elf-m10300.c

基于4个mips核的noc设计

/* Matsushita 10300 specific support for 32-bit ELF
   Copyright 1996, 1997, 1998, 1999, 2000, 2001
   Free Software Foundation, Inc.

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 "elf-bfd.h"
#include "elf/mn10300.h"

struct elf32_mn10300_link_hash_entry {
  /* The basic elf link hash table entry.  */
  struct elf_link_hash_entry root;

  /* For function symbols, the number of times this function is
     called directly (ie by name).  */
  unsigned int direct_calls;

  /* For function symbols, the size of this function's stack
     (if <= 255 bytes).  We stuff this into "call" instructions
     to this target when it's valid and profitable to do so.

     This does not include stack allocated by movm!  */
  unsigned char stack_size;

  /* For function symbols, arguments (if any) for movm instruction
     in the prologue.  We stuff this value into "call" instructions
     to the target when it's valid and profitable to do so.  */
  unsigned char movm_args;

  /* For funtion symbols, the amount of stack space that would be allocated
     by the movm instruction.  This is redundant with movm_args, but we
     add it to the hash table to avoid computing it over and over.  */
  unsigned char movm_stack_size;

/* When set, convert all "call" instructions to this target into "calls"
   instructions.  */
#define MN10300_CONVERT_CALL_TO_CALLS 0x1

/* Used to mark functions which have had redundant parts of their
   prologue deleted.  */
#define MN10300_DELETED_PROLOGUE_BYTES 0x2
  unsigned char flags;
};

/* We derive a hash table from the main elf linker hash table so
   we can store state variables and a secondary hash table without
   resorting to global variables.  */
struct elf32_mn10300_link_hash_table {
  /* The main hash table.  */
  struct elf_link_hash_table root;

  /* A hash table for static functions.  We could derive a new hash table
     instead of using the full elf32_mn10300_link_hash_table if we wanted
     to save some memory.  */
  struct elf32_mn10300_link_hash_table *static_hash_table;

  /* Random linker state flags.  */
#define MN10300_HASH_ENTRIES_INITIALIZED 0x1
  char flags;
};

/* For MN10300 linker hash table.  */

/* Get the MN10300 ELF linker hash table from a link_info structure.  */

#define elf32_mn10300_hash_table(p) \
  ((struct elf32_mn10300_link_hash_table *) ((p)->hash))

#define elf32_mn10300_link_hash_traverse(table, func, info)		\
  (elf_link_hash_traverse						\
   (&(table)->root,							\
    (boolean (*) PARAMS ((struct elf_link_hash_entry *, PTR))) (func),	\
    (info)))

static struct bfd_hash_entry *elf32_mn10300_link_hash_newfunc
  PARAMS ((struct bfd_hash_entry *, struct bfd_hash_table *, const char *));
static struct bfd_link_hash_table *elf32_mn10300_link_hash_table_create
  PARAMS ((bfd *));

static reloc_howto_type *bfd_elf32_bfd_reloc_type_lookup
  PARAMS ((bfd *abfd, bfd_reloc_code_real_type code));
static void mn10300_info_to_howto
  PARAMS ((bfd *, arelent *, Elf32_Internal_Rela *));
static boolean mn10300_elf_check_relocs
  PARAMS ((bfd *, struct bfd_link_info *, asection *,
	   const Elf_Internal_Rela *));
static asection *mn10300_elf_gc_mark_hook
  PARAMS ((bfd *, struct bfd_link_info *info, Elf_Internal_Rela *,
	   struct elf_link_hash_entry *, Elf_Internal_Sym *));
static boolean mn10300_elf_relax_delete_bytes
  PARAMS ((bfd *, asection *, bfd_vma, int));
static boolean mn10300_elf_symbol_address_p
  PARAMS ((bfd *, asection *, Elf32_External_Sym *, bfd_vma));
static boolean elf32_mn10300_finish_hash_table_entry
  PARAMS ((struct bfd_hash_entry *, PTR));
static void compute_function_info
  PARAMS ((bfd *, struct elf32_mn10300_link_hash_entry *,
	   bfd_vma, unsigned char *));

/* We have to use RELA instructions since md_apply_fix3 in the assembler
   does absolutely nothing.  */
#define USE_RELA

static reloc_howto_type elf_mn10300_howto_table[] = {
  /* Dummy relocation.  Does nothing.  */
  HOWTO (R_MN10300_NONE,
	 0,
	 2,
	 16,
	 false,
	 0,
	 complain_overflow_bitfield,
	 bfd_elf_generic_reloc,
	 "R_MN10300_NONE",
	 false,
	 0,
	 0,
	 false),
  /* Standard 32 bit reloc.  */
  HOWTO (R_MN10300_32,
	 0,
	 2,
	 32,
	 false,
	 0,
	 complain_overflow_bitfield,
	 bfd_elf_generic_reloc,
	 "R_MN10300_32",
	 false,
	 0xffffffff,
	 0xffffffff,
	 false),
  /* Standard 16 bit reloc.  */
  HOWTO (R_MN10300_16,
	 0,
	 1,
	 16,
	 false,
	 0,
	 complain_overflow_bitfield,
	 bfd_elf_generic_reloc,
	 "R_MN10300_16",
	 false,
	 0xffff,
	 0xffff,
	 false),
  /* Standard 8 bit reloc.  */
  HOWTO (R_MN10300_8,
	 0,
	 0,
	 8,
	 false,
	 0,
	 complain_overflow_bitfield,
	 bfd_elf_generic_reloc,
	 "R_MN10300_8",
	 false,
	 0xff,
	 0xff,
	 false),
  /* Standard 32bit pc-relative reloc.  */
  HOWTO (R_MN10300_PCREL32,
	 0,
	 2,
	 32,
	 true,
	 0,
	 complain_overflow_bitfield,
	 bfd_elf_generic_reloc,
	 "R_MN10300_PCREL32",
	 false,
	 0xffffffff,
	 0xffffffff,
	 true),
  /* Standard 16bit pc-relative reloc.  */
  HOWTO (R_MN10300_PCREL16,
	 0,
	 1,
	 16,
	 true,
	 0,
	 complain_overflow_bitfield,
	 bfd_elf_generic_reloc,
	 "R_MN10300_PCREL16",
	 false,
	 0xffff,
	 0xffff,
	 true),
  /* Standard 8 pc-relative reloc.  */
  HOWTO (R_MN10300_PCREL8,
	 0,
	 0,
	 8,
	 true,
	 0,
	 complain_overflow_bitfield,
	 bfd_elf_generic_reloc,
	 "R_MN10300_PCREL8",
	 false,
	 0xff,
	 0xff,
	 true),

  /* GNU extension to record C++ vtable hierarchy */
  HOWTO (R_MN10300_GNU_VTINHERIT, /* type */
	 0,			/* rightshift */
	 0,			/* size (0 = byte, 1 = short, 2 = long) */
	 0,			/* bitsize */
	 false,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_dont, /* complain_on_overflow */
	 NULL,			/* special_function */
	 "R_MN10300_GNU_VTINHERIT", /* name */
	 false,			/* partial_inplace */
	 0,			/* src_mask */
	 0,			/* dst_mask */
	 false),		/* pcrel_offset */

  /* GNU extension to record C++ vtable member usage */
  HOWTO (R_MN10300_GNU_VTENTRY,	/* type */
	 0,			/* rightshift */
	 0,			/* size (0 = byte, 1 = short, 2 = long) */
	 0,			/* bitsize */
	 false,			/* pc_relative */
	 0,			/* bitpos */
	 complain_overflow_dont, /* complain_on_overflow */
	 NULL,			/* special_function */
	 "R_MN10300_GNU_VTENTRY", /* name */
	 false,			/* partial_inplace */
	 0,			/* src_mask */
	 0,			/* dst_mask */
	 false),		/* pcrel_offset */

  /* Standard 24 bit reloc.  */
  HOWTO (R_MN10300_24,
	 0,
	 2,
	 24,
	 false,
	 0,
	 complain_overflow_bitfield,
	 bfd_elf_generic_reloc,
	 "R_MN10300_24",
	 false,
	 0xffffff,
	 0xffffff,
	 false),
};

struct mn10300_reloc_map {
  bfd_reloc_code_real_type bfd_reloc_val;
  unsigned char elf_reloc_val;
};

static const struct mn10300_reloc_map mn10300_reloc_map[] = {
  { BFD_RELOC_NONE, R_MN10300_NONE, },
  { BFD_RELOC_32, R_MN10300_32, },
  { BFD_RELOC_16, R_MN10300_16, },
  { BFD_RELOC_8, R_MN10300_8, },
  { BFD_RELOC_32_PCREL, R_MN10300_PCREL32, },
  { BFD_RELOC_16_PCREL, R_MN10300_PCREL16, },
  { BFD_RELOC_8_PCREL, R_MN10300_PCREL8, },
  { BFD_RELOC_24, R_MN10300_24, },
  { BFD_RELOC_VTABLE_INHERIT, R_MN10300_GNU_VTINHERIT },
  { BFD_RELOC_VTABLE_ENTRY, R_MN10300_GNU_VTENTRY },
};

static reloc_howto_type *
bfd_elf32_bfd_reloc_type_lookup (abfd, code)
     bfd *abfd ATTRIBUTE_UNUSED;
     bfd_reloc_code_real_type code;
{
  unsigned int i;

  for (i = 0;
       i < sizeof (mn10300_reloc_map) / sizeof (struct mn10300_reloc_map);
       i++)
    {
      if (mn10300_reloc_map[i].bfd_reloc_val == code)
	return &elf_mn10300_howto_table[mn10300_reloc_map[i].elf_reloc_val];
    }

  return NULL;
}

/* Set the howto pointer for an MN10300 ELF reloc.  */

static void
mn10300_info_to_howto (abfd, cache_ptr, dst)
     bfd *abfd ATTRIBUTE_UNUSED;
     arelent *cache_ptr;
     Elf32_Internal_Rela *dst;
{
  unsigned int r_type;

  r_type = ELF32_R_TYPE (dst->r_info);
  BFD_ASSERT (r_type < (unsigned int) R_MN10300_MAX);
  cache_ptr->howto = &elf_mn10300_howto_table[r_type];
}

/* Look through the relocs for a section during the first phase.
   Since we don't do .gots or .plts, we just need to consider the
   virtual table relocs for gc.  */

static boolean
mn10300_elf_check_relocs (abfd, info, sec, relocs)
     bfd *abfd;
     struct bfd_link_info *info;
     asection *sec;
     const Elf_Internal_Rela *relocs;
{
  Elf_Internal_Shdr *symtab_hdr;
  struct elf_link_hash_entry **sym_hashes, **sym_hashes_end;
  const Elf_Internal_Rela *rel;
  const Elf_Internal_Rela *rel_end;

  if (info->relocateable)
    return true;

  symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
  sym_hashes = elf_sym_hashes (abfd);
  sym_hashes_end = sym_hashes + symtab_hdr->sh_size/sizeof (Elf32_External_Sym);
  if (!elf_bad_symtab (abfd))
    sym_hashes_end -= symtab_hdr->sh_info;

  rel_end = relocs + sec->reloc_count;
  for (rel = relocs; rel < rel_end; rel++)
    {
      struct elf_link_hash_entry *h;
      unsigned long r_symndx;

      r_symndx = ELF32_R_SYM (rel->r_info);
      if (r_symndx < symtab_hdr->sh_info)
	h = NULL;
      else
	h = sym_hashes[r_symndx - symtab_hdr->sh_info];

      switch (ELF32_R_TYPE (rel->r_info))
	{
	/* This relocation describes the C++ object vtable hierarchy.
	   Reconstruct it for later use during GC.  */
	case R_MN10300_GNU_VTINHERIT:
	  if (!_bfd_elf32_gc_record_vtinherit (abfd, sec, h, rel->r_offset))
	    return false;
	  break;

	/* This relocation describes which C++ vtable entries are actually
	   used.  Record for later use during GC.  */
	case R_MN10300_GNU_VTENTRY:
	  if (!_bfd_elf32_gc_record_vtentry (abfd, sec, h, rel->r_addend))
	    return false;
	  break;
	}
    }

  return true;
}

/* Return the section that should be marked against GC for a given
   relocation.  */

static asection *
mn10300_elf_gc_mark_hook (abfd, info, rel, h, sym)
     bfd *abfd;
     struct bfd_link_info *info ATTRIBUTE_UNUSED;
     Elf_Internal_Rela *rel;
     struct elf_link_hash_entry *h;
     Elf_Internal_Sym *sym;
{
  if (h != NULL)
    {
      switch (ELF32_R_TYPE (rel->r_info))
	{
	case R_MN10300_GNU_VTINHERIT:
	case R_MN10300_GNU_VTENTRY:
	  break;

	default:
	  switch (h->root.type)
	    {
	    case bfd_link_hash_defined:
	    case bfd_link_hash_defweak:
	      return h->root.u.def.section;

	    case bfd_link_hash_common:
	      return h->root.u.c.p->section;

	    default:
	      break;
	    }
	}
    }
  else
    {
      if (!(elf_bad_symtab (abfd)
	    && ELF_ST_BIND (sym->st_info) != STB_LOCAL)
	  && ! ((sym->st_shndx <= 0 || sym->st_shndx >= SHN_LORESERVE)
		&& sym->st_shndx != SHN_COMMON))
	{
	  return bfd_section_from_elf_index (abfd, sym->st_shndx);
	}
    }

  return NULL;
}

/* Perform a relocation as part of a final link.  */
static bfd_reloc_status_type
mn10300_elf_final_link_relocate (howto, input_bfd, output_bfd,
				 input_section, contents, offset, value,
				 addend, info, sym_sec, is_local)
     reloc_howto_type *howto;
     bfd *input_bfd;
     bfd *output_bfd ATTRIBUTE_UNUSED;
     asection *input_section;
     bfd_byte *contents;
     bfd_vma offset;
     bfd_vma value;
     bfd_vma addend;
     struct bfd_link_info *info ATTRIBUTE_UNUSED;
     asection *sym_sec ATTRIBUTE_UNUSED;
     int is_local ATTRIBUTE_UNUSED;
{
  unsigned long r_type = howto->type;
  bfd_byte *hit_data = contents + offset;

  switch (r_type)