Don't access elf tdata in dwarf.c without first checking for an ELF bfd
[platform/upstream/binutils.git] / bfd / dwarf2.c
index c9349da..93236a6 100644 (file)
@@ -1,5 +1,5 @@
 /* DWARF 2 support.
-   Copyright 1994-2013 Free Software Foundation, Inc.
+   Copyright (C) 1994-2014 Free Software Foundation, Inc.
 
    Adapted from gdb/dwarf2read.c by Gavin Koch of Cygnus Solutions
    (gavin@cygnus.com).
@@ -156,8 +156,11 @@ struct dwarf2_debug
      use. */
   struct funcinfo *inliner_chain;
 
+  /* Section VMAs at the time the stash was built.  */
+  bfd_vma *sec_vma;
+
   /* Number of sections whose VMA we must adjust.  */
-  unsigned int adjusted_section_count;
+  int adjusted_section_count;
 
   /* Array of sections with adjusted VMA.  */
   struct adjusted_section *adjusted_sections;
@@ -398,7 +401,7 @@ info_hash_table_newfunc (struct bfd_hash_entry *entry,
   if (ret == NULL)
     {
       ret = (struct info_hash_entry *) bfd_hash_allocate (table,
-                                                          sizeof (* ret));
+                                                         sizeof (* ret));
       if (ret == NULL)
        return NULL;
     }
@@ -458,7 +461,7 @@ insert_info_hash_table (struct info_hash_table *hash_table,
     return FALSE;
 
   node = (struct info_list_node *) bfd_hash_allocate (&hash_table->base,
-                                                      sizeof (*node));
+                                                     sizeof (*node));
   if (!node)
     return FALSE;
 
@@ -506,13 +509,13 @@ read_section (bfd *           abfd,
       if (! msec)
        {
          section_name = sec->compressed_name;
-          if (section_name != NULL)
-            msec = bfd_get_section_by_name (abfd, section_name);
+         if (section_name != NULL)
+           msec = bfd_get_section_by_name (abfd, section_name);
        }
       if (! msec)
        {
          (*_bfd_error_handler) (_("Dwarf Error: Can't find %s section."),
-                                 sec->uncompressed_name);
+                                sec->uncompressed_name);
          bfd_set_error (bfd_error_bad_value);
          return FALSE;
        }
@@ -631,7 +634,7 @@ read_indirect_string (struct comp_unit * unit,
   *bytes_read_ptr = unit->offset_size;
 
   if (! read_section (unit->abfd, &stash->debug_sections[debug_str],
-                      stash->syms, offset,
+                     stash->syms, offset,
                      &stash->dwarf_str_buffer, &stash->dwarf_str_size))
     return NULL;
 
@@ -642,7 +645,7 @@ read_indirect_string (struct comp_unit * unit,
 }
 
 /* Like read_indirect_string but uses a .debug_str located in
-   an alternate filepointed to by the .gnu_debuglink section.
+   an alternate file pointed to by the .gnu_debugaltlink section.
    Used to impement DW_FORM_GNU_strp_alt.  */
 
 static char *
@@ -742,7 +745,10 @@ read_alt_indirect_ref (struct comp_unit * unit,
 static bfd_uint64_t
 read_address (struct comp_unit *unit, bfd_byte *buf)
 {
-  int signed_vma = get_elf_backend_data (unit->abfd)->sign_extend_vma;
+  int signed_vma = 0;
+
+  if (bfd_get_flavour (unit->abfd) == bfd_target_elf_flavour)
+    signed_vma = get_elf_backend_data (unit->abfd)->sign_extend_vma;
 
   if (signed_vma)
     {
@@ -812,7 +818,7 @@ read_abbrevs (bfd *abfd, bfd_uint64_t offset, struct dwarf2_debug *stash)
   bfd_size_type amt;
 
   if (! read_section (abfd, &stash->debug_sections[debug_abbrev],
-                      stash->syms, offset,
+                     stash->syms, offset,
                      &stash->dwarf_abbrev_buffer, &stash->dwarf_abbrev_size))
     return NULL;
 
@@ -908,6 +914,14 @@ read_abbrevs (bfd *abfd, bfd_uint64_t offset, struct dwarf2_debug *stash)
   return abbrevs;
 }
 
+/* Returns true if the form is one which has a string value.  */
+
+static inline bfd_boolean
+is_str_attr (enum dwarf_form form)
+{
+  return form == DW_FORM_string || form == DW_FORM_strp || form == DW_FORM_GNU_strp_alt;
+}
+
 /* Read an attribute value described by an attribute form.  */
 
 static bfd_byte *
@@ -1310,7 +1324,7 @@ add_line_info (struct line_info_table *table,
       info->prev_line = table->lcl_head->prev_line;
       table->lcl_head->prev_line = info;
       if (address < seq->low_pc)
-        seq->low_pc = address;
+       seq->low_pc = address;
     }
   return TRUE;
 }
@@ -1501,21 +1515,21 @@ sort_line_sequences (struct line_info_table* table)
   for (n = 1; n < table->num_sequences; n++)
     {
       if (sequences[n].low_pc < last_high_pc)
-        {
+       {
          if (sequences[n].last_line->address <= last_high_pc)
            /* Skip nested entries.  */
            continue;
 
          /* Trim overlapping entries.  */
          sequences[n].low_pc = last_high_pc;
-        }
+       }
       last_high_pc = sequences[n].last_line->address;
       if (n > num_sequences)
-        {
-          /* Close up the gap.  */
-          sequences[num_sequences].low_pc = sequences[n].low_pc;
-          sequences[num_sequences].last_line = sequences[n].last_line;
-        }
+       {
+         /* Close up the gap.  */
+         sequences[num_sequences].low_pc = sequences[n].low_pc;
+         sequences[num_sequences].last_line = sequences[n].last_line;
+       }
       num_sequences++;
     }
 
@@ -1541,7 +1555,7 @@ decode_line_info (struct comp_unit *unit, struct dwarf2_debug *stash)
   bfd_size_type amt;
 
   if (! read_section (abfd, &stash->debug_sections[debug_line],
-                      stash->syms, unit->line_offset,
+                     stash->syms, unit->line_offset,
                      &stash->dwarf_line_buffer, &stash->dwarf_line_size))
     return NULL;
 
@@ -1734,7 +1748,7 @@ decode_line_info (struct comp_unit *unit, struct dwarf2_debug *stash)
              if (!add_line_info (table, address, op_index, filename,
                                  line, column, discriminator, 0))
                goto line_fail;
-              discriminator = 0;
+             discriminator = 0;
              if (address < low_pc)
                low_pc = address;
              if (address > high_pc)
@@ -1755,7 +1769,7 @@ decode_line_info (struct comp_unit *unit, struct dwarf2_debug *stash)
                  if (!add_line_info (table, address, op_index, filename, line,
                                      column, discriminator, end_sequence))
                    goto line_fail;
-                  discriminator = 0;
+                 discriminator = 0;
                  if (address < low_pc)
                    low_pc = address;
                  if (address > high_pc)
@@ -1796,7 +1810,7 @@ decode_line_info (struct comp_unit *unit, struct dwarf2_debug *stash)
                  break;
                case DW_LNE_set_discriminator:
                  discriminator =
-                      read_unsigned_leb128 (abfd, line_ptr, &bytes_read);
+                   read_unsigned_leb128 (abfd, line_ptr, &bytes_read);
                  line_ptr += bytes_read;
                  break;
                case DW_LNE_HP_source_file_correlation:
@@ -1816,7 +1830,7 @@ decode_line_info (struct comp_unit *unit, struct dwarf2_debug *stash)
              if (!add_line_info (table, address, op_index,
                                  filename, line, column, discriminator, 0))
                goto line_fail;
-              discriminator = 0;
+             discriminator = 0;
              if (address < low_pc)
                low_pc = address;
              if (address > high_pc)
@@ -1909,11 +1923,13 @@ decode_line_info (struct comp_unit *unit, struct dwarf2_debug *stash)
   return NULL;
 }
 
-/* If ADDR is within TABLE set the output parameters and return TRUE,
-   otherwise return FALSE.  The output parameters, FILENAME_PTR and
-   LINENUMBER_PTR, are pointers to the objects to be filled in.  */
+/* If ADDR is within TABLE set the output parameters and return the
+   range of addresses covered by the entry used to fill them out.
+   Otherwise set * FILENAME_PTR to NULL and return 0.
+   The parameters FILENAME_PTR, LINENUMBER_PTR and DISCRIMINATOR_PTR
+   are pointers to the objects to be filled in.  */
 
-static bfd_boolean
+static bfd_vma
 lookup_address_in_line_info_table (struct line_info_table *table,
                                   bfd_vma addr,
                                   const char **filename_ptr,
@@ -1943,24 +1959,24 @@ lookup_address_in_line_info_table (struct line_info_table *table,
     {
       /* Note: seq->last_line should be a descendingly sorted list.  */
       for (each_line = seq->last_line;
-           each_line;
-           each_line = each_line->prev_line)
-        if (addr >= each_line->address)
-          break;
+          each_line;
+          each_line = each_line->prev_line)
+       if (addr >= each_line->address)
+         break;
 
       if (each_line
-          && !(each_line->end_sequence || each_line == seq->last_line))
-        {
-          *filename_ptr = each_line->filename;
-          *linenumber_ptr = each_line->line;
-          if (discriminator_ptr)
-            *discriminator_ptr = each_line->discriminator;
-          return TRUE;
-        }
+         && !(each_line->end_sequence || each_line == seq->last_line))
+       {
+         *filename_ptr = each_line->filename;
+         *linenumber_ptr = each_line->line;
+         if (discriminator_ptr)
+           *discriminator_ptr = each_line->discriminator;
+         return seq->last_line->address - seq->low_pc;
+       }
     }
 
   *filename_ptr = NULL;
-  return FALSE;
+  return 0;
 }
 
 /* Read in the .debug_ranges section for future reference.  */
@@ -1970,16 +1986,16 @@ read_debug_ranges (struct comp_unit *unit)
 {
   struct dwarf2_debug *stash = unit->stash;
   return read_section (unit->abfd, &stash->debug_sections[debug_ranges],
-                       stash->syms, 0,
+                      stash->syms, 0,
                       &stash->dwarf_ranges_buffer, &stash->dwarf_ranges_size);
 }
 
 /* Function table functions.  */
 
-/* If ADDR is within TABLE, set FUNCTIONNAME_PTR, and return TRUE.
-   Note that we need to find the function that has the smallest
-   range that contains ADDR, to handle inlined functions without
-   depending upon them being ordered in TABLE by increasing range. */
+/* If ADDR is within UNIT's function tables, set FUNCTIONNAME_PTR, and return
+   TRUE.  Note that we need to find the function that has the smallest range
+   that contains ADDR, to handle inlined functions without depending upon
+   them being ordered in TABLE by increasing range.  */
 
 static bfd_boolean
 lookup_address_in_function_table (struct comp_unit *unit,
@@ -1989,6 +2005,7 @@ lookup_address_in_function_table (struct comp_unit *unit,
 {
   struct funcinfo* each_func;
   struct funcinfo* best_fit = NULL;
+  bfd_vma best_fit_len = 0;
   struct arange *arange;
 
   for (each_func = unit->function_table;
@@ -2002,9 +2019,11 @@ lookup_address_in_function_table (struct comp_unit *unit,
          if (addr >= arange->low && addr < arange->high)
            {
              if (!best_fit
-                 || (arange->high - arange->low
-                     < best_fit->arange.high - best_fit->arange.low))
-               best_fit = each_func;
+                 || arange->high - arange->low < best_fit_len)
+               {
+                 best_fit = each_func;
+                 best_fit_len = arange->high - arange->low;
+               }
            }
        }
     }
@@ -2033,6 +2052,7 @@ lookup_symbol_in_function_table (struct comp_unit *unit,
 {
   struct funcinfo* each_func;
   struct funcinfo* best_fit = NULL;
+  bfd_vma best_fit_len = 0;
   struct arange *arange;
   const char *name = bfd_asymbol_name (sym);
   asection *sec = bfd_get_section (sym);
@@ -2051,9 +2071,11 @@ lookup_symbol_in_function_table (struct comp_unit *unit,
              && each_func->name
              && strcmp (name, each_func->name) == 0
              && (!best_fit
-                 || (arange->high - arange->low
-                     < best_fit->arange.high - best_fit->arange.low)))
-           best_fit = each_func;
+                 || arange->high - arange->low < best_fit_len))
+           {
+             best_fit = each_func;
+             best_fit_len = arange->high - arange->low;
+           }
        }
     }
 
@@ -2126,6 +2148,28 @@ find_abstract_instance_name (struct comp_unit *unit,
        abort ();
 
       info_ptr = unit->sec_info_ptr + die_ref;
+
+      /* Now find the CU containing this pointer.  */
+      if (info_ptr >= unit->info_ptr_unit && info_ptr < unit->end_ptr)
+       ;
+      else
+       {
+         /* Check other CUs to see if they contain the abbrev.  */
+         struct comp_unit * u;
+
+         for (u = unit->prev_unit; u != NULL; u = u->prev_unit)
+           if (info_ptr >= u->info_ptr_unit && info_ptr < u->end_ptr)
+             break;
+
+         if (u == NULL)
+           for (u = unit->next_unit; u != NULL; u = u->next_unit)
+             if (info_ptr >= u->info_ptr_unit && info_ptr < u->end_ptr)
+               break;
+
+         if (u)
+           unit = u;
+         /* else FIXME: What do we do now ?  */
+       }
     }
   else if (attr_ptr->form == DW_FORM_GNU_ref_alt)
     {
@@ -2137,6 +2181,8 @@ find_abstract_instance_name (struct comp_unit *unit,
          bfd_set_error (bfd_error_bad_value);
          return name;
        }
+      /* FIXME: Do we need to locate the correct CU, in a similar
+        fashion to the code in the DW_FORM_ref_addr case above ?  */
     }
   else
     info_ptr = unit->info_ptr_unit + die_ref;
@@ -2166,7 +2212,7 @@ find_abstract_instance_name (struct comp_unit *unit,
                case DW_AT_name:
                  /* Prefer DW_AT_MIPS_linkage_name or DW_AT_linkage_name
                     over DW_AT_name.  */
-                 if (name == NULL)
+                 if (name == NULL && is_str_attr (attr.form))
                    name = attr.u.str;
                  break;
                case DW_AT_specification:
@@ -2174,7 +2220,10 @@ find_abstract_instance_name (struct comp_unit *unit,
                  break;
                case DW_AT_linkage_name:
                case DW_AT_MIPS_linkage_name:
-                 name = attr.u.str;
+                 /* PR 16949:  Corrupt debug info can place
+                    non-string forms into these attributes.  */
+                 if (is_str_attr (attr.form))
+                   name = attr.u.str;
                  break;
                default:
                  break;
@@ -2346,13 +2395,16 @@ scan_unit_for_symbols (struct comp_unit *unit)
                case DW_AT_name:
                  /* Prefer DW_AT_MIPS_linkage_name or DW_AT_linkage_name
                     over DW_AT_name.  */
-                 if (func->name == NULL)
+                 if (func->name == NULL && is_str_attr (attr.form))
                    func->name = attr.u.str;
                  break;
 
                case DW_AT_linkage_name:
                case DW_AT_MIPS_linkage_name:
-                 func->name = attr.u.str;
+                 /* PR 16949:  Corrupt debug info can place
+                    non-string forms into these attributes.  */
+                 if (is_str_attr (attr.form))
+                   func->name = attr.u.str;
                  break;
 
                case DW_AT_low_pc:
@@ -2687,10 +2739,10 @@ comp_unit_contains_address (struct comp_unit *unit, bfd_vma addr)
    FUNCTIONNAME_PTR, and LINENUMBER_PTR, are pointers to the objects
    to be filled in.
 
-   Return TRUE if UNIT contains ADDR, and no errors were encountered;
-   FALSE otherwise.  */
+   Returns the range of addresses covered by the entry that was used
+   to fill in *LINENUMBER_PTR or 0 if it was not filled in.  */
 
-static bfd_boolean
+static bfd_vma
 comp_unit_find_nearest_line (struct comp_unit *unit,
                             bfd_vma addr,
                             const char **filename_ptr,
@@ -2699,7 +2751,6 @@ comp_unit_find_nearest_line (struct comp_unit *unit,
                             unsigned int *discriminator_ptr,
                             struct dwarf2_debug *stash)
 {
-  bfd_boolean line_p;
   bfd_boolean func_p;
   struct funcinfo *function;
 
@@ -2735,11 +2786,11 @@ comp_unit_find_nearest_line (struct comp_unit *unit,
                                             &function, functionname_ptr);
   if (func_p && (function->tag == DW_TAG_inlined_subroutine))
     stash->inliner_chain = function;
-  line_p = lookup_address_in_line_info_table (unit->line_table, addr,
-                                             filename_ptr,
-                                             linenumber_ptr,
-                                             discriminator_ptr);
-  return line_p || func_p;
+
+  return lookup_address_in_line_info_table (unit->line_table, addr,
+                                           filename_ptr,
+                                           linenumber_ptr,
+                                           discriminator_ptr);
 }
 
 /* Check to see if line info is already decoded in a comp_unit.
@@ -2918,7 +2969,7 @@ comp_unit_hash_info (struct dwarf2_debug *stash,
 
 static asection *
 find_debug_info (bfd *abfd, const struct dwarf_debug_section *debug_sections,
-                 asection *after_sec)
+                asection *after_sec)
 {
   asection *msec;
   const char *look;
@@ -2962,12 +3013,36 @@ find_debug_info (bfd *abfd, const struct dwarf_debug_section *debug_sections,
   return NULL;
 }
 
+/* Transfer VMAs from object file to separate debug file.  */
+
+static void
+set_debug_vma (bfd *orig_bfd, bfd *debug_bfd)
+{
+  asection *s, *d;
+
+  for (s = orig_bfd->sections, d = debug_bfd->sections;
+       s != NULL && d != NULL;
+       s = s->next, d = d->next)
+    {
+      if ((d->flags & SEC_DEBUGGING) != 0)
+       break;
+      /* ??? Assumes 1-1 correspondence between sections in the
+        two files.  */
+      if (strcmp (s->name, d->name) == 0)
+       {
+         d->output_section = s->output_section;
+         d->output_offset = s->output_offset;
+         d->vma = s->vma;
+       }
+    }
+}
+
 /* Unset vmas for adjusted sections in STASH.  */
 
 static void
 unset_sections (struct dwarf2_debug *stash)
 {
-  unsigned int i;
+  int i;
   struct adjusted_section *p;
 
   i = stash->adjusted_section_count;
@@ -2976,14 +3051,23 @@ unset_sections (struct dwarf2_debug *stash)
     p->section->vma = 0;
 }
 
-/* Set unique VMAs for loadable and DWARF sections in ABFD and save
-   VMAs in STASH for unset_sections.  */
+/* Set VMAs for allocated and .debug_info sections in ORIG_BFD, a
+   relocatable object file.  VMAs are normally all zero in relocatable
+   object files, so if we want to distinguish locations in sections by
+   address we need to set VMAs so the sections do not overlap.  We
+   also set VMA on .debug_info so that when we have multiple
+   .debug_info sections (or the linkonce variant) they also do not
+   overlap.  The multiple .debug_info sections make up a single
+   logical section.  ??? We should probably do the same for other
+   debug sections.  */
 
 static bfd_boolean
-place_sections (bfd *abfd, struct dwarf2_debug *stash)
+place_sections (bfd *orig_bfd, struct dwarf2_debug *stash)
 {
+  bfd *abfd;
   struct adjusted_section *p;
-  unsigned int i;
+  int i;
+  const char *debug_info_name;
 
   if (stash->adjusted_section_count != 0)
     {
@@ -2991,103 +3075,109 @@ place_sections (bfd *abfd, struct dwarf2_debug *stash)
       p = stash->adjusted_sections;
       for (; i > 0; i--, p++)
        p->section->vma = p->adj_vma;
+      return TRUE;
     }
-  else
+
+  debug_info_name = stash->debug_sections[debug_info].uncompressed_name;
+  i = 0;
+  abfd = orig_bfd;
+  while (1)
     {
       asection *sect;
-      bfd_vma last_vma = 0, last_dwarf = 0;
-      bfd_size_type amt;
-      const char *debug_info_name;
 
-      debug_info_name = stash->debug_sections[debug_info].uncompressed_name;
-      i = 0;
       for (sect = abfd->sections; sect != NULL; sect = sect->next)
        {
-         bfd_size_type sz;
          int is_debug_info;
 
-         if (sect->vma != 0)
+         if ((sect->output_section != NULL
+              && sect->output_section != sect
+              && (sect->flags & SEC_DEBUGGING) == 0)
+             || sect->vma != 0)
            continue;
 
-         /* We need to adjust the VMAs of any .debug_info sections.
-            Skip compressed ones, since no relocations could target
-            them - they should not appear in object files anyway.  */
-         if (strcmp (sect->name, debug_info_name) == 0)
-           is_debug_info = 1;
-         else if (CONST_STRNEQ (sect->name, GNU_LINKONCE_INFO))
-           is_debug_info = 1;
-         else
-           is_debug_info = 0;
-
-         if (!is_debug_info && (sect->flags & SEC_LOAD) == 0)
-           continue;
+         is_debug_info = (strcmp (sect->name, debug_info_name) == 0
+                          || CONST_STRNEQ (sect->name, GNU_LINKONCE_INFO));
 
-         sz = sect->rawsize ? sect->rawsize : sect->size;
-         if (sz == 0)
+         if (!((sect->flags & SEC_ALLOC) != 0 && abfd == orig_bfd)
+             && !is_debug_info)
            continue;
 
          i++;
        }
+      if (abfd == stash->bfd_ptr)
+       break;
+      abfd = stash->bfd_ptr;
+    }
 
-      amt = i * sizeof (struct adjusted_section);
-      p = (struct adjusted_section *) bfd_alloc (abfd, amt);
-      if (! p)
+  if (i <= 1)
+    stash->adjusted_section_count = -1;
+  else
+    {
+      bfd_vma last_vma = 0, last_dwarf = 0;
+      bfd_size_type amt = i * sizeof (struct adjusted_section);
+
+      p = (struct adjusted_section *) bfd_malloc (amt);
+      if (p == NULL)
        return FALSE;
 
       stash->adjusted_sections = p;
       stash->adjusted_section_count = i;
 
-      for (sect = abfd->sections; sect != NULL; sect = sect->next)
+      abfd = orig_bfd;
+      while (1)
        {
-         bfd_size_type sz;
-         int is_debug_info;
+         asection *sect;
 
-         if (sect->vma != 0)
-           continue;
+         for (sect = abfd->sections; sect != NULL; sect = sect->next)
+           {
+             bfd_size_type sz;
+             int is_debug_info;
 
-         /* We need to adjust the VMAs of any .debug_info sections.
-            Skip compressed ones, since no relocations could target
-            them - they should not appear in object files anyway.  */
-         if (strcmp (sect->name, debug_info_name) == 0)
-           is_debug_info = 1;
-         else if (CONST_STRNEQ (sect->name, GNU_LINKONCE_INFO))
-           is_debug_info = 1;
-         else
-           is_debug_info = 0;
+             if ((sect->output_section != NULL
+                  && sect->output_section != sect
+                  && (sect->flags & SEC_DEBUGGING) == 0)
+                 || sect->vma != 0)
+               continue;
 
-         if (!is_debug_info && (sect->flags & SEC_LOAD) == 0)
-           continue;
+             is_debug_info = (strcmp (sect->name, debug_info_name) == 0
+                              || CONST_STRNEQ (sect->name, GNU_LINKONCE_INFO));
 
-         sz = sect->rawsize ? sect->rawsize : sect->size;
-         if (sz == 0)
-           continue;
+             if (!((sect->flags & SEC_ALLOC) != 0 && abfd == orig_bfd)
+                 && !is_debug_info)
+               continue;
 
-         p->section = sect;
-         if (is_debug_info)
-           {
-             BFD_ASSERT (sect->alignment_power == 0);
-             sect->vma = last_dwarf;
-             last_dwarf += sz;
-           }
-         else if (last_vma != 0)
-           {
-             /* Align the new address to the current section
-                alignment.  */
-             last_vma = ((last_vma
-                          + ~((bfd_vma) -1 << sect->alignment_power))
-                         & ((bfd_vma) -1 << sect->alignment_power));
-             sect->vma = last_vma;
-             last_vma += sect->vma + sz;
-           }
-         else
-           last_vma += sect->vma + sz;
+             sz = sect->rawsize ? sect->rawsize : sect->size;
 
-         p->adj_vma = sect->vma;
+             if (is_debug_info)
+               {
+                 BFD_ASSERT (sect->alignment_power == 0);
+                 sect->vma = last_dwarf;
+                 last_dwarf += sz;
+               }
+             else
+               {
+                 /* Align the new address to the current section
+                    alignment.  */
+                 last_vma = ((last_vma
+                              + ~((bfd_vma) -1 << sect->alignment_power))
+                             & ((bfd_vma) -1 << sect->alignment_power));
+                 sect->vma = last_vma;
+                 last_vma += sz;
+               }
 
-         p++;
+             p->section = sect;
+             p->adj_vma = sect->vma;
+             p++;
+           }
+         if (abfd == stash->bfd_ptr)
+           break;
+         abfd = stash->bfd_ptr;
        }
     }
 
+  if (orig_bfd != stash->bfd_ptr)
+    set_debug_vma (orig_bfd, stash->bfd_ptr);
+
   return TRUE;
 }
 
@@ -3106,6 +3196,7 @@ info_hash_lookup_funcinfo (struct info_hash_table *hash_table,
 {
   struct funcinfo* each_func;
   struct funcinfo* best_fit = NULL;
+  bfd_vma best_fit_len = 0;
   struct info_list_node *node;
   struct arange *arange;
   const char *name = bfd_asymbol_name (sym);
@@ -3124,9 +3215,11 @@ info_hash_lookup_funcinfo (struct info_hash_table *hash_table,
              && addr >= arange->low
              && addr < arange->high
              && (!best_fit
-                 || (arange->high - arange->low
-                     < best_fit->arange.high - best_fit->arange.low)))
-           best_fit = each_func;
+                 || arange->high - arange->low < best_fit_len))
+           {
+             best_fit = each_func;
+             best_fit_len = arange->high - arange->low;
+           }
        }
     }
 
@@ -3316,6 +3409,56 @@ stash_find_line_fast (struct dwarf2_debug *stash,
                                   filename_ptr, linenumber_ptr);
 }
 
+/* Save current section VMAs.  */
+
+static bfd_boolean
+save_section_vma (const bfd *abfd, struct dwarf2_debug *stash)
+{
+  asection *s;
+  unsigned int i;
+
+  if (abfd->section_count == 0)
+    return TRUE;
+  stash->sec_vma = bfd_malloc (sizeof (*stash->sec_vma) * abfd->section_count);
+  if (stash->sec_vma == NULL)
+    return FALSE;
+  for (i = 0, s = abfd->sections; i < abfd->section_count; i++, s = s->next)
+    {
+      if (s->output_section != NULL)
+       stash->sec_vma[i] = s->output_section->vma + s->output_offset;
+      else
+       stash->sec_vma[i] = s->vma;
+    }
+  return TRUE;
+}
+
+/* Compare current section VMAs against those at the time the stash
+   was created.  If find_nearest_line is used in linker warnings or
+   errors early in the link process, the debug info stash will be
+   invalid for later calls.  This is because we relocate debug info
+   sections, so the stashed section contents depend on symbol values,
+   which in turn depend on section VMAs.  */
+
+static bfd_boolean
+section_vma_same (const bfd *abfd, const struct dwarf2_debug *stash)
+{
+  asection *s;
+  unsigned int i;
+
+  for (i = 0, s = abfd->sections; i < abfd->section_count; i++, s = s->next)
+    {
+      bfd_vma vma;
+
+      if (s->output_section != NULL)
+       vma = s->output_section->vma + s->output_offset;
+      else
+       vma = s->vma;
+      if (vma != stash->sec_vma[i])
+       return FALSE;
+    }
+  return TRUE;
+}
+
 /* Read debug information from DEBUG_BFD when DEBUG_BFD is specified.
    If DEBUG_BFD is not specified, we read debug information from ABFD
    or its gnu_debuglink. The results will be stored in PINFO.
@@ -3323,9 +3466,10 @@ stash_find_line_fast (struct dwarf2_debug *stash,
 
 bfd_boolean
 _bfd_dwarf2_slurp_debug_info (bfd *abfd, bfd *debug_bfd,
-                              const struct dwarf_debug_section *debug_sections,
-                              asymbol **symbols,
-                              void **pinfo)
+                             const struct dwarf_debug_section *debug_sections,
+                             asymbol **symbols,
+                             void **pinfo,
+                             bfd_boolean do_place)
 {
   bfd_size_type amt = sizeof (struct dwarf2_debug);
   bfd_size_type total_size;
@@ -3333,13 +3477,22 @@ _bfd_dwarf2_slurp_debug_info (bfd *abfd, bfd *debug_bfd,
   struct dwarf2_debug *stash = (struct dwarf2_debug *) *pinfo;
 
   if (stash != NULL)
-    return TRUE;
-
-  stash = (struct dwarf2_debug *) bfd_zalloc (abfd, amt);
-  if (! stash)
-    return FALSE;
+    {
+      if (section_vma_same (abfd, stash))
+       return TRUE;
+      _bfd_dwarf2_cleanup_debug_info (abfd, pinfo);
+      memset (stash, 0, amt);
+    }
+  else
+    {
+      stash = (struct dwarf2_debug *) bfd_zalloc (abfd, amt);
+      if (! stash)
+       return FALSE;
+    }
   stash->debug_sections = debug_sections;
   stash->syms = symbols;
+  if (!save_section_vma (abfd, stash))
+    return FALSE;
 
   *pinfo = stash;
 
@@ -3361,7 +3514,8 @@ _bfd_dwarf2_slurp_debug_info (bfd *abfd, bfd *debug_bfd,
       if ((debug_bfd = bfd_openr (debug_filename, NULL)) == NULL
          || ! bfd_check_format (debug_bfd, bfd_object)
          || (msec = find_debug_info (debug_bfd,
-                                     debug_sections, NULL)) == NULL)
+                                     debug_sections, NULL)) == NULL
+         || !bfd_generic_link_read_symbols (debug_bfd))
        {
          if (debug_bfd)
            bfd_close (debug_bfd);
@@ -3369,10 +3523,17 @@ _bfd_dwarf2_slurp_debug_info (bfd *abfd, bfd *debug_bfd,
          free (debug_filename);
          return FALSE;
        }
+
+      symbols = bfd_get_outsymbols (debug_bfd);
+      stash->syms = symbols;
       stash->close_on_cleanup = TRUE;
     }
   stash->bfd_ptr = debug_bfd;
 
+  if (do_place
+      && !place_sections (abfd, stash))
+    return FALSE;
+
   /* There can be more than one DWARF2 info section in a BFD these
      days.  First handle the easy case when there's only one.  If
      there's more than one, try case two: none of the sections is
@@ -3444,19 +3605,19 @@ _bfd_dwarf2_slurp_debug_info (bfd *abfd, bfd *debug_bfd,
    field and in the abbreviation offset, or zero to indicate that the
    default value should be used.  */
 
-static bfd_boolean
-find_line (bfd *abfd,
-           const struct dwarf_debug_section *debug_sections,
-          asection *section,
-          bfd_vma offset,
-          asymbol *symbol,
-          asymbol **symbols,
-          const char **filename_ptr,
-          const char **functionname_ptr,
-          unsigned int *linenumber_ptr,
-          unsigned int *discriminator_ptr,
-          unsigned int addr_size,
-          void **pinfo)
+bfd_boolean
+_bfd_dwarf2_find_nearest_line (bfd *abfd,
+                              asymbol **symbols,
+                              asymbol *symbol,
+                              asection *section,
+                              bfd_vma offset,
+                              const char **filename_ptr,
+                              const char **functionname_ptr,
+                              unsigned int *linenumber_ptr,
+                              unsigned int *discriminator_ptr,
+                              const struct dwarf_debug_section *debug_sections,
+                              unsigned int addr_size,
+                              void **pinfo)
 {
   /* Read each compilation unit from the section .debug_info, and check
      to see if it contains the address we are searching for.  If yes,
@@ -3470,7 +3631,7 @@ find_line (bfd *abfd,
   /* What address are we looking for?  */
   bfd_vma addr;
   struct comp_unit* each;
-  bfd_vma found = FALSE;
+  bfd_boolean found = FALSE;
   bfd_boolean do_line;
 
   *filename_ptr = NULL;
@@ -3480,35 +3641,25 @@ find_line (bfd *abfd,
   if (discriminator_ptr)
     *discriminator_ptr = 0;
 
-  if (! _bfd_dwarf2_slurp_debug_info (abfd, NULL,
-                                     debug_sections, symbols, pinfo))
+  if (! _bfd_dwarf2_slurp_debug_info (abfd, NULL, debug_sections,
+                                     symbols, pinfo,
+                                     (abfd->flags & (EXEC_P | DYNAMIC)) == 0))
     return FALSE;
 
   stash = (struct dwarf2_debug *) *pinfo;
 
-  /* In a relocatable file, 2 functions may have the same address.
-     We change the section vma so that they won't overlap.  */
-  if ((abfd->flags & (EXEC_P | DYNAMIC)) == 0)
-    {
-      if (! place_sections (abfd, stash))
-       return FALSE;
-    }
-
-  do_line = (section == NULL
-            && offset == 0
-            && functionname_ptr == NULL
-            && symbol != NULL);
+  do_line = symbol != NULL;
   if (do_line)
     {
-      addr = symbol->value;
+      BFD_ASSERT (section == NULL && offset == 0 && functionname_ptr == NULL);
       section = bfd_get_section (symbol);
+      addr = symbol->value;
     }
-  else if (section != NULL
-          && functionname_ptr != NULL
-          && symbol == NULL)
-    addr = offset;
   else
-    abort ();
+    {
+      BFD_ASSERT (section != NULL && functionname_ptr != NULL);
+      addr = offset;
+    }
 
   if (section->output_section)
     addr += section->output_section->vma + section->output_offset;
@@ -3560,18 +3711,56 @@ find_line (bfd *abfd,
     }
   else
     {
+      bfd_vma min_range = (bfd_vma) -1;
+      const char * local_filename = NULL;
+      const char * local_functionname = NULL;
+      unsigned int local_linenumber = 0;
+      unsigned int local_discriminator = 0;
+
       for (each = stash->all_comp_units; each; each = each->next_unit)
        {
+         bfd_vma range = (bfd_vma) -1;
+
          found = ((each->arange.high == 0
                    || comp_unit_contains_address (each, addr))
-                  && comp_unit_find_nearest_line (each, addr,
-                                                  filename_ptr,
-                                                  functionname_ptr,
-                                                  linenumber_ptr,
-                                                  discriminator_ptr,
-                                                  stash));
+                  && (range = comp_unit_find_nearest_line (each, addr,
+                                                           & local_filename,
+                                                           & local_functionname,
+                                                           & local_linenumber,
+                                                           & local_discriminator,
+                                                           stash)) != 0);
          if (found)
-           goto done;
+           {
+             /* PRs 15935 15994: Bogus debug information may have provided us
+                with an erroneous match.  We attempt to counter this by
+                selecting the match that has the smallest address range
+                associated with it.  (We are assuming that corrupt debug info
+                will tend to result in extra large address ranges rather than
+                extra small ranges).
+
+                This does mean that we scan through all of the CUs associated
+                with the bfd each time this function is called.  But this does
+                have the benefit of producing consistent results every time the
+                function is called.  */
+             if (range <= min_range)
+               {
+                 if (filename_ptr && local_filename)
+                   * filename_ptr = local_filename;
+                 if (functionname_ptr && local_functionname)
+                   * functionname_ptr = local_functionname;
+                 if (discriminator_ptr && local_discriminator)
+                   * discriminator_ptr = local_discriminator;
+                 if (local_linenumber)
+                   * linenumber_ptr = local_linenumber;
+                 min_range = range;
+               }
+           }
+       }
+
+      if (* linenumber_ptr)
+       {
+         found = TRUE;
+         goto done;
        }
     }
 
@@ -3663,13 +3852,13 @@ find_line (bfd *abfd,
                                                     functionname_ptr,
                                                     linenumber_ptr,
                                                     discriminator_ptr,
-                                                    stash));
+                                                    stash) != 0);
 
          if ((bfd_vma) (stash->info_ptr - stash->sec_info_ptr)
              == stash->sec->size)
            {
              stash->sec = find_debug_info (stash->bfd_ptr, debug_sections,
-                                            stash->sec);
+                                           stash->sec);
              stash->sec_info_ptr = stash->info_ptr;
            }
 
@@ -3685,45 +3874,6 @@ find_line (bfd *abfd,
   return found;
 }
 
-/* The DWARF2 version of find_nearest_line.
-   Return TRUE if the line is found without error.  */
-
-bfd_boolean
-_bfd_dwarf2_find_nearest_line (bfd *abfd,
-                               const struct dwarf_debug_section *debug_sections,
-                              asection *section,
-                              asymbol **symbols,
-                              bfd_vma offset,
-                              const char **filename_ptr,
-                              const char **functionname_ptr,
-                              unsigned int *linenumber_ptr,
-                               unsigned int *discriminator_ptr,
-                              unsigned int addr_size,
-                              void **pinfo)
-{
-  return find_line (abfd, debug_sections, section, offset, NULL, symbols,
-                    filename_ptr, functionname_ptr, linenumber_ptr,
-                    discriminator_ptr, addr_size, pinfo);
-}
-
-/* The DWARF2 version of find_line.
-   Return TRUE if the line is found without error.  */
-
-bfd_boolean
-_bfd_dwarf2_find_line (bfd *abfd,
-                      asymbol **symbols,
-                      asymbol *symbol,
-                      const char **filename_ptr,
-                      unsigned int *linenumber_ptr,
-                       unsigned int *discriminator_ptr,
-                      unsigned int addr_size,
-                      void **pinfo)
-{
-  return find_line (abfd, dwarf_debug_sections, NULL, 0, symbol, symbols,
-                    filename_ptr, NULL, linenumber_ptr, discriminator_ptr,
-                    addr_size, pinfo);
-}
-
 bfd_boolean
 _bfd_dwarf2_find_inliner_info (bfd *abfd ATTRIBUTE_UNUSED,
                               const char **filename_ptr,
@@ -3828,6 +3978,10 @@ _bfd_dwarf2_cleanup_debug_info (bfd *abfd, void **pinfo)
     free (stash->alt_dwarf_str_buffer);
   if (stash->alt_dwarf_info_buffer)
     free (stash->alt_dwarf_info_buffer);
+  if (stash->sec_vma)
+    free (stash->sec_vma);
+  if (stash->adjusted_sections)
+    free (stash->adjusted_sections);
   if (stash->alt_bfd_ptr)
     bfd_close (stash->alt_bfd_ptr);
 }