Patchwork [v3] define string::pop_back()

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Submitter Jonathan Wakely
Date Nov. 7, 2011, 12:06 a.m.
Message ID <CAH6eHdSWO3Cq9LT6BnKfRYmQDQp=pyk-kBRqSvnJQFr34=UPGg@mail.gmail.com>
Download mbox | patch
Permalink /patch/123986/
State New
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Comments

Jonathan Wakely - Nov. 7, 2011, 12:06 a.m.
I first posted this a month ago, this adjusts the exports and moves
the tests under separate char and wchar_t directories as requested by
Paolo.

        * include/bits/basic_string.h (basic_string::at): Move adjacent to other
        overload.
        (basic_string::pop_back): Define.
        * include/debug/string (__gnu_debug::basic_string::pop_back): Likewise.
        * include/ext/vstring.h (__versa_string::pop_back): Likewise.
        * config/abi/pre/gnu.ver: Add new symbols.
        * testsuite/21_strings/basic_string/modifiers/char/pop_back.cc: New.
        * testsuite/21_strings/basic_string/modifiers/wchar_t/pop_back.cc: New.
        * testsuite/21_strings/basic_string/range_access.cc: Split to ...
        * testsuite/21_strings/basic_string/range_access/char/1.cc: Here and ...
        * testsuite/21_strings/basic_string/range_access/wchar_t/1.cc: Here.
        * testsuite/ext/vstring/modifiers/char/pop_back.cc: New.
        * testsuite/ext/vstring/modifiers/wchar_t/pop_back.cc: New.

Tested x86_64-linux, committed to trunk.
Eric Botcazou - Nov. 7, 2011, 9:17 a.m.
>         * include/bits/basic_string.h (basic_string::at): Move adjacent to
> other overload.
>         (basic_string::pop_back): Define.
>         * include/debug/string (__gnu_debug::basic_string::pop_back):
> Likewise. * include/ext/vstring.h (__versa_string::pop_back): Likewise. *
> config/abi/pre/gnu.ver: Add new symbols.
>         * testsuite/21_strings/basic_string/modifiers/char/pop_back.cc:
> New. * testsuite/21_strings/basic_string/modifiers/wchar_t/pop_back.cc:
> New. * testsuite/21_strings/basic_string/range_access.cc: Split to ... *
> testsuite/21_strings/basic_string/range_access/char/1.cc: Here and ... *
> testsuite/21_strings/basic_string/range_access/wchar_t/1.cc: Here. *
> testsuite/ext/vstring/modifiers/char/pop_back.cc: New.
>         * testsuite/ext/vstring/modifiers/wchar_t/pop_back.cc: New.

This breaks bootstrap on Solaris:

ld: fatal: libstdc++-symbols.ver-sun: 4806: symbol `std::basic_string<char, 
std::char_traits<char>, std::allocator<char> >::pop_back()' is already defined 
in file: libstdc++-symbols.ver-sun

_ZNSs8pop_backEv is referenced twice in the version file.
Jonathan Wakely - Nov. 7, 2011, 9:20 a.m.
On 7 November 2011 09:17, Eric Botcazou wrote:
>>         * include/bits/basic_string.h (basic_string::at): Move adjacent to
>> other overload.
>>         (basic_string::pop_back): Define.
>>         * include/debug/string (__gnu_debug::basic_string::pop_back):
>> Likewise. * include/ext/vstring.h (__versa_string::pop_back): Likewise. *
>> config/abi/pre/gnu.ver: Add new symbols.
>>         * testsuite/21_strings/basic_string/modifiers/char/pop_back.cc:
>> New. * testsuite/21_strings/basic_string/modifiers/wchar_t/pop_back.cc:
>> New. * testsuite/21_strings/basic_string/range_access.cc: Split to ... *
>> testsuite/21_strings/basic_string/range_access/char/1.cc: Here and ... *
>> testsuite/21_strings/basic_string/range_access/wchar_t/1.cc: Here. *
>> testsuite/ext/vstring/modifiers/char/pop_back.cc: New.
>>         * testsuite/ext/vstring/modifiers/wchar_t/pop_back.cc: New.
>
> This breaks bootstrap on Solaris:
>
> ld: fatal: libstdc++-symbols.ver-sun: 4806: symbol `std::basic_string<char,
> std::char_traits<char>, std::allocator<char> >::pop_back()' is already defined
> in file: libstdc++-symbols.ver-sun
>
> _ZNSs8pop_backEv is referenced twice in the version file.

Thanks, I'll try to work out the right adjustment for the solaris
symbols file but can't test it.
Eric Botcazou - Nov. 7, 2011, 9:40 a.m.
> Thanks, I'll try to work out the right adjustment for the solaris
> symbols file but can't test it.

The 2 new symbols are duplicated, because they are matched by a regexp:

    ##_ZNSs[0-58-9][g-z]* (glob)
    _ZNSs4nposE;
    _ZNSs4rendEv;
    _ZNSs4swapERSs;
    _ZNSs8pop_backEv;
    _ZNSs9push_backEc;

    ##_ZNSbIwSt11char_traitsIwESaIwEE[0-58-9][g-z]* (glob)
    _ZNSbIwSt11char_traitsIwESaIwEE4nposE;
    _ZNSbIwSt11char_traitsIwESaIwEE4rendEv;
    _ZNSbIwSt11char_traitsIwESaIwEE4swapERS2_;
    _ZNSbIwSt11char_traitsIwESaIwEE8pop_backEv;
    _ZNSbIwSt11char_traitsIwESaIwEE9push_backEw;

so removing the 8 in the regexp seems to be sufficient.
Jonathan Wakely - Nov. 7, 2011, 10:34 a.m.
On 7 November 2011 09:40, Eric Botcazou wrote:
>> Thanks, I'll try to work out the right adjustment for the solaris
>> symbols file but can't test it.
>
> The 2 new symbols are duplicated, because they are matched by a regexp:
>
>    ##_ZNSs[0-58-9][g-z]* (glob)
>    _ZNSs4nposE;
>    _ZNSs4rendEv;
>    _ZNSs4swapERSs;
>    _ZNSs8pop_backEv;
>    _ZNSs9push_backEc;
>
>    ##_ZNSbIwSt11char_traitsIwESaIwEE[0-58-9][g-z]* (glob)
>    _ZNSbIwSt11char_traitsIwESaIwEE4nposE;
>    _ZNSbIwSt11char_traitsIwESaIwEE4rendEv;
>    _ZNSbIwSt11char_traitsIwESaIwEE4swapERS2_;
>    _ZNSbIwSt11char_traitsIwESaIwEE8pop_backEv;
>    _ZNSbIwSt11char_traitsIwESaIwEE9push_backEw;
>
> so removing the 8 in the regexp seems to be sufficient.

Won't that fail to match string::max_size?  For GNU I added a regex
for that explicitly:

+    _ZNKSs8max_size*;
+    _ZNKSbIwSt11char_traitsIwESaIwEE8max_size*;
Eric Botcazou - Nov. 7, 2011, 10:57 a.m.
> Won't that fail to match string::max_size?

No, if it doesn't appear in the list, then it isn't matched by the regexp.

> For GNU I added a regex for that explicitly:
>
> +    _ZNKSs8max_size*;
> +    _ZNKSbIwSt11char_traitsIwESaIwEE8max_size*;

What is GNU here?  The Solaris version file is a massaged version of gnu.ver.
You patched gnu.ver incorrectly so symbols are now matched twice; you need to 
fix that by avoiding the double matching.

Patch

Index: include/bits/basic_string.h
===================================================================
--- include/bits/basic_string.h	(revision 181047)
+++ include/bits/basic_string.h	(working copy)
@@ -865,6 +865,26 @@ 
 	return _M_data()[__n];
       }
 
+      /**
+       *  @brief  Provides access to the data contained in the %string.
+       *  @param __n The index of the character to access.
+       *  @return  Read/write reference to the character.
+       *  @throw  std::out_of_range  If @a n is an invalid index.
+       *
+       *  This function provides for safer data access.  The parameter is
+       *  first checked that it is in the range of the string.  The function
+       *  throws out_of_range if the check fails.  Success results in
+       *  unsharing the string.
+       */
+      reference
+      at(size_type __n)
+      {
+	if (__n >= size())
+	  __throw_out_of_range(__N("basic_string::at"));
+	_M_leak();
+	return _M_data()[__n];
+      }
+
 #ifdef __GXX_EXPERIMENTAL_CXX0X__
       /**
        *  Returns a read/write reference to the data at the first
@@ -899,26 +919,6 @@ 
       { return operator[](this->size() - 1); }
 #endif
 
-      /**
-       *  @brief  Provides access to the data contained in the %string.
-       *  @param __n The index of the character to access.
-       *  @return  Read/write reference to the character.
-       *  @throw  std::out_of_range  If @a n is an invalid index.
-       *
-       *  This function provides for safer data access.  The parameter is
-       *  first checked that it is in the range of the string.  The function
-       *  throws out_of_range if the check fails.  Success results in
-       *  unsharing the string.
-       */
-      reference
-      at(size_type __n)
-      {
-	if (__n >= size())
-	  __throw_out_of_range(__N("basic_string::at"));
-	_M_leak();
-	return _M_data()[__n];
-      }
-
       // Modifiers:
       /**
        *  @brief  Append a string to this string.
@@ -1394,7 +1394,18 @@ 
       iterator
       erase(iterator __first, iterator __last);
  
+#ifdef __GXX_EXPERIMENTAL_CXX0X__
       /**
+       *  @brief  Remove the last character.
+       *
+       *  The string must be non-empty.
+       */
+      void
+      pop_back()
+      { erase(size()-1, 1); }
+#endif // __GXX_EXPERIMENTAL_CXX0X__
+
+      /**
        *  @brief  Replace characters with value from another string.
        *  @param __pos  Index of first character to replace.
        *  @param __n  Number of characters to be replaced.
Index: include/debug/string
===================================================================
--- include/debug/string	(revision 181047)
+++ include/debug/string	(working copy)
@@ -580,6 +580,16 @@ 
       return iterator(__res, this);
     }
 
+#ifdef __GXX_EXPERIMENTAL_CXX0X__
+    void
+    pop_back()
+    {
+      __glibcxx_check_nonempty();
+      _Base::pop_back();
+      this->_M_invalidate_all();
+    }
+#endif // __GXX_EXPERIMENTAL_CXX0X__
+
     basic_string&
     replace(size_type __pos1, size_type __n1, const basic_string& __str)
     {
Index: include/ext/vstring.h
===================================================================
--- include/ext/vstring.h	(revision 181047)
+++ include/ext/vstring.h	(working copy)
@@ -1140,7 +1140,18 @@ 
 	return iterator(this->_M_data() + __pos);
       }
 
+#ifdef __GXX_EXPERIMENTAL_CXX0X__
       /**
+       *  @brief  Remove the last character.
+       *
+       *  The string must be non-empty.
+       */
+      void
+      pop_back()
+      { this->_M_erase(size()-1, 1); }
+#endif // __GXX_EXPERIMENTAL_CXX0X__
+
+      /**
        *  @brief  Replace characters with value from another string.
        *  @param __pos  Index of first character to replace.
        *  @param __n  Number of characters to be replaced.
Index: config/abi/pre/gnu.ver
===================================================================
--- config/abi/pre/gnu.ver	(revision 181047)
+++ config/abi/pre/gnu.ver	(working copy)
@@ -225,9 +225,10 @@ 
     _ZNKSs[0-3][a-b]*;
     _ZNKSs[5-9][a-b]*;
     _ZNKSs[0-9][d-e]*;
-    _ZNKSs[0-9][g-z]*;
+    _ZNKSs[0-79][g-z]*;
     _ZNKSs[0-9][0-9][a-z]*;
     _ZNKSs4find*;
+    _ZNKSs8max_size*;
     _ZNKSs[a-z]*;
     _ZNKSs4_Rep12_M_is_leakedEv;
     _ZNKSs4_Rep12_M_is_sharedEv;
@@ -286,10 +287,11 @@ 
     _ZNKSbIwSt11char_traitsIwESaIwEE[0-3][a-b]*;
     _ZNKSbIwSt11char_traitsIwESaIwEE[5-9][a-b]*;
     _ZNKSbIwSt11char_traitsIwESaIwEE[0-9][d-e]*;
-    _ZNKSbIwSt11char_traitsIwESaIwEE[0-9][g-z]*;
+    _ZNKSbIwSt11char_traitsIwESaIwEE[0-79][g-z]*;
     _ZNKSbIwSt11char_traitsIwESaIwEE[0-9][0-9][a-z]*;
     _ZNKSbIwSt11char_traitsIwESaIwEE[a-z]*;
     _ZNKSbIwSt11char_traitsIwESaIwEE4find*;
+    _ZNKSbIwSt11char_traitsIwESaIwEE8max_size*;
     _ZNKSbIwSt11char_traitsIwESaIwEE4_Rep12_M_is_leakedEv;
     _ZNKSbIwSt11char_traitsIwESaIwEE4_Rep12_M_is_sharedEv;
     _ZNKSbIwSt11char_traitsIwESaIwEE6_M_repEv;
@@ -1302,6 +1304,11 @@ 
     _ZNSt14numeric_limitsInE*;
     _ZNSt14numeric_limitsIoE*;
 
+    # std::string::pop_back()
+    _ZNSs8pop_backEv;
+    # std::wstring::pop_back()
+    _ZNSbIwSt11char_traitsIwESaIwEE8pop_backEv;
+
 } GLIBCXX_3.4.16;
 
 # Symbols in the support library (libsupc++) have their own tag.
Index: testsuite/21_strings/basic_string/modifiers/wchar_t/pop_back.cc
===================================================================
--- testsuite/21_strings/basic_string/modifiers/wchar_t/pop_back.cc	(revision 0)
+++ testsuite/21_strings/basic_string/modifiers/wchar_t/pop_back.cc	(revision 0)
@@ -0,0 +1,41 @@ 
+// Copyright (C) 2011 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 21.4.6.5 basic_string::pop_back
+// { dg-options "-std=gnu++0x" }
+
+#include <string>
+#include <testsuite_hooks.h>
+
+void test01()
+{
+  bool test __attribute__((unused)) = true;
+
+  const std::wstring cstr(L"Badger");
+  std::wstring str = cstr;
+  str.pop_back();
+  VERIFY( str.size() == cstr.size() - 1 );
+
+  str += cstr.back();
+  VERIFY( str == cstr );
+}
+
+int main()
+{ 
+  test01();
+  return 0;
+}
Index: testsuite/21_strings/basic_string/modifiers/char/pop_back.cc
===================================================================
--- testsuite/21_strings/basic_string/modifiers/char/pop_back.cc	(revision 0)
+++ testsuite/21_strings/basic_string/modifiers/char/pop_back.cc	(revision 0)
@@ -0,0 +1,41 @@ 
+// Copyright (C) 2011 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 21.4.6.5 basic_string::pop_back
+// { dg-options "-std=gnu++0x" }
+
+#include <string>
+#include <testsuite_hooks.h>
+
+void test01()
+{
+  bool test __attribute__((unused)) = true;
+
+  const std::string cstr("Badger");
+  std::string str = cstr;
+  str.pop_back();
+  VERIFY( str.size() == cstr.size() - 1 );
+
+  str += cstr.back();
+  VERIFY( str == cstr );
+}
+
+int main()
+{ 
+  test01();
+  return 0;
+}
Index: testsuite/21_strings/basic_string/range_access.cc
===================================================================
--- testsuite/21_strings/basic_string/range_access.cc	(revision 181047)
+++ testsuite/21_strings/basic_string/range_access.cc	(working copy)
@@ -1,37 +0,0 @@ 
-// { dg-do compile }
-// { dg-options "-std=gnu++0x" }
-
-// Copyright (C) 2010 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
-// terms of the GNU General Public License as published by the
-// Free Software Foundation; either version 3, or (at your option)
-// any later version.
-
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without Pred 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 COPYING3.  If not see
-// <http://www.gnu.org/licenses/>.
-
-// 24.6.5, range access [iterator.range]
-
-#include <string>
-
-void
-test01()
-{
-  std::string s("Hello, World!");
-  std::begin(s);
-  std::end(s);
-
-#ifdef _GLIBCXX_USE_WCHAR_T
-  std::wstring ws(L"Hello, World!");
-  std::begin(ws);
-  std::end(ws);
-#endif
-}
Index: testsuite/21_strings/basic_string/range_access/wchar_t/1.cc
===================================================================
--- testsuite/21_strings/basic_string/range_access/wchar_t/1.cc	(revision 0)
+++ testsuite/21_strings/basic_string/range_access/wchar_t/1.cc	(revision 0)
@@ -0,0 +1,33 @@ 
+// { dg-do compile }
+// { dg-options "-std=gnu++0x" }
+
+// Copyright (C) 2010. 2011 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without Pred 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 24.6.5, range access [iterator.range]
+
+#include <string>
+
+void
+test01()
+{
+#ifdef _GLIBCXX_USE_WCHAR_T
+  std::wstring ws(L"Hello, World!");
+  std::begin(ws);
+  std::end(ws);
+#endif
+}
Index: testsuite/21_strings/basic_string/range_access/char/1.cc
===================================================================
--- testsuite/21_strings/basic_string/range_access/char/1.cc	(revision 0)
+++ testsuite/21_strings/basic_string/range_access/char/1.cc	(revision 0)
@@ -0,0 +1,31 @@ 
+// { dg-do compile }
+// { dg-options "-std=gnu++0x" }
+
+// Copyright (C) 2010, 2011 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without Pred 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 24.6.5, range access [iterator.range]
+
+#include <string>
+
+void
+test01()
+{
+  std::string s("Hello, World!");
+  std::begin(s);
+  std::end(s);
+}
Index: testsuite/ext/vstring/modifiers/wchar_t/pop_back.cc
===================================================================
--- testsuite/ext/vstring/modifiers/wchar_t/pop_back.cc	(revision 0)
+++ testsuite/ext/vstring/modifiers/wchar_t/pop_back.cc	(revision 0)
@@ -0,0 +1,45 @@ 
+// Copyright (C) 2011 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 21.4.6.5 basic_string::pop_back
+// { dg-options "-std=gnu++0x" }
+
+#include <ext/vstring.h>
+#include <testsuite_hooks.h>
+
+template<typename StrT>
+int test01()
+{
+  bool test __attribute__((unused)) = true;
+
+  const StrT cstr(L"Badger");
+  StrT str = cstr;
+  str.pop_back();
+  VERIFY( str.size() == cstr.size() - 1 );
+
+  str += cstr.back();
+  VERIFY( str == cstr );
+
+  return test;
+}
+
+int main()
+{ 
+  test01<__gnu_cxx::__wsso_string>();
+  test01<__gnu_cxx::__wrc_string>();
+  return 0;
+}
Index: testsuite/ext/vstring/modifiers/char/pop_back.cc
===================================================================
--- testsuite/ext/vstring/modifiers/char/pop_back.cc	(revision 0)
+++ testsuite/ext/vstring/modifiers/char/pop_back.cc	(revision 0)
@@ -0,0 +1,45 @@ 
+// Copyright (C) 2011 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 21.4.6.5 basic_string::pop_back
+// { dg-options "-std=gnu++0x" }
+
+#include <ext/vstring.h>
+#include <testsuite_hooks.h>
+
+template<typename StrT>
+int test01()
+{
+  bool test __attribute__((unused)) = true;
+
+  const StrT cstr("Badger");
+  StrT str = cstr;
+  str.pop_back();
+  VERIFY( str.size() == cstr.size() - 1 );
+
+  str += cstr.back();
+  VERIFY( str == cstr );
+
+  return test;
+}
+
+int main()
+{ 
+  test01<__gnu_cxx::__sso_string>();
+  test01<__gnu_cxx::__rc_string>();
+  return 0;
+}