cplus-dem.c

gcc库的原代码,对编程有很大帮助.

    string_appendn (declp, *mangled, p - *mangled);
    string_append (declp, "<");
    /* should do error checking here */
    while (args < e) {
      string_clear (&arg);
      do_type (work, &args, &arg);
      string_appends (declp, &arg);
      string_append (declp, ",");
    }
    string_delete (&arg);
    --declp->p;
    string_append (declp, ">");
  }
  else
  {
    string_appendn (declp, *mangled, n);
  }
  *mangled += n;
}

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

  n = consume_count (mangled);
  if (strlen (*mangled) >= n)
  {
    demangle_arm_pt (work, mangled, n, declp);
    success = 1;
  }

  return (success);
}

/*

LOCAL FUNCTION

	demangle_class -- demangle a mangled class sequence

SYNOPSIS

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

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

  string_init (&class_name);
  if (demangle_class_name (work, mangled, &class_name))
    {
      if ((work->constructor & 1) || (work->destructor & 1))
	{
	  string_prepends (declp, &class_name);
	  if (work -> destructor & 1)
	    {
	      string_prepend (declp, "~");
              work -> destructor -= 1;
	    }
	  else
	    {
	      work -> constructor -= 1; 
	    }
	}
      string_prepend (declp, "::");
      string_prepends (declp, &class_name);
      success = 1;
    }
  string_delete (&class_name);
  return (success);
}

/*

LOCAL FUNCTION

	demangle_prefix -- consume the mangled name prefix and find signature

SYNOPSIS

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

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

  if (strlen(*mangled) >= 11 && strncmp(*mangled, "_GLOBAL_", 8) == 0)
    {
      char *marker = strchr (cplus_markers, (*mangled)[8]);
      if (marker != NULL && *marker == (*mangled)[10])
	{
	  if ((*mangled)[9] == 'D')
	    {
	      /* it's a GNU global destructor to be executed at program exit */
	      (*mangled) += 11;
	      work->destructor = 2;
	      if (gnu_special (work, mangled, declp))
		return success;
	    }
	  else if ((*mangled)[9] == 'I')
	    {
	      /* it's a GNU global constructor to be executed at program init */
	      (*mangled) += 11;
	      work->constructor = 2;
	      if (gnu_special (work, mangled, declp))
		return success;
	    }
	}
    }
  else if (ARM_DEMANGLING && strncmp(*mangled, "__std__", 7) == 0)
    {
      /* it's a ARM global destructor to be executed at program exit */
      (*mangled) += 7;
      work->destructor = 2;
    }
  else if (ARM_DEMANGLING && strncmp(*mangled, "__sti__", 7) == 0)
    {
      /* it's a ARM global constructor to be executed at program initial */
      (*mangled) += 7;
      work->constructor = 2;
    }

/*  This block of code is a reduction in strength time optimization
    of:
    	scan = mystrstr (*mangled, "__"); */

  {
    scan = *mangled;

    do {
      scan = strchr (scan, '_');
    } while (scan != NULL && *++scan != '_');

    if (scan != NULL) --scan;
  }

  if (scan != NULL)
    {
      /* We found a sequence of two or more '_', ensure that we start at
	 the last pair in the sequence. */
      i = strspn (scan, "_");
      if (i > 2)
	{
	  scan += (i - 2); 
	}
    }
 
  if (scan == NULL)
    {
      success = 0;
    }
  else if (work -> static_type)
    {
      if (!isdigit (scan[0]) && (scan[0] != 't'))
	{
	  success = 0;
	}
    }
  else if ((scan == *mangled) &&
	   (isdigit (scan[2]) || (scan[2] == 'Q') || (scan[2] == 't')))
    {
      /* The ARM says nothing about the mangling of local variables.
	 But cfront mangles local variables by prepending __<nesting_level>
	 to them. As an extension to ARM demangling we handle this case.  */
      if ((LUCID_DEMANGLING || ARM_DEMANGLING) && isdigit (scan[2]))
	{
	  *mangled = scan + 2;
	  consume_count (mangled);
	  string_append (declp, *mangled);
	  *mangled += strlen (*mangled);
	  success = 1; 
	}
      else
	{
	  /* A GNU style constructor starts with __[0-9Qt].  But cfront uses
	     names like __Q2_3foo3bar for nested type names.  So don't accept
	     this style of constructor for cfront demangling.  */
	  if (!(LUCID_DEMANGLING || ARM_DEMANGLING))
	    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.
	 */
      if (!(ARM_DEMANGLING || LUCID_DEMANGLING)
	  || (arm_special (work, mangled, declp) == 0))
	{
	  while (*scan == '_')
	    {
	      scan++;
	    }
	  if ((scan = mystrstr (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 (work, mangled, declp, scan);
	    }
	}
    }
  else if (ARM_DEMANGLING && scan[2] == 'p' && scan[3] == 't')
    {
      /* Cfront-style parameterized type.  Handled later as a signature. */
      success = 1;

      /* ARM template? */
      demangle_arm_pt (work, mangled, strlen (*mangled), declp);
    }
  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 (work, mangled, declp, scan);
    }
  else
    {
      /* Doesn't look like a mangled name */
      success = 0;
    }

  if (!success && (work->constructor == 2 || work->destructor == 2))
    {
      string_append (declp, *mangled);
      *mangled += strlen (*mangled);
      success = 1;
    } 
  return (success);
}

/*

LOCAL FUNCTION

	gnu_special -- special handling of gnu mangled strings

SYNOPSIS

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


DESCRIPTION

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

		_$_3foo		(destructor for class foo)
		_vt$foo		(foo virtual table)
		_vt$foo$bar	(foo::bar virtual table)
		__vt_foo	(foo virtual table, new style with thunks)
		_3foo$varname	(static data member)
		_Q22rs2tu$vw	(static data member)
		__t6vector1Zii	(constructor with template)
		__thunk_4__$_7ostream (virtual function thunk)
 */

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

  if ((*mangled)[0] == '_'
      && strchr (cplus_markers, (*mangled)[1]) != NULL
      && (*mangled)[2] == '_')
    {
      /* Found a GNU style destructor, get past "_<CPLUS_MARKER>_" */
      (*mangled) += 3;
      work -> destructor += 1;
    }
  else if ((*mangled)[0] == '_'
	   && (((*mangled)[1] == '_'
		&& (*mangled)[2] == 'v'
		&& (*mangled)[3] == 't'
		&& (*mangled)[4] == '_')
	     || ((*mangled)[1] == 'v'
		 && (*mangled)[2] == 't'
		 && strchr (cplus_markers, (*mangled)[3]) != NULL)))
    {
      /* 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. */
      if ((*mangled)[2] == 'v')
	(*mangled) += 5; /* New style, with thunks: "__vt_" */
      else
	(*mangled) += 4; /* Old style, no thunks: "_vt<CPLUS_MARKER>" */
      while (**mangled != '\0')
	{
	  p = strpbrk (*mangled, cplus_markers);
	  switch (**mangled)
	    {
	    case 'Q':
	      success = demangle_qualified (work, mangled, declp, 0, 1);
	      break;
	    case 't':
	      success = demangle_template (work, mangled, declp, 0);
	      break;
	    default:
	      if (isdigit(*mangled[0]))
		{
		  n = consume_count(mangled);
		}
	      else
		{
		  n = strcspn (*mangled, cplus_markers);
		}
	      string_appendn (declp, *mangled, n);
	      (*mangled) += n;
	    }

	  if (success && ((p == NULL) || (p == *mangled)))
	    {
	      if (p != NULL)
		{
		  string_append (declp, "::");
		  (*mangled)++;
		}
	    }
	  else
	    {
	      success = 0;
	      break;
	    }
	}
      if (success)
	string_append (declp, " virtual table");
    }
  else if ((*mangled)[0] == '_'
	   && (strchr("0123456789Qt", (*mangled)[1]) != NULL)
	   && (p = strpbrk (*mangled, cplus_markers)) != NULL)
    {
      /* static data member, "_3foo$varname" for example */
      (*mangled)++;
      switch (**mangled)
	{
	  case 'Q':
	    success = demangle_qualified (work, mangled, declp, 0, 1);
	    break;
	  case 't':
	    success = demangle_template (work, mangled, declp, 0);
	    break;
	  default:
	    n = consume_count (mangled);
	    string_appendn (declp, *mangled, n);
	    (*mangled) += n;
	}
      if (success && (p == *mangled))
	{
	  /* Consumed everything up to the cplus_marker, append the
	     variable name. */
	  (*mangled)++;
	  string_append (declp, "::");
	  n = strlen (*mangled);
	  string_appendn (declp, *mangled, n);
	  (*mangled) += n;
	}
      else
	{
	  success = 0;
	}
    }
  else if (strncmp (*mangled, "__thunk_", 8) == 0)
    {
      int delta = ((*mangled) += 8, consume_count (mangled));
      char *method = cplus_demangle (++*mangled, work->options);
      if (method)
	{
	  char buf[50];
	  sprintf (buf, "virtual function thunk (delta:%d) for ", -delta);
	  string_append (declp, buf);
	  string_append (declp, method);
	  free (method);
	  n = strlen (*mangled);
	  (*mangled) += n;
	}
      else
	{
	  success = 0;
	}
    }
  else
    {
      success = 0;
    }
  return (success);
}

/*

LOCAL FUNCTION

	arm_special -- special handling of ARM/lucid mangled strings

SYNOPSIS

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


DESCRIPTION

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

		__vtbl__3foo		(foo virtual table)
		__vtbl__3foo__3bar	(bar::foo virtual table)

 */

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

  if (strncmp (*mangled, ARM_VTABLE_STRING, ARM_VTABLE_STRLEN) == 0)
    {
      /* Found a ARM style virtual table, get past ARM_VTABLE_STRING
         and create the decl.  Note that we consume the entire mangled
	 input string, which means that demangle_signature has no work
	 to do. */
      scan = *mangled + ARM_VTABLE_STRLEN;
      while (*scan != '\0')        /* first check it can be demangled */
        {
          n = consume_count (&scan);
          if (n==0)
	    {
	      return (0);           /* no good */
	    }
          scan += n;
          if (scan[0] == '_' && scan[1] == '_')
	    {
	      scan += 2;
	    }
        }
      (*mangled) += ARM_VTABLE_STRLEN;
      while (**mangled != '\0')
	{
	  n = consume_count (mangled);
	  string_prependn (declp, *mangled, n);
	  (*mangled) += n;
	  if ((*mangled)[0] == '_' && (*mangled)[1] == '_')
	    {
	      string_prepend (declp, "::");
	      (*mangled) += 2;
	    }
	}
      string_append (declp, " virtual table");
    }
  else
    {
      success = 0;
    }
  return (success);
}

/*

LOCAL FUNCTION

	demangle_qualified -- demangle 'Q' qualified name strings

SYNOPSIS

	static int
	demangle_qualified (struct work_stuff *, const char *mangled,
			    string *result, int isfuncname, int append);

DESCRIPTION

	Demangle a qualified name, such as "Q25Outer5Inner" which is
	the mangled form of "Outer::Inner".  The demangled output is
	prepended or appended to the result string according to the
	state of the append flag.

	If isfuncname is nonzero, then the qualified name we are building
	is going to be used as a member function name, so if it is a
	constructor or destructor function, append an appropriate
	constructor or destructor name.  I.E. for the above example,
	the result for use as a constructor is "Outer::Inner::Inner"
	and the result for use as a destructor is "Outer::Inner::~Inner".

BUGS