19990502 sourceware importbinu_ss_19990502

1 files changed, 651 insertions, 0 deletions

diff --git a/bfd/stabs.c b/bfd/stabs.c
new file mode 100644
index 0000000..ffc000d
--- /dev/null
+++ b/bfd/stabs.c
@@ -0,0 +1,651 @@
+/* Stabs in sections linking support.
+   Copyright 1996, 1997, 1998 Free Software Foundation, Inc.
+   Written by Ian Lance Taylor, Cygnus Support.
+
+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.  */
+
+/* This file contains support for linking stabs in sections, as used
+   on COFF and ELF.  */
+
+#include "bfd.h"
+#include "sysdep.h"
+#include "libbfd.h"
+#include "aout/stab_gnu.h"
+
+#include <ctype.h>
+
+/* Stabs entries use a 12 byte format:
+     4 byte string table index
+     1 byte stab type
+     1 byte stab other field
+     2 byte stab desc field
+     4 byte stab value
+   FIXME: This will have to change for a 64 bit object format.
+
+   The stabs symbols are divided into compilation units.  For the
+   first entry in each unit, the type of 0, the value is the length of
+   the string table for this unit, and the desc field is the number of
+   stabs symbols for this unit.  */
+
+#define STRDXOFF (0)
+#define TYPEOFF (4)
+#define OTHEROFF (5)
+#define DESCOFF (6)
+#define VALOFF (8)
+#define STABSIZE (12)
+
+/* A hash table used for header files with N_BINCL entries.  */
+
+struct stab_link_includes_table
+{
+  struct bfd_hash_table root;
+};
+
+/* A linked list of totals that we have found for a particular header
+   file.  */
+
+struct stab_link_includes_totals
+{
+  struct stab_link_includes_totals *next;
+  bfd_vma total;
+};
+
+/* An entry in the header file hash table.  */
+
+struct stab_link_includes_entry
+{
+  struct bfd_hash_entry root;
+  /* List of totals we have found for this file.  */
+  struct stab_link_includes_totals *totals;
+};
+
+/* Look up an entry in an the header file hash table.  */
+
+#define stab_link_includes_lookup(table, string, create, copy) \
+  ((struct stab_link_includes_entry *) \
+   bfd_hash_lookup (&(table)->root, (string), (create), (copy)))
+
+/* This structure is used to hold a list of N_BINCL symbols, some of
+   which might be converted into N_EXCL symbols.  */
+
+struct stab_excl_list
+{
+  /* The next symbol to convert.  */
+  struct stab_excl_list *next;
+  /* The offset to this symbol in the section contents.  */
+  bfd_size_type offset;
+  /* The value to use for the symbol.  */
+  bfd_vma val;
+  /* The type of this symbol (N_BINCL or N_EXCL).  */
+  int type;
+};
+
+/* This structure is stored with each .stab section.  */
+
+struct stab_section_info
+{
+  /* This is a linked list of N_BINCL symbols which should be
+     converted into N_EXCL symbols.  */
+  struct stab_excl_list *excls;
+
+  /* This is used to map input stab offsets within their sections
+     to output stab offsets, to take into account stabs that have
+     been deleted.  If it is NULL, the output offsets are the same
+     as the input offsets, because no stabs have been deleted from
+     this section.  Otherwise the i'th entry is the number of
+     bytes of stabs that have been deleted prior to the i'th
+     stab. */
+  bfd_size_type *cumulative_skips;
+
+  /* This is an array of string indices.  For each stab symbol, we
+     store the string index here.  If a stab symbol should not be
+     included in the final output, the string index is -1.  */
+  bfd_size_type stridxs[1];
+};
+
+/* This structure is used to keep track of stabs in sections
+   information while linking.  */
+
+struct stab_info
+{
+  /* A hash table used to hold stabs strings.  */
+  struct bfd_strtab_hash *strings;
+  /* The header file hash table.  */
+  struct stab_link_includes_table includes;
+  /* The first .stabstr section.  */
+  asection *stabstr;
+};
+
+static struct bfd_hash_entry *stab_link_includes_newfunc
+  PARAMS ((struct bfd_hash_entry *, struct bfd_hash_table *, const char *));
+
+/* The function to create a new entry in the header file hash table.  */
+
+static struct bfd_hash_entry *
+stab_link_includes_newfunc (entry, table, string)
+     struct bfd_hash_entry *entry;
+     struct bfd_hash_table *table;
+     const char *string;
+{
+  struct stab_link_includes_entry *ret =
+    (struct stab_link_includes_entry *) entry;
+
+  /* Allocate the structure if it has not already been allocated by a
+     subclass.  */
+  if (ret == (struct stab_link_includes_entry *) NULL)
+    ret = ((struct stab_link_includes_entry *)
+	   bfd_hash_allocate (table,
+			      sizeof (struct stab_link_includes_entry)));
+  if (ret == (struct stab_link_includes_entry *) NULL)
+    return (struct bfd_hash_entry *) ret;
+
+  /* Call the allocation method of the superclass.  */
+  ret = ((struct stab_link_includes_entry *)
+	 bfd_hash_newfunc ((struct bfd_hash_entry *) ret, table, string));
+  if (ret)
+    {
+      /* Set local fields.  */
+      ret->totals = NULL;
+    }
+
+  return (struct bfd_hash_entry *) ret;
+}
+
+/* This function is called for each input file from the add_symbols
+   pass of the linker.  */
+
+boolean
+_bfd_link_section_stabs (abfd, psinfo, stabsec, stabstrsec, psecinfo)
+     bfd *abfd;
+     PTR *psinfo;
+     asection *stabsec;
+     asection *stabstrsec;
+     PTR *psecinfo;
+{
+  boolean first;
+  struct stab_info *sinfo;
+  bfd_size_type count;
+  struct stab_section_info *secinfo;
+  bfd_byte *stabbuf = NULL;
+  bfd_byte *stabstrbuf = NULL;
+  bfd_byte *sym, *symend;
+  bfd_size_type stroff, next_stroff, skip;
+  bfd_size_type *pstridx;
+
+  if (stabsec->_raw_size == 0
+      || stabstrsec->_raw_size == 0)
+    {
+      /* This file does not contain stabs debugging information.  */
+      return true;
+    }
+
+  if (stabsec->_raw_size % STABSIZE != 0)
+    {
+      /* Something is wrong with the format of these stab symbols.
+         Don't try to optimize them.  */
+      return true;
+    }
+
+  if ((stabstrsec->flags & SEC_RELOC) != 0)
+    {
+      /* We shouldn't see relocations in the strings, and we aren't
+         prepared to handle them.  */
+      return true;
+    }
+
+  if ((stabsec->output_section != NULL
+       && bfd_is_abs_section (stabsec->output_section))
+      || (stabstrsec->output_section != NULL
+	  && bfd_is_abs_section (stabstrsec->output_section)))
+    {
+      /* At least one of the sections is being discarded from the
+         link, so we should just ignore them.  */
+      return true;
+    }
+
+  first = false;
+
+  if (*psinfo == NULL)
+    {
+      /* Initialize the stabs information we need to keep track of.  */
+      first = true;
+      *psinfo = (PTR) bfd_alloc (abfd, sizeof (struct stab_info));
+      if (*psinfo == NULL)
+	goto error_return;
+      sinfo = (struct stab_info *) *psinfo;
+      sinfo->strings = _bfd_stringtab_init ();
+      if (sinfo->strings == NULL)
+	goto error_return;
+      if (! bfd_hash_table_init_n (&sinfo->includes.root,
+				   stab_link_includes_newfunc,
+				   251))
+	goto error_return;
+      sinfo->stabstr = bfd_make_section_anyway (abfd, ".stabstr");
+      sinfo->stabstr->flags |= SEC_HAS_CONTENTS | SEC_READONLY | SEC_DEBUGGING;
+    }
+
+  sinfo = (struct stab_info *) *psinfo;
+
+  /* Initialize the information we are going to store for this .stab
+     section.  */
+
+  count = stabsec->_raw_size / STABSIZE;
+
+  *psecinfo = bfd_alloc (abfd,
+			 (sizeof (struct stab_section_info)
+			  + (count - 1) * sizeof (bfd_size_type)));
+  if (*psecinfo == NULL)
+    goto error_return;
+
+  secinfo = (struct stab_section_info *) *psecinfo;
+  secinfo->excls = NULL;
+  secinfo->cumulative_skips = NULL;
+  memset (secinfo->stridxs, 0, count * sizeof (bfd_size_type));
+
+  /* Read the stabs information from abfd.  */
+
+  stabbuf = (bfd_byte *) bfd_malloc (stabsec->_raw_size);
+  stabstrbuf = (bfd_byte *) bfd_malloc (stabstrsec->_raw_size);
+  if (stabbuf == NULL || stabstrbuf == NULL)
+    goto error_return;
+
+  if (! bfd_get_section_contents (abfd, stabsec, stabbuf, 0,
+				  stabsec->_raw_size)
+      || ! bfd_get_section_contents (abfd, stabstrsec, stabstrbuf, 0,
+				     stabstrsec->_raw_size))
+    goto error_return;
+
+  /* Look through the stabs symbols, work out the new string indices,
+     and identify N_BINCL symbols which can be eliminated.  */
+
+  stroff = 0;
+  next_stroff = 0;
+  skip = 0;
+
+  symend = stabbuf + stabsec->_raw_size;
+  for (sym = stabbuf, pstridx = secinfo->stridxs;
+       sym < symend;
+       sym += STABSIZE, ++pstridx)
+    {
+      int type;
+      const char *string;
+
+      if (*pstridx != 0)
+	{
+	  /* This symbol has already been handled by an N_BINCL pass.  */
+	  continue;
+	}
+
+      type = sym[TYPEOFF];
+
+      if (type == 0)
+	{
+	  /* Special type 0 stabs indicate the offset to the next
+             string table.  We only copy the very first one.  */
+	  stroff = next_stroff;
+	  next_stroff += bfd_get_32 (abfd, sym + 8);
+	  if (! first)
+	    {
+	      *pstridx = (bfd_size_type) -1;
+	      ++skip;
+	      continue;
+	    }
+	  first = false;
+	}
+
+      /* Store the string in the hash table, and record the index.  */
+      string = ((char *) stabstrbuf
+		+ stroff
+		+ bfd_get_32 (abfd, sym + STRDXOFF));
+      *pstridx = _bfd_stringtab_add (sinfo->strings, string, true, true);
+
+      /* An N_BINCL symbol indicates the start of the stabs entries
+	 for a header file.  We need to scan ahead to the next N_EINCL
+	 symbol, ignoring nesting, adding up all the characters in the
+	 symbol names, not including the file numbers in types (the
+	 first number after an open parenthesis).  */
+      if (type == N_BINCL)
+	{
+	  bfd_vma val;
+	  int nest;
+	  bfd_byte *incl_sym;
+	  struct stab_link_includes_entry *incl_entry;
+	  struct stab_link_includes_totals *t;
+	  struct stab_excl_list *ne;
+
+	  val = 0;
+	  nest = 0;
+	  for (incl_sym = sym + STABSIZE;
+	       incl_sym < symend;
+	       incl_sym += STABSIZE)
+	    {
+	      int incl_type;
+
+	      incl_type = incl_sym[TYPEOFF];
+	      if (incl_type == 0)
+		break;
+	      else if (incl_type == N_EINCL)
+		{
+		  if (nest == 0)
+		    break;
+		  --nest;
+		}
+	      else if (incl_type == N_BINCL)
+		++nest;
+	      else if (nest == 0)
+		{
+		  const char *str;
+
+		  str = ((char *) stabstrbuf
+			 + stroff
+			 + bfd_get_32 (abfd, incl_sym + STRDXOFF));
+		  for (; *str != '\0'; str++)
+		    {
+		      val += *str;
+		      if (*str == '(')
+			{
+			  /* Skip the file number.  */
+			  ++str;
+			  while (isdigit ((unsigned char) *str))
+			    ++str;
+			  --str;
+			}
+		    }
+		}
+	    }
+
+	  /* If we have already included a header file with the same
+	     value, then replaced this one with an N_EXCL symbol.  */
+	  incl_entry = stab_link_includes_lookup (&sinfo->includes, string,
+						  true, true);
+	  if (incl_entry == NULL)
+	    goto error_return;
+
+	  for (t = incl_entry->totals; t != NULL; t = t->next)
+	    if (t->total == val)
+	      break;
+
+	  /* Record this symbol, so that we can set the value
+             correctly.  */
+	  ne = (struct stab_excl_list *) bfd_alloc (abfd, sizeof *ne);
+	  if (ne == NULL)
+	    goto error_return;
+	  ne->offset = sym - stabbuf;
+	  ne->val = val;
+	  ne->type = N_BINCL;
+	  ne->next = secinfo->excls;
+	  secinfo->excls = ne;
+
+	  if (t == NULL)
+	    {
+	      /* This is the first time we have seen this header file
+		 with this set of stabs strings.  */
+	      t = ((struct stab_link_includes_totals *)
+		   bfd_hash_allocate (&sinfo->includes.root, sizeof *t));
+	      if (t == NULL)
+		goto error_return;
+	      t->total = val;
+	      t->next = incl_entry->totals;
+	      incl_entry->totals = t;
+	    }
+	  else
+	    {
+	      bfd_size_type *incl_pstridx;
+
+	      /* We have seen this header file before.  Tell the final
+		 pass to change the type to N_EXCL.  */
+	      ne->type = N_EXCL;
+
+	      /* Mark the skipped symbols.  */
+
+	      nest = 0;
+	      for (incl_sym = sym + STABSIZE, incl_pstridx = pstridx + 1;
+		   incl_sym < symend;
+		   incl_sym += STABSIZE, ++incl_pstridx)
+		{
+		  int incl_type;
+
+		  incl_type = incl_sym[TYPEOFF];
+
+		  if (incl_type == N_EINCL)
+		    {
+		      if (nest == 0)
+			{
+			  *incl_pstridx = (bfd_size_type) -1;
+			  ++skip;
+			  break;
+			}
+		      --nest;
+		    }
+		  else if (incl_type == N_BINCL)
+		    ++nest;
+		  else if (nest == 0)
+		    {
+		      *incl_pstridx = (bfd_size_type) -1;
+		      ++skip;
+		    }
+		}
+	    }
+	}
+    }
+
+  free (stabbuf);
+  stabbuf = NULL;
+  free (stabstrbuf);
+  stabstrbuf = NULL;
+
+  /* We need to set the section sizes such that the linker will
+     compute the output section sizes correctly.  We set the .stab
+     size to not include the entries we don't want.  We set
+     SEC_EXCLUDE for the .stabstr section, so that it will be dropped
+     from the link.  We record the size of the strtab in the first
+     .stabstr section we saw, and make sure we don't set SEC_EXCLUDE
+     for that section.  */
+  stabsec->_cooked_size = (count - skip) * STABSIZE;
+  if (stabsec->_cooked_size == 0)
+    stabsec->flags |= SEC_EXCLUDE;
+  stabstrsec->flags |= SEC_EXCLUDE;
+  sinfo->stabstr->_cooked_size = _bfd_stringtab_size (sinfo->strings);
+
+  /* Calculate the `cumulative_skips' array now that stabs have been
+     deleted for this section. */
+
+  if (skip != 0)
+    {
+      bfd_size_type i, offset;
+      bfd_size_type *pskips;
+
+      secinfo->cumulative_skips =
+	(bfd_size_type *) bfd_alloc (abfd, count * sizeof (bfd_size_type));
+      if (secinfo->cumulative_skips == NULL)
+	goto error_return;
+
+      pskips = secinfo->cumulative_skips;
+      pstridx = secinfo->stridxs;
+      offset = 0;
+
+      for (i = 0; i < count; i++, pskips++, pstridx++)
+	{
+	  *pskips = offset;
+	  if (*pstridx == (bfd_size_type) -1)
+	    offset += STABSIZE;
+	}
+
+      BFD_ASSERT (offset != 0);
+    }
+
+  return true;
+
+ error_return:
+  if (stabbuf != NULL)
+    free (stabbuf);
+  if (stabstrbuf != NULL)
+    free (stabstrbuf);
+  return false;
+}
+
+/* Write out the stab section.  This is called with the relocated
+   contents.  */
+
+boolean
+_bfd_write_section_stabs (output_bfd, psinfo, stabsec, psecinfo, contents)
+     bfd *output_bfd;
+     PTR *psinfo;
+     asection *stabsec;
+     PTR *psecinfo;
+     bfd_byte *contents;
+{
+  struct stab_info *sinfo;
+  struct stab_section_info *secinfo;
+  struct stab_excl_list *e;
+  bfd_byte *sym, *tosym, *symend;
+  bfd_size_type *pstridx;
+
+  sinfo = (struct stab_info *) *psinfo;
+  secinfo = (struct stab_section_info *) *psecinfo;
+
+  if (secinfo == NULL)
+    return bfd_set_section_contents (output_bfd, stabsec->output_section,
+				     contents, stabsec->output_offset,
+				     stabsec->_raw_size);
+
+  /* Handle each N_BINCL entry.  */
+  for (e = secinfo->excls; e != NULL; e = e->next)
+    {
+      bfd_byte *excl_sym;
+
+      BFD_ASSERT (e->offset < stabsec->_raw_size);
+      excl_sym = contents + e->offset;
+      bfd_put_32 (output_bfd, e->val, excl_sym + VALOFF);
+      excl_sym[TYPEOFF] = e->type;
+    }
+
+  /* Copy over all the stabs symbols, omitting the ones we don't want,
+     and correcting the string indices for those we do want.  */
+  tosym = contents;
+  symend = contents + stabsec->_raw_size;
+  for (sym = contents, pstridx = secinfo->stridxs;
+       sym < symend;
+       sym += STABSIZE, ++pstridx)
+    {
+      if (*pstridx != (bfd_size_type) -1)
+	{
+	  if (tosym != sym)
+	    memcpy (tosym, sym, STABSIZE);
+	  bfd_put_32 (output_bfd, *pstridx, tosym + STRDXOFF);
+
+	  if (sym[TYPEOFF] == 0)
+	    {
+	      /* This is the header symbol for the stabs section.  We
+                 don't really need one, since we have merged all the
+                 input stabs sections into one, but we generate one
+                 for the benefit of readers which expect to see one.  */
+	      BFD_ASSERT (sym == contents);
+	      bfd_put_32 (output_bfd, _bfd_stringtab_size (sinfo->strings),
+			  tosym + VALOFF);
+	      bfd_put_16 (output_bfd,
+			  stabsec->output_section->_raw_size / STABSIZE - 1,
+			  tosym + DESCOFF);
+	    }
+
+	  tosym += STABSIZE;
+	}
+    }
+
+  BFD_ASSERT ((bfd_size_type) (tosym - contents) == stabsec->_cooked_size);
+
+  return bfd_set_section_contents (output_bfd, stabsec->output_section,
+				   contents, stabsec->output_offset,
+				   stabsec->_cooked_size);
+}
+
+/* Write out the .stabstr section.  */
+
+boolean
+_bfd_write_stab_strings (output_bfd, psinfo)
+     bfd *output_bfd;
+     PTR *psinfo;
+{
+  struct stab_info *sinfo;
+
+  sinfo = (struct stab_info *) *psinfo;
+
+  if (sinfo == NULL)
+    return true;
+
+  if (bfd_is_abs_section (sinfo->stabstr->output_section))
+    {
+      /* The section was discarded from the link.  */
+      return true;
+    }
+
+  BFD_ASSERT ((sinfo->stabstr->output_offset
+	       + _bfd_stringtab_size (sinfo->strings))
+	      <= sinfo->stabstr->output_section->_raw_size);
+
+  if (bfd_seek (output_bfd,
+		(sinfo->stabstr->output_section->filepos
+		 + sinfo->stabstr->output_offset),
+		SEEK_SET) != 0)
+    return false;
+
+  if (! _bfd_stringtab_emit (output_bfd, sinfo->strings))
+    return false;
+
+  /* We no longer need the stabs information.  */
+  _bfd_stringtab_free (sinfo->strings);
+  bfd_hash_table_free (&sinfo->includes.root);
+
+  return true;
+}
+
+/* Adjust an address in the .stab section.  Given OFFSET within
+   STABSEC, this returns the new offset in the adjusted stab section,
+   or -1 if the address refers to a stab which has been removed.  */
+
+bfd_vma
+_bfd_stab_section_offset (output_bfd, psinfo, stabsec, psecinfo, offset)
+     bfd *output_bfd;
+     PTR *psinfo;
+     asection *stabsec;
+     PTR *psecinfo;
+     bfd_vma offset;
+{
+  struct stab_section_info *secinfo;
+
+  secinfo = (struct stab_section_info *) *psecinfo;
+
+  if (secinfo == NULL)
+    return offset;
+
+  if (offset >= stabsec->_raw_size)
+    return offset - (stabsec->_cooked_size - stabsec->_raw_size);
+
+  if (secinfo->cumulative_skips)
+    {
+      bfd_vma i;
+
+      i = offset / STABSIZE;
+
+      if (secinfo->stridxs [i] == (bfd_size_type) -1)
+	return (bfd_vma) -1;
+
+      return offset - secinfo->cumulative_skips [i];
+    }
+
+  return offset;
+}