gdb-3.1

[binutils.git] / gdb / dbxread.c

/* Read dbx symbol tables and convert to internal format, for GDB.
   Copyright (C) 1986, 1987, 1988, 1989 Free Software Foundation, Inc.

GDB is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY.  No author or distributor accepts responsibility to anyone
for the consequences of using it or for whether it serves any
particular purpose or works at all, unless he says so in writing.
Refer to the GDB General Public License for full details.

Everyone is granted permission to copy, modify and redistribute GDB,
but only under the conditions described in the GDB General Public
License.  A copy of this license is supposed to have been given to you
along with GDB so you can know your rights and responsibilities.  It
should be in a file named COPYING.  Among other things, the copyright
notice and this notice must be preserved on all copies.

In other words, go ahead and share GDB, but don't try to stop
anyone else from sharing it farther.  Help stamp out software hoarding!
*/
\f
#include "param.h"

#ifdef READ_DBX_FORMAT

#ifdef USG
#include <sys/types.h>
#include <fcntl.h>
#define L_SET 0
#define L_INCR 1
#endif

#ifdef COFF_ENCAPSULATE
#include "a.out.encap.h"
#include "stab.gnu.h"
#else
#include <a.out.h>
#include <stab.h>
#endif

/*
 * Define specifically gnu symbols here.
 */

/* The following type indicates the definition of a symbol as being
   an indirect reference to another symbol.  The other symbol
   appears as an undefined reference, immediately following this symbol.

   Indirection is asymmetrical.  The other symbol's value will be used
   to satisfy requests for the indirect symbol, but not vice versa.
   If the other symbol does not have a definition, libraries will
   be searched to find a definition.  */
#ifndef N_INDR
#define N_INDR 0xa
#endif

/* The following symbols refer to set elements.
   All the N_SET[ATDB] symbols with the same name form one set.
   Space is allocated for the set in the text section, and each set
   element's value is stored into one word of the space.
   The first word of the space is the length of the set (number of elements).

   The address of the set is made into an N_SETV symbol
   whose name is the same as the name of the set.
   This symbol acts like a N_DATA global symbol
   in that it can satisfy undefined external references.  */

#ifndef N_SETA
#define N_SETA  0x14            /* Absolute set element symbol */
#endif                          /* This is input to LD, in a .o file.  */

#ifndef N_SETT
#define N_SETT  0x16            /* Text set element symbol */
#endif                          /* This is input to LD, in a .o file.  */

#ifndef N_SETD
#define N_SETD  0x18            /* Data set element symbol */
#endif                          /* This is input to LD, in a .o file.  */

#ifndef N_SETB
#define N_SETB  0x1A            /* Bss set element symbol */
#endif                          /* This is input to LD, in a .o file.  */

/* Macros dealing with the set element symbols defined in a.out.h */
#define SET_ELEMENT_P(x)        ((x)>=N_SETA&&(x)<=(N_SETB|N_EXT))
#define TYPE_OF_SET_ELEMENT(x)  ((x)-N_SETA+N_ABS)

#ifndef N_SETV
#define N_SETV  0x1C            /* Pointer to set vector in data area.  */
#endif                          /* This is output from LD.  */

#ifndef N_WARNING
#define N_WARNING 0x1E          /* Warning message to print if file included */
#endif                          /* This is input to ld */

#ifndef __GNU_STAB__

/* Line number for the data section.  This is to be used to describe
   the source location of a variable declaration.  */
#ifndef N_DSLINE
#define N_DSLINE (N_SLINE+N_DATA-N_TEXT)
#endif

/* Line number for the bss section.  This is to be used to describe
   the source location of a variable declaration.  */
#ifndef N_BSLINE
#define N_BSLINE (N_SLINE+N_BSS-N_TEXT)
#endif

#endif /* not __GNU_STAB__ */

#include <stdio.h>
#include <obstack.h>
#include <sys/param.h>
#include <sys/file.h>
#include <sys/stat.h>
#include "defs.h"
#include "symtab.h"

#ifndef COFF_FORMAT
#define AOUTHDR         struct exec
#endif

static void add_symbol_to_list ();
static void read_dbx_symtab ();
static void process_one_symbol ();
static void free_all_psymbols ();
static struct type *read_type ();
static struct type *read_range_type ();
static struct type *read_enum_type ();
static struct type *read_struct_type ();
static struct type *read_array_type ();
static long read_number ();
static void finish_block ();
static struct blockvector *make_blockvector ();
static struct symbol *define_symbol ();
static void start_subfile ();
static int hashname ();
static void hash_symsegs ();

extern struct symtab *read_symsegs ();
extern void free_all_symtabs ();
extern void free_all_psymtabs ();
extern void free_inclink_symtabs ();

/* C++ */
static struct type **read_args();

/* Macro to determine which symbols to ignore when reading the first symbol
   of a file.  Some machines override this definition. */
#ifdef N_NSYMS
#ifndef IGNORE_SYMBOL
/* This code is used on Ultrix systems.  Ignore it */
#define IGNORE_SYMBOL(type)  (type == N_NSYMS)
#endif
#else
#ifndef IGNORE_SYMBOL
/* Don't ignore any symbols. */
#define IGNORE_SYMBOL(type) (0)
#endif
#endif /* not N_NSYMS */

/* Macro for number of symbol table entries (in usual a.out format).
   Some machines override this definition.  */
#ifndef NUMBER_OF_SYMBOLS
#ifdef COFF_HEADER
#define NUMBER_OF_SYMBOLS \
  ((COFF_HEADER(hdr) ? hdr.coffhdr.filehdr.f_nsyms : hdr.a_syms) /      \
   sizeof (struct nlist))
#else
#define NUMBER_OF_SYMBOLS (hdr.a_syms / sizeof (struct nlist))
#endif
#endif

/* Macro for file-offset of symbol table (in usual a.out format).  */
#ifndef SYMBOL_TABLE_OFFSET
#define SYMBOL_TABLE_OFFSET N_SYMOFF (hdr)
#endif

/* Macro for file-offset of string table (in usual a.out format).  */
#ifndef STRING_TABLE_OFFSET
#define STRING_TABLE_OFFSET (N_SYMOFF (hdr) + hdr.a_syms)
#endif

/* Macro to store the length of the string table data in INTO.  */
#ifndef READ_STRING_TABLE_SIZE
#define READ_STRING_TABLE_SIZE(INTO)            \
{ val = myread (desc, &INTO, sizeof INTO);      \
  if (val < 0) perror_with_name (name); }
#endif

/* Macro to declare variables to hold the file's header data.  */
#ifndef DECLARE_FILE_HEADERS
#define DECLARE_FILE_HEADERS  AOUTHDR hdr
#endif

/* Macro to read the header data from descriptor DESC and validate it.
   NAME is the file name, for error messages.  */
#ifndef READ_FILE_HEADERS
#ifdef HEADER_SEEK_FD
#define READ_FILE_HEADERS(DESC, NAME)           \
{ HEADER_SEEK_FD (DESC);                        \
  val = myread (DESC, &hdr, sizeof hdr);        \
  if (val < 0) perror_with_name (NAME);         \
  if (N_BADMAG (hdr))                           \
    error ("File \"%s\" not in executable format.", NAME); }
#else
#define READ_FILE_HEADERS(DESC, NAME)           \
{ val = myread (DESC, &hdr, sizeof hdr);        \
  if (val < 0) perror_with_name (NAME);         \
  if (N_BADMAG (hdr))                           \
    error ("File \"%s\" not in executable format.", NAME); }
#endif
#endif

/* Macro for size of text segment */
#ifndef SIZE_OF_TEXT_SEGMENT
#define SIZE_OF_TEXT_SEGMENT hdr.a_text
#endif

/* Macro for name of symbol to indicate a file compiled with gcc. */
#ifndef GCC_COMPILED_FLAG_SYMBOL
#define GCC_COMPILED_FLAG_SYMBOL "gcc_compiled."
#endif
\f
/* Chain of symtabs made from reading the file's symsegs.
   These symtabs do not go into symtab_list themselves,
   but the information is copied from them when appropriate
   to make the symtabs that will exist permanently.  */

static struct symtab *symseg_chain;

/* Symseg symbol table for the file whose data we are now processing.
   It is one of those in symseg_chain.  Or 0, for a compilation that
   has no symseg.  */

static struct symtab *current_symseg;

/* Name of source file whose symbol data we are now processing.
   This comes from a symbol of type N_SO.  */

static char *last_source_file;

/* Core address of start of text of current source file.
   This too comes from the N_SO symbol.  */

static CORE_ADDR last_source_start_addr;

/* End of the text segment of the executable file,
   as found in the symbol _etext.  */

static CORE_ADDR end_of_text_addr;

/* The list of sub-source-files within the current individual compilation.
   Each file gets its own symtab with its own linetable and associated info,
   but they all share one blockvector.  */

struct subfile
{
  struct subfile *next;
  char *name;
  struct linetable *line_vector;
  int line_vector_length;
  int line_vector_index;
  int prev_line_number;
};

static struct subfile *subfiles;

static struct subfile *current_subfile;

/* Count symbols as they are processed, for error messages.  */

static int symnum;

/* Vector of types defined so far, indexed by their dbx type numbers.
   (In newer sun systems, dbx uses a pair of numbers in parens,
    as in "(SUBFILENUM,NUMWITHINSUBFILE)".  Then these numbers must be
    translated through the type_translations hash table to get
    the index into the type vector.)  */

static struct typevector *type_vector;

/* Number of elements allocated for type_vector currently.  */

static int type_vector_length;

/* Vector of line number information.  */

static struct linetable *line_vector;

/* Index of next entry to go in line_vector_index.  */

static int line_vector_index;

/* Last line number recorded in the line vector.  */

static int prev_line_number;

/* Number of elements allocated for line_vector currently.  */

static int line_vector_length;

/* Hash table of global symbols whose values are not known yet.
   They are chained thru the SYMBOL_VALUE, since we don't
   have the correct data for that slot yet.  */

#define HASHSIZE 127
static struct symbol *global_sym_chain[HASHSIZE];

/* Record the symbols defined for each context in a list.
   We don't create a struct block for the context until we
   know how long to make it.  */

#define PENDINGSIZE 100

struct pending
{
  struct pending *next;
  int nsyms;
  struct symbol *symbol[PENDINGSIZE];
};

/* List of free `struct pending' structures for reuse.  */
struct pending *free_pendings;

/* Here are the three lists that symbols are put on.  */

struct pending *file_symbols;   /* static at top level, and types */

struct pending *global_symbols; /* global functions and variables */

struct pending *local_symbols;  /* everything local to lexical context */

/* Stack representing unclosed lexical contexts
   (that will become blocks, eventually).  */

struct context_stack
{
  struct pending *locals;
  struct pending_block *old_blocks;
  struct symbol *name;
  CORE_ADDR start_addr;
  int depth;
};

struct context_stack *context_stack;

/* Index of first unused entry in context stack.  */
int context_stack_depth;

/* Currently allocated size of context stack.  */

int context_stack_size;

/* Nonzero if within a function (so symbols should be local,
   if nothing says specifically).  */

int within_function;

/* List of blocks already made (lexical contexts already closed).
   This is used at the end to make the blockvector.  */

struct pending_block
{
  struct pending_block *next;
  struct block *block;
};

struct pending_block *pending_blocks;

extern CORE_ADDR first_object_file_end; /* From blockframe.c */

/* File name symbols were loaded from.  */

static char *symfile;

/* Low and high symbol values (inclusive) for the global variable
   entries in the symbol file. */

static int first_global_sym, last_global_sym;

/* Partial symbol list for all of the global and static symbols found
   in a file */

struct partial_symbol *global_psymbols, *static_psymbols;
int global_psymbols_allocated, static_psymbols_allocated;

/* Position for next psymbol to be added */

struct partial_symbol *next_ps_global, *next_ps_static;

/* Global variable which, when set, indicates that we are processing a
   .o file compiled with gcc */

static unsigned char processing_gcc_compilation;

static int
xxmalloc (n)
{
  int v = malloc (n);
  if (v == 0)
    abort ();
  return v;
}

/* Make a copy of the string at PTR with SIZE characters in the symbol obstack
   (and add a null character at the end in the copy).
   Returns the address of the copy.  */

static char *
obsavestring (ptr, size)
     char *ptr;
     int size;
{
  register char *p = (char *) obstack_alloc (symbol_obstack, size + 1);
  /* Open-coded bcopy--saves function call time.
     These strings are usually short.  */
  {
    register char *p1 = ptr;
    register char *p2 = p;
    char *end = ptr + size;
    while (p1 != end)
      *p2++ = *p1++;
  }
  p[size] = 0;
  return p;
}

/* Concatenate strings S1, S2 and S3; return the new string.
   Space is found in the symbol_obstack.  */

static char *
obconcat (s1, s2, s3)
     char *s1, *s2, *s3;
{
  register int len = strlen (s1) + strlen (s2) + strlen (s3) + 1;
  register char *val = (char *) obstack_alloc (symbol_obstack, len);
  strcpy (val, s1);
  strcat (val, s2);
  strcat (val, s3);
  return val;
}
\f
/* Support for Sun changes to dbx symbol format */

/* For each identified header file, we have a table of types defined
   in that header file.

   header_files maps header file names to their type tables.
   It is a vector of n_header_files elements.
   Each element describes one header file.
   It contains a vector of types.

   Sometimes it can happen that the same header file produces
   different results when included in different places.
   This can result from conditionals or from different
   things done before including the file.
   When this happens, there are multiple entries for the file in this table,
   one entry for each distinct set of results.
   The entries are distinguished by the INSTANCE field.
   The INSTANCE field appears in the N_BINCL and N_EXCL symbol table and is
   used to match header-file references to their corresponding data.  */

struct header_file
{
  char *name;                   /* Name of header file */
  int instance;                 /* Numeric code distinguishing instances
                                   of one header file that produced
                                   different results when included.
                                   It comes from the N_BINCL or N_EXCL.  */
  struct type **vector;         /* Pointer to vector of types */
  int length;                   /* Allocated length (# elts) of that vector */
};

static struct header_file *header_files;

static int n_header_files;

static int n_allocated_header_files;

/* During initial symbol readin, we need to have a structure to keep
   track of which psymtabs have which bincls in them.  This structure
   is used during readin to setup the list of dependencies within each
   partial symbol table. */
 
struct header_file_location
{
  char *name;                   /* Name of header file */
  int instance;                 /* See above */
  struct partial_symtab *pst;   /* Partial symtab that has the
                                   BINCL/EINCL defs for this file */
};

/* The actual list and controling variables */
static struct header_file_location *bincl_list, *next_bincl;
static int bincls_allocated;
  
/* Within each object file, various header files are assigned numbers.
   A type is defined or referred to with a pair of numbers
   (FILENUM,TYPENUM) where FILENUM is the number of the header file
   and TYPENUM is the number within that header file.
   TYPENUM is the index within the vector of types for that header file.

   FILENUM == 1 is special; it refers to the main source of the object file,
   and not to any header file.  FILENUM != 1 is interpreted by looking it up
   in the following table, which contains indices in header_files.  */

static int *this_object_header_files;

static int n_this_object_header_files;

static int n_allocated_this_object_header_files;

/* When a header file is getting special overriding definitions
   for one source file, record here the header_files index
   of its normal definition vector.
   At other times, this is -1.  */

static int header_file_prev_index;

/* At the start of reading dbx symbols, allocate our tables.  */

static void
init_header_files ()
{
  n_allocated_header_files = 10;
  header_files = (struct header_file *) xxmalloc (10 * sizeof (struct header_file));
  n_header_files = 0;

  n_allocated_this_object_header_files = 10;
  this_object_header_files = (int *) xxmalloc (10 * sizeof (int));
}

/* At the end of reading dbx symbols, free our tables.  */

static void
free_header_files ()
{
  register int i;
  for (i = 0; i < n_header_files; i++)
    free (header_files[i].name);
  if (header_files) free (header_files);
  if (this_object_header_files)
    free (this_object_header_files);
}

/* Called at the start of each object file's symbols.
   Clear out the mapping of header file numbers to header files.  */

static void
new_object_header_files ()
{
  /* Leave FILENUM of 0 free for builtin types and this file's types.  */
  n_this_object_header_files = 1;
  header_file_prev_index = -1;
}

/* Add header file number I for this object file
   at the next successive FILENUM.  */

static void
add_this_object_header_file (i)
     int i;
{
  if (n_this_object_header_files == n_allocated_this_object_header_files)
    {
      n_allocated_this_object_header_files *= 2;
      this_object_header_files
        = (int *) xrealloc (this_object_header_files,
                            n_allocated_this_object_header_files * sizeof (int));
    }

  this_object_header_files[n_this_object_header_files++] = i;
}

/* Add to this file an "old" header file, one already seen in
   a previous object file.  NAME is the header file's name.
   INSTANCE is its instance code, to select among multiple
   symbol tables for the same header file.  */

static void
add_old_header_file (name, instance)
     char *name;
     int instance;
{
  register struct header_file *p = header_files;
  register int i;

  for (i = 0; i < n_header_files; i++)
    if (!strcmp (p[i].name, name) && instance == p[i].instance)
      {
        add_this_object_header_file (i);
        return;
      }
  error ("Invalid symbol data: \"repeated\" header file that hasn't been seen before, at symtab pos %d.",
         symnum);
}

/* Add to this file a "new" header file: definitions for its types follow.
   NAME is the header file's name.
   Most often this happens only once for each distinct header file,
   but not necessarily.  If it happens more than once, INSTANCE has
   a different value each time, and references to the header file
   use INSTANCE values to select among them.

   dbx output contains "begin" and "end" markers for each new header file,
   but at this level we just need to know which files there have been;
   so we record the file when its "begin" is seen and ignore the "end".  */

static void
add_new_header_file (name, instance)
     char *name;
     int instance;
{
  register int i;
  register struct header_file *p = header_files;
  header_file_prev_index = -1;

#if 0
  /* This code was used before I knew about the instance codes.
     My first hypothesis is that it is not necessary now
     that instance codes are handled.  */

  /* Has this header file a previous definition?
     If so, make a new entry anyway so that this use in this source file
     gets a separate entry.  Later source files get the old entry.
     Record here the index of the old entry, so that any type indices
     not previously defined can get defined in the old entry as
     well as in the new one.  */

  for (i = 0; i < n_header_files; i++)
    if (!strcmp (p[i].name, name))
      {
        header_file_prev_index = i;
      }

#endif

  /* Make sure there is room for one more header file.  */

  if (n_header_files == n_allocated_header_files)
    {
      n_allocated_header_files *= 2;
      header_files = (struct header_file *)
        xrealloc (header_files,
                  (n_allocated_header_files
                   * sizeof (struct header_file)));
    }

  /* Create an entry for this header file.  */

  i = n_header_files++;
  header_files[i].name = savestring (name, strlen(name));
  header_files[i].instance = instance;
  header_files[i].length = 10;
  header_files[i].vector
    = (struct type **) xxmalloc (10 * sizeof (struct type *));
  bzero (header_files[i].vector, 10 * sizeof (struct type *));

  add_this_object_header_file (i);
}

/* Look up a dbx type-number pair.  Return the address of the slot
   where the type for that number-pair is stored.
   The number-pair is in TYPENUMS.

   This can be used for finding the type associated with that pair
   or for associating a new type with the pair.  */

static struct type **
dbx_lookup_type (typenums)
     int typenums[2];
{
  register int filenum = typenums[0], index = typenums[1];

  if (filenum < 0 || filenum >= n_this_object_header_files)
    error ("Invalid symbol data: type number (%d,%d) out of range at symtab pos %d.",
           filenum, index, symnum);

  if (filenum == 0)
    {
      /* Type is defined outside of header files.
         Find it in this object file's type vector.  */
      if (index >= type_vector_length)
        {
          type_vector_length *= 2;
          type_vector = (struct typevector *)
            xrealloc (type_vector,
                      (sizeof (struct typevector)
                       + type_vector_length * sizeof (struct type *)));
          bzero (&type_vector->type[type_vector_length / 2],
                 type_vector_length * sizeof (struct type *) / 2);
        }
      return &type_vector->type[index];
    }
  else
    {
      register int real_filenum = this_object_header_files[filenum];
      register struct header_file *f;

      if (real_filenum >= n_header_files)
        abort ();

      f = &header_files[real_filenum];

      if (index >= f->length)
        {
          f->length *= 2;
          f->vector = (struct type **)
            xrealloc (f->vector, f->length * sizeof (struct type *));
          bzero (&f->vector[f->length / 2],
                 f->length * sizeof (struct type *) / 2);
        }
      return &f->vector[index];
    }
}

/* Make sure there is a type allocated for type numbers TYPENUMS
   and return the type object.
   This can create an empty (zeroed) type object.  */

static struct type *
dbx_alloc_type (typenums)
     int typenums[2];
{
  register struct type **type_addr = dbx_lookup_type (typenums);
  register struct type *type = *type_addr;

  /* If we are referring to a type not known at all yet,
     allocate an empty type for it.
     We will fill it in later if we find out how.  */
  if (type == 0)
    {
      type = (struct type *) obstack_alloc (symbol_obstack,
                                            sizeof (struct type));
      bzero (type, sizeof (struct type));
      TYPE_VPTR_FIELDNO (type) = -1;
      *type_addr = type;
    }
  return type;
}

#if 0
static struct type **
explicit_lookup_type (real_filenum, index)
     int real_filenum, index;
{
  register struct header_file *f = &header_files[real_filenum];

  if (index >= f->length)
    {
      f->length *= 2;
      f->vector = (struct type **)
        xrealloc (f->vector, f->length * sizeof (struct type *));
      bzero (&f->vector[f->length / 2],
             f->length * sizeof (struct type *) / 2);
    }
  return &f->vector[index];
}
#endif
\f
/* maintain the lists of symbols and blocks */

/* Add a symbol to one of the lists of symbols.  */
static void
add_symbol_to_list (symbol, listhead)
     struct symbol *symbol;
     struct pending **listhead;
{
  /* We keep PENDINGSIZE symbols in each link of the list.
     If we don't have a link with room in it, add a new link.  */
  if (*listhead == 0 || (*listhead)->nsyms == PENDINGSIZE)
    {
      register struct pending *link;
      if (free_pendings)
        {
          link = free_pendings;
          free_pendings = link->next;
        }
      else
        link = (struct pending *) xxmalloc (sizeof (struct pending));

      link->next = *listhead;
      *listhead = link;
      link->nsyms = 0;
    }

  (*listhead)->symbol[(*listhead)->nsyms++] = symbol;
}

/* At end of reading syms, or in case of quit,
   really free as many `struct pending's as we can easily find.  */

static void
really_free_pendings ()
{
  struct pending *next, *next1;
  struct pending_block *bnext, *bnext1;

  for (next = free_pendings; next; next = next1)
    {
      next1 = next->next;
      free (next);
    }
  free_pendings = 0;

  for (bnext = pending_blocks; bnext; bnext = bnext1)
    {
      bnext1 = bnext->next;
      free (bnext);
    }
  pending_blocks = 0;

  for (next = file_symbols; next; next = next1)
    {
      next1 = next->next;
      free (next);
    }
  for (next = global_symbols; next; next = next1)
    {
      next1 = next->next;
      free (next);
    }
}

/* Take one of the lists of symbols and make a block from it.
   Keep the order the symbols have in the list (reversed from the input file).
   Put the block on the list of pending blocks.  */

static void
finish_block (symbol, listhead, old_blocks, start, end)
     struct symbol *symbol;
     struct pending **listhead;
     struct pending_block *old_blocks;
     CORE_ADDR start, end;
{
  register struct pending *next, *next1;
  register struct block *block;
  register struct pending_block *pblock;
  struct pending_block *opblock;
  register int i;

  /* Count the length of the list of symbols.  */

  for (next = *listhead, i = 0; next; i += next->nsyms, next = next->next);

  block = (struct block *) obstack_alloc (symbol_obstack,
                                          (sizeof (struct block)
                                           + ((i - 1)
                                              * sizeof (struct symbol *))));

  /* Copy the symbols into the block.  */

  BLOCK_NSYMS (block) = i;
  for (next = *listhead; next; next = next->next)
    {
      register int j;
      for (j = next->nsyms - 1; j >= 0; j--)
        BLOCK_SYM (block, --i) = next->symbol[j];
    }

  BLOCK_START (block) = start;
  BLOCK_END (block) = end;
  BLOCK_SUPERBLOCK (block) = 0; /* Filled in when containing block is made */
  BLOCK_GCC_COMPILED (block) = processing_gcc_compilation;

  /* Put the block in as the value of the symbol that names it.  */

  if (symbol)
    {
      SYMBOL_BLOCK_VALUE (symbol) = block;
      BLOCK_FUNCTION (block) = symbol;
    }
  else
    BLOCK_FUNCTION (block) = 0;

  /* Now "free" the links of the list, and empty the list.  */

  for (next = *listhead; next; next = next1)
    {
      next1 = next->next;
      next->next = free_pendings;
      free_pendings = next;
    }
  *listhead = 0;

  /* Install this block as the superblock
     of all blocks made since the start of this scope
     that don't have superblocks yet.  */

  opblock = 0;
  for (pblock = pending_blocks; pblock != old_blocks; pblock = pblock->next)
    {
      if (BLOCK_SUPERBLOCK (pblock->block) == 0)
        BLOCK_SUPERBLOCK (pblock->block) = block;
      opblock = pblock;
    }

  /* Record this block on the list of all blocks in the file.
     Put it after opblock, or at the beginning if opblock is 0.
     This puts the block in the list after all its subblocks.  */

  /* Allocate in the symbol_obstack to save time.
     It wastes a little space.  */
  pblock = (struct pending_block *)
    obstack_alloc (symbol_obstack,
                   sizeof (struct pending_block));
  pblock->block = block;
  if (opblock)
    {
      pblock->next = opblock->next;
      opblock->next = pblock;
    }
  else
    {
      pblock->next = pending_blocks;
      pending_blocks = pblock;
    }
}

static struct blockvector *
make_blockvector ()
{
  register struct pending_block *next, *next1;
  register struct blockvector *blockvector;
  register int i;

  /* Count the length of the list of blocks.  */

  for (next = pending_blocks, i = 0; next; next = next->next, i++);

  blockvector = (struct blockvector *)
    obstack_alloc (symbol_obstack,
                   (sizeof (struct blockvector)
                    + (i - 1) * sizeof (struct block *)));

  /* Copy the blocks into the blockvector.
     This is done in reverse order, which happens to put
     the blocks into the proper order (ascending starting address).
     finish_block has hair to insert each block into the list
     after its subblocks in order to make sure this is true.  */

  BLOCKVECTOR_NBLOCKS (blockvector) = i;
  for (next = pending_blocks; next; next = next->next)
    BLOCKVECTOR_BLOCK (blockvector, --i) = next->block;

#if 0 /* Now we make the links in the obstack, so don't free them.  */
  /* Now free the links of the list, and empty the list.  */

  for (next = pending_blocks; next; next = next1)
    {
      next1 = next->next;
      free (next);
    }
#endif
  pending_blocks = 0;

  return blockvector;
}
\f
/* Manage the vector of line numbers.  */

static void
record_line (line, pc)
     int line;
     CORE_ADDR pc;
{
  struct linetable_entry *e;
  /* Ignore the dummy line number in libg.o */

  if (line == 0xffff)
    return;

  /* Make sure line vector is big enough.  */

  if (line_vector_index + 1 >= line_vector_length)
    {
      line_vector_length *= 2;
      line_vector = (struct linetable *)
        xrealloc (line_vector,
                  (sizeof (struct linetable)
                   + line_vector_length * sizeof (struct linetable_entry)));
      current_subfile->line_vector = line_vector;
    }

  e = line_vector->item + line_vector_index++;
  e->line = line; e->pc = pc;
}
\f
/* Start a new symtab for a new source file.
   This is called when a dbx symbol of type N_SO is seen;
   it indicates the start of data for one original source file.  */

static void
start_symtab (name, start_addr)
     char *name;
     CORE_ADDR start_addr;
{
  register struct symtab *s;

  last_source_file = name;
  last_source_start_addr = start_addr;
  file_symbols = 0;
  global_symbols = 0;
  within_function = 0;

  /* Context stack is initially empty, with room for 10 levels.  */
  context_stack
    = (struct context_stack *) xxmalloc (10 * sizeof (struct context_stack));
  context_stack_size = 10;
  context_stack_depth = 0;

  new_object_header_files ();

  for (s = symseg_chain; s; s = s->next)
    if (s->ldsymoff == symnum * sizeof (struct nlist))
      break;
  current_symseg = s;
  if (s != 0)
    return;

  type_vector_length = 160;
  type_vector = (struct typevector *)
    xxmalloc (sizeof (struct typevector)
              + type_vector_length * sizeof (struct type *));
  bzero (type_vector->type, type_vector_length * sizeof (struct type *));

  /* Initialize the list of sub source files with one entry
     for this file (the top-level source file).  */

  subfiles = 0;
  current_subfile = 0;
  start_subfile (name);

  /* Set default for compiler to pcc; assume that we aren't processing
     a gcc compiled file until proved otherwise.  */

  processing_gcc_compilation = 0;
}

/* Handle an N_SOL symbol, which indicates the start of
   code that came from an included (or otherwise merged-in)
   source file with a different name.  */

static void
start_subfile (name)
     char *name;
{
  register struct subfile *subfile;

  /* Save the current subfile's line vector data.  */

  if (current_subfile)
    {
      current_subfile->line_vector_index = line_vector_index;
      current_subfile->line_vector_length = line_vector_length;
      current_subfile->prev_line_number = prev_line_number;
    }

  /* See if this subfile is already known as a subfile of the
     current main source file.  */

  for (subfile = subfiles; subfile; subfile = subfile->next)
    {
      if (!strcmp (subfile->name, name))
        {
          line_vector = subfile->line_vector;
          line_vector_index = subfile->line_vector_index;
          line_vector_length = subfile->line_vector_length;
          prev_line_number = subfile->prev_line_number;
          current_subfile = subfile;
          return;
        }
    }

  /* This subfile is not known.  Add an entry for it.  */

  line_vector_index = 0;
  line_vector_length = 1000;
  prev_line_number = -2;        /* Force first line number to be explicit */
  line_vector = (struct linetable *)
    xxmalloc (sizeof (struct linetable)
              + line_vector_length * sizeof (struct linetable_entry));

  /* Make an entry for this subfile in the list of all subfiles
     of the current main source file.  */

  subfile = (struct subfile *) xxmalloc (sizeof (struct subfile));
  subfile->next = subfiles;
  subfile->name = savestring (name, strlen (name));
  subfile->line_vector = line_vector;
  subfiles = subfile;
  current_subfile = subfile;
}

/* Finish the symbol definitions for one main source file,
   close off all the lexical contexts for that file
   (creating struct block's for them), then make the struct symtab
   for that file and put it in the list of all such.

   END_ADDR is the address of the end of the file's text.  */

static void
end_symtab (end_addr)
     CORE_ADDR end_addr;
{
  register struct symtab *symtab;
  register struct blockvector *blockvector;
  register struct subfile *subfile;
  register struct linetable *lv;
  struct subfile *nextsub;

  if (current_symseg != 0)
    {
      last_source_file = 0;
      current_symseg = 0;
      return;
    }

  /* Finish the lexical context of the last function in the file;
     pop the context stack.  */

  if (context_stack_depth > 0)
    {
      register struct context_stack *cstk;
      context_stack_depth--;
      cstk = &context_stack[context_stack_depth];
      /* Make a block for the local symbols within.  */
      finish_block (cstk->name, &local_symbols, cstk->old_blocks,
                    cstk->start_addr, end_addr);
    }

  /* Finish defining all the blocks of this symtab.  */
  finish_block (0, &file_symbols, 0, last_source_start_addr, end_addr);
  finish_block (0, &global_symbols, 0, last_source_start_addr, end_addr);
  blockvector = make_blockvector ();

  current_subfile->line_vector_index = line_vector_index;

  /* Now create the symtab objects proper, one for each subfile.  */
  /* (The main file is one of them.)  */

  for (subfile = subfiles; subfile; subfile = nextsub)
    {
      symtab = (struct symtab *) xxmalloc (sizeof (struct symtab));
      symtab->free_ptr = 0;

      /* Fill in its components.  */
      symtab->blockvector = blockvector;
      type_vector->length = type_vector_length;
      symtab->typevector = type_vector;
      symtab->free_code = free_linetable;
      if (subfile->next == 0)
        symtab->free_ptr = (char *) type_vector;

      symtab->filename = subfile->name;
      lv = subfile->line_vector;
      lv->nitems = subfile->line_vector_index;
      symtab->linetable = (struct linetable *)
        xrealloc (lv, (sizeof (struct linetable)
                       + lv->nitems * sizeof (struct linetable_entry)));
      symtab->nlines = 0;
      symtab->line_charpos = 0;

      /* Link the new symtab into the list of such.  */
      symtab->next = symtab_list;
      symtab_list = symtab;

      nextsub = subfile->next;
      free (subfile);
    }

  type_vector = 0;
  type_vector_length = -1;
  line_vector = 0;
  line_vector_length = -1;
  last_source_file = 0;
}
\f
#ifdef N_BINCL

/* Handle the N_BINCL and N_EINCL symbol types
   that act like N_SOL for switching source files
   (different subfiles, as we call them) within one object file,
   but using a stack rather than in an arbitrary order.  */

struct subfile_stack
{
  struct subfile_stack *next;
  char *name;
  int prev_index;
};

struct subfile_stack *subfile_stack;

static void
push_subfile ()
{
  register struct subfile_stack *tem
    = (struct subfile_stack *) xxmalloc (sizeof (struct subfile_stack));

  tem->next = subfile_stack;
  subfile_stack = tem;
  if (current_subfile == 0 || current_subfile->name == 0)
    abort ();
  tem->name = current_subfile->name;
  tem->prev_index = header_file_prev_index;
}

static char *
pop_subfile ()
{
  register char *name;
  register struct subfile_stack *link = subfile_stack;

  if (link == 0)
    abort ();

  name = link->name;
  subfile_stack = link->next;
  header_file_prev_index = link->prev_index;
  free (link);

  return name;
}
#endif /* Have N_BINCL */
\f
/* Accumulate the misc functions in bunches of 127.
   At the end, copy them all into one newly allocated structure.  */

#define MISC_BUNCH_SIZE 127

struct misc_bunch
{
  struct misc_bunch *next;
  struct misc_function contents[MISC_BUNCH_SIZE];
};

/* Bunch currently being filled up.
   The next field points to chain of filled bunches.  */

static struct misc_bunch *misc_bunch;

/* Number of slots filled in current bunch.  */

static int misc_bunch_index;

/* Total number of misc functions recorded so far.  */

static int misc_count;

static void
init_misc_functions ()
{
  misc_count = 0;
  misc_bunch = 0;
  misc_bunch_index = MISC_BUNCH_SIZE;
}

static void
record_misc_function (name, address)
     char *name;
     CORE_ADDR address;
{
  register struct misc_bunch *new;

  if (misc_bunch_index == MISC_BUNCH_SIZE)
    {
      new = (struct misc_bunch *) xxmalloc (sizeof (struct misc_bunch));
      misc_bunch_index = 0;
      new->next = misc_bunch;
      misc_bunch = new;
    }
  misc_bunch->contents[misc_bunch_index].name = name;
  misc_bunch->contents[misc_bunch_index].address = address;
  misc_bunch_index++;
  misc_count++;
}

static int
compare_misc_functions (fn1, fn2)
     struct misc_function *fn1, *fn2;
{
  /* Return a signed result based on unsigned comparisons
     so that we sort into unsigned numeric order.  */
  if (fn1->address < fn2->address)
    return -1;
  if (fn1->address > fn2->address)
    return 1;
  return 0;
}

static void
discard_misc_bunches ()
{
  register struct misc_bunch *next;

  while (misc_bunch)
    {
      next = misc_bunch->next;
      free (misc_bunch);
      misc_bunch = next;
    }
}

/* INCLINK nonzero means bunches are from an incrementally-linked file.
   Add them to the existing bunches.
   Otherwise INCLINK is zero, and we start from scratch. */
static void
condense_misc_bunches (inclink)
     int inclink;
{
  register int i, j;
  register struct misc_bunch *bunch;
#ifdef NAMES_HAVE_UNDERSCORE
  int offset = 1;
#else
  int offset = 0;
#endif

  if (inclink)
    {
      misc_function_vector
        = (struct misc_function *)
          xrealloc (misc_function_vector, (misc_count + misc_function_count)
                    * sizeof (struct misc_function));
      j = misc_function_count;
    }
  else
    {
      misc_function_vector
        = (struct misc_function *)
          xxmalloc (misc_count * sizeof (struct misc_function));
      j = 0;
    }
  
  bunch = misc_bunch;
  while (bunch)
    {
      for (i = 0; i < misc_bunch_index; i++)
        {
          misc_function_vector[j] = bunch->contents[i];
          misc_function_vector[j].name
            = obconcat (misc_function_vector[j].name
                        + (misc_function_vector[j].name[0] == '_' ? offset : 0),
                        "", "");
          j++;
        }
      bunch = bunch->next;
      misc_bunch_index = MISC_BUNCH_SIZE;
    }

  if (inclink)
    misc_function_count += misc_count;
  else
    misc_function_count = j;

  /* Sort the misc functions by address.  */

  qsort (misc_function_vector, misc_function_count, 
         sizeof (struct misc_function),
         compare_misc_functions);
}
\f
/* Call sort_syms to sort alphabetically
   the symbols of each block of each symtab.  */

static int
compare_symbols (s1, s2)
     struct symbol **s1, **s2;
{
  register int namediff;

  /* Compare the initial characters.  */
  namediff = SYMBOL_NAME (*s1)[0] - SYMBOL_NAME (*s2)[0];
  if (namediff != 0) return namediff;

  /* If they match, compare the rest of the names.  */
  namediff = strcmp (SYMBOL_NAME (*s1), SYMBOL_NAME (*s2));
  if (namediff != 0) return namediff;

  /* For symbols of the same name, registers should come first.  */
  return ((SYMBOL_CLASS (*s2) == LOC_REGISTER)
          - (SYMBOL_CLASS (*s1) == LOC_REGISTER));
}

static void sort_symtab_syms ();

static void
sort_syms ()
{
  register struct symtab *s;

  for (s = symtab_list; s; s = s->next)
    sort_symtab_syms (s);
}

static void
sort_symtab_syms (s)
     register struct symtab *s;
{
  register struct blockvector *bv = BLOCKVECTOR (s);
  int nbl = BLOCKVECTOR_NBLOCKS (bv);
  int i;
  register struct block *b;

  /* Note that in the following sort, we always make sure that
     register debug symbol declarations always come before regular
     debug symbol declarations (as might happen when parameters are
     then put into registers by the compiler).  We do this by a
     correct compare in compare_symbols, and by the reversal of the
     symbols if we don't sort.  This works as long as a register debug
     symbol always comes after a parameter debug symbol. */

  /* This is no longer necessary; lookup_block_symbol now always
     prefers some other declaration over a parameter declaration.  We
     still sort the thing (that is necessary), but we don't reverse it
     if we shouldn't sort it.  */

  for (i = 0; i < nbl; i++)
    {
      b = BLOCKVECTOR_BLOCK (bv, i);
      if (BLOCK_SHOULD_SORT (b))
        qsort (&BLOCK_SYM (b, 0), BLOCK_NSYMS (b),
               sizeof (struct symbol *), compare_symbols);
    }
}
  
\f
extern struct symtab *psymtab_to_symtab ();

/* This is the symbol-file command.  Read the file, analyze its symbols,
   and add a struct symtab to symtab_list.  */

void
symbol_file_command (name)
     char *name;
{
  register int desc;
  DECLARE_FILE_HEADERS;
  struct nlist *nlist;
  char *stringtab;
  long buffer;
  register int val;
  extern void close ();
  struct cleanup *old_chain;
  struct symtab *symseg;
  struct stat statbuf;

  dont_repeat ();

  if (name == 0)
    {
      if ((symtab_list || partial_symtab_list)
          && !query ("Discard symbol table? ", 0))
        error ("Not confirmed.");
      if (symfile)
        free (symfile);
      symfile = 0;
      free_all_symtabs ();
      free_all_psymtabs ();
      return;
    }

  if ((symtab_list || partial_symtab_list)
      && !query ("Load new symbol table from \"%s\"? ", name))
    error ("Not confirmed.");

  {
    char *absolute_name;
    desc = openp (getenv ("PATH"), 1, name, O_RDONLY, 0, &absolute_name);
    if (desc < 0)
      perror_with_name (name);
    else
      name = absolute_name;
  }

  old_chain = make_cleanup (close, desc);
  make_cleanup (free_current_contents, &name);

  READ_FILE_HEADERS (desc, name);

  if (NUMBER_OF_SYMBOLS == 0)
    {
      if (symfile)
        free (symfile);
      symfile = 0;
      free_all_symtabs ();
      free_all_psymtabs ();
      printf ("%s has no symbol-table; symbols discarded.\n", name);
      fflush (stdout);
      do_cleanups (old_chain);
      return;
    }

  printf ("Reading symbol data from %s...", name);
  fflush (stdout);

  /* Now read the string table, all at once.  */
  val = lseek (desc, STRING_TABLE_OFFSET, 0);
  if (val < 0)
    perror_with_name (name);
  stat (name, &statbuf);
  READ_STRING_TABLE_SIZE (buffer);
  if (buffer >= 0 && buffer < statbuf.st_size)
    stringtab = (char *) alloca (buffer);
  else
    stringtab = NULL;
  if (stringtab == NULL)
    error ("ridiculous string table size: %d bytes", name, buffer);

  bcopy (&buffer, stringtab, sizeof buffer);
  val = myread (desc, stringtab + sizeof buffer, buffer - sizeof buffer);
  if (val < 0)
    perror_with_name (name);

  /* Throw away the old symbol table.  */

  if (symfile)
    free (symfile);
  symfile = 0;
  free_all_symtabs ();
  free_all_psymtabs ();

  /* Empty the hash table of global syms looking for values.  */
  bzero (global_sym_chain, sizeof global_sym_chain);

#ifdef READ_GDB_SYMSEGS
  /* That puts us at the symsegs.  Read them.  */
  symseg_chain = read_symsegs (desc, name);
  hash_symsegs ();

  /* Free the symtabs made by read_symsegs, but not their contents,
     which have been copied into symtabs on symtab_list.  */
  for (symseg = symseg_chain; symseg; symseg = symseg->next)
    {
      int i;
      struct sourcevector *sv = (struct sourcevector *) symseg->linetable;

      for (i = 0; i < sv->length; i++)
        {
          int j;
          struct source *source = sv->source[i];
          struct symtab *sp1
            = (struct symtab *) xxmalloc (sizeof (struct symtab));

          bcopy (symseg, sp1, sizeof (struct symtab));
          sp1->filename = savestring (source->name, strlen (source->name));
          sp1->linetable = &source->contents;
          sp1->free_code = free_nothing;
          sp1->free_ptr = (i == 0) ? (char *) symseg : 0;

          sp1->next = symtab_list;
          symtab_list = sp1;
        }
    }
#else
  /* Where people are using the 4.2 ld program, must not check for
     symsegs, because that ld puts randonm garbage at the end of
     the output file and that would trigger an error message.  */
  symseg_chain = 0;
#endif

  /* Position to read the symbol table.  Do not read it all at once. */
  val = lseek (desc, SYMBOL_TABLE_OFFSET, 0);
  if (val < 0)
    perror_with_name (name);

  /* Don't put these on the cleanup chain; they need to stick around
     until the next call to symbol_file_command.  *Then* we'll free
     them. */
  free_header_files ();
  init_header_files ();

  init_misc_functions ();
  make_cleanup (discard_misc_bunches, 0);

  free_pendings = 0;
  pending_blocks = 0;
  file_symbols = 0;
  global_symbols = 0;
  make_cleanup (really_free_pendings, 0);

  /* Now that the symbol table data of the executable file are all in core,
     process them and define symbols accordingly.  Closes desc.  */

  read_dbx_symtab (desc, stringtab, NUMBER_OF_SYMBOLS, 0, 0, 0);

  /* Go over the misc functions and install them in vector.  */

  condense_misc_bunches (0);

  /* Don't allow char * to have a typename (else would get caddr_t.)  */

  TYPE_NAME (lookup_pointer_type (builtin_type_char)) = 0;

  /* Make a default for file to list.  */

  symfile = savestring (name, strlen (name));

  /* Call to select_source_symtab used to be here; it was using too
     much time.  I'll make sure that list_sources can handle the lack
     of current_source_symtab */

  do_cleanups (old_chain);      /* Descriptor closed here */

  /* Free the symtabs made by read_symsegs, but not their contents,
     which have been copied into symtabs on symtab_list.  */
  while (symseg_chain)
    {
      register struct symtab *s = symseg_chain->next;
      free (symseg_chain);
      symseg_chain = s;
    }

  if (!partial_symtab_list)
    printf ("\n(no debugging symbols found)...");

  printf ("done.\n");
  fflush (stdout);
}

/* Return name of file symbols were loaded from, or 0 if none..  */

char *
get_sym_file ()
{
  return symfile;
}
\f
/* Buffer for reading the symbol table entries.  */
static struct nlist symbuf[4096];
static int symbuf_idx;
static int symbuf_end;

/* I/O descriptor for reading the symbol table.  */
static int symtab_input_desc;

/* The address of the string table
   of the object file we are reading (as copied into core).  */
static char *stringtab_global;

/* Refill the symbol table input buffer
   and set the variables that control fetching entries from it.
   Reports an error if no data available.
   This function can read past the end of the symbol table
   (into the string table) but this does no harm.  */

static int
fill_symbuf ()
{
  int nbytes = myread (symtab_input_desc, symbuf, sizeof (symbuf));
  if (nbytes <= 0)
    error ("error or end of file reading symbol table");
  symbuf_end = nbytes / sizeof (struct nlist);
  symbuf_idx = 0;
  return 1;
}

/* dbx allows the text of a symbol name to be continued into the
   next symbol name!  When such a continuation is encountered
   (a \ at the end of the text of a name)
   call this function to get the continuation.  */

static char *
next_symbol_text ()
{
  if (symbuf_idx == symbuf_end)
    fill_symbuf ();
  symnum++;
  return symbuf[symbuf_idx++].n_un.n_strx + stringtab_global;
}
\f
/*
 * Initializes storage for all of the partial symbols that will be
 * created by read_dbx_symtab and subsidiaries.
 */
void 
init_psymbol_list (total_symbols)
     int total_symbols;
{
  /* Current best guess is that there are approximately a twentieth
     of the total symbols (in a debugging file) are global or static
     oriented symbols */
  global_psymbols_allocated = total_symbols / 10;
  static_psymbols_allocated = total_symbols / 10;
  next_ps_global = global_psymbols = (struct partial_symbol *)
    xmalloc (global_psymbols_allocated * sizeof (struct partial_symbol));
  next_ps_static = static_psymbols = (struct partial_symbol *)
    xmalloc (static_psymbols_allocated * sizeof (struct partial_symbol));
}

/*
 * Initialize the list of bincls to contain none and have some
 * allocated.
 */
static void
init_bincl_list (number)
     int number;
{
  bincls_allocated = number;
  next_bincl = bincl_list = (struct header_file_location *)
      xmalloc (bincls_allocated * sizeof(struct header_file_location));
}

/*
 * Add a bincl to the list.
 */
static void
add_bincl_to_list (pst, name, instance)
     struct partial_symtab *pst;
     char *name;
     int instance;
{
  if (next_bincl >= bincl_list + bincls_allocated)
    {
      int offset = next_bincl - bincl_list;
      bincls_allocated *= 2;
      bincl_list = (struct header_file_location *)
        xrealloc (bincl_list,
                  bincls_allocated * sizeof (struct header_file_location));
      next_bincl = bincl_list + offset;
    }
  next_bincl->pst = pst;
  next_bincl->instance = instance;
  next_bincl++->name = name;
}

/*
 * Given a name, value pair, find the corresponding
 * bincl in the list.  Return the partial symtab associated
 * with that header_file_location.
 */
struct partial_symtab *
find_corresponding_bincl_psymtab (name, instance)
     char *name;
     int instance;
{
  struct header_file_location *bincl;

  for (bincl = bincl_list; bincl < next_bincl; bincl++)
    if (bincl->instance == instance
        && !strcmp (name, bincl->name))
      return bincl->pst;

  return (struct partial_symtab *) 0;
}

/*
 * Free the storage allocated for the bincl list.
 */
static void
free_bincl_list ()
{
  free (bincl_list);
  bincls_allocated = 0;
}

static struct partial_symtab *start_psymtab ();
static void add_psymtab_dependency ();
static void end_psymtab();

/* Given pointers to an a.out symbol table in core containing dbx
   style data, setup partial_symtab's describing each source file for
   which debugging information is available.  NLISTLEN is the number
   of symbols in the symbol table.  All symbol names are given as
   offsets relative to STRINGTAB.

   I have no idea whether or not this routine should be setup to deal
   with inclinks.  It seems reasonable to me that they be dealt with
   standardly, so I am not going to make a strong effort to deal with
   them here.
   */

static void process_symbol_for_psymtab ();

static void
read_dbx_symtab (desc, stringtab, nlistlen, inclink, text_addr, text_size)
     int desc;
     register char *stringtab;
     register int nlistlen;
     int inclink;
     unsigned text_addr;
     int text_size;
{
  register char *namestring;
  register struct symbol *sym, *prev;
  int hash;
  int num_object_files = 0;
  int past_first_source_file = 0;
  struct cleanup *old_chain;
  int current_text_start, current_file_symbol_start;
  struct pending *global_symbols, *static_symbols;
  int nsl;                      /* Length of namestring, when needed */

  /* Current partial symtab */
  struct partial_symtab *pst;

  /* List of current psymtab's include files */
  char **psymtab_include_list;
  int includes_allocated;
  int includes_used;

  /* Index within current psymtab dependency list */
  struct partial_symtab **dependency_list;
  int dependencies_used, dependencies_allocated;

  /* Setup a define to deal cleanly with the underscore problem */
  
#ifdef NAMES_HAVE_UNDERSCORE
#define HASH_OFFSET 1
#else
#define HASH_OFFSET 0
#endif

  global_symbols = static_symbols =
    (struct pending *) 0;
  pst = (struct partial_symtab *) 0;

  includes_allocated = 30;
  includes_used = 0;
  psymtab_include_list = (char **) alloca (includes_allocated *
                                           sizeof (char *));

  dependencies_allocated = 30;
  dependencies_used = 0;
  dependency_list =
    (struct partial_symtab **) alloca (dependencies_allocated *
                                       sizeof (struct partial_symtab *));

  old_chain = make_cleanup (free_all_psymtabs, 0);

  /* Init bincl list */
  init_bincl_list (20);
  make_cleanup (free_bincl_list, 0);

  /* Setup global partial symbol list */
  init_psymbol_list (nlistlen);

  last_source_file = 0;
  
#ifdef END_OF_TEXT_DEFAULT
  end_of_text_addr = END_OF_TEXT_DEFAULT;
#endif
  
  symtab_input_desc = desc;     /* This is needed for fill_symbuf below */
  symbuf_end = symbuf_idx = 0;
  
  for (symnum = 0; symnum < nlistlen; symnum++)
    {
      struct nlist *bufp;
      unsigned char type;
      
      /* Get the symbol for this run and pull out some info */
      QUIT;     /* allow this to be interruptable */
      if (symbuf_idx == symbuf_end)
        fill_symbuf ();
      bufp = &symbuf[symbuf_idx++];
      type = bufp->n_type;

      /*
       * Special cases to speed up readin.
       */
      if (type == N_SLINE) continue;
      
      namestring = bufp->n_un.n_strx ? bufp->n_un.n_strx + stringtab : "";

      switch (type)
        {
          /*
           * Standard, non-debugger, symbols
           */

        case N_TEXT | N_EXT:
          /* Catch etext */

          if (!strcmp (namestring, "_etext"))
            end_of_text_addr = bufp->n_value;
          /* Fall through */

#ifdef N_NBTEXT
        case N_NBTEXT | N_EXT:
#endif
#ifdef N_NBDATA
        case N_NBDATA | N_EXT:
#endif
#ifdef N_NBBSS
        case N_NBBSS | N_EXT:
#endif
        case N_ABS | N_EXT:
        case N_DATA | N_EXT:
        case N_BSS | N_EXT:
          /* Figure out beginning and end of global linker symbol
             section and put non-debugger specified symbols on
             tmp_symchain */
          
          last_global_sym = symnum;
          if (!first_global_sym) first_global_sym = symnum;
          
          record_misc_function (namestring, bufp->n_value); /* Always */

          continue;

#ifdef N_NBTEXT
        case N_NBTEXT:
#endif
        case N_TEXT:
          if (!strcmp (namestring + strlen (namestring) - 2, ".o")
              || !strncmp (namestring, "-l", 2))
            {
              if (num_object_files++ == 1)
                first_object_file_end = bufp->n_value;
              if (past_first_source_file && pst)
                {
                  end_psymtab (pst, psymtab_include_list, includes_used,
                               symnum * sizeof (struct nlist), bufp->n_value,
                               dependency_list, dependencies_used,
                               next_ps_global, next_ps_static);
                  pst = (struct partial_symtab *) 0;
                  includes_used = 0;
                  dependencies_used = 0;
                }
              else
                past_first_source_file = 1;
            }
          continue;
              
        case N_UNDF:
        case N_UNDF | N_EXT:
        case N_ABS:
        case N_DATA:
        case N_BSS:
#ifdef N_NBDATA
        case N_NBDATA:
#endif
#ifdef N_NBBSS
        case N_NBBSS:
#endif
        case N_FN:
          /* Keep going . . .*/
          
          /*
           * Special symbol types for GNU
           */
#ifdef N_INDR
        case N_INDR:
        case N_INDR | N_EXT:
#endif
#ifdef N_SETA
        case N_SETA:
        case N_SETA | N_EXT:
        case N_SETT:
        case N_SETT | N_EXT:
        case N_SETD:
        case N_SETD | N_EXT:
        case N_SETB:
        case N_SETB | N_EXT:
        case N_SETV:
        case N_SETV | N_EXT:
#endif
          continue;
          
          /*
           * Debugger symbols
           */

        case N_SO:
          /* End the current partial symtab and start a new one */

          if (past_first_source_file && pst)
            {
              end_psymtab (pst, psymtab_include_list, includes_used,
                           symnum * sizeof (struct nlist), bufp->n_value,
                           dependency_list, dependencies_used,
                           next_ps_global, next_ps_static);
              pst = (struct partial_symtab *) 0;
              includes_used = 0;
              dependencies_used = 0;
            }
          else
            past_first_source_file = 1;
          
          pst = start_psymtab (namestring, bufp->n_value,
                               symnum * sizeof (struct nlist),
                               next_ps_global, next_ps_static);
          
          continue;

#ifdef N_BINCL
        case N_BINCL:
          /* Add this bincl to the bincl_list for future EXCLs.  No
             need to save the string; it'll be around until
             read_dbx_symtab function return */
          add_bincl_to_list (pst, namestring, bufp->n_value);

          /* Fall through */
#endif

        case N_SOL:
          /* Mark down an include file in the current psymtab */

          psymtab_include_list[includes_used++] = namestring;
          if (includes_used >= includes_allocated)
            {
              char **orig = psymtab_include_list;

              psymtab_include_list = (char **)
                alloca ((includes_allocated *= 2) *
                        sizeof (char *));
              bcopy (orig, psymtab_include_list,
                     includes_used * sizeof (char *));
#ifdef DEBUG_INFO
              fprintf (stderr, "Had to realloc includes.  New size: %d\n",
                       includes_allocated);
#endif        
            }
          continue;

        case N_FUN:
        case N_SSYM:
        case N_GSYM:
        case N_LSYM:
        case N_STSYM:
        case N_LCSYM:
        case N_ENTRY:
#ifdef N_MAIN
        case N_MAIN:
#endif
#ifdef N_BSLINE
        case N_BSLINE:
#endif
        case N_PC:
#ifdef N_M2C
        case N_M2C:
        case N_SCOPE:
#endif
          /* Process a symbol as appropriate for the type (this
             information is contained in the name of the symbol) */

          if (namestring[0] != '\0')
#if 1       
            process_symbol_for_psymtab (namestring);
#else
            process_symbol_for_psymtab (namestring, tmp_symchain);
#endif    
          continue;

#ifdef N_BINCL
        case N_EXCL:
          /* Find the corresponding bincl and mark that psymtab on the
             psymtab dependency list */
          {
            struct partial_symtab *needed_pst =
              find_corresponding_bincl_psymtab (namestring, bufp->n_value);

            /* If this include file was defined earlier in this file,
               leave it alone.  */
            if (needed_pst == pst) continue;

            if (needed_pst)
              {
                int i;
                int found = 0;
                
                for (i = 0; i < dependencies_used; i++)
                  if (dependency_list[i] == needed_pst)
                    {
                      found = 1;
                      break;
                    }

                /* If it's already in the list, skip the rest.  */
                if (found) continue;
                
                dependency_list[dependencies_used++] = needed_pst;
                if (dependencies_used >= dependencies_allocated)
                  {
                    struct partial_symtab **orig = dependency_list;
                    dependency_list =
                      (struct partial_symtab **)
                        alloca ((dependencies_allocated *= 2)
                                * sizeof (struct partial_symtab *));
                    bcopy (orig, dependency_list,
                           (dependencies_used
                            * sizeof (struct partial_symtab *)));
#ifdef DEBUG_INFO
                    fprintf (stderr, "Had to reallocate dependency list.\n");
                    fprintf (stderr, "New dependencies allocated: %d\n",
                             dependencies_allocated);
#endif
                  }
              }
            else
              error ("Invalid symbol data: \"repeated\" header file not previously seen, at symtab pos %d.",
                     symnum);
          }
          continue;
          
        case N_EINCL:
#endif
#ifdef N_DSLINE
        case N_DSLINE:
#endif
        case N_LENG:
        case N_BCOMM:
        case N_ECOMM:
        case N_ECOML:
        case N_FNAME:
        case N_SLINE:
        case N_RSYM:
        case N_PSYM:
        case N_LBRAC:
        case N_RBRAC:
          /* These symbols aren't interesting; don't worry about them */

          continue;

        default:
          /* If we haven't found it yet, we've got problems */

          if (IGNORE_SYMBOL (type))
            continue;

          fatal ("Bad symbol type 0x%x encountered in gdb scan", type);
        }
    }
      
  if (last_source_file)
    {
      end_psymtab (pst, psymtab_include_list, includes_used,
                   symnum * sizeof (struct nlist), end_of_text_addr,
                   dependency_list, dependencies_used,
                   next_ps_global, next_ps_static);
      includes_used = 0;
      dependencies_used = 0;
      pst = (struct partial_symtab *) 0;
    }
  
  free_bincl_list ();
  discard_cleanups (old_chain);
}

/*
 * Take a single symbol (name: NAME) and process it (add it to the
 * app psymbol list or not).
 */
static void
process_symbol_for_psymtab (name)
     char *name;
{
  char *p = (char *) index(name, ':') + 1;
  int deftype;
  struct partial_symbol *sym;
  enum { T_IGNORE, T_STATIC, T_GLOBAL } symbol_type;
  enum namespace ns = UNDEF_NAMESPACE;
  enum address_class class;
  int hash;

  if (p == (char *) 0x1)
    /* No ":" ; I guess it's not a debuggging symbol */
    return;

  if ((*p >= '0' && *p <= '9') || *p == '(')
    deftype = 'l';
  else
    deftype = *p;
  
  /* Figure out how to handle this symbol */
  switch (deftype)
    {
      /* T is a struct/union/enum, t is a typedef */
    case 'T':
      symbol_type = T_STATIC;
      ns = STRUCT_NAMESPACE;
      class = LOC_TYPEDEF;
      break;
    case 't':
      symbol_type = T_STATIC;
      ns = VAR_NAMESPACE;
      class = LOC_TYPEDEF;
      break;
    case 'c':
      symbol_type = T_STATIC;
      ns = VAR_NAMESPACE;
      class = LOC_CONST;
      break;
    case 'S':
      symbol_type = T_STATIC;
      ns = VAR_NAMESPACE;
      class = LOC_STATIC;
      break;
    case 'f':
      symbol_type = T_STATIC;
      ns = VAR_NAMESPACE;
      class = LOC_BLOCK;
      break;
    case 'F':
      symbol_type = T_GLOBAL;
      ns = VAR_NAMESPACE;
      class = LOC_BLOCK;
      break;
    case 'G':
      symbol_type = T_GLOBAL;
      ns = VAR_NAMESPACE;
      class = LOC_STATIC;
      break;
    default:
      return;
    }
  
  /* Create the symbol and store it on the list */
  /* There's a better algorithm possible for the allocation; figure
     out how far through the symbol table we are and do a reestimate */
  if (symbol_type == T_STATIC)
    {
      if (next_ps_static >= static_psymbols + static_psymbols_allocated)
        {
          static_psymbols = (struct partial_symbol *)
            xrealloc (static_psymbols,
                      (static_psymbols_allocated * 2
                       * sizeof (struct partial_symbol)));
          /* Next assumes we only went one over.  Should be good if
             program works correctly */
          next_ps_static = static_psymbols + static_psymbols_allocated;
          static_psymbols_allocated *= 2;
#ifdef DEBUGINFO
          fprintf(stderr, "debuginfo: Had to realloc statics\n");
#endif
        }
      sym = next_ps_static++;
    }
  else
    {
      if (next_ps_global >= global_psymbols + global_psymbols_allocated)
        {
          global_psymbols = (struct partial_symbol *)
            xrealloc (global_psymbols,
                      (global_psymbols_allocated * 2
                       * sizeof (struct partial_symbol)));
          next_ps_global = global_psymbols + global_psymbols_allocated;
          global_psymbols_allocated *= 2;
#ifdef DEBUGINFO
          fprintf(stderr, "debuginfo: Had to realloc globals\n");
#endif
        }
      sym = next_ps_global++;
    }

  SYMBOL_NAME(sym) = (char *) obstack_alloc (psymbol_obstack,
                                             p - name);
  strncpy(SYMBOL_NAME(sym), name, p - name - 1);
  SYMBOL_NAME(sym)[p - name - 1] = '\0';
  SYMBOL_NAMESPACE(sym) = ns;
  SYMBOL_CLASS(sym) = class;
}
#undef HASH_OFFSET

/*
 * Allocate and partially fill a partial symtab.  It will be
 * completely filled at the end of the symbol list.
 */
static struct partial_symtab *
start_psymtab (filename, textlow, ldsymoff, global_syms, static_syms)
     char *filename;
     int textlow;
     int ldsymoff;
     struct partial_symbol *global_syms;
     struct partial_symbol *static_syms;
{
  struct partial_symtab *result =
    (struct partial_symtab *) obstack_alloc (psymbol_obstack,
                                             sizeof (struct partial_symtab));
  
  result->filename =
    (char *) obstack_alloc (psymbol_obstack,
                            strlen (filename) + 1);
  strcpy (result->filename, filename);
              
  result->textlow = textlow;
  result->ldsymoff = ldsymoff;

  result->readin = 0;

  result->globals_offset = global_syms - global_psymbols;
  result->statics_offset = static_syms - static_psymbols;

  result->n_global_syms = 0;
  result->n_static_syms = 0;

  return result;
}

static int
compare_psymbols (s1, s2)
     register struct partial_symbol *s1, *s2;
{
  register char
    *st1 = SYMBOL_NAME (s1),
    *st2 = SYMBOL_NAME (s2);

  return (st1[0] - st2[0] ? st1[0] - st2[0] :
          strcmp (st1 + 1, st2 + 1));
}

  
/* Close off the current usage of a partial_symbol table entry.  This
   involves setting the correct number of includes (with a realloc),
   setting the high text mark, setting the symbol length in the
   executable, and setting the length of the global and static lists
   of psymbols.

   The global symbols and static symbols are then seperately sorted.

   Then the partial symtab is put on the global list.
   *** List variables and peculiarities of same. ***
   */
static void
end_psymtab (pst, include_list, num_includes, capping_symbol_offset,
             capping_text, dependency_list, number_dependencies,
             capping_global, capping_static)
     struct partial_symtab *pst;
     char **include_list;
     int num_includes;
     int capping_symbol_offset;
     int capping_text;
     struct partial_symtab **dependency_list;
     int number_dependencies;
     struct partial_symbol *capping_global, *capping_static;
{
  int i;

  pst->ldsymlen = capping_symbol_offset - pst->ldsymoff;
  pst->texthigh = capping_text;

  pst->n_global_syms =
    capping_global - (global_psymbols + pst->globals_offset);
  pst->n_static_syms =
    capping_static - (static_psymbols + pst->statics_offset);

  pst->dependencies = (struct partial_symtab **)
    obstack_alloc (psymbol_obstack,
                   number_dependencies * sizeof (struct partial_symtab *));
  bcopy (dependency_list, pst->dependencies,
         number_dependencies * sizeof (struct partial_symtab *));
  pst->number_of_dependencies = number_dependencies;

  for (i = 0; i < num_includes; i++)
    {
      /* Eventually, put this on obstack */
      struct partial_symtab *subpst =
        (struct partial_symtab *)
          obstack_alloc (psymbol_obstack,
                         sizeof (struct partial_symtab));

      subpst->filename =
        (char *) obstack_alloc (psymbol_obstack,
                                strlen (include_list[i]) + 1);
      strcpy (subpst->filename, include_list[i]);

      subpst->ldsymoff =
        subpst->ldsymlen =
          subpst->textlow =
            subpst->texthigh = 0;
      subpst->readin = 0;

      subpst->dependencies = (struct partial_symtab **)
        obstack_alloc (psymbol_obstack,
                       sizeof (struct partial_symtab *));
      subpst->dependencies[0] = pst;
      subpst->number_of_dependencies = 1;

      subpst->globals_offset =
        subpst->n_global_syms =
          subpst->statics_offset =
            subpst->n_static_syms = 0;

      subpst->next = partial_symtab_list;
      partial_symtab_list = subpst;
    }
  
  /* Sort the global list; don't sort the static list */
  qsort (global_psymbols + pst->globals_offset, pst->n_global_syms,
         sizeof (struct partial_symbol), compare_psymbols);

  /* Put the psymtab on the psymtab list */
  pst->next = partial_symtab_list;
  partial_symtab_list = pst;
}
\f
/*
 * Read in all of the symbols for a given psymtab for real.  Return
 * the value of the symtab you create.  Do not free the storage
 * allocated to the psymtab; it may have pointers to it.
 */
static void scan_file_globals ();
static void read_ofile_symtab ();

struct symtab *
psymtab_to_symtab(pst)
     struct partial_symtab *pst;
{
  int desc;
  DECLARE_FILE_HEADERS;
  char *stringtab;
  struct partial_symtab **list_patch;
  int stsize, val;
  struct stat statbuf;
  struct cleanup *old_chain;
  extern void close ();
  int i;
  struct symtab *result;
  char *name = symfile;         /* Some of the macros require the */
                                /* variable "name" to be defined in */
                                /* the context in which they execute */
                                /* (Yech!)  */

  if (!pst)
    return 0;

  if (pst->readin)
    {
      fprintf (stderr, "Psymtab for %s already read in.  Shouldn't happen.\n",
               pst->filename);
      return 0;
    }
  
  if (!name)
    error("No symbol file currently specified; use command symbol-file");

  /* Read in all partial symbtabs on which this one is dependent */
  for (i = 0; i < pst->number_of_dependencies; i++)
    if (!pst->dependencies[i]->readin)
      psymtab_to_symtab (pst->dependencies[i]);

  if (pst->ldsymlen)            /* Otherwise it's a dummy */
    {
      /* Open symbol file and read in string table */
      stat (name, &statbuf);
      desc = open(name, O_RDONLY, 0); /* symbol_file_command
                                         guarrantees that the symbol file name
                                         will be absolute, so there is no
                                         need for openp */
      
      old_chain = make_cleanup (close, desc);
      
      if (desc < 0)
        error("Symbol file not readable");
      
      READ_FILE_HEADERS (desc, name);
      
      /* Read in the string table */
      lseek (desc, STRING_TABLE_OFFSET, L_SET);
      READ_STRING_TABLE_SIZE (stsize);
      if (stsize >= 0 && stsize < statbuf.st_size)
        stringtab = (char *) alloca (stsize);
      else
        stringtab = NULL;
      if (stringtab == NULL)
        error ("ridiculous string table size: %d bytes", name, stsize);
      
      bcopy (&stsize, stringtab, sizeof stsize);
      val = myread (desc, stringtab + sizeof stsize, stsize - sizeof stsize);
      if (val < 0)
        perror_with_name (name);
      
      /* Init stuff necessary for reading in symbols */
      free_pendings = 0;
      pending_blocks = 0;
      file_symbols = 0;
      global_symbols = 0;
      make_cleanup (really_free_pendings, 0);
      
      /* Read in this files symbols */
      lseek (desc, SYMBOL_TABLE_OFFSET, L_SET);
      read_ofile_symtab (desc, stringtab, pst->ldsymoff,
                         pst->ldsymlen, pst->textlow,
                         pst->texthigh - pst->textlow, 0);
      sort_symtab_syms (symtab_list); /* At beginning since just added */
      
      /* Match with global symbols */
      lseek (desc, SYMBOL_TABLE_OFFSET, L_SET);
      scan_file_globals (desc, stringtab,
                         first_global_sym * sizeof(struct nlist),
                         last_global_sym - first_global_sym + 1);
      
      do_cleanups (old_chain);
    }

  /* Find pst in list, prune it, and free it's storage */
  for (list_patch = &partial_symtab_list;
       *list_patch && *list_patch != pst;
       list_patch = &((*list_patch)->next))
    ;

  if (!(*list_patch))           /* pst not in list.  Don't worry about it? */
    fatal ("internal: psymtab_to_symtab called with non-listed pst");

  *list_patch = (*list_patch)->next; /* Prune */

  pst->readin = 1;              /* Mark as read in */

  /* It's the last one if we actually read something in */
  if (pst->ldsymlen)
    return symtab_list;
  else
    /* Search through list for correct name. */
    for (result = symtab_list; result; result = result->next)
      if (!strcmp (result->filename, pst->filename))
        return result;

  return 0;
}

/*
 * Scan through all of the global symbols defined in the object file,
 * assigning values to the debugging symbols that need to be assigned
 * to.
 *
 * DESC is the file descriptor of the symbol file, with the seek
 * pointer pointing at the beginning of the symbol table.
 * STRINGTAB is the file's string table, already read in.
 * OFFSET is the offset (in bytes) of the beginning of the global
 * symbols from the beginning of the symbol table.
 * NUMSYMS is the number of symbols that have to be checked.
 */
static void
scan_file_globals (desc, stringtab, offset, numsyms)
     int desc;
     char *stringtab;
     int offset;
     int numsyms;
{
  int hash;

  lseek(desc, offset, L_INCR);
  symtab_input_desc = desc;
  symbuf_end = symbuf_idx = 0;

  for (symnum = 0; symnum < numsyms; symnum++)
    {
      struct nlist *bufp;
      unsigned char type;
      char *namestring;

      QUIT;
      if (symbuf_idx == symbuf_end)
        fill_symbuf ();

      bufp = &symbuf[symbuf_idx++];
      type = bufp->n_type;

      if (type & N_EXT && type != N_EXT)
        {
          struct symbol *sym, *prev;
          
          namestring = bufp->n_un.n_strx ?
            bufp->n_un.n_strx + stringtab : "";
          prev = (struct symbol *) 0;

          /* Get the hash index and check all the symbols
             under that hash index. */
          
#ifdef NAMES_HAVE_UNDERSCORE
          hash = hashname (namestring + 1);
#else /* ! NAMES_HAVE_UNDERSCORE */
          hash = hashname (namestring);
#endif /* ! NAMES_HAVE_UNDERSCORE */
          for (sym = global_sym_chain[hash]; sym;)
            {
              if (
#ifdef NAMES_HAVE_UNDERSCORE
                  *namestring == '_'
                  && namestring[1] == SYMBOL_NAME (sym)[0]
                  && !strcmp(namestring + 2, SYMBOL_NAME (sym) + 1)
#else /* ! NAMES_HAVE_UNDERSCORE */
                  namestring[0] == SYMBOL_NAME (sym) [0]
                  && !strcmp(namestring + 1, SYMBOL_NAME(sym) + 1)
#endif /* ! NAMES_HAVE_UNDERSCORE */
                  )
                {
                  /* Splice this symbol out of the hash chain and
                     assign the value we have to it. */
                  if (prev)
                    SYMBOL_VALUE (prev) = SYMBOL_VALUE (sym);
                  else
                    global_sym_chain[hash]
                      = (struct symbol *) SYMBOL_VALUE (sym);
                  SYMBOL_VALUE (sym) = bufp->n_value;
                  if (prev)
                    sym = (struct symbol *) SYMBOL_VALUE (prev);
                  else
                    sym = global_sym_chain[hash];
                  break;        /* Only one reference per file */
                }
              else
                {
                  prev = sym;
                  sym = (struct symbol *) SYMBOL_VALUE (sym);
                }
            }
        }
    }
  /* There shouldn't be anything left on the hash list at this point.
     If there is, we have done something wrong.  For right now it's
     worth checking, until I get the bugs out. */
  /* Sigh.  Unfortunately, the above is not true.  If an extern
     variable is mentioned in an include file (or a program) and the
     variable is never either referenced or defined, there will be a
     debugger symbol with no "real" symbol.  Oh well. */
}
              
/*
 * Read in a defined section of a specific object file's symbols.
 *
 * DESC is the file descriptor for the file, positioned at the
 * beginning of the symtab
 * STRINGTAB is a pointer to the files string
 * table, already read in
 * SYM_OFFSET is the offset within the file of
 * the beginning of the symbols we want to read, NUM_SUMBOLS is the
 * number of symbols to read
 * TEXT_OFFSET is the offset to be added to
 * all values of symbols coming in and
 * TEXT_SIZE is the size of the text segment read in.
 * OFFSET is a flag which indicates that the value of all of the
 * symbols should be offset by TEXT_OFFSET (for the purposes of
 * incremental linking). 
 */
    
static void
read_ofile_symtab (desc, stringtab, sym_offset,
                   sym_size, text_offset, text_size, offset)
     int desc;
     register char *stringtab;
     int sym_offset;
     int sym_size;
     int text_offset;
     int text_size;
     int offset;
{
  register char *namestring;
  register struct symbol *sym, *prev;
  int hash;
  struct cleanup *old_chain;
  struct nlist *bufp;
  unsigned char type;
#ifdef N_BINCL
  subfile_stack = 0;
#endif

  stringtab_global = stringtab;
  last_source_file = 0;

  symtab_input_desc = desc;
  symbuf_end = symbuf_idx = 0;
  lseek(desc, sym_offset, L_INCR);

  fill_symbuf();
  bufp = &symbuf[symbuf_idx];
  if ((unsigned char) bufp->n_type != N_SO)
    fatal("First symbol in segment of executable not a source symbol");

  for (symnum = 0;
       symnum < sym_size / sizeof(struct nlist);
       symnum++)
    {
      QUIT;                     /* Allow this to be interruptable */
      if (symbuf_idx == symbuf_end)
        fill_symbuf();
      bufp = &symbuf[symbuf_idx++];
      type = bufp->n_type;

      if (offset &&
          (type == N_TEXT || type == N_DATA || type == N_BSS))
        bufp->n_value += text_offset;

      namestring = bufp->n_un.n_strx ? bufp->n_un.n_strx + stringtab : "";

      if (type & N_STAB)
        process_one_symbol(type, bufp->n_desc,
                           bufp->n_value, namestring);
      /* We skip checking for a new .o or -l file; that should never
         happen in this routine. */
      else if (type == N_TEXT
               && !strcmp (namestring, GCC_COMPILED_FLAG_SYMBOL))
        processing_gcc_compilation = 1;
      else if (type & N_EXT || type == N_TEXT
#ifdef N_NBTEXT
               || type == N_NBTEXT
#endif
               )
          /* Global symbol: see if we came across a dbx defintion for
             a corresponding symbol.  If so, store the value.  Remove
             syms from the chain when their values are stored, but
             search the whole chain, as there may be several syms from
             different files with the same name. */
          /* This is probably not true.  Since the files will be read
             in one at a time, each reference to a global symbol will
             be satisfied in each file as it appears. So we skip this
             section. */
        &stringtab_global;      /* For debugger; am I right? */
    }
  end_symtab (text_offset + text_size);
}
\f
static int
hashname (name)
     char *name;
{
  register char *p = name;
  register int total = p[0];
  register int c;

  c = p[1];
  total += c << 2;
  if (c)
    {
      c = p[2];
      total += c << 4;
      if (c)
        total += p[3] << 6;
    }

  /* Ensure result is positive.  */
  if (total < 0) total += (1000 << 6);
  return total % HASHSIZE;
}

/* Put all appropriate global symbols in the symseg data
   onto the hash chains so that their addresses will be stored
   when seen later in loader global symbols.  */

static void
hash_symsegs ()
{
  /* Look at each symbol in each block in each symseg symtab.  */
  struct symtab *s;
  for (s = symseg_chain; s; s = s->next)
    {
      register int n;
      for (n = BLOCKVECTOR_NBLOCKS (BLOCKVECTOR (s)) - 1; n >= 0; n--)
        {
          register struct block *b = BLOCKVECTOR_BLOCK (BLOCKVECTOR (s), n);
          register int i;
          for (i = BLOCK_NSYMS (b) - 1; i >= 0; i--)
            {
              register struct symbol *sym = BLOCK_SYM (b, i);

              /* Put the symbol on a chain if its value is an address
                 that is figured out by the loader.  */

              if (SYMBOL_CLASS (sym) == LOC_EXTERNAL)
                {
                  register int hash = hashname (SYMBOL_NAME (sym));
                  SYMBOL_VALUE (sym) = (int) global_sym_chain[hash];
                  global_sym_chain[hash] = sym;
                  SYMBOL_CLASS (sym) = LOC_STATIC;
                }
            }
        }
    }
}
\f
static void
process_one_symbol (type, desc, value, name)
     int type, desc;
     CORE_ADDR value;
     char *name;
{
  register struct context_stack *new;

  /* Something is wrong if we see real data before
     seeing a source file name.  */

  if (last_source_file == 0 && type != N_SO)
    {
      /* Currently this ignores N_ENTRY on Gould machines, N_NSYM on machines
         where that code is defined, and all symbols on the Convex. */
      if (IGNORE_SYMBOL (type))
        return;

      error ("Invalid symbol data: does not start by identifying a source file.");
    }

  switch (type)
    {
    case N_FUN:
    case N_FNAME:
      /* Either of these types of symbols indicates the start of
         a new function.  We must process its "name" normally for dbx,
         but also record the start of a new lexical context, and possibly
         also the end of the lexical context for the previous function.  */
      
      within_function = 1;
      if (context_stack_depth > 0)
        {
          new = &context_stack[--context_stack_depth];
          /* Make a block for the local symbols within.  */
          finish_block (new->name, &local_symbols, new->old_blocks,
                        new->start_addr, value);
        }
      /* Stack must be empty now.  */
      if (context_stack_depth != 0)
        error ("Invalid symbol data: unmatched N_LBRAC before symtab pos %d.",
               symnum);

      new = &context_stack[context_stack_depth++];
      new->old_blocks = pending_blocks;
      new->start_addr = value;
      new->name = define_symbol (value, name, desc);
      local_symbols = 0;
      break;

    case N_LBRAC:
      /* This "symbol" just indicates the start of an inner lexical
         context within a function.  */

      if (context_stack_depth == context_stack_size)
        {
          context_stack_size *= 2;
          context_stack = (struct context_stack *)
            xrealloc (context_stack,
                      (context_stack_size
                       * sizeof (struct context_stack)));
        }

      new = &context_stack[context_stack_depth++];
      new->depth = desc;
      new->locals = local_symbols;
      new->old_blocks = pending_blocks;
      new->start_addr = value;
      new->name = 0;
      local_symbols = 0;
      break;

    case N_RBRAC:
      /* This "symbol" just indicates the end of an inner lexical
         context that was started with N_RBRAC.  */
      new = &context_stack[--context_stack_depth];
      if (desc != new->depth)
        error ("Invalid symbol data: N_LBRAC/N_RBRAC symbol mismatch, symtab pos %d.", symnum);
      local_symbols = new->locals;

      /* If this is not the outermost LBRAC...RBRAC pair in the
         function, its local symbols preceded it, and are the ones
         just recovered from the context stack.  Defined the block for them.

         If this is the outermost LBRAC...RBRAC pair, there is no
         need to do anything; leave the symbols that preceded it
         to be attached to the function's own block.  */
      if (local_symbols && context_stack_depth > 1)
        {
          /* Muzzle a compiler bug that makes end > start.  */
          if (new->start_addr > value)
            new->start_addr = value;
          /* Make a block for the local symbols within.  */
          finish_block (0, &local_symbols, new->old_blocks,
                        new->start_addr + last_source_start_addr,
                        value + last_source_start_addr);
        }
      break;

    case N_FN:
      /* This kind of symbol supposedly indicates the start
         of an object file.  In fact this type does not appear.  */
      break;

    case N_SO:
      /* This type of symbol indicates the start of data
         for one source file.
         Finish the symbol table of the previous source file
         (if any) and start accumulating a new symbol table.  */
      if (last_source_file)
        end_symtab (value);
      start_symtab (name, value);
      break;

    case N_SOL:
      /* This type of symbol indicates the start of data for
         a sub-source-file, one whose contents were copied or
         included in the compilation of the main source file
         (whose name was given in the N_SO symbol.)  */
      start_subfile (name);
      break;

#ifdef N_BINCL
    case N_BINCL:
      push_subfile ();
      add_new_header_file (name, value);
      start_subfile (name);
      break;

    case N_EINCL:
      start_subfile (pop_subfile ());
      break;

    case N_EXCL:
      add_old_header_file (name, value);
      break;
#endif /* have N_BINCL */

    case N_SLINE:
      /* This type of "symbol" really just records
         one line-number -- core-address correspondence.
         Enter it in the line list for this symbol table.  */
      record_line (desc, value);
      break;

    case N_BCOMM:
    case N_ECOMM:
    case N_ECOML:
    case N_LENG:
      break;

    default:
      if (name)
        define_symbol (value, name, desc);
    }
}
\f
/* This function was added for C++ functionality.  I presume that it
   condenses the bunches formed by reading in an additional .o file
   (incremental linking). */

static void
condense_addl_misc_bunches ()
{ 
  register int i, j;
  register struct misc_bunch *bunch;
#ifdef NAMES_HAVE_UNDERSCORE
  int offset = 1;
#else
  int offset = 0;
#endif

  misc_function_vector
    = (struct misc_function *)  xrealloc (misc_function_vector,
                                          (misc_count + misc_function_count) * sizeof (struct misc_function));

  j = misc_function_count;
  bunch = misc_bunch;
  while (bunch)
    {
      for (i = 0; i < misc_bunch_index; i++)
        {
          misc_function_vector[j] = bunch->contents[i];
          misc_function_vector[j].name
            = concat (misc_function_vector[j].name
                      + (misc_function_vector[j].name[0] == '_' ? offset : 0),
                      "", "");
          j++;
        }
      bunch = bunch->next;
      misc_bunch_index = MISC_BUNCH_SIZE;
    }

  misc_function_count += misc_count;

  /* Sort the misc functions by address.  */

  qsort (misc_function_vector, misc_function_count,
         sizeof (struct misc_function),  compare_misc_functions);
}
\f

/* Read in another .o file and create a symtab entry for it.*/
 
static void
read_addl_syms (desc, stringtab, nlistlen, text_addr, text_size)
     int desc;
     register char *stringtab;
     register int nlistlen;
     unsigned text_addr;
     int text_size;
{
  FILE *stream = fdopen (desc, "r");
  register char *namestring;
  register struct symbol *sym, *prev;
  int hash;
  int num_object_files = 0;

#ifdef N_BINCL
  subfile_stack = 0;
#endif

  last_source_file = 0;
  bzero (global_sym_chain, sizeof global_sym_chain);
  symtab_input_desc = desc;
  stringtab_global = stringtab;
  fill_symbuf ();

  for (symnum = 0; symnum < nlistlen; symnum++)
    {
      struct nlist *bufp;
      unsigned char type;

      QUIT;     /* allow this to be interruptable */
      if (symbuf_idx == symbuf_end)
        fill_symbuf ();
      bufp = &symbuf[symbuf_idx++];
      type = bufp->n_type & N_TYPE;
      namestring = bufp->n_un.n_strx ? bufp->n_un.n_strx + stringtab : "";

      if( (type == N_TEXT) || (type == N_DATA) || (type == N_BSS) )
        {
          /* Relocate this file's symbol table information
             to the address it has been loaded into.  */
          bufp->n_value += text_addr;        
        }

      type = bufp->n_type;

      if (type & N_STAB)
        process_one_symbol (type, bufp->n_desc,
                            bufp->n_value, namestring);
      /* A static text symbol whose name ends in ".o"
         can only mean the start of another object file.
         So end the symtab of the source file we have been processing.
         This is how we avoid counting the libraries as part
         or the last source file.
         Also this way we find end of first object file (crt0).  */
      else if ((type == N_TEXT
#ifdef N_NBTEXT
                || type == N_NBTEXT
#endif
                )
               && (!strcmp (namestring + strlen (namestring) - 2, ".o"))
               || ! strcmp (namestring, "-l", 2))
        {
          if (num_object_files++ == 1)
            first_object_file_end = bufp->n_value;
          if (last_source_file)
            end_symtab (bufp->n_value);
        }
      else if (type & N_EXT || type == N_TEXT
#ifdef N_NBTEXT
               || type == N_NBTEXT
#endif
               )
        {
          int used_up = 0;

          /* Record the location of _etext.  */
          if (type == (N_TEXT | N_EXT)
              && !strcmp (namestring, "_etext"))
            end_of_text_addr = bufp->n_value;

          /* Global symbol: see if we came across a dbx definition
             for a corresponding symbol.  If so, store the value.
             Remove syms from the chain when their values are stored,
             but search the whole chain, as there may be several syms
             from different files with the same name.  */
          if (type & N_EXT)
            {
              prev = 0;
#ifdef NAMES_HAVE_UNDERSCORE
              hash = hashname (namestring + 1);
#else /* not NAMES_HAVE_UNDERSCORE */
              hash = hashname (namestring);
#endif /* not NAMES_HAVE_UNDERSCORE */
              for (sym = global_sym_chain[hash];
                   sym;)
                {
                  if (
#ifdef NAMES_HAVE_UNDERSCORE
                      *namestring == '_'
                      && namestring[1] == SYMBOL_NAME (sym)[0]
                      &&
                      !strcmp (namestring + 2, SYMBOL_NAME (sym) + 1)
#else /* NAMES_HAVE_UNDERSCORE */
                      namestring[0] == SYMBOL_NAME (sym)[0]
                      &&
                      !strcmp (namestring + 1, SYMBOL_NAME (sym) + 1)
#endif /* NAMES_HAVE_UNDERSCORE */
                      )
                    {
                      if (prev)
                        SYMBOL_VALUE (prev) = SYMBOL_VALUE (sym);
                      else
                        global_sym_chain[hash]
                          = (struct symbol *) SYMBOL_VALUE (sym);
                      SYMBOL_VALUE (sym) = bufp->n_value;
                      if (prev)
                        sym = (struct symbol *) SYMBOL_VALUE (prev);
                      else
                        sym = global_sym_chain[hash];

                      used_up = 1;
                    }
                  else
                    {
                      prev = sym;
                      sym = (struct symbol *) SYMBOL_VALUE (sym);
                    }
                }
            }

          /* Defined global or text symbol: record as a misc function
             if it didn't give its address to a debugger symbol above.  */
          if (type <= (N_TYPE | N_EXT)
              && type != N_EXT
              && ! used_up)
            record_misc_function (namestring, bufp->n_value);
        }
    }

  if (last_source_file)
    end_symtab (text_addr + text_size);

  fclose (stream);
}

/* C++:
   This function allows the addition of incrementally linked object files.
   Since this has a fair amount of code in common with symbol_file_command,
   it might be worthwhile to consolidate things, as was done with 
   read_dbx_symtab and condense_misc_bunches. */

void
add_file_command (arg_string)
     char* arg_string;
{ 
  register int desc;
  DECLARE_FILE_HEADERS;
  struct nlist *nlist;
  char *stringtab;
  long buffer;
  register int val;
  extern void close ();
  struct cleanup *old_chain;
  struct symtab *symseg;
  struct stat statbuf;
  char *name;
  unsigned text_addr;
  
  if (arg_string == 0)
    error ("add-file takes a file name and an address");

  for( ; *arg_string == ' '; arg_string++ );
  name = arg_string;
  for( ; *arg_string && *arg_string != ' ' ; arg_string++ );
  *arg_string++ = (char) 0;

  if (name[0] == 0)
    error ("add-file takes a file name and an address");

  text_addr = parse_and_eval_address (arg_string);

  dont_repeat ();

  if (!query ("add symbol table from filename \"%s\" at text_addr = 0x%x\n", 
              name, text_addr))
    error ("Not confirmed.");

  desc = open (name, O_RDONLY);
  if (desc < 0)
    perror_with_name (name);
  
  old_chain = make_cleanup (close, desc);
  make_cleanup (free_current_contents, &name);
  
  READ_FILE_HEADERS (desc, name);
  
  if (NUMBER_OF_SYMBOLS == 0)
    {
      printf ("%s does not have a symbol-table.\n", name);
      fflush (stdout);
      return;
    }
  
  printf ("Reading symbol data from %s...", name);
  fflush (stdout);
  
  /* Now read the string table, all at once.  */
  val = lseek (desc, STRING_TABLE_OFFSET, 0);
  if (val < 0)
    perror_with_name (name);
  stat (name, &statbuf);
  READ_STRING_TABLE_SIZE (buffer);
  if (buffer >= 0 && buffer < statbuf.st_size)
    stringtab = (char *) alloca (buffer);
  else
    stringtab = NULL;
  if (stringtab == NULL)
    error ("ridiculous string table size: %d bytes", name, buffer);
  
  bcopy (&buffer, stringtab, sizeof buffer);
  val = myread (desc, stringtab + sizeof buffer, buffer - sizeof buffer);
  if (val < 0)
    perror_with_name (name);
  
#ifdef READ_GDB_SYMSEGS
  /* That puts us at the symsegs.  Read them.  */
  symseg_chain = read_symsegs (desc, name);
  hash_symsegs ();

  /* Free the symtabs made by read_symsegs, but not their contents,
     which have been copied into symtabs on symtab_list.  */
  for (symseg = symseg_chain; symseg; symseg = symseg->next)
    {
      int i;
      struct sourcevector *sv = (struct sourcevector *) symseg->linetable;

      for (i = 0; i < sv->length; i++)
        {
          int j;
          struct source *source = sv->source[i];
          struct symtab *sp1
            = (struct symtab *) xxmalloc (sizeof (struct symtab));

          bcopy (symseg, sp1, sizeof (struct symtab));
          sp1->filename = savestring (source->name, strlen (source->name));
          sp1->linetable = &source->contents;
          sp1->free_code = free_nothing;
          sp1->free_ptr = (i == 0) ? (char *) symseg : 0;

          sp1->next = symtab_list;
          symtab_list = sp1;
        }
    }
#else
  /* Where people are using the 4.2 ld program, must not check for
     symsegs, because that ld puts randonm garbage at the end of
     the output file and that would trigger an error message.  */
  symseg_chain = 0;
#endif
  
  /* Position to read the symbol table.  Do not read it all at once. */
  val = lseek (desc, SYMBOL_TABLE_OFFSET, 0);
  if (val < 0)
    perror_with_name (name);
  
  init_misc_functions ();
  make_cleanup (discard_misc_bunches, 0);
  init_header_files ();
  make_cleanup (free_header_files, 0);
  free_pendings = 0;
  pending_blocks = 0;
  file_symbols = 0;
  global_symbols = 0;
  make_cleanup (really_free_pendings, 0);

  read_addl_syms (desc, stringtab, NUMBER_OF_SYMBOLS, text_addr,
                  SIZE_OF_TEXT_SEGMENT);
                  
  
  /* Sort symbols alphabetically within each block.  */
  
  sort_syms ();
  
  /* Go over the misc functions and install them in vector.  */
  
  condense_addl_misc_bunches (1);
  
  /* Don't allow char * to have a typename (else would get caddr_t.)  */
  
  TYPE_NAME (lookup_pointer_type (builtin_type_char)) = 0;
  
  /* Make a default for file to list.  */
  /* Hmmm.  I'd say we don't want this in add_file_command, but . . . */
  
  select_source_symtab (symtab_list);
  
  do_cleanups (old_chain);
  
  /* Free the symtabs made by read_symsegs, but not their contents,
     which have been copied into symtabs on symtab_list.  */
  while (symseg_chain)
    {
      register struct symtab *s = symseg_chain->next;
      free (symseg_chain);
      symseg_chain = s;
    }
  
  printf ("done.\n");
  fflush (stdout);
}
\f
static struct symbol *
define_symbol (value, string, desc)
     int value;
     char *string;
     int desc;
{
  register struct symbol *sym
    = (struct symbol *) obstack_alloc (symbol_obstack, sizeof (struct symbol));
  char *p = (char *) index (string, ':');
  int deftype;
  register int i;

  /* Ignore syms with empty names.  */
  if (string[0] == 0)
    return 0;

  SYMBOL_NAME (sym)
    = (char *) obstack_alloc (symbol_obstack, ((p - string) + 1));
  /* Open-coded bcopy--saves function call time.  */
  {
    register char *p1 = string;
    register char *p2 = SYMBOL_NAME (sym);
    while (p1 != p)
      *p2++ = *p1++;
    *p2++ = '\0';
  }
  p++;
  /* Determine the type of name being defined.  */
  if ((*p >= '0' && *p <= '9') || *p == '(')
    deftype = 'l';
  else
    deftype = *p++;

  /* c is a special case, not followed by a type-number.
     SYMBOL:c=iVALUE for an integer constant symbol.
     SYMBOL:c=rVALUE for a floating constant symbol.  */
  if (deftype == 'c')
    {
      if (*p++ != '=')
        error ("Invalid symbol data at symtab pos %d.", symnum);
      switch (*p++)
        {
        case 'r':
          {
            double d = atof (p);
            char *value;

            SYMBOL_TYPE (sym) = builtin_type_double;
            value = (char *) obstack_alloc (symbol_obstack, sizeof (double));
            bcopy (&d, value, sizeof (double));
            SYMBOL_VALUE_BYTES (sym) = value;
            SYMBOL_CLASS (sym) = LOC_CONST;
          }
          break;
        case 'i':
          {
            SYMBOL_TYPE (sym) = builtin_type_int;
            SYMBOL_VALUE (sym) = atoi (p);
            SYMBOL_CLASS (sym) = LOC_CONST_BYTES;
          }
          break;
        default:
          error ("Invalid symbol data at symtab pos %d.", symnum);
        }
      SYMBOL_NAMESPACE (sym) = VAR_NAMESPACE;
      add_symbol_to_list (sym, &file_symbols);
      return sym;
    }

  /* Now usually comes a number that says which data type,
     and possibly more stuff to define the type
     (all of which is handled by read_type)  */

  if (deftype == 'p' && *p == 'F')
    /* pF is a two-letter code that means a function parameter in Fortran.
       The type-number specifies the type of the return value.
       Translate it into a pointer-to-function type.  */
    {
      p++;
      SYMBOL_TYPE (sym)
        = lookup_pointer_type (lookup_function_type (read_type (&p)));
    }
  else 
    {
      struct type *type = read_type (&p);
      
      if ((deftype == 'F' || deftype == 'f') 
          && TYPE_CODE (type) != TYPE_CODE_FUNC)
        SYMBOL_TYPE (sym) = lookup_function_type (type);
      else
        SYMBOL_TYPE (sym) = type;
    }

  switch (deftype)
    {
    case 'f':
      SYMBOL_CLASS (sym) = LOC_BLOCK;
      SYMBOL_NAMESPACE (sym) = VAR_NAMESPACE;
      add_symbol_to_list (sym, &file_symbols);
      break;

    case 'F':
      SYMBOL_CLASS (sym) = LOC_BLOCK;
      SYMBOL_NAMESPACE (sym) = VAR_NAMESPACE;
      add_symbol_to_list (sym, &global_symbols);
      break;

    case 'G':
      /* For a class G (global) symbol, it appears that the
         value is not correct.  It is necessary to search for the
         corresponding linker definition to find the value.
         These definitions appear at the end of the namelist.  */
      i = hashname (SYMBOL_NAME (sym));
      SYMBOL_VALUE (sym) = (int) global_sym_chain[i];
      global_sym_chain[i] = sym;
      SYMBOL_CLASS (sym) = LOC_STATIC;
      SYMBOL_NAMESPACE (sym) = VAR_NAMESPACE;
      add_symbol_to_list (sym, &global_symbols);
      break;

      /* This case is faked by a conditional above,
         when there is no code letter in the dbx data.
         Dbx data never actually contains 'l'.  */
    case 'l':
      SYMBOL_CLASS (sym) = LOC_LOCAL;
      SYMBOL_VALUE (sym) = value;
      SYMBOL_NAMESPACE (sym) = VAR_NAMESPACE;
      add_symbol_to_list (sym, &local_symbols);
      break;

    case 'p':
      SYMBOL_CLASS (sym) = LOC_ARG;
      SYMBOL_VALUE (sym) = value;
      SYMBOL_NAMESPACE (sym) = VAR_NAMESPACE;
      add_symbol_to_list (sym, &local_symbols);
      /* DESC == 0 implies compiled with GCC.
         In this case, if it says `short', believe it.  */
      if (desc == 0)
        break;
      /* If PCC says a parameter is a short or a char,
         it is really an int.  */
      if (SYMBOL_TYPE (sym) == builtin_type_char
          || SYMBOL_TYPE (sym) == builtin_type_short)
        SYMBOL_TYPE (sym) = builtin_type_int;
      else if (SYMBOL_TYPE (sym) == builtin_type_unsigned_char
               || SYMBOL_TYPE (sym) == builtin_type_unsigned_short)
        SYMBOL_TYPE (sym) = builtin_type_unsigned_int;
      break;

    case 'P':
      SYMBOL_CLASS (sym) = LOC_REGPARM;
      SYMBOL_VALUE (sym) = value;
      SYMBOL_NAMESPACE (sym) = VAR_NAMESPACE;
      add_symbol_to_list (sym, &local_symbols);
      break;

    case 'r':
      SYMBOL_CLASS (sym) = LOC_REGISTER;
      SYMBOL_VALUE (sym) = value;
      SYMBOL_NAMESPACE (sym) = VAR_NAMESPACE;
      add_symbol_to_list (sym, &local_symbols);
      break;

    case 'S':
      /* Static symbol at top level of file */
      SYMBOL_CLASS (sym) = LOC_STATIC;
      SYMBOL_VALUE (sym) = value;
      SYMBOL_NAMESPACE (sym) = VAR_NAMESPACE;
      add_symbol_to_list (sym, &file_symbols);
      break;

    case 't':
      SYMBOL_CLASS (sym) = LOC_TYPEDEF;
      SYMBOL_VALUE (sym) = value;
      SYMBOL_NAMESPACE (sym) = VAR_NAMESPACE;
      if (TYPE_NAME (SYMBOL_TYPE (sym)) == 0
          && (TYPE_FLAGS (SYMBOL_TYPE (sym)) & TYPE_FLAG_PERM) == 0)
        TYPE_NAME (SYMBOL_TYPE (sym)) =
          obsavestring (SYMBOL_NAME (sym),
                        strlen (SYMBOL_NAME (sym)));
       /* C++ vagaries: we may have a type which is derived from
         a base type which did not have its name defined when the
         derived class was output.  We fill in the derived class's
         base part member's name here in that case.  */
       else if ((TYPE_CODE (SYMBOL_TYPE (sym)) == TYPE_CODE_STRUCT
                 || TYPE_CODE (SYMBOL_TYPE (sym)) == TYPE_CODE_UNION)
                && TYPE_N_BASECLASSES (SYMBOL_TYPE (sym)))
         {
           int i;
           for (i = TYPE_N_BASECLASSES (SYMBOL_TYPE (sym)); i > 0; i--)
             if (TYPE_FIELD_NAME (SYMBOL_TYPE (sym), i - 1) == 0)
               TYPE_FIELD_NAME (SYMBOL_TYPE (sym), i - 1) =
                 TYPE_NAME (TYPE_BASECLASS (SYMBOL_TYPE (sym), i));
         }
      
      add_symbol_to_list (sym, &file_symbols);
      break;

    case 'T':
      SYMBOL_CLASS (sym) = LOC_TYPEDEF;
      SYMBOL_VALUE (sym) = value;
      SYMBOL_NAMESPACE (sym) = STRUCT_NAMESPACE;
      if (TYPE_NAME (SYMBOL_TYPE (sym)) == 0
          && (TYPE_FLAGS (SYMBOL_TYPE (sym)) & TYPE_FLAG_PERM) == 0)
        TYPE_NAME (SYMBOL_TYPE (sym))
          = obconcat ("",
                      (TYPE_CODE (SYMBOL_TYPE (sym)) == TYPE_CODE_ENUM
                       ? "enum "
                       : (TYPE_CODE (SYMBOL_TYPE (sym)) == TYPE_CODE_STRUCT
                          ? "struct " : "union ")),
                      SYMBOL_NAME (sym));
      add_symbol_to_list (sym, &file_symbols);
      break;

    case 'V':
    case 'v':
      /* Static symbol of local scope */
      SYMBOL_CLASS (sym) = LOC_STATIC;
      SYMBOL_VALUE (sym) = value;
      SYMBOL_NAMESPACE (sym) = VAR_NAMESPACE;
      add_symbol_to_list (sym, &local_symbols);
      break;

    default:
      error ("Invalid symbol data: unknown symbol-type code `%c' at symtab pos %d.", deftype, symnum);
    }
  return sym;
}
\f
/* Read a number by which a type is referred to in dbx data,
   or perhaps read a pair (FILENUM, TYPENUM) in parentheses.
   Just a single number N is equivalent to (0,N).
   Return the two numbers by storing them in the vector TYPENUMS.
   TYPENUMS will then be used as an argument to dbx_lookup_type.  */

static void
read_type_number (pp, typenums)
     register char **pp;
     register int *typenums;
{
  if (**pp == '(')
    {
      (*pp)++;
      typenums[0] = read_number (pp, ',');
      typenums[1] = read_number (pp, ')');
    }
  else
    {
      typenums[0] = 0;
      typenums[1] = read_number (pp, 0);
    }
}

/* Read a dbx type reference or definition;
   return the type that is meant.
   This can be just a number, in which case it references
   a type already defined and placed in type_vector.
   Or the number can be followed by an =, in which case
   it means to define a new type according to the text that
   follows the =.  */

static
struct type *
read_type (pp)
     register char **pp;
{
  register struct type *type = 0;
  register int n;
  struct type *type1;
  int typenums[2];
  int xtypenums[2];

  read_type_number (pp, typenums);

  /* Detect random reference to type not yet defined.
     Allocate a type object but leave it zeroed.  */
  if (**pp != '=')
    return dbx_alloc_type (typenums);

  *pp += 2;
  switch ((*pp)[-1])
    {
    case 'x':
      type = dbx_alloc_type (typenums);
      /* Set the type code according to the following letter.  */
      switch ((*pp)[0])
        {
        case 's':
          TYPE_CODE (type) = TYPE_CODE_STRUCT;
          break;
        case 'u':
          TYPE_CODE (type) = TYPE_CODE_UNION;
          break;
        case 'e':
          TYPE_CODE (type) = TYPE_CODE_ENUM;
          break;
        }
      /* Skip the name the cross-ref points to.  */
      /* Note: for C++, the cross reference may be to a base type which
         has not yet been seen.  In this case, we skip to the comma,
         which will mark the end of the base class name.  (The ':'
         at the end of the base class name will be skipped as well.)  */
      *pp = (char *) index (*pp, ',');
      /* Just allocate the type and leave it zero if nothing known */
      return dbx_alloc_type (typenums);

    case '0':
    case '1':
    case '2':
    case '3':
    case '4':
    case '5':
    case '6':
    case '7':
    case '8':
    case '9':
    case '(':
      (*pp)--;
      read_type_number (pp, xtypenums);
      type = *dbx_lookup_type (xtypenums);
      if (type == 0)
        type = builtin_type_void;
      *dbx_lookup_type (typenums) = type;
      break;
      
    case '*':
      type1 = read_type (pp);
      if (TYPE_POINTER_TYPE (type1))
        {
          type = TYPE_POINTER_TYPE (type1);
          *dbx_lookup_type (typenums) = type;
        }
      else
        {
          type = dbx_alloc_type (typenums);
          smash_to_pointer_type (type, type1);
        }
      break;

    case '@':
      {
        struct type *domain = read_type (pp);
        char c;
        struct type *memtype;

        if (*(*pp)++ != ',')
          error ("invalid member type data format, at symtab pos %d.",
                 symnum);

        memtype = read_type (pp);
        type = dbx_alloc_type (typenums);
        smash_to_member_type (type, domain, memtype);
      }
      break;

    case '&':
      type1 = read_type (pp);
      if (TYPE_REFERENCE_TYPE (type1))
        {
          type = TYPE_REFERENCE_TYPE (type1);
          *dbx_lookup_type (typenums) = type;
        }
      else
        {
          type = dbx_alloc_type (typenums);
          smash_to_reference_type (type, type1);
        }
      break;

    case 'f':
      type1 = read_type (pp);
      if (TYPE_FUNCTION_TYPE (type1))
        {
          type = TYPE_FUNCTION_TYPE (type1);
          *dbx_lookup_type (typenums) = type;
        }
      else
        {
          type = dbx_alloc_type (typenums);
          smash_to_function_type (type, type1);
        }
      break;

    case 'r':
      type = read_range_type (pp, typenums);
      *dbx_lookup_type (typenums) = type;
      break;

    case 'e':
      type = dbx_alloc_type (typenums);
      type = read_enum_type (pp, type);
      *dbx_lookup_type (typenums) = type;
      break;

    case 's':
      type = dbx_alloc_type (typenums);
      type = read_struct_type (pp, type);
      break;

    case 'u':
      type = dbx_alloc_type (typenums);
      type = read_struct_type (pp, type);
      TYPE_CODE (type) = TYPE_CODE_UNION;
      break;

    case 'a':
      if (*(*pp)++ != 'r')
        error ("Invalid symbol data: unrecognized type-code `a%c' %s %d.",
               (*pp)[-1], "at symtab position", symnum);
      
      type = dbx_alloc_type (typenums);
      type = read_array_type (pp, type);
      break;

#if 0
      /* Format of an array type:
         "ar<index type>;lower;upper;<array_contents_type>".  Put code
         in to handle this.  */

      /* dbx expresses array types in terms of a range type for the index,
         and that range type is specified right inside the array type spec
         making ar1;MIN;MAX;VALTYPE  */
      if (!strncmp (*pp, "r1;0;", 5))
        (*pp) += 5;
      else if (!strncmp (*pp, "r(0,1);0;", 9))
        (*pp) += 9;
      else break;

      TYPE_CODE (type) = TYPE_CODE_ARRAY;
      /* In Fortran, an upper bound may be T... meaning a parameter specifies
         the length of the data.  In this case, just pretend the bound is 1.
         This happens only for array parameters, which are really passed
         as pointers anyway, and we will translate them into such.  */
      if (**pp == 'T')
        {
          n = 1;
          while (**pp != ';')
            (*pp)++;
        }
      else
        n = read_number (pp, ';') + 1;
      TYPE_TARGET_TYPE (type) = read_type (pp);
      TYPE_LENGTH (type) = TYPE_LENGTH (TYPE_TARGET_TYPE (type)) * n;
      break;
#endif

    default:
      error ("Invalid symbol data: unrecognized type-code `%c' at symtab pos %d.",
             (*pp)[-1], symnum);
    }

  if (type == 0)
    abort ();

#if 0
  /* If this is an overriding temporary alteration for a header file's
     contents, and this type number is unknown in the global definition,
     put this type into the global definition at this type number.  */
  if (header_file_prev_index >= 0)
    {
      register struct type **tp
        = explicit_lookup_type (header_file_prev_index, typenums[1]);
      if (*tp == 0)
        *tp = type;
    }
#endif
  return type;
}
\f
/* This page contains subroutines of read_type.  */

/* Read the description of a structure (or union type)
   and return an object describing the type.  */

static struct type *
read_struct_type (pp, type)
     char **pp;
     register struct type *type;
{
  struct nextfield
    {
      struct nextfield *next;
      int visibility;
      struct field field;
    };

  struct next_fnfield
    {
      struct next_fnfield *next;
      int visibility;
      struct fn_field fn_field;
    };

  struct next_fnfieldlist
    {
      struct next_fnfieldlist *next;
      struct fn_fieldlist fn_fieldlist;
    };

  register struct nextfield *list = 0;
  struct nextfield *new;
  int totalsize;
  char *name;
  register char *p;
  int nfields = 0;
  register int n;

  register struct next_fnfieldlist *mainlist = 0;
  int nfn_fields = 0;
  struct type *baseclass = NULL;
  int read_possible_virtual_info = 0;

  TYPE_CODE (type) = TYPE_CODE_STRUCT;

  /* First comes the total size in bytes.  */

  TYPE_LENGTH (type) = read_number (pp, 0);

  /* C++: Now, if the class is a derived class, then the next character
     will be a '!', followed by the number of base classes derived from.
     Each element in the list contains visibility information,
     the offset of this base class in the derived structure,
     and then the base type. */
  if (**pp == '!')
    {
      int i, n_baseclasses, offset;
      struct type **baseclass_vec;
      struct type *baseclass;
      int via_public, via_virtual;
      
      *pp += 1;

      n_baseclasses = read_number (pp, ',');
      baseclass_vec = (struct type **)
        obstack_alloc (symbol_obstack,
                       (n_baseclasses) * sizeof (struct type **)) - 1;

      for (i = 1; i <= n_baseclasses; i++)
        {
          if (**pp == '\\')
            *pp = next_symbol_text ();

          switch (*(*pp)++)
            {
            case '0':
              via_virtual = 0;
              break;
            case '1':
              via_virtual = 1;
              break;
            default:
              error ("Invalid symbol data: bad visibility format at symtab pos %d",
                     symnum);
            }

          switch (*(*pp)++)
            {
            case '0':
              via_public = 0;
              break;
            case '2':
              via_public = 1;
              break;
            default:
              error ("Invalid symbol data: bad visibility format at symtab pos %d.",
                     symnum);
            }
          offset = read_number (pp, ',');
          baseclass = read_type (pp);
          *pp += 1;             /* skip trailing ';' */
          baseclass_vec[i] = lookup_basetype_type (baseclass, offset, via_virtual, via_public);

          /* Make this baseclass visible for structure-printing purposes.  */
          new = (struct nextfield *) alloca (sizeof (struct nextfield));
          new->next = list;
          list = new;
          list->field.type = baseclass_vec[i];
          list->field.name = TYPE_NAME (baseclass_vec[i]);
          list->field.bitpos = offset;
          list->field.bitsize = 0;      /* this should be an unpacked field! */
          nfields++;
        }
      TYPE_N_BASECLASSES (type) = n_baseclasses;
      TYPE_BASECLASSES (type) = baseclass_vec;
    }

  /* Now come the fields, as NAME:?TYPENUM,BITPOS,BITSIZE; for each one.
     At the end, we see a semicolon instead of a field.

     In C++, this may wind up being NAME:?TYPENUM:PHYSNAME; for
     a static field.

     The `?' is a placeholder for one of '+' (public visibility),
     '0' (protected visibility), and '-' (private visibility).  */

  while (**pp != ';')
    {
      int visibility;

      /* Check for and handle cretinous dbx symbol name continuation!  */
      if (**pp == '\\') *pp = next_symbol_text ();

      /* Get space to record the next field's data.  */
      new = (struct nextfield *) alloca (sizeof (struct nextfield));
      new->next = list;
      list = new;

      /* Read the data.  */
      p = *pp;
      while (*p != ':') p++;
      list->field.name = obsavestring (*pp, p - *pp);

      /* C++: Check to see if we have hit the methods yet. */
      if (p[1] == ':')
        break;

      *pp = p + 1;

      /* This means we have a visibility for a field coming. */
      if (**pp == '/')
        {
          switch (*++*pp)
            {
            case '0':
              visibility = 0;
              *pp += 1;
              break;

            case '1':
              visibility = 1;
              *pp += 1;
              break;
 
            case '2':
              visibility = 2;
              *pp += 1;
              break;
            }
        }
       /* else normal dbx-style format.  */

      list->field.type = read_type (pp);
      if (**pp == ':')
        {
          list->field.bitpos = (long)-1;
          p = ++(*pp);
          while (*p != ';') p++;
          list->field.bitsize = (long) savestring (*pp, p - *pp);
          *pp = p + 1;
          nfields++;
          continue;
        }
       else if (**pp != ',')
         error ("Invalid symbol data: bad structure-type format at symtab pos %d.",
               symnum);
      (*pp)++;                  /* Skip the comma.  */
      list->field.bitpos = read_number (pp, ',');
      list->field.bitsize = read_number (pp, ';');
      /* Detect an unpacked field and mark it as such.
         dbx gives a bit size for all fields.
         Note that forward refs cannot be packed,
         and treat enums as if they had the width of ints.  */
      if (TYPE_CODE (list->field.type) != TYPE_CODE_INT
          && TYPE_CODE (list->field.type) != TYPE_CODE_ENUM)
        list->field.bitsize = 0;
      if ((list->field.bitsize == 8 * TYPE_LENGTH (list->field.type)
           || (TYPE_CODE (list->field.type) == TYPE_CODE_ENUM
               && list->field.bitsize == 8 * TYPE_LENGTH (builtin_type_int)))
          &&
          list->field.bitpos % 8 == 0)
        list->field.bitsize = 0;
      nfields++;
    }

  /* Now come the method fields, as NAME::methods
     where each method is of the form TYPENUM,ARGS,...:PHYSNAME;
     At the end, we see a semicolon instead of a field.

     For the case of overloaded operators, the format is
     OPERATOR::*.methods, where OPERATOR is the string "operator",
     `*' holds the place for an operator name (such as `+=')
     and `.' marks the end of the operator name.  */
  if (p[1] == ':')
    {
      /* Now, read in the methods.  To simplify matters, we
         "unread" the name that has been read, so that we can
         start from the top.  */

      p = *pp;

      /* chill the list of fields: the last entry (at the head)
         is a partially constructed entry which we now scrub.  */
      list = list->next;

      /* For each list of method lists... */
      do
        {
          int i;
          struct next_fnfield *sublist = 0;
          struct fn_field *fn_fields = 0;
          int length = 0;
          struct next_fnfieldlist *new_mainlist =
            (struct next_fnfieldlist *)alloca (sizeof (struct next_fnfieldlist));

          /* read in the name.  */
          while (*p != ':') p++;
          if ((*pp)[0] == 'o' && (*pp)[1] == 'p' && (*pp)[2] == '$')
            {
              static char opname[32] = "operator ";
              char *o = opname + 9;

              /* Skip past '::'.  */
              p += 2;
              while (*p != '.')
                *o++ = *p++;
              new_mainlist->fn_fieldlist.name = savestring (opname, o - opname);
              /* Skip past '.'  */
              *pp = p + 1;
            }
          else
            {
              i = 0;
              new_mainlist->fn_fieldlist.name = savestring (*pp, p - *pp);
              /* Skip past '::'.  */
              *pp = p + 2;
            }

          do
            {
              struct next_fnfield *new_sublist =
                (struct next_fnfield *)alloca (sizeof (struct next_fnfield));

              /* Check for and handle cretinous dbx symbol name continuation!  */
              if (**pp == '\\') *pp = next_symbol_text ();

              new_sublist->fn_field.type = read_type (pp);
              new_sublist->fn_field.args = read_args (pp, ':');
              p = *pp;
              while (*p != ';') p++;
              new_sublist->fn_field.physname = savestring (*pp, p - *pp);
              *pp = p + 1;
              new_sublist->visibility = *(*pp)++ - '0';
              if (**pp == '\\') *pp = next_symbol_text ();

              if (*(*pp)++ == '*')
                new_sublist->fn_field.voffset = read_number (pp, ';') + 1;
              else
                new_sublist->fn_field.voffset = 0;

              new_sublist->next = sublist;
              sublist = new_sublist;
              length++;
            }
          while (**pp != ';');

          *pp += 1;

          new_mainlist->fn_fieldlist.fn_fields =
            (struct fn_field *) obstack_alloc (symbol_obstack,
                                               sizeof (struct fn_field) * length);
          TYPE_FN_PRIVATE_BITS (new_mainlist->fn_fieldlist) =
            (int *) obstack_alloc (symbol_obstack,
                                   sizeof (int) * (1 + (length >> 5)));

          TYPE_FN_PROTECTED_BITS (new_mainlist->fn_fieldlist) =
            (int *) obstack_alloc (symbol_obstack,
                                   sizeof (int) * (1 + (length >> 5)));

          for (i = length; sublist; sublist = sublist->next)
            {
              new_mainlist->fn_fieldlist.fn_fields[--i] = sublist->fn_field;
              if (sublist->visibility == 0)
                B_SET (new_mainlist->fn_fieldlist.private_fn_field_bits, i);
              else if (sublist->visibility == 1)
                B_SET (new_mainlist->fn_fieldlist.protected_fn_field_bits, i);
            }

          new_mainlist->fn_fieldlist.length = length;
          new_mainlist->next = mainlist;
          mainlist = new_mainlist;
          nfn_fields++;
        }
      while (**pp != ';');
    }

  *pp += 1;

  /* Now create the vector of fields, and record how big it is.  */

  TYPE_NFIELDS (type) = nfields;
  TYPE_FIELDS (type) = (struct field *) obstack_alloc (symbol_obstack,
                                                       sizeof (struct field) * nfields);
  TYPE_FIELD_PRIVATE_BITS (type) =
    (int *) obstack_alloc (symbol_obstack,
                           sizeof (int) * (1 + (nfields >> 5)));
  TYPE_FIELD_PROTECTED_BITS (type) =
    (int *) obstack_alloc (symbol_obstack,
                           sizeof (int) * (1 + (nfields >> 5)));

  TYPE_NFN_FIELDS (type) = nfn_fields;
  TYPE_NFN_FIELDS_TOTAL (type) = nfn_fields;
  if (baseclass)
    TYPE_NFN_FIELDS_TOTAL (type) += TYPE_NFN_FIELDS_TOTAL (baseclass);

  TYPE_FN_FIELDLISTS (type) =
    (struct fn_fieldlist *) obstack_alloc (symbol_obstack,
                                           sizeof (struct fn_fieldlist) * nfn_fields);

  /* Copy the saved-up fields into the field vector.  */

  for (n = nfields; list; list = list->next)
    {
      TYPE_FIELD (type, --n) = list->field;
      if (list->visibility == 0)
        SET_TYPE_FIELD_PRIVATE (type, n);
      else if (list->visibility == 1)
        SET_TYPE_FIELD_PROTECTED (type, n);
    }

  for (n = nfn_fields; mainlist; mainlist = mainlist->next)
    TYPE_FN_FIELDLISTS (type)[--n] = mainlist->fn_fieldlist;

  if (**pp == '~')
    {
      *pp += 1;

      if (**pp == '=')
        {
          TYPE_FLAGS (type)
            |= TYPE_FLAG_HAS_CONSTRUCTOR | TYPE_FLAG_HAS_DESTRUCTOR;
          *pp += 1;
        }
      else if (**pp == '+')
        {
          TYPE_FLAGS (type) |= TYPE_FLAG_HAS_CONSTRUCTOR;
          *pp += 1;
        }
      else if (**pp == '-')
        {
          TYPE_FLAGS (type) |= TYPE_FLAG_HAS_DESTRUCTOR;
          *pp += 1;
        }

      /* Read either a '%' or the final ';'.  */
      if (*(*pp)++ == '%')
        {
          /* Now we must record the virtual function table pointer's
             field information.  */

          struct type *t;
          int i;

          t = read_type (pp);
          p = (*pp)++;
          while (*p != ';') p++;
          TYPE_VPTR_BASETYPE (type) = t;
          if (type == t)
            {
              if (TYPE_FIELD_NAME (t, 0) == 0)
                TYPE_VPTR_FIELDNO (type) = i = 0;
              else for (i = TYPE_NFIELDS (t) - 1; i >= 0; --i)
                if (! strncmp (TYPE_FIELD_NAME (t, i), *pp,
                               strlen (TYPE_FIELD_NAME (t, i))))
                  {
                    TYPE_VPTR_FIELDNO (type) = i;
                    break;
                  }
              if (i < 0)
                error ("virtual function table field not found");
            }
          else
            TYPE_VPTR_FIELDNO (type) = TYPE_VPTR_FIELDNO (TYPE_BASECLASS (type, 1));
          *pp = p + 1;
        }
      else
        {
          TYPE_VPTR_BASETYPE (type) = 0;
          TYPE_VPTR_FIELDNO (type) = -1;
        }
    }
  else
    {
      TYPE_VPTR_BASETYPE (type) = 0;
      TYPE_VPTR_FIELDNO (type) = -1;
    }

  return type;
}

/* Read a definition of an enumberation type,
   and create and return a suitable type object.
   Also creates a range type which represents the bounds of that
   array.  */
static struct type *
read_array_type (pp, type)
     register char **pp;
     register struct type *type;
{
  struct type *index_type, *element_type, *range_type;
  int lower, upper;
  
  /* Format of an array type:
     "ar<index type>;lower;upper;<array_contents_type>".  Put code in
     to handle this.  */

  index_type = read_type (pp);
  if (*(*pp)++ != ';')
    error ("Invalid symbol data; improper format of array type decl.");
  lower = read_number (pp, ';');
  upper = read_number (pp, ';');
  element_type = read_type (pp);

  {
    /* Create range type.  */
    range_type = (struct type *) obstack_alloc (symbol_obstack,
                                                sizeof (struct type));
    TYPE_CODE (range_type) = TYPE_CODE_RANGE;
    TYPE_TARGET_TYPE (range_type) = index_type;

    /* This should never be needed.  */
    TYPE_LENGTH (range_type) = sizeof (int);

    TYPE_NFIELDS (range_type) = 2;
    TYPE_FIELDS (range_type) =
      (struct field *) obstack_alloc (symbol_obstack,
                                      2 * sizeof (struct field));
    TYPE_FIELD_BITPOS (range_type, 0) = lower;
    TYPE_FIELD_BITPOS (range_type, 1) = upper;
  }

  TYPE_CODE (type) = TYPE_CODE_ARRAY;
  TYPE_TARGET_TYPE (type) = element_type;
  TYPE_LENGTH (type) = (upper - lower + 1) * TYPE_LENGTH (element_type);
  TYPE_NFIELDS (type) = 1;
  TYPE_FIELDS (type) =
    (struct field *) obstack_alloc (symbol_obstack,
                                    sizeof (struct field));
  TYPE_FIELD_TYPE (type, 0) = range_type;

  return type;
}


/* Read a definition of an enumeration type,
   and create and return a suitable type object.
   Also defines the symbols that represent the values of the type.  */

static struct type *
read_enum_type (pp, type)
     register char **pp;
     register struct type *type;
{
  register char *p;
  char *name;
  register long n;
  register struct symbol *sym;
  int nsyms = 0;
  struct pending **symlist;
  struct pending *osyms, *syms;
  int o_nsyms;

  if (within_function)
    symlist = &local_symbols;
  else
    symlist = &file_symbols;
  osyms = *symlist;
  o_nsyms = osyms ? osyms->nsyms : 0;

  /* Read the value-names and their values.
     The input syntax is NAME:VALUE,NAME:VALUE, and so on.
     A semicolon instead of a NAME means the end.  */
  while (**pp && **pp != ';')
    {
      /* Check for and handle cretinous dbx symbol name continuation!  */
      if (**pp == '\\') *pp = next_symbol_text ();

      p = *pp;
      while (*p != ':') p++;
      name = obsavestring (*pp, p - *pp);
      *pp = p + 1;
      n = read_number (pp, ',');
      
      sym = (struct symbol *) obstack_alloc (symbol_obstack, sizeof (struct symbol));
      bzero (sym, sizeof (struct symbol));
      SYMBOL_NAME (sym) = name;
      SYMBOL_CLASS (sym) = LOC_CONST;
      SYMBOL_NAMESPACE (sym) = VAR_NAMESPACE;
      SYMBOL_VALUE (sym) = n;
      add_symbol_to_list (sym, symlist);
      nsyms++;
    }

  (*pp)++;                      /* Skip the semicolon.  */

  /* Now fill in the fields of the type-structure.  */

  TYPE_LENGTH (type) = sizeof (int);
  TYPE_CODE (type) = TYPE_CODE_ENUM;
  TYPE_NFIELDS (type) = nsyms;
  TYPE_FIELDS (type) = (struct field *) obstack_alloc (symbol_obstack, sizeof (struct field) * nsyms);

  /* Find the symbols for the values and put them into the type.
     The symbols can be found in the symlist that we put them on
     to cause them to be defined.  osyms contains the old value
     of that symlist; everything up to there was defined by us.  */

  for (syms = *symlist, n = nsyms; syms; syms = syms->next)
    {
      int j = 0;
      if (syms == osyms)
        j = o_nsyms;
      for (; j < syms->nsyms; j++)
        {
          struct symbol *sym = syms->symbol[j];
          SYMBOL_TYPE (sym) = type;
          TYPE_FIELD_NAME (type, --n) = SYMBOL_NAME (sym);
          TYPE_FIELD_VALUE (type, n) = 0;
          TYPE_FIELD_BITPOS (type, n) = SYMBOL_VALUE (sym);
          TYPE_FIELD_BITSIZE (type, n) = 0;
        }
      if (syms == osyms)
        break;
    }

  return type;
}
  
#define MAX_OF_TYPE(t)  ((1 << (sizeof (t) - 1)) - 1)
#define MIN_OF_TYPE(t)  (-(1 << (sizeof (t) - 1)))

static struct type *
read_range_type (pp, typenums)
     char **pp;
     int typenums[2];
{
  char *errp = *pp;
  int rangenums[2];
  int n2, n3;
  int self_subrange;
  struct type *result_type;

  /* First comes a type we are a subrange of.
     In C it is usually 0, 1 or the type being defined.  */
  read_type_number (pp, rangenums);
  self_subrange = (rangenums[0] == typenums[0] &&
                   rangenums[1] == typenums[1]);

  /* A semicolon should now follow; skip it.  */
  if (**pp == ';')
    (*pp)++;

  /* The remaining two operands are usually lower and upper bounds
     of the range.  But in some special cases they mean something else.  */
  n2 = read_number (pp, ';');
  n3 = read_number (pp, ';');

  /* A type defined as a subrange of itself, with bounds both 0, is void.  */
  if (self_subrange && n2 == 0 && n3 == 0)
    return builtin_type_void;

  /* If n3 is zero and n2 is not, we want a floating type,
     and n2 is the width in bytes.

     Fortran programs appear to use this for complex types also,
     and they give no way to distinguish between double and single-complex!
     We don't have complex types, so we would lose on all fortran files!
     So return type `double' for all of those.  It won't work right
     for the complex values, but at least it makes the file loadable.  */

  if (n3 == 0 && n2 > 0)
    {
      if (n2 == sizeof (float))
        return builtin_type_float;
      return builtin_type_double;
    }

  /* If the upper bound is -1, it must really be an unsigned int.  */

  else if (n2 == 0 && n3 == -1)
    {
      if (sizeof (int) == sizeof (long))
        return builtin_type_unsigned_int;
      else
        return builtin_type_unsigned_long;
    }

  /* Special case: char is defined (Who knows why) as a subrange of
     itself with range 0-127.  */
  else if (self_subrange && n2 == 0 && n3 == 127)
    return builtin_type_char;

  /* Assumptions made here: Subrange of self is equivalent to subrange
     of int.  */
  else if (n2 == 0
           && (self_subrange ||
               *dbx_lookup_type (rangenums) == builtin_type_int))
    {
      /* an unsigned type */
      if (n3 == (1 << (8 * sizeof (int))) - 1)
        return builtin_type_unsigned_int;
      if (n3 == (1 << (8 * sizeof (short))) - 1)
        return builtin_type_unsigned_short;
      if (n3 == (1 << (8 * sizeof (char))) - 1)
        return builtin_type_unsigned_char;
    }
  else if (n2 == -n3 -1)
    {
      /* a signed type */
      if (n3 == (1 << (8 * sizeof (int) - 1)) - 1)
        return builtin_type_int;
      if (n3 == (1 << (8 * sizeof (long) - 1)) - 1)
         return builtin_type_long;
      if (n3 == (1 << (8 * sizeof (short) - 1)) - 1)
        return builtin_type_short;
      if (n3 == (1 << (8 * sizeof (char) - 1)) - 1)
        return builtin_type_char;
    }

  /* We have a real range type on our hands.  Allocate space and
     return a real pointer.  */

  /* At this point I don't have the faintest idea how to deal with
     a self_subrange type; I'm going to assume that this is used
     as an idiom, and that all of them are special cases.  So . . .  */
  if (self_subrange)
    error ("Type defined as subrange of itself.");
  
  result_type = (struct type *) obstack_alloc (symbol_obstack,
                                               sizeof (struct type));
  bzero (result_type, sizeof (struct type));

  TYPE_TARGET_TYPE (result_type) = (self_subrange ?
                                    builtin_type_int :
                                    *dbx_lookup_type(rangenums));

  /* We have to figure out how many bytes it takes to hold this
     range type.  I'm going to assume that anything that is pushing
     the bounds of a long was taken care of above.  */
  if (n2 >= MIN_OF_TYPE(char) && n3 <= MAX_OF_TYPE(char))
    TYPE_LENGTH (result_type) = 1;
  else if (n2 >= MIN_OF_TYPE(short) && n3 <= MAX_OF_TYPE(short))
    TYPE_LENGTH (result_type) = sizeof (short);
  else if (n2 >= MIN_OF_TYPE(int) && n3 <= MAX_OF_TYPE(int))
    TYPE_LENGTH (result_type) = sizeof (int);
  else if (n2 >= MIN_OF_TYPE(long) && n3 <= MAX_OF_TYPE(long))
    TYPE_LENGTH (result_type) = sizeof (long);
  else
    error ("Ranged type doesn't fit within known sizes.");

  TYPE_LENGTH (result_type) = TYPE_LENGTH (TYPE_TARGET_TYPE (result_type));
  TYPE_CODE (result_type) = TYPE_CODE_RANGE;
  TYPE_NFIELDS (result_type) = 2;
  TYPE_FIELDS (result_type) =
    (struct field *) obstack_alloc (symbol_obstack,
                                    2 * sizeof (struct field));
  bzero (TYPE_FIELDS (result_type), 2 * sizeof (struct field));
  TYPE_FIELD_BITPOS (result_type, 0) = n2;
  TYPE_FIELD_BITPOS (result_type, 1) = n3;
    
  return result_type;
}

/* Read a number from the string pointed to by *PP.
   The value of *PP is advanced over the number.
   If END is nonzero, the character that ends the
   number must match END, or an error happens;
   and that character is skipped if it does match.
   If END is zero, *PP is left pointing to that character.  */

static long
read_number (pp, end)
     char **pp;
     int end;
{
  register char *p = *pp;
  register long n = 0;
  register int c;
  int sign = 1;

  /* Handle an optional leading minus sign.  */

  if (*p == '-')
    {
      sign = -1;
      p++;
    }

  /* Read the digits, as far as they go.  */

  while ((c = *p++) >= '0' && c <= '9')
    {
      n *= 10;
      n += c - '0';
    }
  if (end)
    {
      if (c && c != end)
        error ("Invalid symbol data: invalid character \\%03o at symbol pos %d.", c, symnum);
    }
  else
    --p;

  *pp = p;
  return n * sign;
}

/* Read in an argument list. This is a list of types. It is terminated with
   a ':', FYI. Return the list of types read in. */
static struct type **
read_args (pp, end)
     char **pp;
     int end;
{
  struct type *types[1024], **rval; /* allow for fns of 1023 parameters */
  int n = 0;

  while (**pp != end)
    {
      if (**pp != ',')
        error ("Invalid argument list: no ',', at symtab pos %d", symnum);
      *pp += 1;

      /* Check for and handle cretinous dbx symbol name continuation! */
      if (**pp == '\\')
        *pp = next_symbol_text ();
      
      types[n++] = read_type (pp);
    }
  *pp += 1;                     /* get past `end' (the ':' character) */

  if (n == 1)
    {
      rval = (struct type **) xmalloc (2 * sizeof (struct type *));
    }
  else if (TYPE_CODE (types[n-1]) != TYPE_CODE_VOID)
    {
      rval = (struct type **) xmalloc ((n + 1) * sizeof (struct type *));
      bzero (rval + n, sizeof (struct type *));
    }
  else
    {
      rval = (struct type **) xmalloc (n * sizeof (struct type *));
    }
  bcopy (types, rval, n * sizeof (struct type *));
  return rval;
}

/* This function is really horrible, but to avoid it, there would need
   to be more filling in of forward references.  THIS SHOULD BE MOVED OUT 
   OF COFFREAD.C AND DBXREAD.C TO SOME PLACE WHERE IT CAN BE SHARED */
int
fill_in_vptr_fieldno (type)
     struct type *type;
{
  if (TYPE_VPTR_FIELDNO (type) < 0)
    TYPE_VPTR_FIELDNO (type) =
      fill_in_vptr_fieldno (TYPE_BASECLASS (type, 1));
  return TYPE_VPTR_FIELDNO (type);
}

void
_initialize_dbxread ()
{
  symfile = 0;
  header_files = (struct header_file *) 0;
  this_object_header_files = (int *) 0;

  add_com ("symbol-file", class_files, symbol_file_command,
           "Load symbol table (in dbx format) from executable file FILE.");

  add_com ("add-file", class_files, add_file_command,
           "Load the symbols from FILE, assuming its code is at TEXT_START.") ;
}

#endif /* READ_DBX_FORMAT */