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[Patch/RFC] Sebor's const correctness issue
- From: Paolo Carlini <pcarlini at unitus dot it>
- To: "libstdc++ at gcc dot gnu dot org" <libstdc++ at gcc dot gnu dot org>
- Cc: bkoz <bkoz at redhat dot com>
- Date: Fri, 31 Jan 2003 23:35:32 +0100
- Subject: [Patch/RFC] Sebor's const correctness issue
Hi,
in privare mail Benjamin suggested (*many* thanks!) using mutable
to fix the const correctness issue put forward by Martin Sebor.
Indeed, the below stems quite straightforwardly from making
locale::facet::_M_references mutable and locale::_Impl::_M_facets
of type const facet**.
Would that approach (regtests ok on x86-linux) be viable for trunk?
Paolo.
////////
Const correctness bug:
http://gcc.gnu.org/ml/libstdc++/2003-01/msg00370.html
* include/bits/locale_classes.h
(locale::_Impl::_M_facets): Change to const facet**.
(locale::_Impl::_M_install_facet): Change declaration to
take const facet*.
(locale::facet::_M_references): Make mutable.
(locale::facet::_M_add_reference): Declare const.
(locale::facet::_M_remove_reference): Likewise.
* include/bits/locale_facets.tcc
(use_facet(const locale&)): Tweak for _M_facets const facet**.
(has_facet(const locale&)): Likewise.
* src/locale.cc
(locale::facet::_M_add_reference): Adjust definition.
(locale::facet::_M_remove_reference): Likewise.
* src/localename.cc
(locale::_Impl::_Impl(const _Impl&, size_t)): Tweak for
_M_facets const facet**.
(locale::_Impl::_Impl(const char*, size_t)): Likewise.
(locale::_Impl::_Impl(facet**, size_t, bool)): Likewise.
(locale::_Impl::_M_install_facet): Adjust definition to take
const facet* and for _M_facets const facet**.
* testsuite/22_locale/locale/cons/8.cc: Add.
diff -urN libstdc++-v3-orig/include/bits/locale_classes.h libstdc++-v3/include/bits/locale_classes.h
--- libstdc++-v3-orig/include/bits/locale_classes.h 2003-01-23 19:56:00.000000000 +0100
+++ libstdc++-v3/include/bits/locale_classes.h 2003-01-31 22:21:50.000000000 +0100
@@ -199,7 +199,7 @@
private:
// Data Members.
_Atomic_word _M_references;
- facet** _M_facets;
+ const facet** _M_facets;
size_t _M_facets_size;
char* _M_names[_S_categories_size
@@ -260,7 +260,7 @@
_M_replace_facet(const _Impl*, const locale::id*);
void
- _M_install_facet(const locale::id*, facet*);
+ _M_install_facet(const locale::id*, const facet*);
template<typename _Facet>
inline void
@@ -291,7 +291,7 @@
friend class locale;
friend class locale::_Impl;
- _Atomic_word _M_references;
+ mutable _Atomic_word _M_references;
protected:
// Contains data from the underlying "C" library for the classic locale.
@@ -318,10 +318,10 @@
private:
void
- _M_add_reference() throw();
+ _M_add_reference() const throw();
void
- _M_remove_reference() throw();
+ _M_remove_reference() const throw();
facet(const facet&); // Not defined.
diff -urN libstdc++-v3-orig/include/bits/locale_facets.tcc libstdc++-v3/include/bits/locale_facets.tcc
--- libstdc++-v3-orig/include/bits/locale_facets.tcc 2003-01-22 17:51:51.000000000 +0100
+++ libstdc++-v3/include/bits/locale_facets.tcc 2003-01-31 21:54:14.000000000 +0100
@@ -71,7 +71,7 @@
use_facet(const locale& __loc)
{
size_t __i = _Facet::id._M_id();
- locale::facet** __facets = __loc._M_impl->_M_facets;
+ const locale::facet** __facets = __loc._M_impl->_M_facets;
if (!(__i < __loc._M_impl->_M_facets_size && __facets[__i]))
__throw_bad_cast();
return static_cast<const _Facet&>(*__facets[__i]);
@@ -82,7 +82,7 @@
has_facet(const locale& __loc) throw()
{
size_t __i = _Facet::id._M_id();
- locale::facet** __facets = __loc._M_impl->_M_facets;
+ const locale::facet** __facets = __loc._M_impl->_M_facets;
return (__i < __loc._M_impl->_M_facets_size && __facets[__i]);
}
diff -urN libstdc++-v3-orig/src/locale.cc libstdc++-v3/src/locale.cc
--- libstdc++-v3-orig/src/locale.cc 2003-01-23 18:21:11.000000000 +0100
+++ libstdc++-v3/src/locale.cc 2003-01-31 21:47:48.000000000 +0100
@@ -461,12 +461,12 @@
void
locale::facet::
- _M_add_reference() throw()
+ _M_add_reference() const throw()
{ __atomic_add(&_M_references, 1); }
void
locale::facet::
- _M_remove_reference() throw()
+ _M_remove_reference() const throw()
{
if (__exchange_and_add(&_M_references, -1) == 1)
{
diff -urN libstdc++-v3-orig/src/localename.cc libstdc++-v3/src/localename.cc
--- libstdc++-v3-orig/src/localename.cc 2003-01-06 22:22:59.000000000 +0100
+++ libstdc++-v3/src/localename.cc 2003-01-31 21:56:25.000000000 +0100
@@ -94,7 +94,7 @@
{
try
{
- _M_facets = new facet*[_M_facets_size];
+ _M_facets = new const facet*[_M_facets_size];
for (size_t __i = 0; __i < _M_facets_size; ++__i)
_M_facets[__i] = 0;
}
@@ -130,7 +130,7 @@
try
{
- _M_facets = new facet*[_M_facets_size];
+ _M_facets = new const facet*[_M_facets_size];
for (size_t __i = 0; __i < _M_facets_size; ++__i)
_M_facets[__i] = 0;
}
@@ -214,7 +214,7 @@
locale::facet::_S_create_c_locale(locale::facet::_S_c_locale,
locale::facet::_S_c_name);
- _M_facets = new(&facet_vec) facet*[_M_facets_size];
+ _M_facets = new(&facet_vec) const facet*[_M_facets_size];
for (size_t __i = 0; __i < _M_facets_size; ++__i)
_M_facets[__i] = 0;
@@ -310,7 +310,7 @@
void
locale::_Impl::
- _M_install_facet(const locale::id* __idp, facet* __fp)
+ _M_install_facet(const locale::id* __idp, const facet* __fp)
{
if (__fp)
{
@@ -319,10 +319,10 @@
// Check size of facet vector to ensure adequate room.
if (__index > _M_facets_size - 1)
{
- facet** __old = _M_facets;
- facet** __new;
+ const facet** __old = _M_facets;
+ const facet** __new;
const size_t __new_size = __index + 4;
- __new = new facet*[__new_size];
+ __new = new const facet*[__new_size];
for (size_t __i = 0; __i < _M_facets_size; ++__i)
__new[__i] = _M_facets[__i];
for (size_t __i2 = _M_facets_size; __i2 < __new_size; ++__i2)
@@ -334,7 +334,7 @@
}
__fp->_M_add_reference();
- facet*& __fpr = _M_facets[__index];
+ const facet*& __fpr = _M_facets[__index];
if (__fpr)
{
// Replacing an existing facet. Order matters.
diff -urN libstdc++-v3-orig/testsuite/22_locale/locale/cons/8.cc libstdc++-v3/testsuite/22_locale/locale/cons/8.cc
--- libstdc++-v3-orig/testsuite/22_locale/locale/cons/8.cc 1970-01-01 01:00:00.000000000 +0100
+++ libstdc++-v3/testsuite/22_locale/locale/cons/8.cc 2003-01-31 22:31:42.000000000 +0100
@@ -0,0 +1,43 @@
+// 2003-01-31 Paolo Carlini <pcarlini@unitus.it>
+
+// Copyright (C) 2003 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.
+
+// 22.1.1.2 locale constructors and destructors [lib.locale.cons]
+
+#include <locale>
+
+// Const correctness issue:
+// http://gcc.gnu.org/ml/libstdc++/2003-01/msg00370.html
+void
+test01()
+{
+ using namespace std;
+ bool test = true;
+
+ const locale l1("C");
+ const locale l2 =
+ locale(locale::classic(), &use_facet<time_get<char> >(l1));
+}
+
+
+int main()
+{
+ test01();
+ return 0;
+}