ecofflink.c

来自「基于4个mips核的noc设计」· C语言 代码 · 共 2,153 行 · 第 1/5 页

      if ((total & (swap->debug_align - 1)) != 0)
	{
	  unsigned int i;
	  bfd_byte *s;

	  i = swap->debug_align - (total & (swap->debug_align - 1));
	  s = (bfd_byte *) bfd_malloc (i);
	  if (s == NULL && i != 0)
	    goto error_return;
	  memset ((PTR) s, 0, i);
	  if (bfd_write ((PTR) s, 1, i, abfd) != i)
	    {
	      free (s);
	      goto error_return;
	    }
	  free (s);
	}
    }

  /* The external strings and symbol are not converted over to using
     shuffles.  FIXME: They probably should be.  */
  if (bfd_write (debug->ssext, 1, debug->symbolic_header.issExtMax, abfd)
      != (bfd_size_type) debug->symbolic_header.issExtMax)
    goto error_return;
  if ((debug->symbolic_header.issExtMax & (swap->debug_align - 1)) != 0)
    {
      unsigned int i;
      bfd_byte *s;

      i = (swap->debug_align
	   - (debug->symbolic_header.issExtMax & (swap->debug_align - 1)));
      s = (bfd_byte *) bfd_malloc (i);
      if (s == NULL && i != 0)
	goto error_return;
      memset ((PTR) s, 0, i);
      if (bfd_write ((PTR) s, 1, i, abfd) != i)
	{
	  free (s);
	  goto error_return;
	}
      free (s);
    }

  if (! ecoff_write_shuffle (abfd, swap, ainfo->fdr, space)
      || ! ecoff_write_shuffle (abfd, swap, ainfo->rfd, space))
    goto error_return;

  BFD_ASSERT (debug->symbolic_header.cbExtOffset == 0
	      || (debug->symbolic_header.cbExtOffset
		  == (bfd_vma) bfd_tell (abfd)));

  if (bfd_write (debug->external_ext, swap->external_ext_size,
		 debug->symbolic_header.iextMax, abfd)
      != debug->symbolic_header.iextMax * swap->external_ext_size)
    goto error_return;

  if (space != NULL)
    free (space);
  return true;

 error_return:
  if (space != NULL)
    free (space);
  return false;
}

/* Handle the find_nearest_line function for both ECOFF and MIPS ELF
   files.  */

/* Compare FDR entries.  This is called via qsort.  */

static int
cmp_fdrtab_entry (leftp, rightp)
     const PTR leftp;
     const PTR rightp;
{
  const struct ecoff_fdrtab_entry *lp =
    (const struct ecoff_fdrtab_entry *) leftp;
  const struct ecoff_fdrtab_entry *rp =
    (const struct ecoff_fdrtab_entry *) rightp;

  if (lp->base_addr < rp->base_addr)
    return -1;
  if (lp->base_addr > rp->base_addr)
    return 1;
  return 0;
}

/* Each file descriptor (FDR) has a memory address, to simplify
   looking up an FDR by address, we build a table covering all FDRs
   that have a least one procedure descriptor in them.  The final
   table will be sorted by address so we can look it up via binary
   search.  */

static boolean
mk_fdrtab (abfd, debug_info, debug_swap, line_info)
     bfd *abfd;
     struct ecoff_debug_info * const debug_info;
     const struct ecoff_debug_swap * const debug_swap;
     struct ecoff_find_line *line_info;
{
  struct ecoff_fdrtab_entry *tab;
  FDR *fdr_ptr;
  FDR *fdr_start;
  FDR *fdr_end;
  boolean stabs;
  long len;

  fdr_start = debug_info->fdr;
  fdr_end = fdr_start + debug_info->symbolic_header.ifdMax;

  /* First, let's see how long the table needs to be: */
  for (len = 0, fdr_ptr = fdr_start; fdr_ptr < fdr_end; fdr_ptr++)
    {
      if (fdr_ptr->cpd == 0)	/* skip FDRs that have no PDRs */
	continue;
      ++len;
    }

  /* Now, create and fill in the table: */

  line_info->fdrtab = ((struct ecoff_fdrtab_entry*)
		       bfd_zalloc (abfd,
				   len * sizeof (struct ecoff_fdrtab_entry)));
  if (line_info->fdrtab == NULL)
    return false;
  line_info->fdrtab_len = len;

  tab = line_info->fdrtab;
  for (fdr_ptr = fdr_start; fdr_ptr < fdr_end; fdr_ptr++)
    {
      if (fdr_ptr->cpd == 0)
	continue;

      /* Check whether this file has stabs debugging information.  In
	 a file with stabs debugging information, the second local
	 symbol is named @stabs.  */
      stabs = false;
      if (fdr_ptr->csym >= 2)
	{
	  char *sym_ptr;
	  SYMR sym;

	  sym_ptr = ((char *) debug_info->external_sym
		     + (fdr_ptr->isymBase + 1)*debug_swap->external_sym_size);
	  (*debug_swap->swap_sym_in) (abfd, sym_ptr, &sym);
	  if (strcmp (debug_info->ss + fdr_ptr->issBase + sym.iss,
		      STABS_SYMBOL) == 0)
	    stabs = true;
	}

      if (!stabs)
	{
	  bfd_size_type external_pdr_size;
	  char *pdr_ptr;
	  PDR pdr;

	  external_pdr_size = debug_swap->external_pdr_size;

	  pdr_ptr = ((char *) debug_info->external_pdr
		     + fdr_ptr->ipdFirst * external_pdr_size);
	  (*debug_swap->swap_pdr_in) (abfd, (PTR) pdr_ptr, &pdr);
	  /* The address of the first PDR is the offset of that
	     procedure relative to the beginning of file FDR.  */
	  tab->base_addr = fdr_ptr->adr - pdr.adr;
	}
      else
	{
	  /* XXX I don't know about stabs, so this is a guess
	     ([e-mail]): */
	  tab->base_addr = fdr_ptr->adr;
	}
      tab->fdr = fdr_ptr;
      ++tab;
    }

  /* Finally, the table is sorted in increasing memory-address order.
     The table is mostly sorted already, but there are cases (e.g.,
     static functions in include files), where this does not hold.
     Use "odump -PFv" to verify...  */
  qsort ((PTR) line_info->fdrtab, len,
	 sizeof (struct ecoff_fdrtab_entry), cmp_fdrtab_entry);

  return true;
}

/* Return index of first FDR that covers to OFFSET.  */

static long
fdrtab_lookup (line_info, offset)
     struct ecoff_find_line *line_info;
     bfd_vma offset;
{
  long low, high, len;
  long mid = -1;
  struct ecoff_fdrtab_entry *tab;

  len = line_info->fdrtab_len;
  if (len == 0)
    return -1;

  tab = line_info->fdrtab;
  for (low = 0, high = len - 1 ; low != high ;)
    {
      mid = (high + low) / 2;
      if (offset >= tab[mid].base_addr && offset < tab[mid + 1].base_addr)
	goto find_min;

      if (tab[mid].base_addr > offset)
	high = mid;
      else
	low = mid + 1;
    }
  ++mid;

  /* last entry is catch-all for all higher addresses: */
  if (offset < tab[mid].base_addr)
    return -1;

 find_min:

  while (mid > 0 && tab[mid - 1].base_addr == tab[mid].base_addr)
    --mid;

  return mid;
}

/* Look up a line given an address, storing the information in
   LINE_INFO->cache.  */

static boolean
lookup_line (abfd, debug_info, debug_swap, line_info)
     bfd *abfd;
     struct ecoff_debug_info * const debug_info;
     const struct ecoff_debug_swap * const debug_swap;
     struct ecoff_find_line *line_info;
{
  struct ecoff_fdrtab_entry *tab;
  bfd_vma offset;
  boolean stabs;
  FDR *fdr_ptr;
  int i;

  offset = line_info->cache.start;

  /* Build FDR table (sorted by object file's base-address) if we
     don't have it already.  */
  if (line_info->fdrtab == NULL
      && !mk_fdrtab (abfd, debug_info, debug_swap, line_info))
    return false;

  tab = line_info->fdrtab;

  /* find first FDR for address OFFSET */
  i = fdrtab_lookup (line_info, offset);
  if (i < 0)
    return false;		/* no FDR, no fun...  */
  fdr_ptr = tab[i].fdr;

  /* Check whether this file has stabs debugging information.  In a
     file with stabs debugging information, the second local symbol is
     named @stabs.  */
  stabs = false;
  if (fdr_ptr->csym >= 2)
    {
      char *sym_ptr;
      SYMR sym;

      sym_ptr = ((char *) debug_info->external_sym
		 + (fdr_ptr->isymBase + 1) * debug_swap->external_sym_size);
      (*debug_swap->swap_sym_in) (abfd, sym_ptr, &sym);
      if (strcmp (debug_info->ss + fdr_ptr->issBase + sym.iss,
		  STABS_SYMBOL) == 0)
	stabs = true;
    }

  if (!stabs)
    {
      bfd_size_type external_pdr_size;
      char *pdr_ptr;
      char *best_pdr = NULL;
      FDR *best_fdr;
      bfd_vma best_dist = ~0;
      PDR pdr;
      unsigned char *line_ptr;
      unsigned char *line_end;
      int lineno;
      /* This file uses ECOFF debugging information.  Each FDR has a
         list of procedure descriptors (PDR).  The address in the FDR
         is the absolute address of the first procedure.  The address
         in the first PDR gives the offset of that procedure relative
         to the object file's base-address.  The addresses in
         subsequent PDRs specify each procedure's address relative to
         the object file's base-address.  To make things more juicy,
         whenever the PROF bit in the PDR is set, the real entry point
         of the procedure may be 16 bytes below what would normally be
         the procedure's entry point.  Instead, DEC came up with a
         wicked scheme to create profiled libraries "on the fly":
         instead of shipping a regular and a profiled version of each
         library, they insert 16 bytes of unused space in front of
         each procedure and set the "prof" bit in the PDR to indicate
         that there is a gap there (this is done automagically by "as"
         when option "-pg" is specified).  Thus, normally, you link
         against such a library and, except for lots of 16 byte gaps
         between functions, things will behave as usual.  However,
         when invoking "ld" with option "-pg", it will fill those gaps
         with code that calls mcount().  It then moves the function's
         entry point down by 16 bytes, and out pops a binary that has
         all functions profiled.

         NOTE: Neither FDRs nor PDRs are strictly sorted in memory
               order.  For example, when including header-files that
               define functions, the FDRs follow behind the including
               file, even though their code may have been generated at
               a lower address.  File coff-alpha.c from libbfd
               illustrates this (use "odump -PFv" to look at a file's
               FDR/PDR).  Similarly, PDRs are sometimes out of order
               as well.  An example of this is OSF/1 v3.0 libc's
               malloc.c.  I'm not sure why this happens, but it could
               be due to optimizations that reorder a function's
               position within an object-file.

         Strategy:

         On the first call to this function, we build a table of FDRs
         that is sorted by the base-address of the object-file the FDR
         is referring to.  Notice that each object-file may contain
         code from multiple source files (e.g., due to code defined in
         include files).  Thus, for any given base-address, there may
         be multiple FDRs (but this case is, fortunately, uncommon).
         lookup(addr) guarantees to return the first FDR that applies
         to address ADDR.  Thus, after invoking lookup(), we have a
         list of FDRs that may contain the PDR for ADDR.  Next, we
         walk through the PDRs of these FDRs and locate the one that
         is closest to ADDR (i.e., for which the difference between
         ADDR and the PDR's entry point is positive and minimal).
         Once, the right FDR and PDR are located, we simply walk
         through the line-number table to lookup the line-number that
         best matches ADDR.  Obviously, things could be sped up by
         keeping a sorted list of PDRs instead of a sorted list of
         FDRs.  However, this would increase space requirements
         considerably, which is undesirable.  */
      external_pdr_size = debug_swap->external_pdr_size;

      /* Make offset relative to object file's start-address: */
      offset -= tab[i].base_addr;
      /* Search FDR list starting at tab[i] for the PDR that best matches
         OFFSET.  Normally, the FDR list is only one entry long.  */
      best_fdr = NULL;
      do
	{
	  bfd_vma dist, min_dist = 0;
	  char *pdr_hold;
	  char *pdr_end;

	  fdr_ptr = tab[i].fdr;

	  pdr_ptr = ((char *) debug_info->external_pdr
		     + fdr_ptr->ipdFirst * external_pdr_size);
	  pdr_end = pdr_ptr + fdr_ptr->cpd * external_pdr_size;
	  (*debug_swap->swap_pdr_in) (abfd, (PTR) pdr_ptr, &pdr);
	  /* Find PDR that is closest to OFFSET.  If pdr.prof is set,
	     the procedure entry-point *may* be 0x10 below pdr.adr.  We
	     simply pretend that pdr.prof *implies* a lower entry-point.
	     This is safe because it just means that may identify 4 NOPs
	     in front of the function as belonging to the function.  */
	  for (pdr_hold = NULL;
	       pdr_ptr < pdr_end;
	       (pdr_ptr += external_pdr_size,
		(*debug_swap->swap_pdr_in) (abfd, (PTR) pdr_ptr, &pdr)))
	    {
	      if (offset >= (pdr.adr - 0x10 * pdr.prof))
		{
		  dist = offset - (pdr.adr - 0x10 * pdr.prof);
		  if (!pdr_hold || dist < min_dist)
		    {
		      min_dist = dist;
		      pdr_hold = pdr_ptr;
		    }
		}
	    }

	  if (!best_pdr || min_dist < best_dist)
	    {
	      best_dist = min_dist;
	      best_fdr = fdr_ptr;
	      best_pdr = pdr_hold;
	    }
	  /* continue looping until base_addr of next entry is different: */
	}
      while (++i < line_info->fdrtab_len
	     && tab[i].base_addr == tab[i - 1].base_addr);

      if (!best_fdr || !best_pdr)
	return false;			/* shouldn't happen...  */

      /* phew, finally we got something that we can hold onto: */
      fdr_ptr = best_fdr;
      pdr_ptr = best_pdr;
      (*debug_swap->swap_pdr_in) (abfd, (PTR) pdr_ptr, &pdr);
      /* Now we can look for the actual line number.  The line numbers
         are stored in a very funky format, which I won't try to
         describe.  The search is bounded by the end of the FDRs line
         number entries.  */
      line_end = debug_info->line + fdr_ptr->cbLineOffset + fdr_ptr->cbLine;

      /* Make offset relative to procedure entry: */
      offset -= pdr.adr - 0x10 * pdr.prof;
      lineno = pdr.lnLow;
      line_ptr = debug_info->line + fdr_ptr->cbLineOffset + pdr.cbLineOffset;
      while (line_ptr < line_end)
	{
	  int delta;
	  unsigned int count;

	  delta = *line_ptr >> 4;
	  if (delta >= 0x8)
	    delta -= 0x10;
	  count = (*line_ptr & 0xf) + 1;
	  ++line_ptr;
	  if (delta == -8)
	    {
	      delta = (((line_ptr[0]) & 0xff) << 8) + ((line_ptr[1]) & 0xff);
	      if (delta >= 0x8000)
		delta -= 0x10000;
	      line_ptr += 2;
	    }
	  lineno += delta;
	  if (offset < cou