[PATCH] Fix PR38720, rel-pointer problems

[Richard Guenther]

On Sun, 4 Jan 2009, Richard Guenther wrote:

> 
> This fixes PR38720 by making rel-pointer use an unsigned integer type
> for all of its calculations.
> 
> Bootstrapped and tested on x86_64-unknown-linux-gnu, ok for trunk?

Sorry, I get excess errors

FAIL: ext/ext_pointer/1_neg.cc  (test for errors, line 289)
FAIL: ext/ext_pointer/1_neg.cc  (test for errors, line 289)
FAIL: ext/ext_pointer/1_neg.cc  (test for errors, line 295)
FAIL: ext/ext_pointer/1_neg.cc  (test for errors, line 295)
FAIL: ext/ext_pointer/1_neg.cc  (test for errors, line 312)
FAIL: ext/ext_pointer/1_neg.cc  (test for errors, line 312)
FAIL: ext/ext_pointer/1_neg.cc  (test for errors, line 320)
FAIL: ext/ext_pointer/1_neg.cc  (test for errors, line 320)

which I don't understand.  Paolo, can you take the patch and finish it?

Thanks,
Richard.

> Thanks,
> Richard.
> 
> 2009-01-04  Richard Guenther  <rguenther@suse.de>
> 
> 	PR libstdc++/38720
> 	* include/ext/pointer.h (_Relative_pointer_impl): Use an unsigned
> 	integer type for storage, arithmetic and comparisons.
> 
> Index: libstdc++-v3/include/ext/pointer.h
> ===================================================================
> *** libstdc++-v3/include/ext/pointer.h	(revision 143048)
> --- libstdc++-v3/include/ext/pointer.h	(working copy)
> ***************
> *** 42,47 ****
> --- 42,48 ----
>   #include <iosfwd>
>   #include <bits/stl_iterator_base_types.h>
>   #include <ext/cast.h>
> + #include <ext/type_traits.h>
>   
>   _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
>   
> *************** _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
> *** 111,119 ****
>           if (_M_diff == 1)
>             return 0;
>           else
> !           return reinterpret_cast<_Tp*>(
> !                  const_cast<char*>(reinterpret_cast<const char*>(this))
> !                  + _M_diff);
>         }
>     
>         void 
> --- 112,119 ----
>           if (_M_diff == 1)
>             return 0;
>           else
> !           return reinterpret_cast<_Tp*>(reinterpret_cast<_UIntPtrType>(this)
> ! 					+ _M_diff);
>         }
>     
>         void 
> *************** _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
> *** 122,142 ****
>           if (!__arg)
>             _M_diff = 1;
>           else
> !           _M_diff = reinterpret_cast<char*>(__arg) 
> !                     - reinterpret_cast<char*>(this);
>         }
>     
>         // Comparison of pointers
>         inline bool
>         operator<(const _Relative_pointer_impl& __rarg) const
> !       { return (this->get() < __rarg.get()); }
>   
>         inline bool
>         operator==(const _Relative_pointer_impl& __rarg) const
> !       { return (this->get() == __rarg.get()); }
>   
>       private:
> !       std::ptrdiff_t _M_diff;
>       };
>     
>     /**
> --- 122,147 ----
>           if (!__arg)
>             _M_diff = 1;
>           else
> !           _M_diff = reinterpret_cast<_UIntPtrType>(__arg) 
> !                     - reinterpret_cast<_UIntPtrType>(this);
>         }
>     
>         // Comparison of pointers
>         inline bool
>         operator<(const _Relative_pointer_impl& __rarg) const
> !       { return (reinterpret_cast<_UIntPtrType>(this->get())
> ! 		< reinterpret_cast<_UIntPtrType>(__rarg.get())); }
>   
>         inline bool
>         operator==(const _Relative_pointer_impl& __rarg) const
> !       { return (reinterpret_cast<_UIntPtrType>(this->get())
> ! 		== reinterpret_cast<_UIntPtrType>(__rarg.get())); }
>   
>       private:
> !       typedef __gnu_cxx::__conditional_type<
> ! 	 (sizeof(unsigned long) >= sizeof(void*)),
> ! 	 unsigned long, unsigned long long>::__type _UIntPtrType;
> !       _UIntPtrType _M_diff;
>       };
>     
>     /**
> *************** _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
> *** 155,162 ****
>           if (_M_diff == 1)
>             return 0;
>           else
> !           return reinterpret_cast<const _Tp*>(
> !                   (reinterpret_cast<const char*>(this)) + _M_diff);
>         }
>     
>         void 
> --- 160,167 ----
>           if (_M_diff == 1)
>             return 0;
>           else
> !           return reinterpret_cast<const _Tp*>
> ! 	      (reinterpret_cast<_UIntPtrType>(this) + _M_diff);
>         }
>     
>         void 
> *************** _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
> *** 165,185 ****
>           if (!__arg)
>             _M_diff = 1;
>           else
> !           _M_diff = reinterpret_cast<const char*>(__arg) 
> !                     - reinterpret_cast<const char*>(this);
>         }
>     
>         // Comparison of pointers
>         inline bool
>         operator<(const _Relative_pointer_impl& __rarg) const
> !       { return (this->get() < __rarg.get()); }
>   
>         inline bool
>         operator==(const _Relative_pointer_impl& __rarg) const
> !       { return (this->get() == __rarg.get()); }
>     
>       private:
> !       std::ptrdiff_t _M_diff;
>       };
>   
>     /**
> --- 170,195 ----
>           if (!__arg)
>             _M_diff = 1;
>           else
> !           _M_diff = reinterpret_cast<_UIntPtrType>(__arg) 
> !                     - reinterpret_cast<_UIntPtrType>(this);
>         }
>     
>         // Comparison of pointers
>         inline bool
>         operator<(const _Relative_pointer_impl& __rarg) const
> !       { return (reinterpret_cast<_UIntPtrType>(this->get())
> ! 		< reinterpret_cast<_UIntPtrType>(__rarg.get())); }
>   
>         inline bool
>         operator==(const _Relative_pointer_impl& __rarg) const
> !       { return (reinterpret_cast<_UIntPtrType>(this->get())
> ! 		== reinterpret_cast<_UIntPtrType>(__rarg.get())); }
>     
>       private:
> !       typedef __gnu_cxx::__conditional_type
> ! 	<(sizeof(unsigned long) >= sizeof(void*)),
> ! 	 unsigned long, unsigned long long>::__type _UIntPtrType;
> !       _UIntPtrType _M_diff;
>       };
>   
>     /**
> 

-- 
Richard Guenther <rguenther@suse.de>
Novell / SUSE Labs
SUSE LINUX Products GmbH - Nuernberg - AG Nuernberg - HRB 16746 - GF: Markus Rex