$OpenBSD: patch-bfd_coff-avr_c,v 1.1 2008/10/01 04:46:19 ckuethe Exp $
--- bfd/coff-avr.c.orig	Sat Sep 27 20:20:27 2008
+++ bfd/coff-avr.c	Sat Sep 27 20:20:27 2008
@@ -0,0 +1,609 @@
+/* BFD back-end for Atmel AVR COFF files.
+   Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1999, 2000, 2001, 2003
+   Free Software Foundation, Inc.
+   Created mostly by substituting "avr" for "i860" in coff-i860.c
+
+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 2 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+#include "bfd.h"
+#include "sysdep.h"
+#include "libbfd.h"
+
+#include "coff/avr.h"
+
+#include "coff/internal.h"
+
+#include "libcoff.h"
+
+static bfd_reloc_status_type coff_avr_reloc
+  PARAMS ((bfd *, arelent *, asymbol *, PTR, asection *, bfd *, char **));
+static reloc_howto_type *coff_avr_rtype_to_howto
+  PARAMS ((bfd *, asection *, struct internal_reloc *,
+	   struct coff_link_hash_entry *, struct internal_syment *,
+	   bfd_vma *));
+static const bfd_target * coff_avr_object_p PARAMS ((bfd *));
+
+#define COFF_DEFAULT_SECTION_ALIGNMENT_POWER (2)
+/* The page size is a guess based on ELF.  */
+
+#define COFF_PAGE_SIZE 0x1000
+
+/* For some reason when using avr COFF the value stored in the .text
+   section for a reference to a common symbol is the value itself plus
+   any desired offset.  Ian Taylor, Cygnus Support.  */
+
+/* If we are producing relocateable output, we need to do some
+   adjustments to the object file that are not done by the
+   bfd_perform_relocation function.  This function is called by every
+   reloc type to make any required adjustments.  */
+
+static bfd_reloc_status_type
+coff_avr_reloc (abfd, reloc_entry, symbol, data, input_section, output_bfd,
+		 error_message)
+     bfd *abfd;
+     arelent *reloc_entry;
+     asymbol *symbol;
+     PTR data;
+     asection *input_section ATTRIBUTE_UNUSED;
+     bfd *output_bfd;
+     char **error_message ATTRIBUTE_UNUSED;
+{
+  symvalue diff;
+
+  if (output_bfd == (bfd *) NULL)
+    return bfd_reloc_continue;
+
+  if (bfd_is_com_section (symbol->section))
+    {
+      /* We are relocating a common symbol.  The current value in the
+	 object file is ORIG + OFFSET, where ORIG is the value of the
+	 common symbol as seen by the object file when it was compiled
+	 (this may be zero if the symbol was undefined) and OFFSET is
+	 the offset into the common symbol (normally zero, but may be
+	 non-zero when referring to a field in a common structure).
+	 ORIG is the negative of reloc_entry->addend, which is set by
+	 the CALC_ADDEND macro below.  We want to replace the value in
+	 the object file with NEW + OFFSET, where NEW is the value of
+	 the common symbol which we are going to put in the final
+	 object file.  NEW is symbol->value.  */
+      diff = symbol->value + reloc_entry->addend;
+    }
+  else
+    {
+      /* For some reason bfd_perform_relocation always effectively
+	 ignores the addend for a COFF target when producing
+	 relocateable output.  This seems to be always wrong for 860
+	 COFF, so we handle the addend here instead.  */
+      diff = reloc_entry->addend;
+    }
+
+#define DOIT(x) \
+  x = ((x & ~howto->dst_mask) | (((x & howto->src_mask) + diff) & howto->dst_mask))
+
+    if (diff != 0)
+      {
+	reloc_howto_type *howto = reloc_entry->howto;
+	unsigned char *addr = (unsigned char *) data + reloc_entry->address;
+
+	switch (howto->size)
+	  {
+	  case 0:
+	    {
+	      char x = bfd_get_8 (abfd, addr);
+	      DOIT (x);
+	      bfd_put_8 (abfd, x, addr);
+	    }
+	    break;
+
+	  case 1:
+	    {
+	      short x = bfd_get_16 (abfd, addr);
+	      DOIT (x);
+	      bfd_put_16 (abfd, (bfd_vma) x, addr);
+	    }
+	    break;
+
+	  case 2:
+	    {
+	      long x = bfd_get_32 (abfd, addr);
+	      DOIT (x);
+	      bfd_put_32 (abfd, (bfd_vma) x, addr);
+	    }
+	    break;
+
+	  default:
+	    abort ();
+	  }
+      }
+
+  /* Now let bfd_perform_relocation finish everything up.  */
+  return bfd_reloc_continue;
+}
+
+#ifndef PCRELOFFSET
+#define PCRELOFFSET FALSE
+#endif
+
+static reloc_howto_type howto_table[] =
+{
+  EMPTY_HOWTO (0),
+  EMPTY_HOWTO (1),
+  EMPTY_HOWTO (2),
+  EMPTY_HOWTO (3),
+  EMPTY_HOWTO (4),
+  EMPTY_HOWTO (5),
+  HOWTO (R_DIR32,               /* type */
+	 0,	                /* rightshift */
+	 2,	                /* size (0 = byte, 1 = short, 2 = long) */
+	 32,	                /* bitsize */
+	 FALSE,	                /* pc_relative */
+	 0,	                /* bitpos */
+	 complain_overflow_bitfield, /* complain_on_overflow */
+	 coff_avr_reloc,       /* special_function */
+	 "dir32",               /* name */
+	 TRUE,	                /* partial_inplace */
+	 0xffffffff,            /* src_mask */
+	 0xffffffff,            /* dst_mask */
+	 TRUE),                /* pcrel_offset */
+  /* {7}, */
+  HOWTO (R_IMAGEBASE,            /* type */
+	 0,	                /* rightshift */
+	 2,	                /* size (0 = byte, 1 = short, 2 = long) */
+	 32,	                /* bitsize */
+	 FALSE,	                /* pc_relative */
+	 0,	                /* bitpos */
+	 complain_overflow_bitfield, /* complain_on_overflow */
+	 coff_avr_reloc,       /* special_function */
+	 "rva32",	           /* name */
+	 TRUE,	                /* partial_inplace */
+	 0xffffffff,            /* src_mask */
+	 0xffffffff,            /* dst_mask */
+	 FALSE),                /* pcrel_offset */
+  EMPTY_HOWTO (010),
+  EMPTY_HOWTO (011),
+  EMPTY_HOWTO (012),
+  EMPTY_HOWTO (013),
+  EMPTY_HOWTO (014),
+  EMPTY_HOWTO (015),
+  EMPTY_HOWTO (016),
+  HOWTO (R_RELBYTE,		/* type */
+	 0,			/* rightshift */
+	 0,			/* size (0 = byte, 1 = short, 2 = long) */
+	 8,			/* bitsize */
+	 FALSE,			/* pc_relative */
+	 0,			/* bitpos */
+	 complain_overflow_bitfield, /* complain_on_overflow */
+	 coff_avr_reloc,	/* special_function */
+	 "8",			/* name */
+	 TRUE,			/* partial_inplace */
+	 0x000000ff,		/* src_mask */
+	 0x000000ff,		/* dst_mask */
+	 PCRELOFFSET),		/* pcrel_offset */
+  HOWTO (R_RELWORD,		/* type */
+	 0,			/* rightshift */
+	 1,			/* size (0 = byte, 1 = short, 2 = long) */
+	 16,			/* bitsize */
+	 FALSE,			/* pc_relative */
+	 0,			/* bitpos */
+	 complain_overflow_bitfield, /* complain_on_overflow */
+	 coff_avr_reloc,	/* special_function */
+	 "16",			/* name */
+	 TRUE,			/* partial_inplace */
+	 0x0000ffff,		/* src_mask */
+	 0x0000ffff,		/* dst_mask */
+	 PCRELOFFSET),		/* pcrel_offset */
+  HOWTO (R_RELLONG,		/* type */
+	 0,			/* rightshift */
+	 2,			/* size (0 = byte, 1 = short, 2 = long) */
+	 32,			/* bitsize */
+	 FALSE,			/* pc_relative */
+	 0,			/* bitpos */
+	 complain_overflow_bitfield, /* complain_on_overflow */
+	 coff_avr_reloc,	/* special_function */
+	 "32",			/* name */
+	 TRUE,			/* partial_inplace */
+	 0xffffffff,		/* src_mask */
+	 0xffffffff,		/* dst_mask */
+	 PCRELOFFSET),		/* pcrel_offset */
+  HOWTO (R_PCRBYTE,		/* type */
+	 0,			/* rightshift */
+	 0,			/* size (0 = byte, 1 = short, 2 = long) */
+	 8,			/* bitsize */
+	 TRUE,			/* pc_relative */
+	 0,			/* bitpos */
+	 complain_overflow_signed, /* complain_on_overflow */
+	 coff_avr_reloc,	/* special_function */
+	 "DISP8",		/* name */
+	 TRUE,			/* partial_inplace */
+	 0x000000ff,		/* src_mask */
+	 0x000000ff,		/* dst_mask */
+	 PCRELOFFSET),		/* pcrel_offset */
+  HOWTO (R_PCRWORD,		/* type */
+	 0,			/* rightshift */
+	 1,			/* size (0 = byte, 1 = short, 2 = long) */
+	 16,			/* bitsize */
+	 TRUE,			/* pc_relative */
+	 0,			/* bitpos */
+	 complain_overflow_signed, /* complain_on_overflow */
+	 coff_avr_reloc,	/* special_function */
+	 "DISP16",		/* name */
+	 TRUE,			/* partial_inplace */
+	 0x0000ffff,		/* src_mask */
+	 0x0000ffff,		/* dst_mask */
+	 PCRELOFFSET),		/* pcrel_offset */
+  HOWTO (R_PCRLONG,		/* type */
+	 0,			/* rightshift */
+	 2,			/* size (0 = byte, 1 = short, 2 = long) */
+	 32,			/* bitsize */
+	 TRUE,			/* pc_relative */
+	 0,			/* bitpos */
+	 complain_overflow_signed, /* complain_on_overflow */
+	 coff_avr_reloc,	/* special_function */
+	 "DISP32",		/* name */
+	 TRUE,			/* partial_inplace */
+	 0xffffffff,		/* src_mask */
+	 0xffffffff,		/* dst_mask */
+	 PCRELOFFSET)		/* pcrel_offset */
+};
+
+/* Turn a howto into a reloc  nunmber */
+
+#define SELECT_RELOC(x,howto) { x.r_type = howto->type; }
+#define BADMAG(x) AVRBADMAG(x)
+#define AVR 1			/* Customize coffcode.h */
+
+#define RTYPE2HOWTO(cache_ptr, dst) \
+	    (cache_ptr)->howto = howto_table + (dst)->r_type;
+
+/* For AVR COFF a STYP_NOLOAD | STYP_BSS section is part of a shared
+   library.  On some other COFF targets STYP_BSS is normally
+   STYP_NOLOAD.  */
+#define BSS_NOLOAD_IS_SHARED_LIBRARY
+
+/* Compute the addend of a reloc.  If the reloc is to a common symbol,
+   the object file contains the value of the common symbol.  By the
+   time this is called, the linker may be using a different symbol
+   from a different object file with a different value.  Therefore, we
+   hack wildly to locate the original symbol from this file so that we
+   can make the correct adjustment.  This macro sets coffsym to the
+   symbol from the original file, and uses it to set the addend value
+   correctly.  If this is not a common symbol, the usual addend
+   calculation is done, except that an additional tweak is needed for
+   PC relative relocs.
+   FIXME: This macro refers to symbols and asect; these are from the
+   calling function, not the macro arguments.  */
+
+#define CALC_ADDEND(abfd, ptr, reloc, cache_ptr)		\
+  {								\
+    coff_symbol_type *coffsym = (coff_symbol_type *) NULL;	\
+    if (ptr && bfd_asymbol_bfd (ptr) != abfd)			\
+      coffsym = (obj_symbols (abfd)				\
+	         + (cache_ptr->sym_ptr_ptr - symbols));		\
+    else if (ptr)						\
+      coffsym = coff_symbol_from (abfd, ptr);			\
+    if (coffsym != (coff_symbol_type *) NULL			\
+	&& coffsym->native->u.syment.n_scnum == 0)		\
+      cache_ptr->addend = - coffsym->native->u.syment.n_value;	\
+    else if (ptr && bfd_asymbol_bfd (ptr) == abfd		\
+	     && ptr->section != (asection *) NULL)		\
+      cache_ptr->addend = - (ptr->section->vma + ptr->value);	\
+    else							\
+      cache_ptr->addend = 0;					\
+    if (ptr && howto_table[reloc.r_type].pc_relative)		\
+      cache_ptr->addend += asect->vma;				\
+  }
+
+/* We use the special COFF backend linker.  */
+#define coff_relocate_section _bfd_coff_generic_relocate_section
+
+static reloc_howto_type *
+coff_avr_rtype_to_howto (abfd, sec, rel, h, sym, addendp)
+     bfd *abfd ATTRIBUTE_UNUSED;
+     asection *sec;
+     struct internal_reloc *rel;
+     struct coff_link_hash_entry *h;
+     struct internal_syment *sym;
+     bfd_vma *addendp;
+{
+
+  reloc_howto_type *howto;
+
+  howto = howto_table + rel->r_type;
+
+  if (howto->pc_relative)
+    *addendp += sec->vma;
+
+  if (sym != NULL && sym->n_scnum == 0 && sym->n_value != 0)
+    {
+      /* This is a common symbol.  The section contents include the
+	 size (sym->n_value) as an addend.  The relocate_section
+	 function will be adding in the final value of the symbol.  We
+	 need to subtract out the current size in order to get the
+	 correct result.  */
+
+      BFD_ASSERT (h != NULL);
+
+      /* I think we *do* want to bypass this.  If we don't, I have seen some data
+	 parameters get the wrong relcation address.  If I link two versions
+	 with and without this section bypassed and then do a binary comparison,
+	 the addresses which are different can be looked up in the map.  The
+	 case in which this section has been bypassed has addresses which correspond
+	 to values I can find in the map.  */
+      *addendp -= sym->n_value;
+    }
+
+  /* If the output symbol is common (in which case this must be a
+     relocateable link), we need to add in the final size of the
+     common symbol.  */
+  if (h != NULL && h->root.type == bfd_link_hash_common)
+    *addendp += h->root.u.c.size;
+
+  return howto;
+}
+
+#define coff_rtype_to_howto coff_avr_rtype_to_howto
+
+#include "coffcode.h"
+
+static const bfd_target *
+coff_avr_object_p(a)
+     bfd *a;
+{
+  return coff_object_p (a);
+}
+
+/* Handle all the abominations of AVR COFF:
+
+   Generic COFF always uses the D1 slot to indicate the "most
+   important" derived type, and the D2...Dn slots for decreasing
+   importance.  E. g., a function symbol will always have its DT_FCN
+   element in D1, an array its DT_ARY (its first DT_ARY in a
+   multi-dimensional array).  In contrast, AVR COFF expects this most
+   important derived type specifier in the upmost Dn slot that is
+   allocated at all (i. e. that is != 0).
+
+   Generic COFF says that "Any symbol that satisfies more than one
+   condition [... for AUX entries] should have a union format in its
+   auxiliary entry."  AVR COFF uses sepearate AUX entries for multiple
+   derived types, and in some cases (like the ISFCN one), even puts
+   the most important one into the last allocated AUX entry.  We
+   join/split them here at the border as well.  Note that when
+   generating AUX entries (where we need to split them), the n_numaux
+   field must already have been set up properly (e. g. in
+   binutils/wrcoff.c) since the entry renumbering and pointerization
+   would not work otherwise.  Thus, we only split the information into
+   multiple records if n_numaux > 1.  For similar reasons, we keep
+   n_numaux > 1 on input to keep the appropriate AUX entries
+   allocated, so a symbol can be reconstructed if it is being passed
+   through one of the GNU tools.
+
+   Note that this adjustment is called after the symbol itself has
+   been swapped in, but before the AUX entries are swapped in.  This
+   is the only hook available that could swap (or merge) AUX entries
+   at all, so we have to operate on the external AUX entries still. */
+
+void
+avr_coff_adjust_sym_in_post (abfd, ext, in)
+     bfd *abfd;
+     PTR ext;
+     PTR in;
+{
+  struct internal_syment *dst = (struct internal_syment *)in;
+  unsigned short dt, bt, ndt;
+  dt = dst->n_type & ~N_BTMASK;
+  bt = BTYPE (dst->n_type);
+
+  /* Some AVR COFF producers seem to violate the COFF specs, and
+     produce symbols for tag names that have the C_FOO filled in
+     properly, but T_NULL as the base type value.  Patch up here,
+     since some of our generic COFF tools (in particular
+     binutils/rdcoff.c) rely on the correct data. */
+  if (bt == T_NULL)
+    switch (dst->n_sclass)
+      {
+      case C_STRTAG:
+	bt = T_STRUCT;
+	break;
+
+      case C_UNTAG:
+	bt = T_UNION;
+	break;
+
+      case C_ENTAG:
+	bt = T_ENUM;
+	break;
+      }
+
+  /* Swap the derived type slots. */
+  if (dt != 0)
+    {
+      ndt = 0;
+      while (dt != 0)
+	{
+	  ndt = (ndt << N_TSHIFT) | (dt & (N_TMASK >> N_BTSHFT));
+	  dt >>= N_TSHIFT;
+	}
+      dst->n_type = (ndt << N_BTSHFT) | bt;
+    }
+  else
+    dst->n_type = bt;
+
+  /* If the derived type is function, and there is more than one AUX
+     entry, swap the first and the last AUX entry, so the most
+     interesting one will become the first.
+
+     If the fundamental type is a tagged type (struct/union/enum), try
+     to find the AUX entry describing the tagged type (the one that
+     has x_sym.x_tagndx filled in), and merge the tag index into the
+     first AUX entry.  Depending on the actual input file, there might
+     be further DT_PTR entries which we just ignore, since we could
+     not handle that information anyway. */
+  if (dst->n_numaux > 1 && dst->n_sclass != C_FILE)
+    {
+      AUXENT caux, *auxp1, *auxp2;
+      size_t symesz;
+      unsigned int i;
+
+      symesz = bfd_coff_symesz (abfd);
+      i = dst->n_numaux;
+
+      auxp1 = (AUXENT *)((char *)ext + symesz);
+      auxp2 = (AUXENT *)((char *)ext + i * symesz);
+
+      if (ISFCN (dst->n_type)
+	  || (ISPTR(dst->n_type)
+	      && (bt == T_STRUCT || bt == T_UNION || bt == T_ENUM)))
+	{
+	  caux = *auxp2;
+	  *auxp2 = *auxp1;
+	  *auxp1 = caux;
+	}
+      else
+	caux = *auxp1;
+
+      if ((ISFCN (dst->n_type) || ISARY (dst->n_type))
+	  && (bt == T_STRUCT || bt == T_UNION || bt == T_ENUM))
+	{
+	  while (i > 1)
+	    {
+	      auxp2 = (AUXENT *)((char *)ext + i * symesz);
+
+	      if (auxp2->x_sym.x_tagndx[0] != 0 || auxp2->x_sym.x_tagndx[1] != 0
+		  || auxp2->x_sym.x_tagndx[2] != 0 || auxp2->x_sym.x_tagndx[3] != 0)
+		{
+		  memcpy (caux.x_sym.x_tagndx, auxp2->x_sym.x_tagndx,
+			  4 * sizeof (char));
+		  break;
+		}
+	      i--;
+	    }
+	  if (i > 1)
+	    *auxp1 = caux;
+	}
+    }
+}
+
+/* When exporting an AVR COFF file, just undo all that has been done
+   above.  Again, we are called after the symbol itself has been
+   swapped out, but before the AUX entries are being written.
+   Unfortunately, we are only given a pointer to the symbol itself, so
+   we have to derive the pointer to the respective aux entries from
+   that address, which is a bit clumsy. */
+void
+avr_coff_adjust_sym_out_post (abfd, in, ext)
+     bfd *abfd;
+     PTR in;
+     PTR ext;
+{
+  struct internal_syment *src = (struct internal_syment *)(in);
+  struct external_syment *dst = (struct external_syment *)(ext);
+  unsigned short dt, bt, ndt;
+
+  dt = src->n_type & ~N_BTMASK;
+  bt = BTYPE (src->n_type);
+
+  if (dt != 0)
+    {
+      ndt = 0;
+      while (dt != 0)
+	{
+	  ndt = (ndt << N_TSHIFT) | (dt & (N_TMASK >> N_BTSHFT));
+	  dt >>= N_TSHIFT;
+	}
+      H_PUT_16 (abfd, (ndt << N_BTSHFT) | bt, dst->e_type);
+    }
+
+  if (src->n_numaux > 1 && src->n_sclass != C_FILE)
+    {
+      combined_entry_type *srce, *dste;
+      char *hackp;
+      unsigned int i;
+
+      /* Recover the original combinend_entry_type *. */
+      hackp = (char *)in;
+      hackp -= offsetof(combined_entry_type, u.syment);
+      srce = (combined_entry_type *)hackp;
+      srce++;
+
+      /* We simply duplicate the first AUX entry as many times as
+	 needed.  Since COFF itself normally uses just a single AUX
+	 entry for all the information, this will work -- each COFF
+	 consumer will then just pick the fields it is particularly
+	 interested in.  This would not work for the AVR COFF specific
+	 DT_PTR AUX entries, but we don't support them anyway. */
+      for (i = 1; i < src->n_numaux; i++)
+	{
+	  dste = srce + i;
+	  *dste = *srce;
+	}
+    }
+}
+
+const bfd_target
+#ifdef TARGET_SYM
+  TARGET_SYM =
+#else
+  avrcoff_vec =
+#endif
+{
+#ifdef TARGET_NAME
+  TARGET_NAME,
+#else
+  "coff-avr",			/* name */
+#endif
+  bfd_target_coff_flavour,
+  BFD_ENDIAN_LITTLE,		/* data byte order is little */
+  BFD_ENDIAN_LITTLE,		/* header byte order is little */
+
+  (HAS_RELOC | EXEC_P |		/* object flags */
+   HAS_LINENO | HAS_DEBUG |
+   HAS_SYMS | HAS_LOCALS | WP_TEXT),
+
+  (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* section flags */
+  0,				/* leading char */
+  '/',				/* ar_pad_char */
+  15,				/* ar_max_namelen */
+
+  bfd_getl64, bfd_getl_signed_64, bfd_putl64,
+     bfd_getl32, bfd_getl_signed_32, bfd_putl32,
+     bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* data */
+  bfd_getl64, bfd_getl_signed_64, bfd_putl64,
+     bfd_getl32, bfd_getl_signed_32, bfd_putl32,
+     bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* hdrs */
+
+/* Note that we allow an object file to be treated as a core file as well.  */
+    {_bfd_dummy_target, coff_avr_object_p, /* bfd_check_format */
+       bfd_generic_archive_p, coff_avr_object_p},
+    {bfd_false, coff_mkobject, _bfd_generic_mkarchive, /* bfd_set_format */
+       bfd_false},
+    {bfd_false, coff_write_object_contents, /* bfd_write_contents */
+       _bfd_write_archive_contents, bfd_false},
+
+     BFD_JUMP_TABLE_GENERIC (coff),
+     BFD_JUMP_TABLE_COPY (coff),
+     BFD_JUMP_TABLE_CORE (_bfd_nocore),
+     BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff),
+     BFD_JUMP_TABLE_SYMBOLS (coff),
+     BFD_JUMP_TABLE_RELOCS (coff),
+     BFD_JUMP_TABLE_WRITE (coff),
+     BFD_JUMP_TABLE_LINK (coff),
+     BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
+
+  NULL,
+
+  COFF_SWAP_TABLE
+};
