re PR libstdc++/19495 (basic_string::_M_rep() can produce an unnaturally aligned pointer to _Rep)

2005-05-18  Paolo Carlini  <pcarlini@suse.de>
	    Nathan Myers  <ncm@cantrip.org>

	PR libstdc++/19495
	* include/bits/basic_string.h (_Raw_bytes_alloc): Rebind to
	size_type instead of char and rename to _Raw_alloc.
	* include/bits/basic_string.tcc (_Rep::_M_destroy, _Rep::_S_create):
	Use the above.
	* src/bitmap_allocator.cc: Add instantiation for size_type.
	* src/mt_allocator.cc: Likewise.
	* src/pool_allocator.cc: Likewise.
	* include/ext/array_allocator.h: Tweak slightly, avoid assuming
	the existence of an _Array::begin() and size() members.
	* testsuite/ext/array_allocator/2.cc: Tweak to use an allocator
	of size_type, instead of char, thus avoiding problems with
	rebinds, not treated correctly by array_allocator.

Co-Authored-By: Nathan Myers <ncm@cantrip.org>

From-SVN: r99933

8 files changed, 47 insertions, 19 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index dfee5d7..50db6bb 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,4 +1,21 @@
 2005-05-18  Paolo Carlini  <pcarlini@suse.de>
+	    Nathan Myers  <ncm@cantrip.org>
+
+	PR libstdc++/19495
+	* include/bits/basic_string.h (_Raw_bytes_alloc): Rebind to
+	size_type instead of char and rename to _Raw_alloc.
+	* include/bits/basic_string.tcc (_Rep::_M_destroy, _Rep::_S_create):
+	Use the above.
+	* src/bitmap_allocator.cc: Add instantiation for size_type.
+	* src/mt_allocator.cc: Likewise.
+	* src/pool_allocator.cc: Likewise.
+	* include/ext/array_allocator.h: Tweak slightly, avoid assuming
+	the existence of an _Array::begin() and size() members.
+	* testsuite/ext/array_allocator/2.cc: Tweak to use an allocator
+	of size_type, instead of char, thus avoiding problems with
+	rebinds, not treated correctly by array_allocator.
+
+2005-05-18  Paolo Carlini  <pcarlini@suse.de>
 
 	* testsuite/22_locale/ctype/is/char/2.cc: Adjust dg-require-namedlocale.
 	* testsuite/22_locale/ctype/is/wchar_t/2.cc: Likewise.
diff --git a/libstdc++-v3/include/bits/basic_string.h b/libstdc++-v3/include/bits/basic_string.h
index d257956..b1fbaaa 100644
--- a/libstdc++-v3/include/bits/basic_string.h
+++ b/libstdc++-v3/include/bits/basic_string.h
@@ -151,7 +151,7 @@ namespace std
       struct _Rep : _Rep_base
       {
 	// Types:
-	typedef typename _Alloc::template rebind<char>::other _Raw_bytes_alloc;
+	typedef typename _Alloc::template rebind<size_type>::other _Raw_alloc;
 
 	// (Public) Data members:
 
diff --git a/libstdc++-v3/include/bits/basic_string.tcc b/libstdc++-v3/include/bits/basic_string.tcc
index 41db0dff..672457f 100644
--- a/libstdc++-v3/include/bits/basic_string.tcc
+++ b/libstdc++-v3/include/bits/basic_string.tcc
@@ -425,9 +425,10 @@ namespace std
     basic_string<_CharT, _Traits, _Alloc>::_Rep::
     _M_destroy(const _Alloc& __a) throw ()
     {
-      const size_type __size = sizeof(_Rep_base) +
-	                       (this->_M_capacity + 1) * sizeof(_CharT);
-      _Raw_bytes_alloc(__a).deallocate(reinterpret_cast<char*>(this), __size);
+      const size_type __size = ((this->_M_capacity + 1) * sizeof(_CharT)
+				+ sizeof(_Rep_base) + sizeof(size_type) - 1);
+      _Raw_alloc(__a).deallocate(reinterpret_cast<size_type*>(this), __size
+				 / sizeof(size_type));
     }
 
   template<typename _CharT, typename _Traits, typename _Alloc>
@@ -568,9 +569,12 @@ namespace std
 	__capacity = 2 * __old_capacity;
 
       // NB: Need an array of char_type[__capacity], plus a terminating
-      // null char_type() element, plus enough for the _Rep data structure.
+      // null char_type() element, plus enough for the _Rep data structure,
+      // plus sizeof(size_type) - 1 to upper round to a size multiple
+      // of sizeof(size_type).
       // Whew. Seemingly so needy, yet so elemental.
-      size_type __size = (__capacity + 1) * sizeof(_CharT) + sizeof(_Rep);
+      size_type __size = ((__capacity + 1) * sizeof(_CharT) + sizeof(_Rep)
+			  + sizeof(size_type) - 1);
 
       const size_type __adj_size = __size + __malloc_header_size;
       if (__adj_size > __pagesize && __capacity > __old_capacity)
@@ -580,12 +584,14 @@ namespace std
 	  // Never allocate a string bigger than _S_max_size.
 	  if (__capacity > _S_max_size)
 	    __capacity = _S_max_size;
-	  __size = (__capacity + 1) * sizeof(_CharT) + sizeof(_Rep);
+	  __size = ((__capacity + 1) * sizeof(_CharT) + sizeof(_Rep)
+		    + sizeof(size_type) - 1);
 	}
 
       // NB: Might throw, but no worries about a leak, mate: _Rep()
       // does not throw.
-      void* __place = _Raw_bytes_alloc(__alloc).allocate(__size);
+      void* __place = _Raw_alloc(__alloc).allocate(__size
+						   / sizeof(size_type));
       _Rep *__p = new (__place) _Rep;
       __p->_M_capacity = __capacity;
       return __p;
diff --git a/libstdc++-v3/include/ext/array_allocator.h b/libstdc++-v3/include/ext/array_allocator.h
index 8689d9d..2716919 100644
--- a/libstdc++-v3/include/ext/array_allocator.h
+++ b/libstdc++-v3/include/ext/array_allocator.h
@@ -121,9 +121,10 @@ namespace __gnu_cxx
       allocate(size_type __n, const void* = 0)
       {
 	static size_type __array_used;
-	if (_M_array == 0 || __array_used + __n > _M_array->size())
+	if (_M_array == 0
+	    || __array_used + __n > sizeof(*_M_array) / sizeof(_Tp))
 	  std::__throw_bad_alloc();
-	pointer __ret = _M_array->begin() + __array_used;
+	pointer __ret = reinterpret_cast<_Tp*>(_M_array) + __array_used;
 	__array_used += __n;
 	return __ret;
       }
diff --git a/libstdc++-v3/src/bitmap_allocator.cc b/libstdc++-v3/src/bitmap_allocator.cc
index c8d94af..4e42cce 100644
--- a/libstdc++-v3/src/bitmap_allocator.cc
+++ b/libstdc++-v3/src/bitmap_allocator.cc
@@ -41,6 +41,10 @@ namespace __gnu_cxx
     <bitmap_allocator<wchar_t>::_Alloc_block*, 
      bitmap_allocator<wchar_t>::_Alloc_block*> >;
 
+    template class __mini_vector<std::pair
+    <bitmap_allocator<size_t>::_Alloc_block*, 
+     bitmap_allocator<size_t>::_Alloc_block*> >;
+
     template class __mini_vector<size_t*>;
 
     template size_t** __lower_bound
diff --git a/libstdc++-v3/src/mt_allocator.cc b/libstdc++-v3/src/mt_allocator.cc
index bb6ab89..9c94bc8 100644
--- a/libstdc++-v3/src/mt_allocator.cc
+++ b/libstdc++-v3/src/mt_allocator.cc
@@ -1,8 +1,8 @@
 // Allocator details.
 
-// Copyright (C) 2004 Free Software Foundation, Inc.
+// Copyright (C) 2004, 2005 Free Software Foundation, Inc.
 //
-// This file is part of the GNU ISO C++ Librarbooly.  This library is free
+// This file is part of the GNU ISO C++ Library.  This library 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)
@@ -552,4 +552,5 @@ namespace __gnu_cxx
   // Instantiations.
   template class __mt_alloc<char>;
   template class __mt_alloc<wchar_t>;
+  template class __mt_alloc<size_t>;  
 } // namespace __gnu_cxx
diff --git a/libstdc++-v3/src/pool_allocator.cc b/libstdc++-v3/src/pool_allocator.cc
index 731cfff..1ad4e9c 100644
--- a/libstdc++-v3/src/pool_allocator.cc
+++ b/libstdc++-v3/src/pool_allocator.cc
@@ -170,4 +170,5 @@ namespace __gnu_cxx
   // Instantiations.
   template class __pool_alloc<char>;
   template class __pool_alloc<wchar_t>;
+  template class __pool_alloc<size_t>;  
 } // namespace __gnu_cxx
diff --git a/libstdc++-v3/testsuite/ext/array_allocator/2.cc b/libstdc++-v3/testsuite/ext/array_allocator/2.cc
index f580ea2..1e83725 100644
--- a/libstdc++-v3/testsuite/ext/array_allocator/2.cc
+++ b/libstdc++-v3/testsuite/ext/array_allocator/2.cc
@@ -1,7 +1,4 @@
-// Expected execution error for PR19495.
-// { dg-do run { xfail powerpc*-*-linux* } }
-
-// Copyright (C) 2004 Free Software Foundation, Inc.
+// Copyright (C) 2004, 2005 Free Software Foundation, Inc.
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
 // software; you can redistribute it and/or modify it under the
@@ -35,7 +32,10 @@
 
 typedef char char_type;
 typedef std::char_traits<char_type> traits_type;
-typedef std::tr1::array<char_type, 32> array_type;
+// NB: Array_allocator doesn't properly support rebinding, used by
+// basic_string. See libstdc++/21609 for details.
+typedef std::tr1::array<size_t, 16> array_type;
+typedef __gnu_cxx::array_allocator<size_t, array_type> allocator_type;
 
 array_type extern_array;
 
@@ -44,10 +44,8 @@ void test01()
   bool test __attribute__((unused)) = true;
 
   using std::basic_string;
-  typedef __gnu_cxx::array_allocator<char_type, array_type> allocator_type;
   typedef basic_string<char_type, traits_type, allocator_type> string_type;
 
-  size_t index = array_type::_S_index;
   allocator_type a(&extern_array);
   string_type s(a);