/* Demangler for GNU C++ 
   Copyright 1989, 1991 Free Software Foundation, Inc.
   Written by James Clark (jjc@jclark.uucp)
   Rewritten by Fred Fish (fnf@cygnus.com) for ARM and Lucid demangling
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */

/* This is for g++ 1.95.03 (November 13 version).  */

/* This file exports two functions; cplus_mangle_opname and cplus_demangle.

   This file imports xmalloc and xrealloc, which are like malloc and
   realloc except that they generate a fatal error if there is no
   available memory. */

/* GDB-specific, FIXME.  */
#include "defs.h"
#include "demangle.h"

#include <ctype.h>
#include <string.h>

#if !defined (GNU_DEMANGLING) && !defined (ARM_DEMANGLING)
# define GNU_DEMANGLING 1
#endif

/* This is '$' on systems where the assembler can deal with that.
   Where the assembler can't, it's '.' (but on many systems '.' is
   used for other things).  */

#if !defined (CPLUS_MARKER)
#define CPLUS_MARKER '$'
#endif

#ifndef __STDC__
#define const
#endif

/* Stuff that is shared between sub-routines.
 * Using a shared structure allows cplus_demangle to be reentrant. */

struct work_stuff
{
  int options;
  char **typevec;
  int ntypes;
  int typevec_size;
  int constructor;
  int destructor;
  int static_type;	/* A static member function */
  int const_type;	/* A const member function */
};

#define PRINT_ANSI_QUALIFIERS (work -> options & DMGL_ANSI)
#define PRINT_ARG_TYPES       (work -> options & DMGL_PARAMS)

static const struct optable
{
  const char *in;
  const char *out;
  int flags;
} optable[] = {
  "nw",		  " new",	DMGL_ANSI,	/* new (1.92,	 ansi) */
  "dl",		  " delete",	DMGL_ANSI,	/* new (1.92,	 ansi) */
  "new",	  " new",	0,		/* old (1.91,	 and 1.x) */
  "delete",	  " delete",	0,		/* old (1.91,	 and 1.x) */
  "as",		  "=",		DMGL_ANSI,	/* ansi */
  "ne",		  "!=",		DMGL_ANSI,	/* old, ansi */
  "eq",		  "==",		DMGL_ANSI,	/* old,	ansi */
  "ge",		  ">=",		DMGL_ANSI,	/* old,	ansi */
  "gt",		  ">",		DMGL_ANSI,	/* old,	ansi */
  "le",		  "<=",		DMGL_ANSI,	/* old,	ansi */
  "lt",		  "<",		DMGL_ANSI,	/* old,	ansi */
  "plus",	  "+",		0,		/* old */
  "pl",		  "+",		DMGL_ANSI,	/* ansi */
  "apl",	  "+=",		DMGL_ANSI,	/* ansi */
  "minus",	  "-",		0,		/* old */
  "mi",		  "-",		DMGL_ANSI,	/* ansi */
  "ami",	  "-=",		DMGL_ANSI,	/* ansi */
  "mult",	  "*",		0,		/* old */
  "ml",		  "*",		DMGL_ANSI,	/* ansi */
#ifdef ARM_DEMANGLING
  "amu",	  "*=",		DMGL_ANSI,	/* ansi */
#else
  "aml",	  "*=",		DMGL_ANSI,	/* ansi */
#endif
  "convert",	  "+",		0,		/* old (unary +) */
  "negate",	  "-",		0,		/* old (unary -) */
  "trunc_mod",	  "%",		0,		/* old */
  "md",		  "%",		DMGL_ANSI,	/* ansi */
  "amd",	  "%=",		DMGL_ANSI,	/* ansi */
  "trunc_div",	  "/",		0,		/* old */
  "dv",		  "/",		DMGL_ANSI,	/* ansi */
  "adv",	  "/=",		DMGL_ANSI,	/* ansi */
  "truth_andif",  "&&",		0,		/* old */
  "aa",		  "&&",		DMGL_ANSI,	/* ansi */
  "truth_orif",	  "||",		0,		/* old */
  "oo",		  "||",		DMGL_ANSI,	/* ansi */
  "truth_not",	  "!",		0,		/* old */
  "nt",		  "!",		DMGL_ANSI,	/* ansi */
  "postincrement","++",		0,		/* old */
  "pp",		  "++",		DMGL_ANSI,	/* ansi */
  "postdecrement","--",		0,		/* old */
  "mm",		  "--",		DMGL_ANSI,	/* ansi */
  "bit_ior",	  "|",		0,		/* old */
  "or",		  "|",		DMGL_ANSI,	/* ansi */
  "aor",	  "|=",		DMGL_ANSI,	/* ansi */
  "bit_xor",	  "^",		0,		/* old */
  "er",		  "^",		DMGL_ANSI,	/* ansi */
  "aer",	  "^=",		DMGL_ANSI,	/* ansi */
  "bit_and",	  "&",		0,		/* old */
  "ad",		  "&",		DMGL_ANSI,	/* ansi */
  "aad",	  "&=",		DMGL_ANSI,	/* ansi */
  "bit_not",	  "~",		0,		/* old */
  "co",		  "~",		DMGL_ANSI,	/* ansi */
  "call",	  "()",		0,		/* old */
  "cl",		  "()",		DMGL_ANSI,	/* ansi */
  "alshift",	  "<<",		0,		/* old */
  "ls",		  "<<",		DMGL_ANSI,	/* ansi */
  "als",	  "<<=",	DMGL_ANSI,	/* ansi */
  "arshift",	  ">>",		0,		/* old */
  "rs",		  ">>",		DMGL_ANSI,	/* ansi */
  "ars",	  ">>=",	DMGL_ANSI,	/* ansi */
  "component",	  "->",		0,		/* old */
#ifdef LUCID_DEMANGLING
  "pt",		  "->",		DMGL_ANSI,	/* ansi; Lucid C++ form */
#else
  "rf",		  "->",		DMGL_ANSI,	/* ansi */
#endif
  "indirect",	  "*",		0,		/* old */
  "method_call",  "->()",	0,		/* old */
  "addr",	  "&",		0,		/* old (unary &) */
  "array",	  "[]",		0,		/* old */
  "vc",		  "[]",		DMGL_ANSI,	/* ansi */
  "compound",	  ", ",		0,		/* old */
  "cm",		  ", ",		DMGL_ANSI,	/* ansi */
  "cond",	  "?:",		0,		/* old */
  "cn",		  "?:",		DMGL_ANSI,	/* psuedo-ansi */
  "max",	  ">?",		0,		/* old */
  "mx",		  ">?",		DMGL_ANSI,	/* psuedo-ansi */
  "min",	  "<?",		0,		/* old */
  "mn",		  "<?",		DMGL_ANSI,	/* psuedo-ansi */
  "nop",	  "",		0,		/* old (for operator=) */
  "rm",		  "->*",	DMGL_ANSI,	/* ansi */
};


typedef struct string		/* Beware: these aren't required to be */
{				/*  '\0' terminated. */
  char *b;			/* pointer to start of string */
  char *p;			/* pointer after last character */
  char *e;			/* pointer after end of allocated space */
} string;

#define STRING_EMPTY(str)	((str) -> b == (str) -> p)
#define PREPEND_BLANK(str)	{if (!STRING_EMPTY(str)) \
				   string_prepend(str, " ");}
#define APPEND_BLANK(str)	{if (!STRING_EMPTY(str)) \
				   string_append(str, " ");}

/* Prototypes for local functions */

static char *
mop_up PARAMS ((string *, struct work_stuff *, int));

#if 0
static int
demangle_method_args PARAMS ((string *, const char **, struct work_stuff *));
#endif

static int
demangle_template PARAMS ((string *declp, const char **, struct work_stuff *));

static int
demangle_qualified PARAMS ((string *, const char **, struct work_stuff *));

static int
demangle_class PARAMS ((string *, const char **, struct work_stuff *));

static int
demangle_fund_type PARAMS ((const char **, string *, struct work_stuff *));

static int
demangle_signature PARAMS ((string *, const char **, struct work_stuff *));

static int
demangle_prefix PARAMS ((string *, const char **, struct work_stuff *));

static int
gnu_special PARAMS ((string *, const char **, struct work_stuff *));

static void
string_need PARAMS ((string *, int));

static void
string_delete PARAMS ((string *));

static void
string_init PARAMS ((string *));

static void
string_clear PARAMS ((string *));

#if 0
static int
string_empty PARAMS ((string *));
#endif

static void
string_append PARAMS ((string *, const char *));

static void
string_appends PARAMS ((string *, string *));

static void
string_appendn PARAMS ((string *, const char *, int));

static void
string_prepend PARAMS ((string *, const char *));

static void
string_prependn PARAMS ((string *, const char *, int));

static int
get_count PARAMS ((const char **, int *));

static int
consume_count PARAMS ((const char **));

static int
demangle_args PARAMS ((string *, const char **, struct work_stuff *));

static int
do_type PARAMS ((const char **, string *, struct work_stuff *));

static int
do_arg PARAMS ((const char **, string *, struct work_stuff*));

static void
demangle_function_name PARAMS ((string *, const char **, struct work_stuff*,
				const char *));

static void
remember_type PARAMS ((const char *, int, struct work_stuff *));

#if 0
static void
string_prepends PARAMS ((string *, string *));
#endif

/*  Translate count to integer, consuming tokens in the process.
    Conversion terminates on the first non-digit character. */

static int
consume_count (type)
    const char **type;
{
    int count = 0;

    do
      {
	count *= 10;
	count += **type - '0';
	(*type)++;
      } while (isdigit (**type));
    return (count);
}

/* Takes operator name as e.g. "++" and returns mangled
   operator name (e.g. "postincrement_expr"), or NULL if not found.

   If OPTIONS & DMGL_ANSI == 1, return the ANSI name;
   if OPTIONS & DMGL_ANSI == 0, return the old GNU name.  */

char *
cplus_mangle_opname (opname, options)
     char *opname;
     int options;
{
  int i;
  int len;

  len = strlen (opname);
  for (i = 0; i < sizeof (optable) / sizeof (optable[0]); i++)
    {
      if (strlen (optable[i].out) == len
	  && (options & DMGL_ANSI) == (optable[i].flags & DMGL_ANSI)
	  && memcmp (optable[i].out, opname, len) == 0)
	return ((char *)optable[i].in);
    }
  return (0);
}

/* char *cplus_demangle (const char *name, int options)

   If NAME is a mangled function name produced by GNU C++, then
   a pointer to a malloced string giving a C++ representation
   of the name will be returned; otherwise NULL will be returned.
   It is the caller's responsibility to free the string which
   is returned.

   The OPTIONS arg may contain one or more of the following bits:

   	DMGL_ANSI	ANSI qualifiers such as `const' and `void' are
			included.
	DMGL_PARAMS	Function parameters are included.

   For example,
   
   cplus_demangle ("foo__1Ai", DMGL_PARAMS)		=> "A::foo(int)"
   cplus_demangle ("foo__1Ai", DMGL_PARAMS | DMGL_ANSI)	=> "A::foo(int)"
   cplus_demangle ("foo__1Ai", 0)			=> "A::foo"

   cplus_demangle ("foo__1Afe", DMGL_PARAMS)		=> "A::foo(float,...)"
   cplus_demangle ("foo__1Afe", DMGL_PARAMS | DMGL_ANSI)=> "A::foo(float,...)"
   cplus_demangle ("foo__1Afe", 0)			=> "A::foo"

   Note that any leading underscores, or other such characters prepended by
   the compilation system, are presumed to have already been stripped from
   TYPE.  */

char *
cplus_demangle (mangled, options)
     const char *mangled;
     int options;
{
  string decl;
  int success = 0;
  struct work_stuff work[1];
  char *demangled = NULL;

  if ((mangled != NULL) && (*mangled != '\0'))
    {
      memset ((char *) work, 0, sizeof (work));
      work -> options = options;
      
      string_init (&decl);
      success = demangle_prefix (&decl, &mangled, work);
      if (success && (*mangled != '\0'))
	{
	  success = demangle_signature (&decl, &mangled, work);
	}
      demangled = mop_up (&decl, work, success);
    }
  return (demangled);
}

static char *
mop_up (declp, work, success)
     string *declp;
     struct work_stuff *work;
     int success;
{
  int i;
  char *demangled = NULL;

  /* Discard the remembered types, if any. */
  
  for (i = 0; i < work -> ntypes; i++)
    {
      if (work -> typevec[i] != NULL)
	{
	  free (work -> typevec[i]);
	}
    }
  if (work -> typevec != NULL)
    {
      free ((char *) work -> typevec);
    }
  
  /* If demangling was successful, ensure that the demangled string is null
     terminated and return it.  Otherwise, free the demangling decl. */
  
  if (!success)
    {
      string_delete (declp);
    }
  else
    {
      string_appendn (declp, "", 1);
      demangled = declp -> b;
    }
  return (demangled);
}

/*

LOCAL FUNCTION

	demangle_signature -- demangle the signature part of a mangled name

SYNOPSIS

	static int
	demangle_signature (string *declp, const char **mangled,
			    struct work_stuff *work);

DESCRIPTION

	Consume and demangle the signature portion of the mangled name.

	DECLP is the string where demangled output is being built.  At
	entry it contains the demangled root name from the mangled name
	prefix.  I.E. either a demangled operator name or the root function
	name.  In some special cases, it may contain nothing.

	*MANGLED points to the current unconsumed location in the mangled
	name.  As tokens are consumed and demangling is performed, the
	pointer is updated to continuously point at the next token to
	be consumed.

	Demangling GNU style mangled names is nasty because there is no
	explicit token that marks the start of the outermost function
	argument list.
*/

static int
demangle_signature (declp, mangled, work)
     string *declp;
     const char **mangled;
     struct work_stuff *work;
{
  int success = 1;
  int func_done = 0;
#ifdef GNU_DEMANGLING
  int expect_func = 0;
#endif
#ifndef LONGERNAMES
  const char *premangle;
#endif

#ifndef LONGERNAMES
  premangle = *mangled;
#endif

  while (success && (**mangled != '\0'))
    {
      switch (**mangled)
	{
	  case 'Q':
	    success = demangle_qualified (declp, mangled, work);
#ifdef GNU_DEMANGLING
	    expect_func = 1;
#endif
	    break;
	  
	  case 'S':
	    /* Static member function */
	    (*mangled)++;
	    work -> static_type = 1;
	    break;

	  case 'C':
	    /* a const member function */
	    (*mangled)++;
	    work -> const_type = 1;
	    break;
	  
	  case '0': case '1': case '2': case '3': case '4':
	  case '5': case '6': case '7': case '8': case '9':
	    success = demangle_class (declp, mangled, work);
#ifndef LONGERNAMES
	    if (success)
	      {
		remember_type (premangle, *mangled - premangle, work);
	      }
#endif
#ifdef GNU_DEMANGLING
	    expect_func = 1;
#endif
	    break;
	  
	  case 'F':
	    /* Function */
	    /* ARM style demangling includes a specific 'F' character after
	     the class name.  For GNU style, it is just implied.  So we can
	     safely just consume any 'F' at this point and be compatible
	     with either style. */
	    func_done = 1;
	    (*mangled)++;
	    success = demangle_args (declp, mangled, work);
	    break;
	  
	  case 't':
	    /* Template */
	    success = demangle_template (declp, mangled, work);
	    break;

	  case '_':
	    /* At the outermost level, we cannot have a return type specified,
	       so if we run into another '_' at this point we are dealing with
	       a mangled name that is either bogus, or has been mangled by
	       some algorithm we don't know how to deal with.  So just
	       reject the entire demangling. */
	    success = 0;
	    break;

	  default:
#ifdef GNU_DEMANGLING
	    /* Assume we have stumbled onto the first outermost function
	       argument token, and start processing args. */
	    func_done = 1;
	    success = demangle_args (declp, mangled, work);
#else
	    /* Non-GNU demanglers use a specific token to mark the start
	       of the outermost function argument tokens.  Typically 'F',
	       for ARM-demangling, for example.  So if we find something
	       we are not prepared for, it must be an error. */
	    success = 0;
#endif
	    break;
	}
#ifdef GNU_DEMANGLING
      if (success && expect_func)
	{
	  func_done = 1;
	  success = demangle_args (declp, mangled, work);
	}
#endif
    }
  if (success && !func_done)
    {
#ifdef GNU_DEMANGLING
      /* With GNU style demangling, bar__3foo is 'foo::bar(void)', and
	 bar__3fooi is 'foo::bar(int)'.  We get here when we find the
	 first case, and need to ensure that the '(void)' gets added to
	 the current declp.  Note that with ARM_DEMANGLING, the first
	 case represents the name of a static data member 'foo::bar',
	 which is in the current declp, so we leave it alone. */
      success = demangle_args (declp, mangled, work);
#endif
    }
  if (success && work -> static_type && PRINT_ARG_TYPES)
    {
      string_append (declp, " static");
    }
  if (success && work -> const_type && PRINT_ARG_TYPES)
    {
      string_append (declp, " const");
    }
  return (success);
}

#if 0

static int
demangle_method_args (declp, mangled, work)
     string *declp;
     const char **mangled;
     struct work_stuff *work;
{
  int success = 0;

  if (work -> static_type)
    {
      string_append (declp, *mangled + 1);
      *mangled += strlen (*mangled);
      success = 1;
    }
  else
    {
      success = demangle_args (declp, mangled, work);
    }
  return (success);
}

#endif

static int
demangle_template (declp, mangled, work)
     string *declp;
     const char **mangled;
     struct work_stuff *work;
{
  int i;
  string tname;
  string trawname;
  int is_pointer;
  int is_real;
  int is_integral;
  int r;
  int need_comma = 0;
  int success = 0;
  int done;
  const char *old_p;
  int symbol_len;
  string temp;

  (*mangled)++;
  string_init (&tname);
  string_init (&trawname);
  /* get template name */
  if (!get_count (mangled, &r))
    {
      return (0);
    }
  string_appendn (&tname, *mangled, r);
  string_appendn (&trawname, *mangled, r);
  string_appendn (&trawname, "", 1);
  *mangled += r;
  string_append (&tname, "<");
  /* get size of template parameter list */
  if (!get_count (mangled, &r))
    {
      return (0);
    }
  for (i = 0; i < r; i++)
    {
      if (need_comma)
	{
	  string_append (&tname, ", ");
	}
      /* Z for type parameters */
      if (**mangled == 'Z')
	{
	  (*mangled)++;
	  success = do_type (mangled, &temp, work);
	  string_appendn (&temp, "", 1);
	  if (success)
	    {
	      string_append (&tname, temp.b);
	    }
	  string_delete(&temp);
	  if (!success)
	    {
	      break;
	    }
	}
      else
	{
	  /* otherwise, value parameter */
	  old_p  = *mangled;
	  is_pointer = 0;
	  is_real = 0;
	  is_integral = 0;
	  done = 0;
	  success = do_type (mangled, &temp, work);
	  string_appendn (&temp, "", 1);
	  if (success)
	    {
	      string_append (&tname, temp.b);
	    }
	  string_delete(&temp);
	  if (!success)
	    {
	      break;
	    }
	  string_append (&tname, "=");
	  while (*old_p && !done)
	    {	
	      switch (*old_p)
		{
		  case 'P':
		  case 'R':
		    done = is_pointer = 1;
		    break;
		  case 'C':	/* const */
		  case 'S':	/* explicitly signed [char] */
		  case 'U':	/* unsigned */
		  case 'V':	/* volatile */
		  case 'F':	/* function */
		  case 'M':	/* member function */
		  case 'O':	/* ??? */
		    old_p++;
		    continue;
		  case 'Q':	/* repetition of following */
		  case 'T':	/* remembered type */
		    abort ();
		    break;
		  case 'v':	/* void */
		    abort ();
		    break;
		  case 'x':	/* long long */
		  case 'l':	/* long */
		  case 'i':	/* int */
		  case 's':	/* short */
		  case 'c':	/* char */
		    done = is_integral = 1;
		    break;
		  case 'r':	/* long double */
		  case 'd':	/* double */
		  case 'f':	/* float */
		    done = is_real = 1;
		    break;
		  default:
		    abort ();
		}
	    }
	  if (is_integral)
	    {
	      if (**mangled == 'm')
		{
		  string_appendn (&tname, "-", 1);
		  (*mangled)++;
		}
	      while (isdigit (**mangled))	
		{
		  string_appendn (&tname, *mangled, 1);
		  (*mangled)++;
		}
	    }
	  else if (is_real)
	    {
	      if (**mangled == 'm')
		{
		  string_appendn (&tname, "-", 1);
		  (*mangled)++;
		}
	      while (isdigit (**mangled))	
		{
		  string_appendn (&tname, *mangled, 1);
		  (*mangled)++;
		}
	      if (**mangled == '.') /* fraction */
		{
		  string_appendn (&tname, ".", 1);
		  (*mangled)++;
		  while (isdigit (**mangled))	
		    {
		      string_appendn (&tname, *mangled, 1);
		      (*mangled)++;
		    }
		}
	      if (**mangled == 'e') /* exponent */
		{
		  string_appendn (&tname, "e", 1);
		  (*mangled)++;
		  while (isdigit (**mangled))	
		    {
		      string_appendn (&tname, *mangled, 1);
		      (*mangled)++;
		    }
		}
	    }
	  else if (is_pointer)
	    {
	      if (!get_count (mangled, &symbol_len))
		{
		  success = 0;
		  break;
		}
	      string_appendn (&tname, *mangled, symbol_len);
	      *mangled += symbol_len;
	    }
	}
      need_comma = 1;
    }
  string_append (&tname, ">::");
  if (work -> destructor)
    {
      string_append (&tname, "~");
    }
  if (work -> constructor || work -> destructor)
    {
      string_append (&tname, trawname.b);
    }
  string_delete(&trawname);
  
  if (!success)
    {
      string_delete(&tname);
    }
  else
    {
      string_prepend (declp, tname.b);
      string_delete (&tname);
      
      if (work -> static_type)
	{
	  string_append (declp, *mangled + 1);
	  *mangled += strlen (*mangled);
	  success = 1;
	}
      else
	{
	  success = demangle_args (declp, mangled, work);
	}
    }
  return (success);
}

/*

LOCAL FUNCTION

	demangle_class -- demangle a mangled class sequence

SYNOPSIS

	static int
	demangle_class (string *declp, const char **mangled,
			struct work_stuff *work)

DESCRIPTION

	DECLP points to the buffer into which demangling is being done.

	*MANGLED points to the current token to be demangled.  On input,
	it points to a mangled class (I.E. "3foo", "13verylongclass", etc.)
	On exit, it points to the next token after the mangled class on
	success, or the first unconsumed token on failure.

	If the CONSTRUCTOR or DESTRUCTOR flags are set in WORK, then
	we are demangling a constructor or destructor.  In this case
	we prepend "class::class" or "class::~class" to DECLP.

	Otherwise, we prepend "class::" to the current DECLP.

	Reset the constructor/destructor flags once they have been
	"consumed".  This allows demangle_class to be called later during
	the same demangling, to do normal class demangling.

	Returns 1 if demangling is successful, 0 otherwise.

*/

static int
demangle_class (declp, mangled, work)
     string *declp;
     const char **mangled;
     struct work_stuff *work;
{
  int n;
  int success = 0;

  n = consume_count (mangled);
  if (strlen (*mangled) >= n)
    {
      if (work -> constructor || work -> destructor)
	{
	  string_prependn (declp, *mangled, n);
	  if (work -> destructor)
	    {
	      string_prepend (declp, "~");
	    }
	  work -> constructor = work -> destructor = 0;
	}
      string_prepend (declp, "::");
      string_prependn (declp, *mangled, n);
      *mangled += n;
      success = 1;
    }
  return (success);
}

/*

LOCAL FUNCTION

	demangle_prefix -- consume the mangled name prefix and find signature

SYNOPSIS

	static int
	demangle_prefix (string *declp, const char **mangled,
			 struct work_stuff *work)

DESCRIPTION

	Consume and demangle the prefix of the mangled name.

	DECLP points to the string buffer into which demangled output is
	placed.  On entry, the buffer is empty.  On exit it contains
	the root function name, the demangled operator name, or in some
	special cases either nothing or the completely demangled result.

	MANGLED points to the current pointer into the mangled name.  As each
	token of the mangled name is consumed, it is updated.  Upon entry
	the current mangled name pointer points to the first character of
	the mangled name.  Upon exit, it should point to the first character
	of the signature if demangling was successful, or to the first
	unconsumed character if demangling of the prefix was unsuccessful.
	
	Returns 1 on success, 0 otherwise.
 */

static int
demangle_prefix (declp, mangled, work)
     string *declp;
     const char **mangled;
     struct work_stuff *work;
{
  int success = 1;
  const char *scan;

  if ((scan = strstr (*mangled, "__")) == NULL)
    {
      success = gnu_special (declp, mangled, work);
    }
  else if (work -> static_type)
    {
      if (!isdigit (scan[0]) && (scan[0] != 't'))
	{
	  success = 0;
	}
    }
  else if ((scan == *mangled) && (isdigit (scan[2]) || (scan[2] == 'Q')))
    {
      /* A GNU style constructor starts with "__<digit>" or "__Q". */
      work -> constructor = 1;
      *mangled = scan + 2;
    }
  else if ((scan == *mangled) && !isdigit (scan[2]) && (scan[2] != 't'))
    {
      /* Mangled name starts with "__".  Skip over any leading '_' characters,
	 then find the next "__" that separates the prefix from the signature.
	 */
      while (*scan == '_')
	{
	  scan++;
	}
      if ((scan = strstr (scan, "__")) == NULL || (*(scan + 2) == '\0'))
	{
	  /* No separator (I.E. "__not_mangled"), or empty signature
	     (I.E. "__not_mangled_either__") */
	  success = 0;
	}
      else
	{
	  demangle_function_name (declp, mangled, work, scan);
	}
    }
  else if (*(scan + 2) != '\0')
    {
      /* Mangled name does not start with "__" but does have one somewhere
	 in there with non empty stuff after it.  Looks like a global
	 function name. */
      demangle_function_name (declp, mangled, work, scan);
    }
  else
    {
      /* Doesn't look like a mangled name */
      success = 0;
    }
  return (success);
}

/*

LOCAL FUNCTION

	gnu_special -- special handling of gnu mangled strings

SYNOPSIS

	static int
	gnu_special (string *declp, const char **mangled,
		     struct work_stuff *work)


DESCRIPTION

	Process some special GNU style mangling forms that don't fit
	the normal pattern.  For example:

		_$_3foo		(destructor for class foo)
		_vt$foo		(virtual table)
		_3foo$varname	(static data member)
 */

static int
gnu_special (declp, mangled, work)
     string *declp;
     const char **mangled;
     struct work_stuff *work;
{
  int n;
  int success = 1;
  const char *p;

  if ((*mangled)[0] == '_'
      && (*mangled)[1] == CPLUS_MARKER
      && (*mangled)[2] == '_')
    {
      /* Found a GNU style destructor, get past "_<CPLUS_MARKER>_" */
      (*mangled) += 3;
      work -> destructor = 1;
    }
  else if ((*mangled)[0] == '_'
	   && (*mangled)[1] == 'v'
	   && (*mangled)[2] == 't'
	   && (*mangled)[3] == CPLUS_MARKER)
    {
      /* Found a GNU style virtual table, get past "_vt<CPLUS_MARKER>"
         and create the decl.  Note that we consume the entire mangled
	 input string, which means that demangle_signature has no work
	 to do. */
      (*mangled) += 4;
      n = strlen (*mangled);
      string_appendn (declp, *mangled, n);
      string_append (declp, " virtual table");
      (*mangled) += n;
    }
  else if ((*mangled)[0] == '_'
	   && isdigit ((*mangled)[1])
	   && (p = strchr (*mangled, CPLUS_MARKER)) != NULL)
    {
      /* static data member, "_3foo$varname" for example */
      (*mangled)++;
      p++;
      n = consume_count (mangled);
      string_appendn (declp, *mangled, n);
      string_append (declp, "::");
      n = strlen (p);
      string_appendn (declp, p, n);
      (*mangled) = p + n;
    }
  else
    {
      success = 0;
    }
  return (success);
}

/* Do a qualified name, such as "Q25Outer5Inner" for "Outer::Inner" */

static int
demangle_qualified (declp, mangled, work)
     string *declp;
     const char **mangled;
     struct work_stuff *work;
{
  int n;
  string class;
  string tmp;
  int success = 0;

  n = (*mangled)[1] - '0';
  if (n >= 0 && n <= 9)
    {
      if ((*mangled)[2] == '_')
	{
	  /* cfront style */
	  (*mangled)++;
	}
      (*mangled) += 2;
      string_init (&class);
      while (n-- > 0)
	{
	  success = do_type (mangled, &tmp, work);
	  string_appends (&class, &tmp);
	  string_append (&class, "::");
	  if (n == 0 && (work -> constructor || work -> destructor))
	    {
	      if (work -> destructor)
		{
		  string_append (&class, "~");
		}
	      string_appends (&class, &tmp);
	    }
	  string_delete (&tmp);
	}
      work -> constructor = work -> destructor = 0;
      string_prependn (declp, class.b, class.p - class.b);
      string_delete (&class);
    }
  return (success);
}

/*

LOCAL FUNCTION

	get_count -- convert an ascii count to integer, consuming tokens

SYNOPSIS

	static int
	get_count (const char **type, int *count)

DESCRIPTION

	Return 0 if no conversion is performed, 1 if a string is converted.
*/

static int
get_count (type, count)
     const char **type;
     int *count;
{
  const char *p;
  int n;

  if (!isdigit (**type))
    {
      return (0);
    }
  else
    {
      *count = **type - '0';
      (*type)++;
      if (isdigit (**type))
	{
	  p = *type;
	  n = *count;
	  do 
	    {
	      n *= 10;
	      n += *p - '0';
	      p++;
	    } 
	  while (isdigit (*p));
	  if (*p == '_')
	    {
	      *type = p + 1;
	      *count = n;
	    }
	}
    }
  return (1);
}

/* result will be initialised here; it will be freed on failure */

static int
do_type (type, result, work)
     const char **type;
     string *result;
     struct work_stuff *work;
{
  int n;
  int done;
  int success;
  string decl;
  const char *remembered_type;
  int constp;
  int volatilep;

  string_init (&decl);
  string_init (result);

  done = 0;
  success = 1;
  while (success && !done)
    {
      int member;
      switch (**type)
	{
	/* A qualified name, such as "Outer::Inner".  Note qualifier count
	   is limited to a single digit (0-9 qualifiers). */
	case 'Q':
	  n = (*type)[1] - '0';
	  if (n < 0 || n > 9)
	    {
	      success = 0;
	    }
	  if ((*type)[2] == '_') /* cfront style */
	    {
	      (*type)++;
	    }
	  *type += 2;
	  while (n-- > 0)
	    {
	      do_type (type, result, work);
	    }
	  break;

	/* A pointer type */
	case 'P':
	  (*type)++;
	  string_prepend (&decl, "*");
	  break;

	/* A reference type */
	case 'R':
	  (*type)++;
	  string_prepend (&decl, "&");
	  break;

	/* A back reference to a previously seen type */
	case 'T':
	  (*type)++;
	  if (!get_count (type, &n) || n >= work -> ntypes)
	    {
	      success = 0;
	    }
	  else
	    {
	      remembered_type = work -> typevec[n];
	      type = &remembered_type;
	    }
	  break;

	/* A function */
	case 'F':
	  (*type)++;
	  if (!STRING_EMPTY (&decl) && decl.b[0] == '*')
	    {
	      string_prepend (&decl, "(");
	      string_append (&decl, ")");
	    }
	  /* After picking off the function args, we expect to either find the
	     function return type (preceded by an '_') or the end of the
	     string. */
	  if (!demangle_args (&decl, type, work)
	      || (**type != '_' && **type != '\0'))
	    {
	      success = 0;
	    }
	  if (success && (**type == '_'))
	    {
	      (*type)++;
	    }
	  break;

	case 'M':
	case 'O':
	  {
	    constp = 0;
	    volatilep = 0;

	    member = **type == 'M';
	    (*type)++;
	    if (!isdigit (**type))
	      {
		success = 0;
		break;
	      }
	    n = consume_count (type);
	    if (strlen (*type) < n)
	      {
		success = 0;
		break;
	      }
	    string_append (&decl, ")");
	    string_prepend (&decl, "::");
	    string_prependn (&decl, *type, n);
	    string_prepend (&decl, "(");
	    *type += n;
	    if (member)
	      {
		if (**type == 'C')
		  {
		    (*type)++;
		    constp = 1;
		  }
		if (**type == 'V')
		  {
		    (*type)++;
		    volatilep = 1;
		  }
		if (*(*type)++ != 'F')
		  {
		    success = 0;
		    break;
		  }
	      }
	    if ((member && !demangle_args (&decl, type, work))
		|| **type != '_')
	      {
		success = 0;
		break;
	      }
	    (*type)++;
	    if (! PRINT_ANSI_QUALIFIERS)
	      {
		break;
	      }
	    if (constp)
	      {
		APPEND_BLANK (&decl);
		string_append (&decl, "const");
	      }
	    if (volatilep)
	      {
		APPEND_BLANK (&decl);
		string_append (&decl, "volatile");
	      }
	    break;
	  }

	case 'C':
	  if ((*type)[1] == 'P')
	    {
	      (*type)++;
	      if (PRINT_ANSI_QUALIFIERS)
		{
		  if (!STRING_EMPTY (&decl))
		    {
		      string_prepend (&decl, " ");
		    }
		  string_prepend (&decl, "const");
		}
	      break;
	    }

	  /* fall through */
	default:
	  done = 1;
	  break;
	}
    }

  success = demangle_fund_type (type, result, work);

  if (success)
    {
      if (!STRING_EMPTY (&decl))
	{
	  string_append (result, " ");
	  string_appends (result, &decl);
	}
    }
  else
    {
      string_delete (result);
    }
  string_delete (&decl);
  return (success);
}

/* Given a pointer to a type string that represents a fundamental type
   argument (int, long, unsigned int, etc) in TYPE, a pointer to the
   string in which the demangled output is being built in RESULT, and
   the WORK structure, decode the types and add them to the result.

   For example:

   	"Ci"	=>	"const int"
	"Sl"	=>	"signed long"
	"CUs"	=>	"const unsigned short"

   */

static int
demangle_fund_type (type, result, work)
     const char **type;
     string *result;
     struct work_stuff *work;
{
  int done = 0;
  int success = 1;
  int n;

  /* First pick off any type qualifiers.  There can be more than one. */

  while (!done)
    {
      switch (**type)
	{
	  case 'C':
	    (*type)++;
	    if (PRINT_ANSI_QUALIFIERS)
	      {
		APPEND_BLANK (result);
		string_append (result, "const");
	      }
	    break;
	  case 'U':
	    (*type)++;
	    APPEND_BLANK (result);
	    string_append (result, "unsigned");
	    break;
	  case 'S': /* signed char only */
	    (*type)++;
	    APPEND_BLANK (result);
	    string_append (result, "signed");
	    break;
	  case 'V':
	    (*type)++;
	    if (PRINT_ANSI_QUALIFIERS)
	      {
		APPEND_BLANK (result);
		string_append (result, "volatile");
	      }
	    break;
	  default:
	    done = 1;
	    break;
	}
    }

  /* Now pick off the fundamental type.  There can be only one. */

  switch (**type)
    {
      case '\0':
      case '_':
	break;
      case 'v':
	(*type)++;
	APPEND_BLANK (result);
	string_append (result, "void");
	break;
      case 'x':
	(*type)++;
	APPEND_BLANK (result);
	string_append (result, "long long");
	break;
      case 'l':
	(*type)++;
	APPEND_BLANK (result);
	string_append (result, "long");
	break;
      case 'i':
	(*type)++;
	APPEND_BLANK (result);
	string_append (result, "int");
	break;
      case 's':
	(*type)++;
	APPEND_BLANK (result);
	string_append (result, "short");
	break;
      case 'c':
	(*type)++;
	APPEND_BLANK (result);
	string_append (result, "char");
	break;
      case 'r':
	(*type)++;
	APPEND_BLANK (result);
	string_append (result, "long double");
	break;
      case 'd':
	(*type)++;
	APPEND_BLANK (result);
	string_append (result, "double");
	break;
      case 'f':
	(*type)++;
	APPEND_BLANK (result);
	string_append (result, "float");
	break;
      case 'G':
	(*type)++;
	if (!isdigit (**type))
	  {
	    success = 0;
	    break;
	  }
	/* fall through */
      /* An explicit type, such as "6mytype" or "7integer" */
      case '0':
      case '1':
      case '2':
      case '3':
      case '4':
      case '5':
      case '6':
      case '7':
      case '8':
      case '9':
	n = consume_count (type);
	if (strlen (*type) < n)
	  {
	    success = 0;
	    break;
	  }
	APPEND_BLANK (result);
	string_appendn (result, *type, n);
	*type += n;
	break;
      default:
	success = 0;
	break;
      }

  return (success);
}

/* `result' will be initialized in do_type; it will be freed on failure */

static int
do_arg (type, result, work)
     const char **type;
     string *result;
     struct work_stuff *work;
{
  const char *start = *type;

  if (!do_type (type, result, work))
    {
      return (0);
    }
  else
    {
      remember_type (start, *type - start, work);
      return (1);
    }
}

static void
remember_type (start, len, work)
     const char *start;
     int len;
     struct work_stuff *work;
{
  char *tem;

  if (work -> ntypes >= work -> typevec_size)
    {
      if (work -> typevec_size == 0)
	{
	  work -> typevec_size = 3;
	  work -> typevec =
	    (char **) xmalloc (sizeof (char *) * work -> typevec_size);
	}
      else
	{
	  work -> typevec_size *= 2;
	  work -> typevec =
	    (char **) xrealloc ((char *)work -> typevec,
				sizeof (char *) * work -> typevec_size);
	}
    }
  tem = (char *) xmalloc (len + 1);
  memcpy (tem, start, len);
  tem[len] = '\0';
  work -> typevec[work -> ntypes++] = tem;
}

/* Process the argument list part of the signature, after any class spec
   has been consumed, as well as the first 'F' character (if any).  For
   example:

   "__als__3fooRT0"		=>	process "RT0"
   "complexfunc5__FPFPc_PFl_i"	=>	process "PFPc_PFl_i"

   DECLP must be already initialised, usually non-empty.  It won't be freed
   on failure */

static int
demangle_args (declp, type, work)
     string *declp;
     const char **type;
     struct work_stuff *work;
{
  string arg;
  int need_comma = 0;
  int r;
  int t;
  const char *tem;
  char temptype;

  if (PRINT_ARG_TYPES)
    {
      string_append (declp, "(");
      if (**type == '\0')
	{
	  string_append (declp, "void");
	}
    }

  while (**type != '_' && **type != '\0' && **type != 'e')
    {
      if ((**type == 'N') || (**type == 'T'))
	{
	  temptype = *(*type)++;
	  
	  if (temptype == 'N')
	    {
	      if (!get_count (type, &r))
		{
		  return (0);
		}
	    }
	  else
	    {
	      r = 1;
	    }
	  if (!get_count (type, &t))
	    {
	      return (0);
	    }
#ifdef ARM_DEMANGLING
	  t--;
#endif
	  /* Validate the type index.  Protect against illegal indices from
	     malformed type strings. */
	  if ((t < 0) || (t >= work -> ntypes))
	    {
	      return (0);
	    }
	  while (--r >= 0)
	    {
	      tem = work -> typevec[t];
	      if (need_comma && PRINT_ARG_TYPES)
		{
		  string_append (declp, ", ");
		}
	      if (!do_arg (&tem, &arg, work))
		{
		  return (0);
		}
	      if (PRINT_ARG_TYPES)
		{
		  string_appends (declp, &arg);
		}
	      string_delete (&arg);
	      need_comma = 1;
	    }
	}
      else
	{
	  if (need_comma & PRINT_ARG_TYPES)
	    {
	      string_append (declp, ", ");
	    }
	  if (!do_arg (type, &arg, work))
	    {
	      return (0);
	    }
	  if (PRINT_ARG_TYPES)
	    {
	      string_appends (declp, &arg);
	    }
	  string_delete (&arg);
	  need_comma = 1;
	}
    }

  if (**type == 'e')
    {
      (*type)++;
      if (PRINT_ARG_TYPES)
	{
	  if (need_comma)
	    {
	      string_append (declp, ",");
	    }
	  string_append (declp, "...");
	}
    }

  if (PRINT_ARG_TYPES)
    {
      string_append (declp, ")");
    }
  return (1);
}

static void
demangle_function_name (declp, mangled, work, scan)
     string *declp;
     const char **mangled;
     struct work_stuff *work;
     const char *scan;
{
  int i;
  int len;
  string type;
  const char *tem;

  string_appendn (declp, (*mangled), scan - (*mangled));
  string_need (declp, 1);
  *(declp -> p) = '\0';

  /* Consume the function name, including the "__" separating the name
     from the signature.  We are guaranteed that SCAN points to the
     separator. */

  (*mangled) = scan + 2;

#ifdef ARM_DEMANGLING

  /* See if we have an ARM style constructor or destructor operator.
     If so, then just record it, clear the decl, and return.
     We can't build the actual constructor/destructor decl until later,
     when we recover the class name from the signature. */

  if (strcmp (declp -> b, "__ct") == 0)
    {
      work -> constructor = 1;
      string_clear (declp);
      return;
    }
  else if (strcmp (declp -> b, "__dt") == 0)
    {
      work -> destructor = 1;
      string_clear (declp);
      return;
    }

#endif

  if (declp->p - declp->b >= 3 
      && declp->b[0] == 'o'
      && declp->b[1] == 'p'
      && declp->b[2] == CPLUS_MARKER)
    {
      /* see if it's an assignment expression */
      if (declp->p - declp->b >= 10 /* op$assign_ */
	  && memcmp (declp->b + 3, "assign_", 7) == 0)
	{
	  for (i = 0; i < sizeof (optable) / sizeof (optable[0]); i++)
	    {
	      len = declp->p - declp->b - 10;
	      if (strlen (optable[i].in) == len
		  && memcmp (optable[i].in, declp->b + 10, len) == 0)
		{
		  string_clear (declp);
		  string_append (declp, "operator");
		  string_append (declp, optable[i].out);
		  string_append (declp, "=");
		  break;
		}
	    }
	}
      else
	{
	  for (i = 0; i < sizeof (optable) / sizeof (optable[0]); i++)
	    {
	      int len = declp->p - declp->b - 3;
	      if (strlen (optable[i].in) == len 
		  && memcmp (optable[i].in, declp->b + 3, len) == 0)
		{
		  string_clear (declp);
		  string_append (declp, "operator");
		  string_append (declp, optable[i].out);
		  break;
		}
	    }
	}
    }
  else if (declp->p - declp->b >= 5 && memcmp (declp->b, "type$", 5) == 0)
    {
      /* type conversion operator */
      tem = declp->b + 5;
      if (do_type (&tem, &type, work))
	{
	  string_clear (declp);
	  string_append (declp, "operator ");
	  string_appends (declp, &type);
	  string_delete (&type);
	}
    }
  else if (declp->b[2] == 'o' && declp->b[3] == 'p')
    {
      /* ANSI.  */
      /* type conversion operator.  */
      tem = declp->b + 4;
      if (do_type (&tem, &type, work))
	{
	  string_clear (declp);
	  string_append (declp, "operator ");
	  string_appends (declp, &type);
	  string_delete (&type);
	}
    }
  else if (declp->b[0] == '_' && declp->b[1] == '_'
	   && declp->b[2] >= 'a' && declp->b[2] <= 'z'
	   && declp->b[3] >= 'a' && declp->b[3] <= 'z')
    {
      if (declp->b[4] == '\0')
	{
	  /* Operator.  */
	  for (i = 0; i < sizeof (optable) / sizeof (optable[0]); i++)
	    {
	      if (strlen (optable[i].in) == 2
		  && memcmp (optable[i].in, declp->b + 2, 2) == 0)
		{
		  string_clear (declp);
		  string_append (declp, "operator");
		  string_append (declp, optable[i].out);
		  break;
		}
	    }
	}
      else
	{
	  if (declp->b[2] == 'a' && declp->b[5] == '\0')
	    {
	      /* Assignment. */
	      for (i = 0; i < sizeof (optable) / sizeof (optable[0]); i++)
		{
		  if (strlen (optable[i].in) == 3
		      && memcmp (optable[i].in, declp->b + 2, 3) == 0)
		    {
		      string_clear (declp);
		      string_append (declp, "operator");
		      string_append (declp, optable[i].out);
		      break;
		    }		      
		}
	    }
	}
    }
}

/* a mini string-handling package */

static void
string_need (s, n)
     string *s;
     int n;
{
  int tem;

  if (s->b == NULL)
    {
      if (n < 32)
	{
	  n = 32;
	}
      s->p = s->b = (char *) xmalloc (n);
      s->e = s->b + n;
    }
  else if (s->e - s->p < n)
    {
      tem = s->p - s->b;
      n += tem;
      n *= 2;
      s->b = (char *) xrealloc (s->b, n);
      s->p = s->b + tem;
      s->e = s->b + n;
    }
}

static void
string_delete (s)
     string *s;
{
  if (s->b != NULL)
    {
      free (s->b);
      s->b = s->e = s->p = NULL;
    }
}

static void
string_init (s)
     string *s;
{
  s->b = s->p = s->e = NULL;
}

static void 
string_clear (s)
     string *s;
{
  s->p = s->b;
}

#if 0

static int
string_empty (s)
     string *s;
{
  return (s->b == s->p);
}

#endif

static void
string_append (p, s)
     string *p;
     const char *s;
{
  int n;
  if (s == NULL || *s == '\0')
    return;
  n = strlen (s);
  string_need (p, n);
  memcpy (p->p, s, n);
  p->p += n;
}

static void
string_appends (p, s)
     string *p, *s;
{
  int n;

  if (s->b != s->p)
    {
      n = s->p - s->b;
      string_need (p, n);
      memcpy (p->p, s->b, n);
      p->p += n;
    }
}

static void
string_appendn (p, s, n)
     string *p;
     const char *s;
     int n;
{
  if (n != 0)
    {
      string_need (p, n);
      memcpy (p->p, s, n);
      p->p += n;
    }
}

static void
string_prepend (p, s)
     string *p;
     const char *s;
{
  if (s != NULL && *s != '\0')
    {
      string_prependn (p, s, strlen (s));
    }
}

#if 0

static void
string_prepends (p, s)
     string *p, *s;
{
  if (s->b != s->p)
    {
      string_prependn (p, s->b, s->p - s->b);
    }
}

#endif

static void
string_prependn (p, s, n)
     string *p;
     const char *s;
     int n;
{
  char *q;

  if (n != 0)
    {
      string_need (p, n);
      for (q = p->p - 1; q >= p->b; q--)
	{
	  q[n] = q[0];
	}
      memcpy (p->b, s, n);
      p->p += n;
    }
}

/* To generate a standalone demangler program for testing purposes, just
   compile and link this file with -DMAIN.   When run, it demangles each
   command line arg, or each stdin string, and prints the result on stdout. */

#ifdef MAIN

static void
demangle_it (mangled_name)
  char *mangled_name;
{
  char *result;

  result = cplus_demangle (mangled_name, DMGL_PARAMS | DMGL_ANSI);
  if (result == NULL)
    {
      printf ("%s\n", mangled_name);
    }
  else
    {
      printf ("%s\n", result);
      free (result);
    }
}

PTR
xmalloc (size)
    long size;
{
  PTR newmem;

  if ((newmem = malloc ((int) size)) == NULL)
    {
      fprintf (stderr, "\nCan't allocate %u bytes\n", size);
      exit (1);
    }
  return (newmem);
}

PTR
xrealloc (oldmem, size)
    PTR oldmem;
    long size;
{
  PTR newmem;

  if ((newmem = realloc ((char *) oldmem, (int) size)) == NULL)
    {
      fprintf (stderr, "\nCan't reallocate %u bytes\n", size);
      exit (1);
    }
  return (newmem);
}

main (argc, argv)
  int argc;
  char **argv;
{
  char mangled_name[128];
  char *result;
  
  if (argc > 1)
    {
      argc--;
      argv++;
      while (argc-- > 0)
	{
	  demangle_it (*argv);
	}
    }
  else
    {
      while (gets (mangled_name))
	{
	  demangle_it (mangled_name);
	}
    }
}

#endif