bfd_vma relocation;

  bfd_reloc_status_type flag = bfd_reloc_ok;

  bfd_size_type addr = reloc_entry->address;

  bfd_vma output_base = 0;

  reloc_howto_type *howto = reloc_entry->howto;

  asection *reloc_target_output_section;

  bfd_byte *location;

  if ((symbol->section == &bfd_abs_section)

      && output_bfd != (bfd *) NULL)

    {

      reloc_entry->address += input_section->output_offset;

      return bfd_reloc_ok;

    }

  /* If we are not producing relocatable output, return an error if

     the symbol is not defined.  An undefined weak symbol is

     considered to have a value of zero (SVR4 ABI, p. 4-27).  */

  if (symbol->section == &bfd_und_section

      && (symbol->flags & BSF_WEAK) == 0

      && output_bfd == (bfd *) NULL)

    flag = bfd_reloc_undefined;

  /* Is the address of the relocation really within the section?  */

  if (reloc_entry->address > bfd_get_section_limit (abfd, input_section))

    return bfd_reloc_outofrange;

  /* Work out which section the relocation is targeted at and the

     initial relocation command value.  */

  /* Get symbol value.  (Common symbols are special.)  */

  if (bfd_is_com_section (symbol->section))

    relocation = 0;

  else

    relocation = symbol->value;

  reloc_target_output_section = symbol->section->output_section;

  /* Convert input-section-relative symbol value to absolute.  */

  if (output_bfd != NULL && ! howto->partial_inplace)

    output_base = 0;

  else

    output_base = reloc_target_output_section->vma;

  relocation += output_base + symbol->section->output_offset;

  /* Add in supplied addend.  */

  relocation += reloc_entry->addend;

  /* Here the variable relocation holds the final address of the

     symbol we are relocating against, plus any addend.  */

  if (howto->pc_relative)

    {

      /* This is a PC relative relocation.  We want to set RELOCATION

         to the distance between the address of the symbol and the

         location.  RELOCATION is already the address of the symbol.

         We start by subtracting the address of the section containing

         the location.

         If pcrel_offset is set, we must further subtract the position

         of the location within the section.  Some targets arrange for

         the addend to be the negative of the position of the location

         within the section; for example, i386-aout does this.  For

         i386-aout, pcrel_offset is FALSE.  Some other targets do not

         include the position of the location; for example, m88kbcs,

         or ELF.  For those targets, pcrel_offset is TRUE.

         If we are producing relocatable output, then we must ensure

         that this reloc will be correctly computed when the final

         relocation is done.  If pcrel_offset is FALSE we want to wind

         up with the negative of the location within the section,

         which means we must adjust the existing addend by the change

         in the location within the section.  If pcrel_offset is TRUE

         we do not want to adjust the existing addend at all.

         FIXME: This seems logical to me, but for the case of

         producing relocatable output it is not what the code

         actually does.  I don't want to change it, because it seems

         far too likely that something will break.  */

      relocation -=

        input_section->output_section->vma + input_section->output_offset;

      if (howto->pcrel_offset)

        relocation -= reloc_entry->address;

    }

  if (output_bfd != (bfd *) NULL)

    {

      if (! howto->partial_inplace)

        {

          /* This is a partial relocation, and we want to apply the relocation

             to the reloc entry rather than the raw data. Modify the reloc

             inplace to reflect what we now know.  */

          reloc_entry->addend = relocation;

          reloc_entry->address += input_section->output_offset;

          return flag;

        }

      else

        {

          /* This is a partial relocation, but inplace, so modify the

             reloc record a bit.

             If we've relocated with a symbol with a section, change

             into a ref to the section belonging to the symbol.  */

          reloc_entry->address += input_section->output_offset;

          /* WTF?? */

          if (abfd->xvec->flavour == bfd_target_coff_flavour)

            {

              /* For m68k-coff, the addend was being subtracted twice during

                 relocation with -r.  Removing the line below this comment

                 fixes that problem; see PR 2953.

                 However, Ian wrote the following, regarding removing the line

                 below, which explains why it is still enabled:  --djm

                 If you put a patch like that into BFD you need to check all

                 the COFF linkers.  I am fairly certain that patch will break

                 coff-i386 (e.g., SCO); see coff_i386_reloc in coff-i386.c

                 where I worked around the problem in a different way.  There

                 may very well be a reason that the code works as it does.

                 Hmmm.  The first obvious point is that bfd_perform_relocation

                 should not have any tests that depend upon the flavour.  It's

                 seem like entirely the wrong place for such a thing.  The

                 second obvious point is that the current code ignores the

                 reloc addend when producing relocatable output for COFF.

                 That's peculiar.  In fact, I really have no idea what the

                 point of the line you want to remove is.

                 A typical COFF reloc subtracts the old value of the symbol

                 and adds in the new value to the location in the object file

                 (if it's a pc relative reloc it adds the difference between

                 the symbol value and the location).  When relocating we need

                 to preserve that property.

                 BFD handles this by setting the addend to the negative of the

                 old value of the symbol.  Unfortunately it handles common

                 symbols in a non-standard way (it doesn't subtract the old

                 value) but that's a different story (we can't change it

                 without losing backward compatibility with old object files)

                 (coff-i386 does subtract the old value, to be compatible with

                 existing coff-i386 targets, like SCO).

                 So everything works fine when not producing relocatable

                 output.  When we are producing relocatable output, logically

                 we should do exactly what we do when not producing

                 relocatable output.  Therefore, your patch is correct.  In

                 fact, it should probably always just set reloc_entry->addend

                 to 0 for all cases, since it is, in fact, going to add the

                 value into the object file.  This won't hurt the COFF code,

                 which doesn't use the addend; I'm not sure what it will do

                 to other formats (the thing to check for would be whether

                 any formats both use the addend and set partial_inplace).

                 When I wanted to make coff-i386 produce relocatable output,

                 I ran into the problem that you are running into: I wanted

                 to remove that line.  Rather than risk it, I made the

                 coff-i386 relocs use a special function; it's coff_i386_reloc

                 in coff-i386.c.  The function specifically adds the addend

                 field into the object file, knowing that bfd_perform_relocation

                 is not going to.  If you remove that line, then coff-i386.c

                 will wind up adding the addend field in twice.  It's trivial

                 to fix; it just needs to be done.

                 The problem with removing the line is just that it may break

                 some working code.  With BFD it's hard to be sure of anything.

                 The right way to deal with this is simply to build and test at

                 least all the supported COFF targets.  It should be

                 straightforward if time and disk space consuming.  For each

                 target:

                   1) build the linker

                   2) generate some executable, and link it using -r (I would

                      probably use paranoia.o and link against newlib/libc.a,

                      which for all the supported targets would be available in

                      /usr/cygnus/progressive/H-host/target/lib/libc.a).

                   3) make the change to reloc.c

                   4) rebuild the linker

                   5) repeat step 2

                   6) if the resulting object files are the same, you have at

                      least made it no worse

                   7) if they are different you have to figure out which

                      version is right.  */

              relocation -= reloc_entry->addend;

              reloc_entry->addend = 0;

            }

          else

            {

              reloc_entry->addend = relocation;

            }

        }

    }

  else

    {

      reloc_entry->addend = 0;

    }

  /* FIXME: This overflow checking is incomplete, because the value

     might have overflowed before we get here.  For a correct check we

     need to compute the value in a size larger than bitsize, but we

     can't reasonably do that for a reloc the same size as a host

     machine word.

     FIXME: We should also do overflow checking on the result after

     adding in the value contained in the object file.  */

  if (howto->complain_on_overflow != complain_overflow_dont)

    {

      bfd_vma check;

      /* Get the value that will be used for the relocation, but

         starting at bit position zero.  */

      if (howto->rightshift > howto->bitpos)

        check = relocation >> (howto->rightshift - howto->bitpos);

      else

        check = relocation << (howto->bitpos - howto->rightshift);

      switch (howto->complain_on_overflow)

        {

        case complain_overflow_signed:

          {

            /* Assumes two's complement.  */

            bfd_signed_vma reloc_signed_max = (1 << (howto->bitsize - 1)) - 1;

            bfd_signed_vma reloc_signed_min = ~reloc_signed_max;

            /* The above right shift is incorrect for a signed value.

               Fix it up by forcing on the upper bits.  */

            if (howto->rightshift > howto->bitpos

                && (bfd_signed_vma) relocation < 0)

              check |= ((bfd_vma) - 1

                        & ~((bfd_vma) - 1

                            >> (howto->rightshift - howto->bitpos)));

            if ((bfd_signed_vma) check > reloc_signed_max

                || (bfd_signed_vma) check < reloc_signed_min)

              flag = bfd_reloc_overflow;

          }

          break;

        case complain_overflow_unsigned:

          {

            /* Assumes two's complement.  This expression avoids

               overflow if howto->bitsize is the number of bits in

               bfd_vma.  */

            bfd_vma reloc_unsigned_max =

            (((1 << (howto->bitsize - 1)) - 1) << 1) | 1;

            if ((bfd_vma) check > reloc_unsigned_max)

              flag = bfd_reloc_overflow;

          }

          break;

        case complain_overflow_bitfield:

          {

            /* Assumes two's complement.  This expression avoids

               overflow if howto->bitsize is the number of bits in

               bfd_vma.  */

            bfd_vma reloc_bits = (((1 << (howto->bitsize - 1)) - 1) << 1) | 1;

            if (((bfd_vma) check & ~reloc_bits) != 0

                && (((bfd_vma) check & ~reloc_bits)

                    != (-(bfd_vma) 1 & ~reloc_bits)))

              {

                /* The above right shift is incorrect for a signed

                   value.  See if turning on the upper bits fixes the

                   overflow.  */

                if (howto->rightshift > howto->bitpos

                    && (bfd_signed_vma) relocation < 0)

                  {

                    check |= ((bfd_vma) - 1

                              & ~((bfd_vma) - 1

                                  >> (howto->rightshift - howto->bitpos)));

                    if (((bfd_vma) check & ~reloc_bits)

                        != (-(bfd_vma) 1 & ~reloc_bits))

                      flag = bfd_reloc_overflow;

                  }

                else

                  flag = bfd_reloc_overflow;

              }

          }

          break;

        default:

          abort ();

        }

    }

  /* Either we are relocating all the way, or we don't want to apply

     the relocation to the reloc entry (probably because there isn't

     any room in the output format to describe addends to relocs).  */

  /* The cast to bfd_vma avoids a bug in the Alpha OSF/1 C compiler

     (OSF version 1.3, compiler version 3.11).  It miscompiles the

     following program:

     struct str

     {

       unsigned int i0;

     } s = { 0 };

     int

     main ()

     {

       unsigned long x;

       x = 0x100000000;

       x <<= (unsigned long) s.i0;

       if (x == 0)

         printf ("failed\n");

       else

         printf ("succeeded (%lx)\n", x);

     }

     */

  relocation >>= (bfd_vma) howto->rightshift;

  /* Shift everything up to where it's going to be used.  */

  relocation <<= (bfd_vma) howto->bitpos;

  /* Wait for the day when all have the mask in them.  */

  /* What we do:

     i instruction to be left alone

     o offset within instruction

     r relocation offset to apply

     S src mask

     D dst mask

     N ~dst mask

     A part 1

     B part 2

     R result

     Do this:

     i i i i i o o o o o        from bfd_get<size>

     and           S S S S S    to get the size offset we want

     +   r r r r r r r r r r  to get the final value to place

     and           D D D D D  to chop to right size

     -----------------------

     A A A A A

     And this:

     ...   i i i i i o o o o o  from bfd_get<size>

     and   N N N N N            get instruction

     -----------------------

     ...   B B B B B

     And then:

     B B B B B

     or              A A A A A

     -----------------------

     R R R R R R R R R R        put into bfd_put<size>.  */

#define DOIT(x) \

  x = ( (x & ~howto->dst_mask) | (((x & howto->src_mask) +  relocation) & howto->dst_mask))

  location = (bfd_byte *) data + addr;

  switch (howto->size)

    {

    case 0:

      {

        bfd_vma x = get_data (location, 1);

        DOIT (x);

        put_data ((bfd_vma) x, location, 1);

      }

      break;

    case 1:

      if (relocation)

        {

          bfd_vma x = get_data (location, 2);

          DOIT (x);

          put_data ((bfd_vma) x, location, 2);

        }

      break;

    case 2:

      if (relocation)

        {

          bfd_vma x = get_data (location, 4);

          DOIT (x);

          put_data ((bfd_vma) x, location, 4);

        }

      break;

    case -2:

      {

        bfd_vma x = get_data (location, 4);

        relocation = -relocation;

        DOIT(x);

        put_data ((bfd_vma) x, location, 4);

      }

      break;

    case 3:

      /* Do nothing.  */

      break;

    case 4:

#ifdef BFD64

      if (relocation)

        {

          bfd_vma x = get_data (location, 8);

          DOIT (x);

          put_data (x, location, 8);

        }

#else

      abort ();

#endif

      break;

    default:

      return bfd_reloc_other;

    }

  if ((howto->complain_on_overflow != complain_overflow_dont) && overflow)

    return bfd_reloc_overflow;

  return flag;

}

/* Relocate a given location using a given value and howto.  */

bfd_reloc_status_type

_bfd_do_ns32k_reloc_contents (howto, input_bfd, relocation, location,

                              get_data, put_data)

     reloc_howto_type *howto;

     bfd *input_bfd ATTRIBUTE_UNUSED;

     bfd_vma relocation;

     bfd_byte *location;

     bfd_vma (*get_data) PARAMS ((bfd_byte *, int));

     void (*put_data) PARAMS ((bfd_vma, bfd_byte *, int));

{

  int size;

  bfd_vma x;

  bfd_boolean overflow;

  /* If the size is negative, negate RELOCATION.  This isn't very

     general.  */

  if (howto->size < 0)

    relocation = -relocation;

  /* Get the value we are going to relocate.  */

  size = bfd_get_reloc_size (howto);

  switch (size)

    {

    default:

    case 0:

      abort ();

    case 1:

    case 2:

    case 4:

#ifdef BFD64

    case 8:

#endif

      x = get_data (location, size);

      break;

    }

  /* Check for overflow.  FIXME: We may drop bits during the addition

     which we don't check for.  We must either check at every single

     operation, which would be tedious, or we must do the computations

     in a type larger than bfd_vma, which would be inefficient.  */

  overflow = FALSE;

  if (howto->complain_on_overflow != complain_overflow_dont)

    {

      bfd_vma check;

      bfd_signed_vma signed_check;

      bfd_vma add;

      bfd_signed_vma signed_add;

      if (howto->rightshift == 0)

        {

          check = relocation;

          signed_check = (bfd_signed_vma) relocation;

        }

      else

        {

          /* Drop unwanted bits from the value we are relocating to.  */

          check = relocation >> howto->rightshift;

          /* If this is a signed value, the rightshift just dropped

             leading 1 bits (assuming twos complement).  */

          if ((bfd_signed_vma) relocation >= 0)

            signed_check = check;

          else

            signed_check = (check

                            | ((bfd_vma) - 1

                               & ~((bfd_vma) - 1 >> howto->rightshift)));

        }

      /* Get the value from the object file.  */

      add = x & howto->src_mask;

      /* Get the value from the object file with an appropriate sign.

         The expression involving howto->src_mask isolates the upper

         bit of src_mask.  If that bit is set in the value we are

         adding, it is negative, and we subtract out that number times

         two.  If src_mask includes the highest possible bit, then we

         can not get the upper bit, but that does not matter since

         signed_add needs no adjustment to become negative in that

         case.  */

      signed_add = add;

      if ((add & (((~howto->src_mask) >> 1) & howto->src_mask)) != 0)

        signed_add -= (((~howto->src_mask) >> 1) & howto->src_mask) << 1;

      /* Add the value from the object file, shifted so that it is a

         straight number.  */

      if (howto->bitpos == 0)

        {

          check += add;

          signed_check += signed_add;

        }

      else

        {

          check += add >> howto->bitpos;

          /* For the signed case we use ADD, rather than SIGNED_ADD,

             to avoid warnings from SVR4 cc.  This is OK since we

             explicitly handle the sign bits.  */

          if (signed_add >= 0)

            signed_check += add >> howto->bitpos;

          else

            signed_check += ((add >> howto->bitpos)

                             | ((bfd_vma) - 1

                                & ~((bfd_vma) - 1 >> howto->bitpos)));

        }

      switch (howto->complain_on_overflow)

        {

        case complain_overflow_signed:

          {

            /* Assumes two's complement.  */

            bfd_signed_vma reloc_signed_max = (1 << (howto->bitsize - 1)) - 1;

            bfd_signed_vma reloc_signed_min = ~reloc_signed_max;

            if (signed_check > reloc_signed_max

                || signed_check < reloc_signed_min)

              overflow = TRUE;

          }

          break;

        case complain_overflow_unsigned:

          {

            /* Assumes two's complement.  This expression avoids

               overflow if howto->bitsize is the number of bits in

               bfd_vma.  */

            bfd_vma reloc_unsigned_max =

            (((1 << (howto->bitsize - 1)) - 1) << 1) | 1;

            if (check > reloc_unsigned_max)

              overflow = TRUE;

          }

          break;

        case complain_overflow_bitfield:

          {

            /* Assumes two's complement.  This expression avoids

               overflow if howto->bitsize is the number of bits in

               bfd_vma.  */

            bfd_vma reloc_bits = (((1 << (howto->bitsize - 1)) - 1) << 1) | 1;