re PR libstdc++/11584 (ios::iword() fails to zero-initialize storage on failure)

2004-01-27  Jerry Quinn  <jlquinn@optonline.net>

	PR libstdc++/11584
	* include/bits/ios_base.h (ios_base::_M_grow_words):  Add
        iword/pword selector.
	(ios_base::iword, ios_base::pword):  Use it.
	* src/ios.cc (ios_base::_M_grow_words):  Clear _M_word_zero
        iword or pword member on alloc failure.
	* testsuite/27_io/ios_base/storage/11584.cc:  New test.

From-SVN: r76725

4 files changed, 83 insertions, 4 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index ea093c2..65c10db 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,13 @@
+2004-01-27  Jerry Quinn  <jlquinn@optonline.net>
+
+	PR libstdc++/11584
+	* include/bits/ios_base.h (ios_base::_M_grow_words):  Add
+        iword/pword selector.
+	(ios_base::iword, ios_base::pword):  Use it.
+	* src/ios.cc (ios_base::_M_grow_words):  Clear _M_word_zero
+        iword or pword member on alloc failure.
+	* testsuite/27_io/ios_base/storage/11584.cc:  New test.
+
 2004-01-27  Ulrich Weigand  <uweigand@de.ibm.com>
 	    PJ Darcy  <darcypj@us.ibm.com>
 
diff --git a/libstdc++-v3/include/bits/ios_base.h b/libstdc++-v3/include/bits/ios_base.h
index 587bda4..b937ac5 100644
--- a/libstdc++-v3/include/bits/ios_base.h
+++ b/libstdc++-v3/include/bits/ios_base.h
@@ -471,7 +471,7 @@ namespace std
     _Words* 		_M_word;
  
     _Words& 
-    _M_grow_words(int __index);
+    _M_grow_words(int __index, bool __iword);
 
     // Members for locale and locale caching.
     locale 		_M_ios_locale;
@@ -692,7 +692,7 @@ namespace std
     iword(int __ix)
     {
       _Words& __word = (__ix < _M_word_size) 
-			? _M_word[__ix] : _M_grow_words(__ix);
+			? _M_word[__ix] : _M_grow_words(__ix, true);
       return __word._M_iword;
     }
 
@@ -713,7 +713,7 @@ namespace std
     pword(int __ix)
     {
       _Words& __word = (__ix < _M_word_size) 
-			? _M_word[__ix] : _M_grow_words(__ix);
+			? _M_word[__ix] : _M_grow_words(__ix, false);
       return __word._M_pword;
     }
 
diff --git a/libstdc++-v3/src/ios.cc b/libstdc++-v3/src/ios.cc
index 0dec323..6f987c2 100644
--- a/libstdc++-v3/src/ios.cc
+++ b/libstdc++-v3/src/ios.cc
@@ -147,7 +147,7 @@ namespace std
 
   // 27.4.2.5  iword/pword storage
   ios_base::_Words&
-  ios_base::_M_grow_words(int ix)
+  ios_base::_M_grow_words(int ix, bool iword)
   {
     // Precondition: _M_word_size <= ix
     int newsize = _S_local_word_size;
@@ -165,6 +165,10 @@ namespace std
 		if (_M_streambuf_state & _M_exception)
 		  __throw_ios_failure(__N("ios_base::_M_grow_words "
 				      "allocation failed"));
+		if (iword)
+		  _M_word_zero._M_iword = 0;
+		else
+		  _M_word_zero._M_pword = 0;
 		return _M_word_zero;
 	      }
 	    for (int i = 0; i < _M_word_size; i++) 
@@ -180,6 +184,10 @@ namespace std
 	    _M_streambuf_state |= badbit;
 	    if (_M_streambuf_state & _M_exception)
 	      __throw_ios_failure(__N("ios_base::_M_grow_words is not valid"));
+	    if (iword)
+	      _M_word_zero._M_iword = 0;
+	    else
+	      _M_word_zero._M_pword = 0;
 	    return _M_word_zero;
 	  }
       }
diff --git a/libstdc++-v3/testsuite/27_io/ios_base/storage/11584.cc b/libstdc++-v3/testsuite/27_io/ios_base/storage/11584.cc
new file mode 100644
index 0000000..8b1a7a7
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/ios_base/storage/11584.cc
@@ -0,0 +1,61 @@
+// 2004-01-25 jlquinn@gcc.gnu.org
+
+// Copyright (C) 2004 Free Software Foundation
+//
+// 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)
+// any later version.
+
+// This library 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 library; see the file COPYING.  If not, write to the Free
+// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+// USA.
+
+// 27.4.2.5 ios_base storage functions
+
+#include <cstdlib>
+#include <new>
+#include <testsuite_hooks.h>
+
+int new_fails;
+
+void* operator new (size_t n)
+{
+    if (new_fails)
+        throw std::bad_alloc();
+
+    return malloc(n);
+}
+
+void operator delete (void *p) { free(p); }
+void* operator new[] (size_t n) { return operator new(n); }
+void operator delete[] (void *p) { operator delete(p); }
+
+int main ()
+{
+    const int i = std::ios::xalloc ();
+
+    new_fails = 1;
+
+    // Successive accesses to failure storage clears to zero.
+    std::cout.iword(100) = 0xdeadbeef;
+    VERIFY(std::cout.iword(100) == 0);
+
+    // Access to pword failure storage shouldn't clear iword pword storage.
+    long& lr = std::cout.iword(100);
+    lr = 0xdeadbeef;
+
+    void* pv = std::cout.pword(100);
+    VERIFY(pv == 0);
+    VERIFY(lr == 0xdeadbeef);
+    
+    return 0;
+}
+