Fixes for memory access violations in the coffdump program.

	PR binutils/17512
	* coffdump.c (dump_coff_section): Check for a symbol being
	available before printing its name.
	(main): Check the return value from coff_grok.
	* coffgrok.c: Reformat and tidy.
	Add range checks to most functions.
	(coff_grok): Return NULL if the input bfd is not in a COFF
	format.
	* coffgrok.h: Reformat and tidy.
	(struct coff_section): Change the nrelocs field to unsigned.
	* srconv.c (main): Check the return value from coff_grok.

	* coff-i860.c (CALC_ADDEND): Always set an addend value.
	* tekhex.c (getvalue): Add an end pointer parameter.  Use it to
	avoid reading off the end of the buffer.
	(getsym): Likewise.
	(first_phase): Likewise.
	(pass_over): Pass an end pointer to the invoked function.

5 files changed, 391 insertions, 259 deletions

diff --git a/binutils/ChangeLog b/binutils/ChangeLog
index a435983..338be86 100644
--- a/binutils/ChangeLog
+++ b/binutils/ChangeLog
@@ -1,3 +1,17 @@
+2015-01-06  Nick Clifton  <nickc@redhat.com>
+
+	PR binutils/17512
+	* coffdump.c (dump_coff_section): Check for a symbol being
+	available before printing its name.
+	(main): Check the return value from coff_grok.
+	* coffgrok.c: Reformat and tidy.
+	Add range checks to most functions.
+	(coff_grok): Return NULL if the input bfd is not in a COFF
+	format.
+	* coffgrok.h: Reformat and tidy.
+	(struct coff_section): Change the nrelocs field to unsigned.
+	* srconv.c (main): Check the return value from coff_grok.
+
 2015-01-05  Nick Clifton  <nickc@redhat.com>
 
 	PR binutils/17512
diff --git a/binutils/coffdump.c b/binutils/coffdump.c
index b952b62..9883e22 100644
--- a/binutils/coffdump.c
+++ b/binutils/coffdump.c
@@ -417,21 +417,23 @@ dump_coff_sfile (struct coff_sfile *p)
 static void
 dump_coff_section (struct coff_section *ptr)
 {
-  int i;
+  unsigned int i;
 
   tab (1);
-  printf (_("section %s %d %d address %x size %x number %d nrelocs %d"),
+  printf (_("section %s %d %d address %x size %x number %d nrelocs %u"),
 	  ptr->name, ptr->code, ptr->data, ptr->address,ptr->size,
 	  ptr->number, ptr->nrelocs);
   nl ();
 
   for (i = 0; i < ptr->nrelocs; i++)
     {
+      struct coff_reloc * r = ptr->relocs + i;
       tab (0);
       printf ("(%x %s %x)",
-	      ptr->relocs[i].offset,
-	      ptr->relocs[i].symbol->name,
-	      ptr->relocs[i].addend);
+	      r->offset,
+	      /* PR 17512: file: 0a38fb7c.  */
+	      r->symbol == NULL ? _("<no sym>") : r->symbol->name,
+	      r->addend);
       nl ();
     }
 
@@ -549,9 +551,11 @@ main (int ac, char **av)
     }
 
   tree = coff_grok (abfd);
-
-  coff_dump (tree);
-  printf ("\n");
+  if (tree)
+    {
+      coff_dump (tree);
+      printf ("\n");
+    }
 
   return 0;
 }
diff --git a/binutils/coffgrok.c b/binutils/coffgrok.c
index 2349a31..a4c9d54 100644
--- a/binutils/coffgrok.c
+++ b/binutils/coffgrok.c
@@ -28,35 +28,30 @@
 #include "sysdep.h"
 #include "bfd.h"
 #include "libiberty.h"
-
 #include "coff/internal.h"
 #include "../bfd/libcoff.h"
 #include "bucomm.h"
 #include "coffgrok.h"
 
-static int lofile = 1;
-static struct coff_scope *top_scope;
-static struct coff_scope *file_scope;
-static struct coff_ofile *ofile;
-
-static struct coff_symbol *last_function_symbol;
-static struct coff_type *last_function_type;
-static struct coff_type *last_struct;
-static struct coff_type *last_enum;
-static struct coff_sfile *cur_sfile;
-
-static struct coff_symbol **tindex;
-
-
-static asymbol **syms;
-static long symcount;
+static int                      lofile = 1;
+
+static struct coff_scope *      top_scope;
+static struct coff_scope *      file_scope;
+static struct coff_ofile *      ofile;
+static struct coff_symbol *     last_function_symbol;
+static struct coff_type *       last_function_type;
+static struct coff_type *       last_struct;
+static struct coff_type *       last_enum;
+static struct coff_sfile *      cur_sfile;
+static struct coff_symbol **    tindex;
+static asymbol **               syms;
+static long                     symcount;
+static struct coff_ptr_struct * rawsyms;
+static unsigned int             rawcount;
+static bfd *                    abfd;
 
 #define N(x) ((x)->_n._n_nptr[1])
 
-static struct coff_ptr_struct *rawsyms;
-static int rawcount;
-static bfd *abfd;
-
 #define PTR_SIZE	4
 #define SHORT_SIZE	2
 #define INT_SIZE	4
@@ -66,25 +61,11 @@ static bfd *abfd;
 
 #define INDEXOF(p)  ((struct coff_ptr_struct *)(p)-(rawsyms))
 
-static struct coff_scope *empty_scope (void);
-static struct coff_symbol *empty_symbol (void);
-static void push_scope (int);
-static void pop_scope (void);
-static void do_sections_p1 (struct coff_ofile *);
-static void do_sections_p2 (struct coff_ofile *);
-static struct coff_where *do_where (int);
-static struct coff_line *do_lines (int, char *);
-static struct coff_type *do_type (int);
-static struct coff_visible *do_visible (int);
-static int do_define (int, struct coff_scope *);
-static struct coff_ofile *doit (void);
 
 static struct coff_scope *
 empty_scope (void)
 {
-  struct coff_scope *l;
-  l = (struct coff_scope *) (xcalloc (sizeof (struct coff_scope), 1));
-  return l;
+  return (struct coff_scope *) (xcalloc (sizeof (struct coff_scope), 1));
 }
 
 static struct coff_symbol *
@@ -93,7 +74,6 @@ empty_symbol (void)
   return (struct coff_symbol *) (xcalloc (sizeof (struct coff_symbol), 1));
 }
 
-/*int l;*/
 static void
 push_scope (int slink)
 {
@@ -122,6 +102,9 @@ push_scope (int slink)
 static void
 pop_scope (void)
 {
+  /* PR 17512: file: 809933ac.  */
+  if (top_scope == NULL)
+    fatal (_("Out of context scope change encountered"));
   top_scope = top_scope->parent;
 }
 
@@ -138,10 +121,14 @@ do_sections_p1 (struct coff_ofile *head)
   for (idx = 0, section = abfd->sections; section; section = section->next, idx++)
     {
       long relsize;
-      int i = section->target_index;
+      unsigned int i = section->target_index;
       arelent **relpp;
       long relcount;
 
+      /* PR 17512: file: 2d6effca.  */
+      if (i > abfd->section_count)
+	fatal (_("Invalid section target index: %u"), i);
+
       relsize = bfd_get_reloc_upper_bound (abfd, section);
       if (relsize < 0)
 	bfd_fatal (bfd_get_filename (abfd));
@@ -178,30 +165,56 @@ static void
 do_sections_p2 (struct coff_ofile *head)
 {
   asection *section;
+
   for (section = abfd->sections; section; section = section->next)
     {
       unsigned int j;
 
+      /* PR 17512: file: 7c1a36e8.
+	 A corrupt COFF binary might have a reloc count but no relocs.
+	 Handle this here.  */
+      if (section->relocation == NULL)
+	continue;
+
       for (j = 0; j < section->reloc_count; j++)
 	{
-	  int idx;
+	  unsigned int idx;
 	  int i = section->target_index;
-	  struct coff_reloc *r = head->sections[i].relocs + j;
+	  struct coff_reloc *r;
 	  arelent *sr = section->relocation + j;
+
+	  if (i > head->nsections)
+	    fatal (_("Invalid section target index: %d"), i);
+	  /* PR 17512: file: db850ff4.  */
+	  if (j >= head->sections[i].nrelocs)
+	    fatal (_("Target section has insufficient relocs"));
+	  r = head->sections[i].relocs + j;
 	  r->offset = sr->address;
 	  r->addend = sr->addend;
 	  idx = ((coff_symbol_type *) (sr->sym_ptr_ptr[0]))->native - rawsyms;
+	  if (idx >= rawcount)
+	    {
+	      if (rawcount == 0)
+		fatal (_("Symbol index %u encountered when there are no symbols"), idx);
+	      non_fatal (_("Invalid symbol index %u encountered"), idx);
+	      idx = 0;
+	    }
 	  r->symbol = tindex[idx];
 	}
     }
 }
 
 static struct coff_where *
-do_where (int i)
+do_where (unsigned int i)
 {
-  struct internal_syment *sym = &rawsyms[i].u.syment;
+  struct internal_syment *sym;
   struct coff_where *where =
     (struct coff_where *) (xmalloc (sizeof (struct coff_where)));
+
+  if (i >= rawcount)
+    fatal ("Invalid symbol index: %d\n", i);
+
+  sym = &rawsyms[i].u.syment;
   where->offset = sym->n_value;
 
   if (sym->n_scnum == -1)
@@ -231,7 +244,16 @@ do_where (int i)
     case C_EXTDEF:
     case C_LABEL:
       where->where = coff_where_memory;
-      where->section = &ofile->sections[sym->n_scnum];
+      /* PR 17512: file: 07a37c40.  */
+      /* PR 17512: file: 0c2eb101.  */
+      if (sym->n_scnum >= ofile->nsections || sym->n_scnum < 0)
+	{
+	  non_fatal (_("Invalid section number (%d) encountered"),
+		     sym->n_scnum);
+	  where->section = ofile->sections;
+	}
+      else
+	where->section = &ofile->sections[sym->n_scnum];
       break;
     case C_REG:
     case C_REGPARM:
@@ -248,47 +270,61 @@ do_where (int i)
       where->where = coff_where_typedef;
       break;
     default:
-      abort ();
+      fatal (_("Unrecognized symbol class: %d"), sym->n_sclass);
       break;
     }
   return where;
 }
 
-static
-struct coff_line *
+static struct coff_line *
 do_lines (int i, char *name ATTRIBUTE_UNUSED)
 {
   struct coff_line *res = (struct coff_line *) xcalloc (sizeof (struct coff_line), 1);
   asection *s;
   unsigned int l;
 
-  /* Find out if this function has any line numbers in the table */
+  /* Find out if this function has any line numbers in the table.  */
   for (s = abfd->sections; s; s = s->next)
     {
+      /* PR 17512: file: 07a37c40.
+	 A corrupt COFF binary can have a linenumber count in the header
+	 but no line number table.  This should be reported elsewhere, but
+	 do not rely upon this.  */
+      if (s->lineno == NULL)
+	continue;
+
       for (l = 0; l < s->lineno_count; l++)
 	{
 	  if (s->lineno[l].line_number == 0)
 	    {
 	      if (rawsyms + i == ((coff_symbol_type *) (&(s->lineno[l].u.sym[0])))->native)
 		{
-		  /* These lines are for this function - so count them and stick them on */
+		  /* These lines are for this function - so count them and stick them on.  */
 		  int c = 0;
 		  /* Find the linenumber of the top of the function, since coff linenumbers
 		     are relative to the start of the function.  */
 		  int start_line = rawsyms[i + 3].u.auxent.x_sym.x_misc.x_lnsz.x_lnno;
 
 		  l++;
-		  for (c = 0; s->lineno[l + c + 1].line_number; c++)
+		  for (c = 0;
+		       /* PR 17512: file: c2825452.  */
+		       l + c + 1 < s->lineno_count
+			 && s->lineno[l + c + 1].line_number;
+		       c++)
 		    ;
 
-		  /* Add two extra records, one for the prologue and one for the epilogue */
+		  /* Add two extra records, one for the prologue and one for the epilogue.  */
 		  c += 1;
 		  res->nlines = c;
 		  res->lines = (int *) (xcalloc (sizeof (int), c));
 		  res->addresses = (int *) (xcalloc (sizeof (int), c));
 		  res->lines[0] = start_line;
 		  res->addresses[0] = rawsyms[i].u.syment.n_value - s->vma;
-		  for (c = 0; s->lineno[l + c + 1].line_number; c++)
+		  for (c = 0;
+		       /* PR 17512: file: c2825452.  */
+		       l + c + 1 < s->lineno_count
+			 && s->lineno[l + c + 1].line_number;
+		       c++)
 		    {
 		      res->lines[c + 1] = s->lineno[l + c].line_number + start_line - 1;
 		      res->addresses[c + 1] = s->lineno[l + c].u.offset;
@@ -301,18 +337,30 @@ do_lines (int i, char *name ATTRIBUTE_UNUSED)
   return res;
 }
 
-static
-struct coff_type *
-do_type (int i)
+static struct coff_type *
+do_type (unsigned int i)
 {
-  struct internal_syment *sym = &rawsyms[i].u.syment;
-  union internal_auxent *aux = &rawsyms[i + 1].u.auxent;
-  struct coff_type *res =
-    (struct coff_type *) xmalloc (sizeof (struct coff_type));
-  int type = sym->n_type;
+  struct internal_syment *sym;
+  union internal_auxent *aux;
+  struct coff_type *res = (struct coff_type *) xmalloc (sizeof (struct coff_type));
+  int type;
   int which_dt = 0;
   int dimind = 0;
 
+  if (i >= rawcount)
+    fatal (_("Type entry %u does not have enough symbolic information"), i);
+
+  if (!rawsyms[i].is_sym)
+    fatal (_("Type entry %u does not refer to a symbol"), i);
+  sym = &rawsyms[i].u.syment;
+
+  if (sym->n_numaux == 0 || i >= rawcount -1 || rawsyms[i + 1].is_sym)
+    aux = NULL;
+  else
+    aux = &rawsyms[i + 1].u.auxent;
+
+  type = sym->n_type;
+
   res->type = coff_basic_type;
   res->u.basic = type & 0xf;
 
@@ -322,28 +370,33 @@ do_type (int i)
     case T_VOID:
       if (sym->n_numaux && sym->n_sclass == C_STAT)
 	{
-	  /* This is probably a section definition */
+	  /* This is probably a section definition.  */
 	  res->type = coff_secdef_type;
+	  if (aux == NULL)
+	    fatal (_("Section definition needs a section length"));
 	  res->size = aux->x_scn.x_scnlen;
+
+	  /* PR 17512: file: 081c955d.
+	     Fill in the asecdef structure as well.  */
+	  res->u.asecdef.address = 0;
+	  res->u.asecdef.size = 0;
 	}
       else
 	{
 	  if (type == 0)
 	    {
-	      /* Don't know what this is, let's make it a simple int */
+	      /* Don't know what this is, let's make it a simple int.  */
 	      res->size = INT_SIZE;
 	      res->u.basic = T_UINT;
 	    }
 	  else
 	    {
-	      /* Else it could be a function or pointer to void */
+	      /* Else it could be a function or pointer to void.  */
 	      res->size = 0;
 	    }
 	}
       break;
 
-
-      break;
     case T_UCHAR:
     case T_CHAR:
       res->size = 1;
@@ -370,17 +423,30 @@ do_type (int i)
     case T_UNION:
       if (sym->n_numaux)
 	{
+	  if (aux == NULL)
+	    fatal (_("Aggregate definition needs auxillary information"));
+
 	  if (aux->x_sym.x_tagndx.p)
 	    {
-	      /* Referring to a struct defined elsewhere */
+	      unsigned int idx = INDEXOF (aux->x_sym.x_tagndx.p);
+
+	      if (idx >= rawcount)
+		{
+		  if (rawcount == 0)
+		    fatal (_("Symbol index %u encountered when there are no symbols"), idx);
+		  non_fatal (_("Invalid symbol index %u encountered"), idx);
+		  idx = 0;
+		}
+
+	      /* Referring to a struct defined elsewhere.  */
 	      res->type = coff_structref_type;
-	      res->u.astructref.ref = tindex[INDEXOF (aux->x_sym.x_tagndx.p)];
+	      res->u.astructref.ref = tindex[idx];
 	      res->size = res->u.astructref.ref ?
 		res->u.astructref.ref->type->size : 0;
 	    }
 	  else
 	    {
-	      /* A definition of a struct */
+	      /* A definition of a struct.  */
 	      last_struct = res;
 	      res->type = coff_structdef_type;
 	      res->u.astructdef.elements = empty_scope ();
@@ -391,23 +457,30 @@ do_type (int i)
 	}
       else
 	{
-	  /* No auxents - it's anonymous */
+	  /* No auxents - it's anonymous.  */
 	  res->type = coff_structref_type;
 	  res->u.astructref.ref = 0;
 	  res->size = 0;
 	}
       break;
     case T_ENUM:
+      if (aux == NULL)
+	fatal (_("Enum definition needs auxillary information"));
       if (aux->x_sym.x_tagndx.p)
 	{
-	  /* Referring to a enum defined elsewhere */
+	  unsigned int idx = INDEXOF (aux->x_sym.x_tagndx.p);
+
+	  /* PR 17512: file: 1ef037c7.  */
+	  if (idx >= rawcount)
+	    fatal (_("Invalid enum symbol index %u encountered"), idx);
+	  /* Referring to a enum defined elsewhere.  */
 	  res->type = coff_enumref_type;
-	  res->u.aenumref.ref = tindex[INDEXOF (aux->x_sym.x_tagndx.p)];
+	  res->u.aenumref.ref = tindex[idx];
 	  res->size = res->u.aenumref.ref->type->size;
 	}
       else
 	{
-	  /* A definition of an enum */
+	  /* A definition of an enum.  */
 	  last_enum = res;
 	  res->type = coff_enumdef_type;
 	  res->u.aenumdef.elements = empty_scope ();
@@ -428,9 +501,14 @@ do_type (int i)
 	  {
 	    struct coff_type *ptr = ((struct coff_type *)
 				     xmalloc (sizeof (struct coff_type)));
-	    int els = (dimind < DIMNUM
-		       ? aux->x_sym.x_fcnary.x_ary.x_dimen[dimind]
-		       : 0);
+	    int els;
+
+	    if (aux == NULL)
+	      fatal (_("Array definition needs auxillary information"));
+	    els = (dimind < DIMNUM
+		   ? aux->x_sym.x_fcnary.x_ary.x_dimen[dimind]
+		   : 0);
+
 	    ++dimind;
 	    ptr->type = coff_array_type;
 	    ptr->size = els * res->size;
@@ -443,6 +521,7 @@ do_type (int i)
 	  {
 	    struct coff_type *ptr =
 	      (struct coff_type *) xmalloc (sizeof (struct coff_type));
+
 	    ptr->size = PTR_SIZE;
 	    ptr->type = coff_pointer_type;
 	    ptr->u.pointer.points_to = res;
@@ -453,11 +532,12 @@ do_type (int i)
 	  {
 	    struct coff_type *ptr
 	      = (struct coff_type *) xmalloc (sizeof (struct coff_type));
+
 	    ptr->size = 0;
 	    ptr->type = coff_function_type;
 	    ptr->u.function.function_returns = res;
 	    ptr->u.function.parameters = empty_scope ();
-	    ptr->u.function.lines = do_lines (i, sym->_n._n_nptr[1]);
+	    ptr->u.function.lines = do_lines (i, N(sym));
 	    ptr->u.function.code = 0;
 	    last_function_type = ptr;
 	    res = ptr;
@@ -475,6 +555,7 @@ do_visible (int i)
   struct coff_visible *visible =
     (struct coff_visible *) (xmalloc (sizeof (struct coff_visible)));
   enum coff_vis_type t;
+
   switch (sym->n_sclass)
     {
     case C_MOS:
@@ -485,11 +566,9 @@ do_visible (int i)
     case C_MOE:
       t = coff_vis_member_of_enum;
       break;
-
     case C_REGPARM:
       t = coff_vis_regparam;
       break;
-
     case C_REG:
       t = coff_vis_register;
       break;
@@ -504,8 +583,6 @@ do_visible (int i)
       t = coff_vis_autoparam;
       break;
     case C_AUTO:
-
-
       t = coff_vis_auto;
       break;
     case C_LABEL:
@@ -524,27 +601,32 @@ do_visible (int i)
 	t = coff_vis_ext_def;
       break;
     default:
-      abort ();
+      fatal (_("Unrecognised symbol class: %d"), sym->n_sclass);
       break;
-
     }
   visible->type = t;
   return visible;
 }
 
+/* Define a symbol and attach to block B.  */
+
 static int
-do_define (int i, struct coff_scope *b)
+do_define (unsigned int i, struct coff_scope *b)
 {
   static int symbol_index;
-  struct internal_syment *sym = &rawsyms[i].u.syment;
-
-  /* Define a symbol and attach to block b */
+  struct internal_syment *sym;
   struct coff_symbol *s = empty_symbol ();
 
+  if (b == NULL)
+    fatal (_("ICE: do_define called without a block"));
+  if (i >= rawcount)
+    fatal (_("Out of range symbol index: %u"), i);
+
+  sym = &rawsyms[i].u.syment;
   s->number = ++symbol_index;
-  s->name = sym->_n._n_nptr[1];
+  s->name = N(sym);
   s->sfile = cur_sfile;
-  /* Glue onto the ofile list */
+  /* Glue onto the ofile list.  */
   if (lofile >= 0)
     {
       if (ofile->symbol_list_tail)
@@ -552,7 +634,7 @@ do_define (int i, struct coff_scope *b)
       else
 	ofile->symbol_list_head = s;
       ofile->symbol_list_tail = s;
-      /* And the block list */
+      /* And the block list.  */
     }
   if (b->vars_tail)
     b->vars_tail->next = s;
@@ -567,21 +649,27 @@ do_define (int i, struct coff_scope *b)
 
   tindex[i] = s;
 
-  /* We remember the lowest address in each section for each source file */
-
+  /* We remember the lowest address in each section for each source file.  */
   if (s->where->where == coff_where_memory
       && s->type->type == coff_secdef_type)
     {
-      struct coff_isection *is = cur_sfile->section + s->where->section->number;
+      struct coff_isection *is;
 
-      if (!is->init)
+      /* PR 17512: file: 4676c97f.  */
+      if (cur_sfile == NULL)
+	non_fatal (_("Section referenced before any file is defined"));
+      else
 	{
-	  is->low = s->where->offset;
-	  is->high = s->where->offset + s->type->size;
-	  is->init = 1;
-	  is->parent = s->where->section;
-	}
+	  is = cur_sfile->section + s->where->section->number;
 
+	  if (!is->init)
+	    {
+	      is->low = s->where->offset;
+	      is->high = s->where->offset + s->type->size;
+	      is->init = 1;
+	      is->parent = s->where->section;
+	    }
+	}
     }
 
   if (s->type->type == coff_function_type)
@@ -590,15 +678,14 @@ do_define (int i, struct coff_scope *b)
   return i + sym->n_numaux + 1;
 }
 
-
-static
-struct coff_ofile *
+static struct coff_ofile *
 doit (void)
 {
-  int i;
-  int infile = 0;
+  unsigned int i;
+  bfd_boolean infile = FALSE;
   struct coff_ofile *head =
     (struct coff_ofile *) xmalloc (sizeof (struct coff_ofile));
+
   ofile = head;
   head->source_head = 0;
   head->source_tail = 0;
@@ -611,23 +698,25 @@ doit (void)
   for (i = 0; i < rawcount;)
     {
       struct internal_syment *sym = &rawsyms[i].u.syment;
+
       switch (sym->n_sclass)
 	{
 	case C_FILE:
 	  {
-	    /* new source file announced */
+	    /* New source file announced.  */
 	    struct coff_sfile *n =
 	      (struct coff_sfile *) xmalloc (sizeof (struct coff_sfile));
+
 	    n->section = (struct coff_isection *) xcalloc (sizeof (struct coff_isection), abfd->section_count + 1);
 	    cur_sfile = n;
-	    n->name = sym->_n._n_nptr[1];
+	    n->name = N(sym);
 	    n->next = 0;
 
 	    if (infile)
-	      {
-		pop_scope ();
-	      }
-	    infile = 1;
+	      pop_scope ();
+	    else
+	      infile = TRUE;
+
 	    push_scope (1);
 	    file_scope = n->scope = top_scope;
 
@@ -642,17 +731,23 @@ doit (void)
 	  break;
 	case C_FCN:
 	  {
-	    char *name = sym->_n._n_nptr[1];
+	    char *name = N(sym);
+
 	    if (name[1] == 'b')
 	      {
-		/* Function start */
+		/* Function start.  */
 		push_scope (0);
-		last_function_type->u.function.code = top_scope;
+		/* PR 17512: file: 0ef7fbaf.  */
+		if (last_function_type)
+		  last_function_type->u.function.code = top_scope;
 		top_scope->sec = ofile->sections + sym->n_scnum;
 		top_scope->offset = sym->n_value;
 	      }
 	    else
 	      {
+		/* PR 17512: file: e92e42e1.  */
+		if (top_scope == NULL)
+		  fatal (_("Function start encountered without a top level scope."));
 		top_scope->size = sym->n_value - top_scope->offset + 1;
 		pop_scope ();
 
@@ -663,17 +758,19 @@ doit (void)
 
 	case C_BLOCK:
 	  {
-	    char *name = sym->_n._n_nptr[1];
+	    char *name = N(sym);
+
 	    if (name[1] == 'b')
 	      {
-		/* Block start */
+		/* Block start.  */
 		push_scope (1);
 		top_scope->sec = ofile->sections + sym->n_scnum;
 		top_scope->offset = sym->n_value;
-
 	      }
 	    else
 	      {
+		if (top_scope == NULL)
+		  fatal (_("Block start encountered without a scope for it."));
 		top_scope->size = sym->n_value - top_scope->offset + 1;
 		pop_scope ();
 	      }
@@ -682,37 +779,50 @@ doit (void)
 	  break;
 	case C_REGPARM:
 	case C_ARG:
+	  if (last_function_symbol == NULL)
+	    fatal (_("Function arguments encountered without a function definition"));
 	  i = do_define (i, last_function_symbol->type->u.function.parameters);
 	  break;
 	case C_MOS:
 	case C_MOU:
 	case C_FIELD:
+	  /* PR 17512: file: 43ab21f4.  */
+	  if (last_struct == NULL)
+	    fatal (_("Structure element encountered without a structure definition"));
 	  i = do_define (i, last_struct->u.astructdef.elements);
 	  break;
 	case C_MOE:
+	  if (last_enum == NULL)
+	    fatal (_("Enum element encountered without an enum definition"));
 	  i = do_define (i, last_enum->u.aenumdef.elements);
 	  break;
 	case C_STRTAG:
 	case C_ENTAG:
 	case C_UNTAG:
-	  /* Various definition */
+	  /* Various definition.  */
+	  if (top_scope == NULL)
+	    fatal (_("Aggregate defintion encountered without a scope"));
 	  i = do_define (i, top_scope);
 	  break;
 	case C_EXT:
 	case C_LABEL:
+	  if (file_scope == NULL)
+	    fatal (_("Label defintion encountered without a file scope"));
 	  i = do_define (i, file_scope);
 	  break;
 	case C_STAT:
 	case C_TPDEF:
 	case C_AUTO:
 	case C_REG:
+	  if (top_scope == NULL)
+	    fatal (_("Variable defintion encountered without a scope"));
 	  i = do_define (i, top_scope);
 	  break;
-	default:
-	  abort ();
 	case C_EOS:
 	  i += sym->n_numaux + 1;
 	  break;
+	default:
+	  fatal (_("Unrecognised symbol class: %d"), sym->n_sclass);
 	}
     }
   do_sections_p2 (head);
@@ -725,6 +835,13 @@ coff_grok (bfd *inabfd)
   long storage;
   struct coff_ofile *p;
   abfd = inabfd;
+
+  if (! bfd_family_coff (abfd))
+    {
+      non_fatal (_("%s: is not a COFF format file"), bfd_get_filename (abfd));
+      return NULL;
+    }
+  
   storage = bfd_get_symtab_upper_bound (abfd);
 
   if (storage < 0)
diff --git a/binutils/coffgrok.h b/binutils/coffgrok.h
index 61384a8..d08a1a4 100644
--- a/binutils/coffgrok.h
+++ b/binutils/coffgrok.h
@@ -19,22 +19,22 @@
    MA 02110-1301, USA.  */
 
 #define T_NULL		0
-#define T_VOID		1	/* function argument (only used by compiler) */
-#define T_CHAR		2	/* character		*/
-#define T_SHORT		3	/* short integer	*/
-#define T_INT		4	/* integer		*/
-#define T_LONG		5	/* long integer		*/
-#define T_FLOAT		6	/* floating point	*/
-#define T_DOUBLE	7	/* double word		*/
-#define T_STRUCT	8	/* structure 		*/
-#define T_UNION		9	/* union 		*/
-#define T_ENUM		10	/* enumeration 		*/
-#define T_MOE		11	/* member of enumeration*/
-#define T_UCHAR		12	/* unsigned character	*/
-#define T_USHORT	13	/* unsigned short	*/
-#define T_UINT		14	/* unsigned integer	*/
-#define T_ULONG		15	/* unsigned long	*/
-#define T_LNGDBL	16	/* long double		*/
+#define T_VOID		1	/* Function argument (only used by compiler).  */
+#define T_CHAR		2	/* Character		*/
+#define T_SHORT		3	/* Short integer	*/
+#define T_INT		4	/* Integer		*/
+#define T_LONG		5	/* Long integer		*/
+#define T_FLOAT		6	/* Floating point	*/
+#define T_DOUBLE	7	/* Double word		*/
+#define T_STRUCT	8	/* Structure 		*/
+#define T_UNION		9	/* Union 		*/
+#define T_ENUM		10	/* Enumeration 		*/
+#define T_MOE		11	/* Member of enumeration*/
+#define T_UCHAR		12	/* Unsigned character	*/
+#define T_USHORT	13	/* Unsigned short	*/
+#define T_UINT		14	/* Unsigned integer	*/
+#define T_ULONG		15	/* Unsigned long	*/
+#define T_LNGDBL	16	/* Long double		*/
 
 
 struct coff_reloc
@@ -51,7 +51,7 @@ struct coff_section
   int data;
   int address;
   int number;  /* 0..n, .text = 0 */
-  int nrelocs;
+  unsigned int nrelocs;
   int size;
   struct coff_reloc *relocs;
   struct bfd_section *bfd_section;
@@ -68,7 +68,8 @@ struct coff_ofile
   struct coff_symbol *symbol_list_tail;
 };
 
-struct coff_isection {
+struct coff_isection
+{
   int low;
   int high;
   int init;
@@ -82,145 +83,139 @@ struct coff_sfile
   struct coff_sfile *next;
 
   /* Vector which maps where in each output section
-     the input file has it's data */
+     the input file has it's data.  */
   struct coff_isection *section;
-
 };
 
-
- struct coff_type
+struct coff_type
 {
   int size;
   enum
     {
       coff_pointer_type, coff_function_type, coff_array_type, coff_structdef_type, coff_basic_type,
       coff_structref_type, coff_enumref_type, coff_enumdef_type, coff_secdef_type
-      } type;
+    } type;
+
   union
     {
       struct
-	{
+      {
 	int address;
 	int size;
       } asecdef;
 
       struct
-	{
-	  int isstruct;
-	  struct coff_scope *elements;
-	  int idx;
-	}
-      astructdef;
+      {
+	int isstruct;
+	struct coff_scope *elements;
+	int idx;
+      } astructdef;
+
       struct
-	{
-	  struct coff_symbol *ref;
-	} astructref;
+      {
+	struct coff_symbol *ref;
+      } astructref;
 
       struct
-	{
-	  struct coff_scope *elements;
-	  int idx;
-	} aenumdef;
+      {
+	struct coff_scope *elements;
+	int idx;
+      } aenumdef;
+
       struct
-	{
-	  struct coff_symbol *ref;
-	} aenumref;
+      {
+	struct coff_symbol *ref;
+      } aenumref;
 
       struct
-	{
-	  struct coff_type *points_to;
-	} pointer;
+      {
+	struct coff_type *points_to;
+      } pointer;
+
       struct
-	{
-	  int dim;
-	  struct coff_type *array_of;
-	} array;
+      {
+	int dim;
+	struct coff_type *array_of;
+      } array;
 
       struct
-	{
-	  struct coff_type *function_returns;
-	  struct coff_scope *parameters;
-	  struct coff_scope *code;
-	  struct coff_line *lines;
-	} function;
+      {
+	struct coff_type *   function_returns;
+	struct coff_scope *  parameters;
+	struct coff_scope *  code;
+	struct coff_line *   lines;
+      } function;
+
       int basic;		/* One of T_VOID.. T_UINT */
-    }  u;
+  } u;
+};
+
+struct coff_line
+{
+  int   nlines;
+  int * lines;
+  int * addresses;
 };
 
+struct coff_scope
+{
+  struct coff_section * sec;     /* Which section.  */
+  int                   offset;  /* Where.  */
+  int                   size;    /* How big.  */
+  struct coff_scope *   parent;	 /* One up.  */
+  struct coff_scope *   next;	 /* Next along.  */
+  int                   nvars;
+  struct coff_symbol *  vars_head;	/* Symbols.  */
+  struct coff_symbol *  vars_tail;
+  struct coff_scope *   list_head;	/* Children.  */
+  struct coff_scope *   list_tail;
+};
+
+struct coff_visible
+{
+  enum coff_vis_type
+  {
+    coff_vis_ext_def,
+    coff_vis_ext_ref,
+    coff_vis_int_def,
+    coff_vis_common,
+    coff_vis_auto,
+    coff_vis_register,
+    coff_vis_tag,
+    coff_vis_member_of_struct,
+    coff_vis_member_of_enum,
+    coff_vis_autoparam,
+    coff_vis_regparam,
+  } type;
+};
+
+struct coff_where
+{
+  enum
+  {
+    coff_where_stack, coff_where_memory, coff_where_register, coff_where_unknown,
+    coff_where_strtag, coff_where_member_of_struct,
+    coff_where_member_of_enum, coff_where_entag, coff_where_typedef
+  } where;
+
+  int offset;
+  int bitoffset;
+  int bitsize;
+  struct coff_section *section;
+};
+
+struct coff_symbol
+{
+  char *                name;
+  int                   tag;
+  struct coff_type *    type;
+  struct coff_where *   where;
+  struct coff_visible * visible;
+  struct coff_symbol *  next;
+  struct coff_symbol *  next_in_ofile_list; /* For the ofile list.  */
+  int                   number;
+  int                   er_number;
+  struct coff_sfile *   sfile;
+};
 
- struct coff_line
- {
-   int nlines;
-   int *lines;
-   int *addresses;
- };
-
-
- struct coff_scope
-   {
-     struct coff_section *sec; /* What section */
-     int offset; /* where */
-     int size; /* How big */
-     struct coff_scope *parent;	/* one up */
-
-     struct coff_scope *next;	/*next along */
-
-     int nvars;
-
-     struct coff_symbol *vars_head;	/* symbols */
-     struct coff_symbol *vars_tail;
-
-     struct coff_scope *list_head;	/* children */
-     struct coff_scope *list_tail;
-
-   };
-
-
- struct coff_visible
-   {
-     enum coff_vis_type
-       {
-	 coff_vis_ext_def,
-	 coff_vis_ext_ref,
-	 coff_vis_int_def,
-	 coff_vis_common,
-	 coff_vis_auto,
-	 coff_vis_register,
-	 coff_vis_tag,
-	 coff_vis_member_of_struct,
-	 coff_vis_member_of_enum,
-	 coff_vis_autoparam,
-	 coff_vis_regparam,
-       } type;
-   };
-
- struct coff_where
-   {
-     enum
-       {
-	 coff_where_stack, coff_where_memory, coff_where_register, coff_where_unknown,
-	 coff_where_strtag, coff_where_member_of_struct,
-	 coff_where_member_of_enum, coff_where_entag, coff_where_typedef
-
-       } where;
-     int offset;
-     int bitoffset;
-     int bitsize;
-     struct coff_section *section;
-   };
-
- struct coff_symbol
-   {
-     char *name;
-     int tag;
-     struct coff_type *type;
-     struct coff_where *where;
-     struct coff_visible *visible;
-     struct coff_symbol *next;
-     struct coff_symbol *next_in_ofile_list; /* For the ofile list */
-     int number;
-     int er_number;
-     struct coff_sfile *sfile;
-  };
-
-struct coff_ofile *coff_grok (bfd *);
+struct coff_ofile * coff_grok (bfd *);
diff --git a/binutils/srconv.c b/binutils/srconv.c
index 3762a25..d2e0cdb 100644
--- a/binutils/srconv.c
+++ b/binutils/srconv.c
@@ -1883,10 +1883,12 @@ main (int ac, char **av)
     printf ("ids %d %d\n", base1, base2);
 
   tree = coff_grok (abfd);
+  if (tree)
+    {
+      if (!noprescan)
+	prescan (tree);
 
-  if (!noprescan)
-    prescan (tree);
-
-  wr_module (tree);
+      wr_module (tree);
+    }
   return 0;
 }