1 // SGI's rope class implementation -*- C++ -*-
2 
3 // Copyright (C) 2001-2018 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library.  This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 // GNU General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 /*
26  * Copyright (c) 1997
27  * Silicon Graphics Computer Systems, Inc.
28  *
29  * Permission to use, copy, modify, distribute and sell this software
30  * and its documentation for any purpose is hereby granted without fee,
31  * provided that the above copyright notice appear in all copies and
32  * that both that copyright notice and this permission notice appear
33  * in supporting documentation.  Silicon Graphics makes no
34  * representations about the suitability of this software for any
35  * purpose.  It is provided "as is" without express or implied warranty.
36  */
37 
38 /** @file ropeimpl.h
39  *  This is an internal header file, included by other library headers.
40  *  Do not attempt to use it directly. @headername{ext/rope}
41  */
42 
43 #include <cstdio>
44 #include <ostream>
45 #include <bits/functexcept.h>
46 
47 #include <ext/algorithm> // For copy_n and lexicographical_compare_3way
48 #include <ext/memory> // For uninitialized_copy_n
49 #include <ext/numeric> // For power
50 
51 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
52 {
53 _GLIBCXX_BEGIN_NAMESPACE_VERSION
54 
55   using std::size_t;
56   using std::printf;
57   using std::basic_ostream;
58   using std::__throw_length_error;
59   using std::_Destroy;
60   using std::__uninitialized_fill_n_a;
61 
62   // Set buf_start, buf_end, and buf_ptr appropriately, filling tmp_buf
63   // if necessary.  Assumes _M_path_end[leaf_index] and leaf_pos are correct.
64   // Results in a valid buf_ptr if the iterator can be legitimately
65   // dereferenced.
66   template <class _CharT, class _Alloc>
67     void
68     _Rope_iterator_base<_CharT, _Alloc>::
69     _S_setbuf(_Rope_iterator_base<_CharT, _Alloc>& __x)
70     {
71       const _RopeRep* __leaf = __x._M_path_end[__x._M_leaf_index];
72       size_t __leaf_pos = __x._M_leaf_pos;
73       size_t __pos = __x._M_current_pos;
74 
75       switch(__leaf->_M_tag)
76 	{
77 	case __detail::_S_leaf:
78 	  __x._M_buf_start = ((_Rope_RopeLeaf<_CharT, _Alloc>*)__leaf)->_M_data;
79 	  __x._M_buf_ptr = __x._M_buf_start + (__pos - __leaf_pos);
80 	  __x._M_buf_end = __x._M_buf_start + __leaf->_M_size;
81 	  break;
82 	case __detail::_S_function:
83 	case __detail::_S_substringfn:
84 	  {
85 	    size_t __len = _S_iterator_buf_len;
86 	    size_t __buf_start_pos = __leaf_pos;
87 	    size_t __leaf_end = __leaf_pos + __leaf->_M_size;
88 	    char_producer<_CharT>* __fn = ((_Rope_RopeFunction<_CharT,
89 					    _Alloc>*)__leaf)->_M_fn;
90 	    if (__buf_start_pos + __len <= __pos)
91 	      {
92 		__buf_start_pos = __pos - __len / 4;
93 		if (__buf_start_pos + __len > __leaf_end)
94 		  __buf_start_pos = __leaf_end - __len;
95 	      }
96 	    if (__buf_start_pos + __len > __leaf_end)
97 	      __len = __leaf_end - __buf_start_pos;
98 	    (*__fn)(__buf_start_pos - __leaf_pos, __len, __x._M_tmp_buf);
99 	    __x._M_buf_ptr = __x._M_tmp_buf + (__pos - __buf_start_pos);
100 	    __x._M_buf_start = __x._M_tmp_buf;
101 	    __x._M_buf_end = __x._M_tmp_buf + __len;
102 	  }
103 	  break;
104 	default:
105 	  break;
106 	}
107     }
108 
109   // Set path and buffer inside a rope iterator.  We assume that
110   // pos and root are already set.
111   template <class _CharT, class _Alloc>
112     void
113     _Rope_iterator_base<_CharT, _Alloc>::
114     _S_setcache(_Rope_iterator_base<_CharT, _Alloc>& __x)
115     {
116       const _RopeRep* __path[int(__detail::_S_max_rope_depth) + 1];
117       const _RopeRep* __curr_rope;
118       int __curr_depth = -1;  /* index into path    */
119       size_t __curr_start_pos = 0;
120       size_t __pos = __x._M_current_pos;
121       unsigned char __dirns = 0; // Bit vector marking right turns in the path
122 
123       if (__pos >= __x._M_root->_M_size)
124 	{
125 	  __x._M_buf_ptr = 0;
126 	  return;
127 	}
128       __curr_rope = __x._M_root;
129       if (0 != __curr_rope->_M_c_string)
130 	{
131 	  /* Treat the root as a leaf. */
132 	  __x._M_buf_start = __curr_rope->_M_c_string;
133 	  __x._M_buf_end = __curr_rope->_M_c_string + __curr_rope->_M_size;
134 	  __x._M_buf_ptr = __curr_rope->_M_c_string + __pos;
135 	  __x._M_path_end[0] = __curr_rope;
136 	  __x._M_leaf_index = 0;
137 	  __x._M_leaf_pos = 0;
138 	  return;
139 	}
140       for(;;)
141 	{
142 	  ++__curr_depth;
143 	  __path[__curr_depth] = __curr_rope;
144 	  switch(__curr_rope->_M_tag)
145 	    {
146 	    case __detail::_S_leaf:
147 	    case __detail::_S_function:
148 	    case __detail::_S_substringfn:
149 	      __x._M_leaf_pos = __curr_start_pos;
150 	      goto done;
151 	    case __detail::_S_concat:
152 	      {
153 		_Rope_RopeConcatenation<_CharT, _Alloc>* __c =
154 		  (_Rope_RopeConcatenation<_CharT, _Alloc>*)__curr_rope;
155 		_RopeRep* __left = __c->_M_left;
156 		size_t __left_len = __left->_M_size;
157 
158 		__dirns <<= 1;
159 		if (__pos >= __curr_start_pos + __left_len)
160 		  {
161 		    __dirns |= 1;
162 		    __curr_rope = __c->_M_right;
163 		    __curr_start_pos += __left_len;
164 		  }
165 		else
166 		  __curr_rope = __left;
167 	      }
168 	      break;
169 	    }
170 	}
171     done:
172       // Copy last section of path into _M_path_end.
173       {
174 	int __i = -1;
175 	int __j = __curr_depth + 1 - int(_S_path_cache_len);
176 
177 	if (__j < 0) __j = 0;
178 	while (__j <= __curr_depth)
179 	  __x._M_path_end[++__i] = __path[__j++];
180 	__x._M_leaf_index = __i;
181       }
182       __x._M_path_directions = __dirns;
183       _S_setbuf(__x);
184     }
185 
186   // Specialized version of the above.  Assumes that
187   // the path cache is valid for the previous position.
188   template <class _CharT, class _Alloc>
189     void
190     _Rope_iterator_base<_CharT, _Alloc>::
191     _S_setcache_for_incr(_Rope_iterator_base<_CharT, _Alloc>& __x)
192     {
193       int __current_index = __x._M_leaf_index;
194       const _RopeRep* __current_node = __x._M_path_end[__current_index];
195       size_t __len = __current_node->_M_size;
196       size_t __node_start_pos = __x._M_leaf_pos;
197       unsigned char __dirns = __x._M_path_directions;
198       _Rope_RopeConcatenation<_CharT, _Alloc>* __c;
199 
200       if (__x._M_current_pos - __node_start_pos < __len)
201 	{
202 	  /* More stuff in this leaf, we just didn't cache it. */
203 	  _S_setbuf(__x);
204 	  return;
205 	}
206       //  node_start_pos is starting position of last_node.
207       while (--__current_index >= 0)
208 	{
209 	  if (!(__dirns & 1) /* Path turned left */)
210 	    break;
211 	  __current_node = __x._M_path_end[__current_index];
212 	  __c = (_Rope_RopeConcatenation<_CharT, _Alloc>*)__current_node;
213 	  // Otherwise we were in the right child.  Thus we should pop
214 	  // the concatenation node.
215 	  __node_start_pos -= __c->_M_left->_M_size;
216 	  __dirns >>= 1;
217 	}
218       if (__current_index < 0)
219 	{
220 	  // We underflowed the cache. Punt.
221 	  _S_setcache(__x);
222 	  return;
223 	}
224       __current_node = __x._M_path_end[__current_index];
225       __c = (_Rope_RopeConcatenation<_CharT, _Alloc>*)__current_node;
226       // current_node is a concatenation node.  We are positioned on the first
227       // character in its right child.
228       // node_start_pos is starting position of current_node.
229       __node_start_pos += __c->_M_left->_M_size;
230       __current_node = __c->_M_right;
231       __x._M_path_end[++__current_index] = __current_node;
232       __dirns |= 1;
233       while (__detail::_S_concat == __current_node->_M_tag)
234 	{
235 	  ++__current_index;
236 	  if (int(_S_path_cache_len) == __current_index)
237 	    {
238 	      int __i;
239 	      for (__i = 0; __i < int(_S_path_cache_len) - 1; __i++)
240 		__x._M_path_end[__i] = __x._M_path_end[__i+1];
241 	      --__current_index;
242 	    }
243 	  __current_node =
244 	    ((_Rope_RopeConcatenation<_CharT, _Alloc>*)__current_node)->_M_left;
245 	  __x._M_path_end[__current_index] = __current_node;
246 	  __dirns <<= 1;
247 	  // node_start_pos is unchanged.
248 	}
249       __x._M_leaf_index = __current_index;
250       __x._M_leaf_pos = __node_start_pos;
251       __x._M_path_directions = __dirns;
252       _S_setbuf(__x);
253     }
254 
255   template <class _CharT, class _Alloc>
256     void
257     _Rope_iterator_base<_CharT, _Alloc>::
258     _M_incr(size_t __n)
259     {
260       _M_current_pos += __n;
261       if (0 != _M_buf_ptr)
262 	{
263 	  size_t __chars_left = _M_buf_end - _M_buf_ptr;
264 	  if (__chars_left > __n)
265 	    _M_buf_ptr += __n;
266 	  else if (__chars_left == __n)
267 	    {
268 	      _M_buf_ptr += __n;
269 	      _S_setcache_for_incr(*this);
270 	    }
271 	  else
272 	    _M_buf_ptr = 0;
273 	}
274     }
275 
276   template <class _CharT, class _Alloc>
277     void
278     _Rope_iterator_base<_CharT, _Alloc>::
279     _M_decr(size_t __n)
280     {
281       if (0 != _M_buf_ptr)
282 	{
283 	  size_t __chars_left = _M_buf_ptr - _M_buf_start;
284 	  if (__chars_left >= __n)
285 	    _M_buf_ptr -= __n;
286 	  else
287 	    _M_buf_ptr = 0;
288 	}
289       _M_current_pos -= __n;
290     }
291 
292   template <class _CharT, class _Alloc>
293     void
294     _Rope_iterator<_CharT, _Alloc>::
295     _M_check()
296     {
297       if (_M_root_rope->_M_tree_ptr != this->_M_root)
298 	{
299 	  // _Rope was modified.  Get things fixed up.
300 	  _RopeRep::_S_unref(this->_M_root);
301 	  this->_M_root = _M_root_rope->_M_tree_ptr;
302 	  _RopeRep::_S_ref(this->_M_root);
303 	  this->_M_buf_ptr = 0;
304 	}
305     }
306 
307   template <class _CharT, class _Alloc>
308     inline
309     _Rope_const_iterator<_CharT, _Alloc>::
310     _Rope_const_iterator(const _Rope_iterator<_CharT, _Alloc>& __x)
311     : _Rope_iterator_base<_CharT, _Alloc>(__x)
312     { }
313 
314   template <class _CharT, class _Alloc>
315     inline
316     _Rope_iterator<_CharT, _Alloc>::
317     _Rope_iterator(rope<_CharT, _Alloc>& __r, size_t __pos)
318     : _Rope_iterator_base<_CharT,_Alloc>(__r._M_tree_ptr, __pos),
319       _M_root_rope(&__r)
320     { _RopeRep::_S_ref(this->_M_root); }
321 
322   template <class _CharT, class _Alloc>
323     inline size_t
324     rope<_CharT, _Alloc>::
325     _S_char_ptr_len(const _CharT* __s)
326     {
327       const _CharT* __p = __s;
328 
329       while (!_S_is0(*__p))
330 	++__p;
331       return (__p - __s);
332     }
333 
334 
335 #ifndef __GC
336 
337   template <class _CharT, class _Alloc>
338     inline void
339     _Rope_RopeRep<_CharT, _Alloc>::
340     _M_free_c_string()
341     {
342       _CharT* __cstr = _M_c_string;
343       if (0 != __cstr)
344 	{
345 	  size_t __size = this->_M_size + 1;
346 	  _Destroy(__cstr, __cstr + __size, _M_get_allocator());
347 	  this->_Data_deallocate(__cstr, __size);
348 	}
349     }
350 
351   template <class _CharT, class _Alloc>
352     inline void
353     _Rope_RopeRep<_CharT, _Alloc>::
354     _S_free_string(_CharT* __s, size_t __n, allocator_type& __a)
355     {
356       if (!_S_is_basic_char_type((_CharT*)0))
357 	_Destroy(__s, __s + __n, __a);
358 
359       //  This has to be a static member, so this gets a bit messy
360       __a.deallocate(__s,
361 		     _Rope_RopeLeaf<_CharT, _Alloc>::_S_rounded_up_size(__n));
362     }
363 
364   //  There are several reasons for not doing this with virtual destructors
365   //  and a class specific delete operator:
366   //  - A class specific delete operator can't easily get access to
367   //    allocator instances if we need them.
368   //  - Any virtual function would need a 4 or byte vtable pointer;
369   //    this only requires a one byte tag per object.
370   template <class _CharT, class _Alloc>
371     void
372     _Rope_RopeRep<_CharT, _Alloc>::
373     _M_free_tree()
374     {
375       switch(_M_tag)
376 	{
377 	case __detail::_S_leaf:
378 	  {
379 	    _Rope_RopeLeaf<_CharT, _Alloc>* __l
380 	      = (_Rope_RopeLeaf<_CharT, _Alloc>*)this;
381 	    __l->_Rope_RopeLeaf<_CharT, _Alloc>::~_Rope_RopeLeaf();
382 	    this->_L_deallocate(__l, 1);
383 	    break;
384 	  }
385 	case __detail::_S_concat:
386 	  {
387 	    _Rope_RopeConcatenation<_CharT,_Alloc>* __c
388 	      = (_Rope_RopeConcatenation<_CharT, _Alloc>*)this;
389 	    __c->_Rope_RopeConcatenation<_CharT, _Alloc>::
390 	      ~_Rope_RopeConcatenation();
391 	    this->_C_deallocate(__c, 1);
392 	    break;
393 	  }
394 	case __detail::_S_function:
395 	  {
396 	    _Rope_RopeFunction<_CharT, _Alloc>* __f
397 	      = (_Rope_RopeFunction<_CharT, _Alloc>*)this;
398 	    __f->_Rope_RopeFunction<_CharT, _Alloc>::~_Rope_RopeFunction();
399 	    this->_F_deallocate(__f, 1);
400 	    break;
401 	  }
402 	case __detail::_S_substringfn:
403 	  {
404 	    _Rope_RopeSubstring<_CharT, _Alloc>* __ss =
405 	      (_Rope_RopeSubstring<_CharT, _Alloc>*)this;
406 	    __ss->_Rope_RopeSubstring<_CharT, _Alloc>::
407 	      ~_Rope_RopeSubstring();
408 	    this->_S_deallocate(__ss, 1);
409 	    break;
410 	  }
411 	}
412     }
413 #else
414 
415   template <class _CharT, class _Alloc>
416     inline void
417     _Rope_RopeRep<_CharT, _Alloc>::
418     _S_free_string(const _CharT*, size_t, allocator_type)
419     { }
420 
421 #endif
422 
423   // Concatenate a C string onto a leaf rope by copying the rope data.
424   // Used for short ropes.
425   template <class _CharT, class _Alloc>
426     typename rope<_CharT, _Alloc>::_RopeLeaf*
427     rope<_CharT, _Alloc>::
428     _S_leaf_concat_char_iter(_RopeLeaf* __r, const _CharT* __iter, size_t __len)
429     {
430       size_t __old_len = __r->_M_size;
431       _CharT* __new_data = (_CharT*)
432 	rope::_Data_allocate(_S_rounded_up_size(__old_len + __len));
433       _RopeLeaf* __result;
434 
435       uninitialized_copy_n(__r->_M_data, __old_len, __new_data);
436       uninitialized_copy_n(__iter, __len, __new_data + __old_len);
437       _S_cond_store_eos(__new_data[__old_len + __len]);
438       __try
439 	{
440 	  __result = _S_new_RopeLeaf(__new_data, __old_len + __len,
441 				     __r->_M_get_allocator());
442 	}
443       __catch(...)
444 	{
445 	  _RopeRep::__STL_FREE_STRING(__new_data, __old_len + __len,
446 				      __r->_M_get_allocator());
447 	  __throw_exception_again;
448 	}
449       return __result;
450     }
451 
452 #ifndef __GC
453   // As above, but it's OK to clobber original if refcount is 1
454   template <class _CharT, class _Alloc>
455     typename rope<_CharT,_Alloc>::_RopeLeaf*
456     rope<_CharT, _Alloc>::
457     _S_destr_leaf_concat_char_iter(_RopeLeaf* __r, const _CharT* __iter,
458 				   size_t __len)
459     {
460       if (__r->_M_ref_count > 1)
461 	return _S_leaf_concat_char_iter(__r, __iter, __len);
462       size_t __old_len = __r->_M_size;
463       if (_S_allocated_capacity(__old_len) >= __old_len + __len)
464 	{
465 	  // The space has been partially initialized for the standard
466 	  // character types.  But that doesn't matter for those types.
467 	  uninitialized_copy_n(__iter, __len, __r->_M_data + __old_len);
468 	  if (_S_is_basic_char_type((_CharT*)0))
469 	    _S_cond_store_eos(__r->_M_data[__old_len + __len]);
470 	  else if (__r->_M_c_string != __r->_M_data && 0 != __r->_M_c_string)
471 	    {
472 	      __r->_M_free_c_string();
473 	      __r->_M_c_string = 0;
474 	    }
475 	  __r->_M_size = __old_len + __len;
476 	  __r->_M_ref_count = 2;
477 	  return __r;
478 	}
479       else
480 	{
481 	  _RopeLeaf* __result = _S_leaf_concat_char_iter(__r, __iter, __len);
482 	  return __result;
483 	}
484     }
485 #endif
486 
487   // Assumes left and right are not 0.
488   // Does not increment (nor decrement on exception) child reference counts.
489   // Result has ref count 1.
490   template <class _CharT, class _Alloc>
491     typename rope<_CharT, _Alloc>::_RopeRep*
492     rope<_CharT, _Alloc>::
493     _S_tree_concat(_RopeRep* __left, _RopeRep* __right)
494     {
495       _RopeConcatenation* __result = _S_new_RopeConcatenation(__left, __right,
496 							      __left->
497 							      _M_get_allocator());
498       size_t __depth = __result->_M_depth;
499 
500       if (__depth > 20
501 	  && (__result->_M_size < 1000
502 	      || __depth > size_t(__detail::_S_max_rope_depth)))
503 	{
504 	  _RopeRep* __balanced;
505 
506 	  __try
507 	    {
508 	      __balanced = _S_balance(__result);
509 	      __result->_M_unref_nonnil();
510 	    }
511 	  __catch(...)
512 	    {
513 	      rope::_C_deallocate(__result,1);
514 	      __throw_exception_again;
515 	    }
516 	  // In case of exception, we need to deallocate
517 	  // otherwise dangling result node.  But caller
518 	  // still owns its children.  Thus unref is
519 	  // inappropriate.
520 	  return __balanced;
521 	}
522       else
523 	return __result;
524     }
525 
526   template <class _CharT, class _Alloc>
527     typename rope<_CharT, _Alloc>::_RopeRep*
528     rope<_CharT, _Alloc>::
529     _S_concat_char_iter(_RopeRep* __r, const _CharT*__s, size_t __slen)
530     {
531       _RopeRep* __result;
532       if (0 == __slen)
533 	{
534 	  _S_ref(__r);
535 	  return __r;
536 	}
537       if (0 == __r)
538 	return __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen,
539 						__r->_M_get_allocator());
540       if (__r->_M_tag == __detail::_S_leaf
541 	  && __r->_M_size + __slen <= size_t(_S_copy_max))
542 	{
543 	  __result = _S_leaf_concat_char_iter((_RopeLeaf*)__r, __s, __slen);
544 	  return __result;
545 	}
546       if (__detail::_S_concat == __r->_M_tag
547 	  && __detail::_S_leaf == ((_RopeConcatenation*) __r)->_M_right->_M_tag)
548 	{
549 	  _RopeLeaf* __right =
550 	    (_RopeLeaf* )(((_RopeConcatenation* )__r)->_M_right);
551 	  if (__right->_M_size + __slen <= size_t(_S_copy_max))
552 	    {
553 	      _RopeRep* __left = ((_RopeConcatenation*)__r)->_M_left;
554 	      _RopeRep* __nright =
555 		_S_leaf_concat_char_iter((_RopeLeaf*)__right, __s, __slen);
556 	      __left->_M_ref_nonnil();
557 	      __try
558 		{ __result = _S_tree_concat(__left, __nright); }
559 	      __catch(...)
560 		{
561 		  _S_unref(__left);
562 		  _S_unref(__nright);
563 		  __throw_exception_again;
564 		}
565 	      return __result;
566 	    }
567 	}
568       _RopeRep* __nright =
569 	__STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen, __r->_M_get_allocator());
570       __try
571 	{
572 	  __r->_M_ref_nonnil();
573 	  __result = _S_tree_concat(__r, __nright);
574 	}
575       __catch(...)
576 	{
577 	  _S_unref(__r);
578 	  _S_unref(__nright);
579 	  __throw_exception_again;
580 	}
581       return __result;
582     }
583 
584 #ifndef __GC
585   template <class _CharT, class _Alloc>
586     typename rope<_CharT,_Alloc>::_RopeRep*
587     rope<_CharT,_Alloc>::
588     _S_destr_concat_char_iter(_RopeRep* __r, const _CharT* __s, size_t __slen)
589     {
590       _RopeRep* __result;
591       if (0 == __r)
592 	return __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen,
593 						__r->_M_get_allocator());
594       size_t __count = __r->_M_ref_count;
595       size_t __orig_size = __r->_M_size;
596       if (__count > 1)
597 	return _S_concat_char_iter(__r, __s, __slen);
598       if (0 == __slen)
599 	{
600 	  __r->_M_ref_count = 2;      // One more than before
601 	  return __r;
602 	}
603       if (__orig_size + __slen <= size_t(_S_copy_max)
604 	  && __detail::_S_leaf == __r->_M_tag)
605 	{
606 	  __result = _S_destr_leaf_concat_char_iter((_RopeLeaf*)__r, __s,
607 						    __slen);
608 	  return __result;
609 	}
610       if (__detail::_S_concat == __r->_M_tag)
611 	{
612 	  _RopeLeaf* __right = (_RopeLeaf*)(((_RopeConcatenation*)
613 					     __r)->_M_right);
614 	  if (__detail::_S_leaf == __right->_M_tag
615 	      && __right->_M_size + __slen <= size_t(_S_copy_max))
616 	    {
617 	      _RopeRep* __new_right =
618 		_S_destr_leaf_concat_char_iter(__right, __s, __slen);
619 	      if (__right == __new_right)
620 		__new_right->_M_ref_count = 1;
621 	      else
622 		__right->_M_unref_nonnil();
623 	      __r->_M_ref_count = 2;    // One more than before.
624 	      ((_RopeConcatenation*)__r)->_M_right = __new_right;
625 	      __r->_M_size = __orig_size + __slen;
626 	      if (0 != __r->_M_c_string)
627 		{
628 		  __r->_M_free_c_string();
629 		  __r->_M_c_string = 0;
630 		}
631 	      return __r;
632 	    }
633 	}
634       _RopeRep* __right =
635 	__STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen, __r->_M_get_allocator());
636       __r->_M_ref_nonnil();
637       __try
638 	{ __result = _S_tree_concat(__r, __right); }
639       __catch(...)
640 	{
641 	  _S_unref(__r);
642 	  _S_unref(__right);
643 	  __throw_exception_again;
644 	}
645       return __result;
646     }
647 #endif /* !__GC */
648 
649   template <class _CharT, class _Alloc>
650     typename rope<_CharT, _Alloc>::_RopeRep*
651     rope<_CharT, _Alloc>::
652     _S_concat(_RopeRep* __left, _RopeRep* __right)
653     {
654       if (0 == __left)
655 	{
656 	  _S_ref(__right);
657 	  return __right;
658 	}
659       if (0 == __right)
660 	{
661 	  __left->_M_ref_nonnil();
662 	  return __left;
663 	}
664       if (__detail::_S_leaf == __right->_M_tag)
665 	{
666 	  if (__detail::_S_leaf == __left->_M_tag)
667 	    {
668 	      if (__right->_M_size + __left->_M_size <= size_t(_S_copy_max))
669 		return _S_leaf_concat_char_iter((_RopeLeaf*)__left,
670 						((_RopeLeaf*)__right)->_M_data,
671 						__right->_M_size);
672 	    }
673 	  else if (__detail::_S_concat == __left->_M_tag
674 		   && __detail::_S_leaf == ((_RopeConcatenation*)
675 						   __left)->_M_right->_M_tag)
676 	    {
677 	      _RopeLeaf* __leftright =
678 		(_RopeLeaf*)(((_RopeConcatenation*)__left)->_M_right);
679 	      if (__leftright->_M_size
680 		  + __right->_M_size <= size_t(_S_copy_max))
681 		{
682 		  _RopeRep* __leftleft = ((_RopeConcatenation*)__left)->_M_left;
683 		  _RopeRep* __rest = _S_leaf_concat_char_iter(__leftright,
684 							      ((_RopeLeaf*)
685 							       __right)->
686 							      _M_data,
687 							      __right->_M_size);
688 		  __leftleft->_M_ref_nonnil();
689 		  __try
690 		    { return(_S_tree_concat(__leftleft, __rest)); }
691 		  __catch(...)
692 		    {
693 		      _S_unref(__leftleft);
694 		      _S_unref(__rest);
695 		      __throw_exception_again;
696 		    }
697 		}
698 	    }
699 	}
700       __left->_M_ref_nonnil();
701       __right->_M_ref_nonnil();
702       __try
703 	{ return(_S_tree_concat(__left, __right)); }
704       __catch(...)
705 	{
706 	  _S_unref(__left);
707 	  _S_unref(__right);
708 	  __throw_exception_again;
709 	}
710     }
711 
712   template <class _CharT, class _Alloc>
713     typename rope<_CharT, _Alloc>::_RopeRep*
714     rope<_CharT, _Alloc>::
715     _S_substring(_RopeRep* __base, size_t __start, size_t __endp1)
716     {
717       if (0 == __base)
718 	return 0;
719       size_t __len = __base->_M_size;
720       size_t __adj_endp1;
721       const size_t __lazy_threshold = 128;
722 
723       if (__endp1 >= __len)
724 	{
725 	  if (0 == __start)
726 	    {
727 	      __base->_M_ref_nonnil();
728 	      return __base;
729 	    }
730 	  else
731 	    __adj_endp1 = __len;
732 
733 	}
734       else
735 	__adj_endp1 = __endp1;
736 
737       switch(__base->_M_tag)
738 	{
739 	case __detail::_S_concat:
740 	    {
741 	      _RopeConcatenation* __c = (_RopeConcatenation*)__base;
742 	      _RopeRep* __left = __c->_M_left;
743 	      _RopeRep* __right = __c->_M_right;
744 	      size_t __left_len = __left->_M_size;
745 	      _RopeRep* __result;
746 
747 	      if (__adj_endp1 <= __left_len)
748 		return _S_substring(__left, __start, __endp1);
749 	      else if (__start >= __left_len)
750 		return _S_substring(__right, __start - __left_len,
751 				    __adj_endp1 - __left_len);
752 	      _Self_destruct_ptr __left_result(_S_substring(__left,
753 							    __start,
754 							    __left_len));
755 	      _Self_destruct_ptr __right_result(_S_substring(__right, 0,
756 							     __endp1
757 							     - __left_len));
758 	      __result = _S_concat(__left_result, __right_result);
759 	      return __result;
760 	    }
761 	case __detail::_S_leaf:
762 	  {
763 	    _RopeLeaf* __l = (_RopeLeaf*)__base;
764 	    _RopeLeaf* __result;
765 	    size_t __result_len;
766 	    if (__start >= __adj_endp1)
767 	      return 0;
768 	    __result_len = __adj_endp1 - __start;
769 	    if (__result_len > __lazy_threshold)
770 	      goto lazy;
771 #ifdef __GC
772 	    const _CharT* __section = __l->_M_data + __start;
773 	    __result = _S_new_RopeLeaf(__section, __result_len,
774 				       __base->_M_get_allocator());
775 	    __result->_M_c_string = 0;  // Not eos terminated.
776 #else
777 	    // We should sometimes create substring node instead.
778 	    __result = __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__l->_M_data + __start,
779 							__result_len,
780 							__base->
781 							_M_get_allocator());
782 #endif
783 	    return __result;
784 	  }
785 	case __detail::_S_substringfn:
786 	  // Avoid introducing multiple layers of substring nodes.
787 	  {
788 	    _RopeSubstring* __old = (_RopeSubstring*)__base;
789 	    size_t __result_len;
790 	    if (__start >= __adj_endp1)
791 	      return 0;
792 	    __result_len = __adj_endp1 - __start;
793 	    if (__result_len > __lazy_threshold)
794 	      {
795 		_RopeSubstring* __result =
796 		  _S_new_RopeSubstring(__old->_M_base,
797 				       __start + __old->_M_start,
798 				       __adj_endp1 - __start,
799 				       __base->_M_get_allocator());
800 		return __result;
801 
802 	      } // *** else fall through: ***
803 	  }
804 	case __detail::_S_function:
805 	  {
806 	    _RopeFunction* __f = (_RopeFunction*)__base;
807 	    _CharT* __section;
808 	    size_t __result_len;
809 	    if (__start >= __adj_endp1)
810 	      return 0;
811 	    __result_len = __adj_endp1 - __start;
812 
813 	    if (__result_len > __lazy_threshold)
814 	      goto lazy;
815 	    __section = (_CharT*)
816 	      rope::_Data_allocate(_S_rounded_up_size(__result_len));
817 	    __try
818 	      {	(*(__f->_M_fn))(__start, __result_len, __section); }
819 	    __catch(...)
820 	      {
821 		_RopeRep::__STL_FREE_STRING(__section, __result_len,
822 					    __base->_M_get_allocator());
823 		__throw_exception_again;
824 	      }
825 	    _S_cond_store_eos(__section[__result_len]);
826 	    return _S_new_RopeLeaf(__section, __result_len,
827 				   __base->_M_get_allocator());
828 	  }
829 	}
830     lazy:
831       {
832 	// Create substring node.
833 	return _S_new_RopeSubstring(__base, __start, __adj_endp1 - __start,
834 				    __base->_M_get_allocator());
835       }
836     }
837 
838   template<class _CharT>
839     class _Rope_flatten_char_consumer
840     : public _Rope_char_consumer<_CharT>
841     {
842     private:
843       _CharT* _M_buf_ptr;
844     public:
845 
846       _Rope_flatten_char_consumer(_CharT* __buffer)
847       { _M_buf_ptr = __buffer; }
848 
849       ~_Rope_flatten_char_consumer() {}
850 
851       bool
852       operator()(const _CharT* __leaf, size_t __n)
853       {
854 	uninitialized_copy_n(__leaf, __n, _M_buf_ptr);
855 	_M_buf_ptr += __n;
856 	return true;
857       }
858     };
859 
860   template<class _CharT>
861     class _Rope_find_char_char_consumer
862     : public _Rope_char_consumer<_CharT>
863     {
864     private:
865       _CharT _M_pattern;
866     public:
867       size_t _M_count;  // Number of nonmatching characters
868 
869       _Rope_find_char_char_consumer(_CharT __p)
870       : _M_pattern(__p), _M_count(0) {}
871 
872       ~_Rope_find_char_char_consumer() {}
873 
874       bool
875       operator()(const _CharT* __leaf, size_t __n)
876       {
877 	size_t __i;
878 	for (__i = 0; __i < __n; __i++)
879 	  {
880 	    if (__leaf[__i] == _M_pattern)
881 	      {
882 		_M_count += __i;
883 		return false;
884 	      }
885 	  }
886 	_M_count += __n; return true;
887       }
888     };
889 
890   template<class _CharT, class _Traits>
891   // Here _CharT is both the stream and rope character type.
892     class _Rope_insert_char_consumer
893     : public _Rope_char_consumer<_CharT>
894     {
895     private:
896       typedef basic_ostream<_CharT,_Traits> _Insert_ostream;
897       _Insert_ostream& _M_o;
898     public:
899       _Rope_insert_char_consumer(_Insert_ostream& __writer)
900 	: _M_o(__writer) {}
901       ~_Rope_insert_char_consumer() { }
902       // Caller is presumed to own the ostream
903       bool operator() (const _CharT* __leaf, size_t __n);
904       // Returns true to continue traversal.
905     };
906 
907   template<class _CharT, class _Traits>
908     bool
909     _Rope_insert_char_consumer<_CharT, _Traits>::
910     operator()(const _CharT* __leaf, size_t __n)
911     {
912       size_t __i;
913       //  We assume that formatting is set up correctly for each element.
914       for (__i = 0; __i < __n; __i++)
915 	_M_o.put(__leaf[__i]);
916       return true;
917     }
918 
919   template <class _CharT, class _Alloc>
920     bool
921     rope<_CharT, _Alloc>::
922     _S_apply_to_pieces(_Rope_char_consumer<_CharT>& __c,
923 		       const _RopeRep* __r, size_t __begin, size_t __end)
924     {
925       if (0 == __r)
926 	return true;
927       switch(__r->_M_tag)
928 	{
929 	case __detail::_S_concat:
930 	  {
931 	    _RopeConcatenation* __conc = (_RopeConcatenation*)__r;
932 	    _RopeRep* __left =  __conc->_M_left;
933 	    size_t __left_len = __left->_M_size;
934 	    if (__begin < __left_len)
935 	      {
936 		size_t __left_end = std::min(__left_len, __end);
937 		if (!_S_apply_to_pieces(__c, __left, __begin, __left_end))
938 		  return false;
939 	      }
940 	    if (__end > __left_len)
941 	      {
942 		_RopeRep* __right =  __conc->_M_right;
943 		size_t __right_start = std::max(__left_len, __begin);
944 		if (!_S_apply_to_pieces(__c, __right,
945 					__right_start - __left_len,
946 					__end - __left_len))
947 		  return false;
948 	      }
949 	  }
950 	  return true;
951 	case __detail::_S_leaf:
952 	  {
953 	    _RopeLeaf* __l = (_RopeLeaf*)__r;
954 	    return __c(__l->_M_data + __begin, __end - __begin);
955 	  }
956 	case __detail::_S_function:
957 	case __detail::_S_substringfn:
958 	    {
959 	      _RopeFunction* __f = (_RopeFunction*)__r;
960 	      size_t __len = __end - __begin;
961 	      bool __result;
962 	      _CharT* __buffer =
963 		(_CharT*)_Alloc().allocate(__len * sizeof(_CharT));
964 	      __try
965 		{
966 		  (*(__f->_M_fn))(__begin, __len, __buffer);
967 		  __result = __c(__buffer, __len);
968                   _Alloc().deallocate(__buffer, __len * sizeof(_CharT));
969                 }
970 	      __catch(...)
971 		{
972 		  _Alloc().deallocate(__buffer, __len * sizeof(_CharT));
973 		  __throw_exception_again;
974 		}
975 	      return __result;
976 	    }
977 	default:
978 	  return false;
979 	}
980     }
981 
982   template<class _CharT, class _Traits>
983     inline void
984     _Rope_fill(basic_ostream<_CharT, _Traits>& __o, size_t __n)
985     {
986       char __f = __o.fill();
987       size_t __i;
988 
989       for (__i = 0; __i < __n; __i++)
990 	__o.put(__f);
991     }
992 
993 
994   template <class _CharT>
995     inline bool
996     _Rope_is_simple(_CharT*)
997     { return false; }
998 
999   inline bool
1000   _Rope_is_simple(char*)
1001   { return true; }
1002 
1003   inline bool
1004   _Rope_is_simple(wchar_t*)
1005   { return true; }
1006 
1007   template<class _CharT, class _Traits, class _Alloc>
1008     basic_ostream<_CharT, _Traits>&
1009     operator<<(basic_ostream<_CharT, _Traits>& __o,
1010 	       const rope<_CharT, _Alloc>& __r)
1011     {
1012       size_t __w = __o.width();
1013       bool __left = bool(__o.flags() & std::ios::left);
1014       size_t __pad_len;
1015       size_t __rope_len = __r.size();
1016       _Rope_insert_char_consumer<_CharT, _Traits> __c(__o);
1017       bool __is_simple = _Rope_is_simple((_CharT*)0);
1018 
1019       if (__rope_len < __w)
1020 	__pad_len = __w - __rope_len;
1021       else
1022 	__pad_len = 0;
1023 
1024       if (!__is_simple)
1025 	__o.width(__w / __rope_len);
1026       __try
1027 	{
1028 	  if (__is_simple && !__left && __pad_len > 0)
1029 	    _Rope_fill(__o, __pad_len);
1030 	  __r.apply_to_pieces(0, __r.size(), __c);
1031 	  if (__is_simple && __left && __pad_len > 0)
1032 	    _Rope_fill(__o, __pad_len);
1033 	  if (!__is_simple)
1034 	    __o.width(__w);
1035 	}
1036       __catch(...)
1037 	{
1038 	  if (!__is_simple)
1039 	    __o.width(__w);
1040 	  __throw_exception_again;
1041 	}
1042       return __o;
1043     }
1044 
1045   template <class _CharT, class _Alloc>
1046     _CharT*
1047     rope<_CharT, _Alloc>::
1048     _S_flatten(_RopeRep* __r, size_t __start, size_t __len,
1049 	       _CharT* __buffer)
1050     {
1051       _Rope_flatten_char_consumer<_CharT> __c(__buffer);
1052       _S_apply_to_pieces(__c, __r, __start, __start + __len);
1053       return(__buffer + __len);
1054     }
1055 
1056   template <class _CharT, class _Alloc>
1057     size_t
1058     rope<_CharT, _Alloc>::
1059     find(_CharT __pattern, size_t __start) const
1060     {
1061       _Rope_find_char_char_consumer<_CharT> __c(__pattern);
1062       _S_apply_to_pieces(__c, this->_M_tree_ptr, __start, size());
1063       size_type __result_pos = __start + __c._M_count;
1064 #ifndef __STL_OLD_ROPE_SEMANTICS
1065       if (__result_pos == size())
1066 	__result_pos = npos;
1067 #endif
1068       return __result_pos;
1069     }
1070 
1071   template <class _CharT, class _Alloc>
1072     _CharT*
1073     rope<_CharT, _Alloc>::
1074     _S_flatten(_RopeRep* __r, _CharT* __buffer)
1075     {
1076       if (0 == __r)
1077 	return __buffer;
1078       switch(__r->_M_tag)
1079 	{
1080 	case __detail::_S_concat:
1081 	  {
1082 	    _RopeConcatenation* __c = (_RopeConcatenation*)__r;
1083 	    _RopeRep* __left = __c->_M_left;
1084 	    _RopeRep* __right = __c->_M_right;
1085 	    _CharT* __rest = _S_flatten(__left, __buffer);
1086 	    return _S_flatten(__right, __rest);
1087 	  }
1088 	case __detail::_S_leaf:
1089 	  {
1090 	    _RopeLeaf* __l = (_RopeLeaf*)__r;
1091 	    return copy_n(__l->_M_data, __l->_M_size, __buffer).second;
1092 	  }
1093 	case __detail::_S_function:
1094 	case __detail::_S_substringfn:
1095 	  // We don't yet do anything with substring nodes.
1096 	  // This needs to be fixed before ropefiles will work well.
1097 	  {
1098 	    _RopeFunction* __f = (_RopeFunction*)__r;
1099 	    (*(__f->_M_fn))(0, __f->_M_size, __buffer);
1100 	    return __buffer + __f->_M_size;
1101 	  }
1102 	default:
1103 	  return 0;
1104 	}
1105     }
1106 
1107   // This needs work for _CharT != char
1108   template <class _CharT, class _Alloc>
1109     void
1110     rope<_CharT, _Alloc>::
1111     _S_dump(_RopeRep* __r, int __indent)
1112     {
1113       for (int __i = 0; __i < __indent; __i++)
1114 	putchar(' ');
1115       if (0 == __r)
1116 	{
1117 	  printf("NULL\n");
1118 	  return;
1119 	}
1120       if (__detail::_S_concat == __r->_M_tag)
1121 	{
1122 	  _RopeConcatenation* __c = (_RopeConcatenation*)__r;
1123 	  _RopeRep* __left = __c->_M_left;
1124 	  _RopeRep* __right = __c->_M_right;
1125 
1126 #ifdef __GC
1127 	  printf("Concatenation %p (depth = %d, len = %ld, %s balanced)\n",
1128 		 __r, __r->_M_depth, __r->_M_size,
1129 		 __r->_M_is_balanced? "" : "not");
1130 #else
1131 	  printf("Concatenation %p (rc = %ld, depth = %d, "
1132 		 "len = %ld, %s balanced)\n",
1133 		 __r, __r->_M_ref_count, __r->_M_depth, __r->_M_size,
1134 		 __r->_M_is_balanced? "" : "not");
1135 #endif
1136 	  _S_dump(__left, __indent + 2);
1137 	  _S_dump(__right, __indent + 2);
1138 	  return;
1139 	}
1140       else
1141 	{
1142 	  const char* __kind;
1143 
1144 	  switch (__r->_M_tag)
1145 	    {
1146 	    case __detail::_S_leaf:
1147 	      __kind = "Leaf";
1148 	      break;
1149 	    case __detail::_S_function:
1150 	      __kind = "Function";
1151 	      break;
1152 	    case __detail::_S_substringfn:
1153 	      __kind = "Function representing substring";
1154 	      break;
1155 	    default:
1156 	      __kind = "(corrupted kind field!)";
1157 	    }
1158 #ifdef __GC
1159 	  printf("%s %p (depth = %d, len = %ld) ",
1160 		 __kind, __r, __r->_M_depth, __r->_M_size);
1161 #else
1162 	  printf("%s %p (rc = %ld, depth = %d, len = %ld) ",
1163 		 __kind, __r, __r->_M_ref_count, __r->_M_depth, __r->_M_size);
1164 #endif
1165 	  if (_S_is_one_byte_char_type((_CharT*)0))
1166 	    {
1167 	      const int __max_len = 40;
1168 	      _Self_destruct_ptr __prefix(_S_substring(__r, 0, __max_len));
1169 	      _CharT __buffer[__max_len + 1];
1170 	      bool __too_big = __r->_M_size > __prefix->_M_size;
1171 
1172 	      _S_flatten(__prefix, __buffer);
1173 	      __buffer[__prefix->_M_size] = _S_eos((_CharT*)0);
1174 	      printf("%s%s\n", (char*)__buffer,
1175 		     __too_big? "...\n" : "\n");
1176 	    }
1177 	  else
1178 	    printf("\n");
1179 	}
1180     }
1181 
1182   template <class _CharT, class _Alloc>
1183     const unsigned long
1184     rope<_CharT, _Alloc>::
1185     _S_min_len[int(__detail::_S_max_rope_depth) + 1] = {
1186       /* 0 */1, /* 1 */2, /* 2 */3, /* 3 */5, /* 4 */8, /* 5 */13, /* 6 */21,
1187       /* 7 */34, /* 8 */55, /* 9 */89, /* 10 */144, /* 11 */233, /* 12 */377,
1188       /* 13 */610, /* 14 */987, /* 15 */1597, /* 16 */2584, /* 17 */4181,
1189       /* 18 */6765, /* 19 */10946, /* 20 */17711, /* 21 */28657, /* 22 */46368,
1190       /* 23 */75025, /* 24 */121393, /* 25 */196418, /* 26 */317811,
1191       /* 27 */514229, /* 28 */832040, /* 29 */1346269, /* 30 */2178309,
1192       /* 31 */3524578, /* 32 */5702887, /* 33 */9227465, /* 34 */14930352,
1193       /* 35 */24157817, /* 36 */39088169, /* 37 */63245986, /* 38 */102334155,
1194       /* 39 */165580141, /* 40 */267914296, /* 41 */433494437,
1195       /* 42 */701408733, /* 43 */1134903170, /* 44 */1836311903,
1196       /* 45 */2971215073u };
1197   // These are Fibonacci numbers < 2**32.
1198 
1199   template <class _CharT, class _Alloc>
1200     typename rope<_CharT, _Alloc>::_RopeRep*
1201     rope<_CharT, _Alloc>::
1202     _S_balance(_RopeRep* __r)
1203     {
1204       _RopeRep* __forest[int(__detail::_S_max_rope_depth) + 1];
1205       _RopeRep* __result = 0;
1206       int __i;
1207       // Invariant:
1208       // The concatenation of forest in descending order is equal to __r.
1209       // __forest[__i]._M_size >= _S_min_len[__i]
1210       // __forest[__i]._M_depth = __i
1211       // References from forest are included in refcount.
1212 
1213       for (__i = 0; __i <= int(__detail::_S_max_rope_depth); ++__i)
1214 	__forest[__i] = 0;
1215       __try
1216 	{
1217 	  _S_add_to_forest(__r, __forest);
1218 	  for (__i = 0; __i <= int(__detail::_S_max_rope_depth); ++__i)
1219 	    if (0 != __forest[__i])
1220 	      {
1221 #ifndef __GC
1222 		_Self_destruct_ptr __old(__result);
1223 #endif
1224 		__result = _S_concat(__forest[__i], __result);
1225 		__forest[__i]->_M_unref_nonnil();
1226 #if !defined(__GC) && __cpp_exceptions
1227 		__forest[__i] = 0;
1228 #endif
1229 	      }
1230 	}
1231       __catch(...)
1232 	{
1233 	  for(__i = 0; __i <= int(__detail::_S_max_rope_depth); __i++)
1234 	    _S_unref(__forest[__i]);
1235 	  __throw_exception_again;
1236 	}
1237 
1238       if (__result->_M_depth > int(__detail::_S_max_rope_depth))
1239 	__throw_length_error(__N("rope::_S_balance"));
1240       return(__result);
1241     }
1242 
1243   template <class _CharT, class _Alloc>
1244     void
1245     rope<_CharT, _Alloc>::
1246     _S_add_to_forest(_RopeRep* __r, _RopeRep** __forest)
1247     {
1248       if (__r->_M_is_balanced)
1249 	{
1250 	  _S_add_leaf_to_forest(__r, __forest);
1251 	  return;
1252 	}
1253 
1254       {
1255 	_RopeConcatenation* __c = (_RopeConcatenation*)__r;
1256 
1257 	_S_add_to_forest(__c->_M_left, __forest);
1258 	_S_add_to_forest(__c->_M_right, __forest);
1259       }
1260     }
1261 
1262 
1263   template <class _CharT, class _Alloc>
1264     void
1265     rope<_CharT, _Alloc>::
1266     _S_add_leaf_to_forest(_RopeRep* __r, _RopeRep** __forest)
1267     {
1268       _RopeRep* __insertee;		// included in refcount
1269       _RopeRep* __too_tiny = 0;		// included in refcount
1270       int __i;				// forest[0..__i-1] is empty
1271       size_t __s = __r->_M_size;
1272 
1273       for (__i = 0; __s >= _S_min_len[__i+1]/* not this bucket */; ++__i)
1274 	{
1275 	  if (0 != __forest[__i])
1276 	    {
1277 #ifndef __GC
1278 	      _Self_destruct_ptr __old(__too_tiny);
1279 #endif
1280 	      __too_tiny = _S_concat_and_set_balanced(__forest[__i],
1281 						      __too_tiny);
1282 	      __forest[__i]->_M_unref_nonnil();
1283 	      __forest[__i] = 0;
1284 	    }
1285 	}
1286       {
1287 #ifndef __GC
1288 	_Self_destruct_ptr __old(__too_tiny);
1289 #endif
1290 	__insertee = _S_concat_and_set_balanced(__too_tiny, __r);
1291       }
1292       // Too_tiny dead, and no longer included in refcount.
1293       // Insertee is live and included.
1294       for (;; ++__i)
1295 	{
1296 	  if (0 != __forest[__i])
1297 	    {
1298 #ifndef __GC
1299 	      _Self_destruct_ptr __old(__insertee);
1300 #endif
1301 	      __insertee = _S_concat_and_set_balanced(__forest[__i],
1302 						      __insertee);
1303 	      __forest[__i]->_M_unref_nonnil();
1304 	      __forest[__i] = 0;
1305 	    }
1306 	  if (__i == int(__detail::_S_max_rope_depth)
1307 	      || __insertee->_M_size < _S_min_len[__i+1])
1308 	    {
1309 	      __forest[__i] = __insertee;
1310 	      // refcount is OK since __insertee is now dead.
1311 	      return;
1312 	    }
1313 	}
1314     }
1315 
1316   template <class _CharT, class _Alloc>
1317     _CharT
1318     rope<_CharT, _Alloc>::
1319     _S_fetch(_RopeRep* __r, size_type __i)
1320     {
1321       __GC_CONST _CharT* __cstr = __r->_M_c_string;
1322 
1323       if (0 != __cstr)
1324 	return __cstr[__i];
1325       for(;;)
1326 	{
1327 	  switch(__r->_M_tag)
1328 	    {
1329 	    case __detail::_S_concat:
1330 	      {
1331 		_RopeConcatenation* __c = (_RopeConcatenation*)__r;
1332 		_RopeRep* __left = __c->_M_left;
1333 		size_t __left_len = __left->_M_size;
1334 
1335 		if (__i >= __left_len)
1336 		  {
1337 		    __i -= __left_len;
1338 		    __r = __c->_M_right;
1339 		  }
1340 		else
1341 		  __r = __left;
1342 	      }
1343 	      break;
1344 	    case __detail::_S_leaf:
1345 	      {
1346 		_RopeLeaf* __l = (_RopeLeaf*)__r;
1347 		return __l->_M_data[__i];
1348 	      }
1349 	    case __detail::_S_function:
1350 	    case __detail::_S_substringfn:
1351 	      {
1352 		_RopeFunction* __f = (_RopeFunction*)__r;
1353 		_CharT __result;
1354 
1355 		(*(__f->_M_fn))(__i, 1, &__result);
1356 		return __result;
1357 	      }
1358 	    }
1359 	}
1360     }
1361 
1362 #ifndef __GC
1363   // Return a uniquely referenced character slot for the given
1364   // position, or 0 if that's not possible.
1365   template <class _CharT, class _Alloc>
1366     _CharT*
1367     rope<_CharT, _Alloc>::
1368     _S_fetch_ptr(_RopeRep* __r, size_type __i)
1369     {
1370       _RopeRep* __clrstack[__detail::_S_max_rope_depth];
1371       size_t __csptr = 0;
1372 
1373       for(;;)
1374 	{
1375 	  if (__r->_M_ref_count > 1)
1376 	    return 0;
1377 	  switch(__r->_M_tag)
1378 	    {
1379 	    case __detail::_S_concat:
1380 	      {
1381 		_RopeConcatenation* __c = (_RopeConcatenation*)__r;
1382 		_RopeRep* __left = __c->_M_left;
1383 		size_t __left_len = __left->_M_size;
1384 
1385 		if (__c->_M_c_string != 0)
1386 		  __clrstack[__csptr++] = __c;
1387 		if (__i >= __left_len)
1388 		  {
1389 		    __i -= __left_len;
1390 		    __r = __c->_M_right;
1391 		  }
1392 		else
1393 		  __r = __left;
1394 	      }
1395 	      break;
1396 	    case __detail::_S_leaf:
1397 	      {
1398 		_RopeLeaf* __l = (_RopeLeaf*)__r;
1399 		if (__l->_M_c_string != __l->_M_data && __l->_M_c_string != 0)
1400 		  __clrstack[__csptr++] = __l;
1401 		while (__csptr > 0)
1402 		  {
1403 		    -- __csptr;
1404 		    _RopeRep* __d = __clrstack[__csptr];
1405 		    __d->_M_free_c_string();
1406 		    __d->_M_c_string = 0;
1407 		  }
1408 		return __l->_M_data + __i;
1409 	      }
1410 	    case __detail::_S_function:
1411 	    case __detail::_S_substringfn:
1412 	      return 0;
1413 	    }
1414 	}
1415     }
1416 #endif /* __GC */
1417 
1418   // The following could be implemented trivially using
1419   // lexicographical_compare_3way.
1420   // We do a little more work to avoid dealing with rope iterators for
1421   // flat strings.
1422   template <class _CharT, class _Alloc>
1423     int
1424     rope<_CharT, _Alloc>::
1425     _S_compare (const _RopeRep* __left, const _RopeRep* __right)
1426     {
1427       size_t __left_len;
1428       size_t __right_len;
1429 
1430       if (0 == __right)
1431 	return 0 != __left;
1432       if (0 == __left)
1433 	return -1;
1434       __left_len = __left->_M_size;
1435       __right_len = __right->_M_size;
1436       if (__detail::_S_leaf == __left->_M_tag)
1437 	{
1438 	  _RopeLeaf* __l = (_RopeLeaf*) __left;
1439 	  if (__detail::_S_leaf == __right->_M_tag)
1440 	    {
1441 	      _RopeLeaf* __r = (_RopeLeaf*) __right;
1442 	      return lexicographical_compare_3way(__l->_M_data,
1443 						  __l->_M_data + __left_len,
1444 						  __r->_M_data, __r->_M_data
1445 						  + __right_len);
1446 	    }
1447 	  else
1448 	    {
1449 	      const_iterator __rstart(__right, 0);
1450 	      const_iterator __rend(__right, __right_len);
1451 	      return lexicographical_compare_3way(__l->_M_data, __l->_M_data
1452 						  + __left_len,
1453 						  __rstart, __rend);
1454 	    }
1455 	}
1456       else
1457 	{
1458 	  const_iterator __lstart(__left, 0);
1459 	  const_iterator __lend(__left, __left_len);
1460 	  if (__detail::_S_leaf == __right->_M_tag)
1461 	    {
1462 	      _RopeLeaf* __r = (_RopeLeaf*) __right;
1463 	      return lexicographical_compare_3way(__lstart, __lend,
1464 						  __r->_M_data, __r->_M_data
1465 						  + __right_len);
1466 	    }
1467 	  else
1468 	    {
1469 	      const_iterator __rstart(__right, 0);
1470 	      const_iterator __rend(__right, __right_len);
1471 	      return lexicographical_compare_3way(__lstart, __lend,
1472 						  __rstart, __rend);
1473 	    }
1474 	}
1475     }
1476 
1477   // Assignment to reference proxies.
1478   template <class _CharT, class _Alloc>
1479     _Rope_char_ref_proxy<_CharT, _Alloc>&
1480     _Rope_char_ref_proxy<_CharT, _Alloc>::
1481     operator=(_CharT __c)
1482     {
1483       _RopeRep* __old = _M_root->_M_tree_ptr;
1484 #ifndef __GC
1485       // First check for the case in which everything is uniquely
1486       // referenced.  In that case we can do this destructively.
1487       _CharT* __ptr = _My_rope::_S_fetch_ptr(__old, _M_pos);
1488       if (0 != __ptr)
1489 	{
1490 	  *__ptr = __c;
1491 	  return *this;
1492 	}
1493 #endif
1494       _Self_destruct_ptr __left(_My_rope::_S_substring(__old, 0, _M_pos));
1495       _Self_destruct_ptr __right(_My_rope::_S_substring(__old, _M_pos + 1,
1496 							__old->_M_size));
1497       _Self_destruct_ptr __result_left(_My_rope::
1498 				       _S_destr_concat_char_iter(__left,
1499 								 &__c, 1));
1500 
1501       _RopeRep* __result = _My_rope::_S_concat(__result_left, __right);
1502 #ifndef __GC
1503       _RopeRep::_S_unref(__old);
1504 #endif
1505       _M_root->_M_tree_ptr = __result;
1506       return *this;
1507     }
1508 
1509   template <class _CharT, class _Alloc>
1510     inline _Rope_char_ref_proxy<_CharT, _Alloc>::
1511     operator _CharT() const
1512     {
1513       if (_M_current_valid)
1514 	return _M_current;
1515       else
1516 	return _My_rope::_S_fetch(_M_root->_M_tree_ptr, _M_pos);
1517     }
1518 
1519   template <class _CharT, class _Alloc>
1520     _Rope_char_ptr_proxy<_CharT, _Alloc>
1521     _Rope_char_ref_proxy<_CharT, _Alloc>::
1522     operator&() const
1523     { return _Rope_char_ptr_proxy<_CharT, _Alloc>(*this); }
1524 
1525   template <class _CharT, class _Alloc>
1526     rope<_CharT, _Alloc>::
1527     rope(size_t __n, _CharT __c, const allocator_type& __a)
1528     : _Base(__a)
1529     {
1530       rope<_CharT,_Alloc> __result;
1531       const size_t __exponentiate_threshold = 32;
1532       size_t __exponent;
1533       size_t __rest;
1534       _CharT* __rest_buffer;
1535       _RopeRep* __remainder;
1536       rope<_CharT, _Alloc> __remainder_rope;
1537 
1538       if (0 == __n)
1539 	return;
1540 
1541       __exponent = __n / __exponentiate_threshold;
1542       __rest = __n % __exponentiate_threshold;
1543       if (0 == __rest)
1544 	__remainder = 0;
1545       else
1546 	{
1547 	  __rest_buffer = this->_Data_allocate(_S_rounded_up_size(__rest));
1548 	  __uninitialized_fill_n_a(__rest_buffer, __rest, __c,
1549 				   _M_get_allocator());
1550 	  _S_cond_store_eos(__rest_buffer[__rest]);
1551 	  __try
1552 	    { __remainder = _S_new_RopeLeaf(__rest_buffer, __rest,
1553 					    _M_get_allocator()); }
1554 	  __catch(...)
1555 	    {
1556 	      _RopeRep::__STL_FREE_STRING(__rest_buffer, __rest,
1557 					  _M_get_allocator());
1558 	      __throw_exception_again;
1559 	    }
1560 	}
1561       __remainder_rope._M_tree_ptr = __remainder;
1562       if (__exponent != 0)
1563 	{
1564 	  _CharT* __base_buffer =
1565 	    this->_Data_allocate(_S_rounded_up_size(__exponentiate_threshold));
1566 	  _RopeLeaf* __base_leaf;
1567 	  rope __base_rope;
1568 	  __uninitialized_fill_n_a(__base_buffer, __exponentiate_threshold, __c,
1569 				   _M_get_allocator());
1570 	  _S_cond_store_eos(__base_buffer[__exponentiate_threshold]);
1571 	  __try
1572 	    {
1573 	      __base_leaf = _S_new_RopeLeaf(__base_buffer,
1574 					    __exponentiate_threshold,
1575 					    _M_get_allocator());
1576 	    }
1577 	  __catch(...)
1578 	    {
1579 	      _RopeRep::__STL_FREE_STRING(__base_buffer,
1580 					  __exponentiate_threshold,
1581 					  _M_get_allocator());
1582 	      __throw_exception_again;
1583 	    }
1584 	  __base_rope._M_tree_ptr = __base_leaf;
1585 	  if (1 == __exponent)
1586 	    __result = __base_rope;
1587 	  else
1588 	    __result = power(__base_rope, __exponent,
1589 			     _Rope_Concat_fn<_CharT, _Alloc>());
1590 
1591 	  if (0 != __remainder)
1592 	    __result += __remainder_rope;
1593 	}
1594       else
1595 	__result = __remainder_rope;
1596 
1597       this->_M_tree_ptr = __result._M_tree_ptr;
1598       this->_M_tree_ptr->_M_ref_nonnil();
1599     }
1600 
1601   template<class _CharT, class _Alloc>
1602     _CharT
1603     rope<_CharT, _Alloc>::_S_empty_c_str[1];
1604 
1605   template<class _CharT, class _Alloc>
1606     const _CharT*
1607     rope<_CharT, _Alloc>::
1608     c_str() const
1609     {
1610       if (0 == this->_M_tree_ptr)
1611 	{
1612 	  _S_empty_c_str[0] = _S_eos((_CharT*)0);  // Possibly redundant,
1613 	                                           // but probably fast.
1614 	  return _S_empty_c_str;
1615 	}
1616       __gthread_mutex_lock (&this->_M_tree_ptr->_M_c_string_lock);
1617       __GC_CONST _CharT* __result = this->_M_tree_ptr->_M_c_string;
1618       if (0 == __result)
1619 	{
1620 	  size_t __s = size();
1621 	  __result = this->_Data_allocate(__s + 1);
1622 	  _S_flatten(this->_M_tree_ptr, __result);
1623 	  __result[__s] = _S_eos((_CharT*)0);
1624 	  this->_M_tree_ptr->_M_c_string = __result;
1625 	}
1626       __gthread_mutex_unlock (&this->_M_tree_ptr->_M_c_string_lock);
1627       return(__result);
1628     }
1629 
1630   template<class _CharT, class _Alloc>
1631     const _CharT* rope<_CharT, _Alloc>::
1632     replace_with_c_str()
1633     {
1634       if (0 == this->_M_tree_ptr)
1635 	{
1636 	  _S_empty_c_str[0] = _S_eos((_CharT*)0);
1637 	  return _S_empty_c_str;
1638 	}
1639       __GC_CONST _CharT* __old_c_string = this->_M_tree_ptr->_M_c_string;
1640       if (__detail::_S_leaf == this->_M_tree_ptr->_M_tag
1641 	  && 0 != __old_c_string)
1642 	return(__old_c_string);
1643       size_t __s = size();
1644       _CharT* __result = this->_Data_allocate(_S_rounded_up_size(__s));
1645       _S_flatten(this->_M_tree_ptr, __result);
1646       __result[__s] = _S_eos((_CharT*)0);
1647       this->_M_tree_ptr->_M_unref_nonnil();
1648       this->_M_tree_ptr = _S_new_RopeLeaf(__result, __s,
1649 					  this->_M_get_allocator());
1650       return(__result);
1651     }
1652 
1653   // Algorithm specializations.  More should be added.
1654 
1655   template<class _Rope_iterator>  // was templated on CharT and Alloc
1656     void		          // VC++ workaround
1657     _Rope_rotate(_Rope_iterator __first,
1658 		 _Rope_iterator __middle,
1659 		 _Rope_iterator __last)
1660     {
1661       typedef typename _Rope_iterator::value_type _CharT;
1662       typedef typename _Rope_iterator::_allocator_type _Alloc;
1663 
1664       rope<_CharT, _Alloc>& __r(__first.container());
1665       rope<_CharT, _Alloc> __prefix = __r.substr(0, __first.index());
1666       rope<_CharT, _Alloc> __suffix =
1667 	__r.substr(__last.index(), __r.size() - __last.index());
1668       rope<_CharT, _Alloc> __part1 =
1669 	__r.substr(__middle.index(), __last.index() - __middle.index());
1670       rope<_CharT, _Alloc> __part2 =
1671 	__r.substr(__first.index(), __middle.index() - __first.index());
1672       __r = __prefix;
1673       __r += __part1;
1674       __r += __part2;
1675       __r += __suffix;
1676     }
1677 
1678 #if !defined(__GNUC__)
1679   // Appears to confuse g++
1680   inline void
1681   rotate(_Rope_iterator<char, __STL_DEFAULT_ALLOCATOR(char)> __first,
1682 	 _Rope_iterator<char, __STL_DEFAULT_ALLOCATOR(char)> __middle,
1683 	 _Rope_iterator<char, __STL_DEFAULT_ALLOCATOR(char)> __last)
1684   { _Rope_rotate(__first, __middle, __last); }
1685 #endif
1686 
1687 # if 0
1688   // Probably not useful for several reasons:
1689   // - for SGIs 7.1 compiler and probably some others,
1690   //   this forces lots of rope<wchar_t, ...> instantiations, creating a
1691   //   code bloat and compile time problem.  (Fixed in 7.2.)
1692   // - wchar_t is 4 bytes wide on most UNIX platforms, making it
1693   //   unattractive for unicode strings.  Unsigned short may be a better
1694   //   character type.
1695   inline void
1696   rotate(_Rope_iterator<wchar_t, __STL_DEFAULT_ALLOCATOR(char)> __first,
1697 	 _Rope_iterator<wchar_t, __STL_DEFAULT_ALLOCATOR(char)> __middle,
1698 	 _Rope_iterator<wchar_t, __STL_DEFAULT_ALLOCATOR(char)> __last)
1699   { _Rope_rotate(__first, __middle, __last); }
1700 # endif
1701 
1702 _GLIBCXX_END_NAMESPACE_VERSION
1703 } // namespace
1704