Re: [Opencxx-users] Make error under Cygwin

[Vinzenz F. <evi...@we...>]

Hi Scott,

this is not a bug. This is a "feature" of the G++ STL to be more 
standard. Since the standard says that std::auto_ptr<> does not meet the 
assignable and copy contructable concept. But std::swap requires those 
both concepts.

If you're using std::swap with std::auto_ptr this is not standard 
compliant. I already implemented the workaround in the CVS version. I've 
just uploaded new CVS Snapshots from the CVS to the 
http://opencxx.sf.net website

BR
Vinzenz


Scott D. Fleming schrieb:

>
> Hi Jonathan,
> I know what the problem is. First of all, here is the error message of 
> interest:
>
>  g++ -DHAVE_CONFIG_H -I. -I. -I.. -I. -I.. -g -O2 -MT driver.lo -MD 
> -MP -MF .deps/driver.Tpo -c driver.cc  -DPIC -o .libs/driver.o
> In file included from 
> /usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/backward/strstream:51,
>                  from driver.cc:47:
> /usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/backward/backward_warning.h:32:2: 
> warning: #warning This file includes at least one deprecated or 
> antiquated header. Please consider using one of the 32 headers found 
> in section 17.4.1.2 of the C++ standard. Examples include substituting 
> the <X> header for the <X.h> header for C++ includes, or <iostream> 
> instead of the deprecated header <iostream.h>. To disable this warning 
> use -Wno-deprecated.
> /usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/stl_algobase.h: In 
> function `void std::swap(_Tp&, _Tp&) [with _Tp = 
> std::auto_ptr<Opencxx::MetacompilerConfiguration::IteratorIface>]':
> ../opencxx/MetacompilerConfiguration.h:50:   instantiated from here
> /usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/stl_algobase.h:132: 
> error: passing `const 
> std::auto_ptr<Opencxx::MetacompilerConfiguration::IteratorIface>' as 
> `this' argument of `std::auto_ptr<_Tp>::operator 
> std::auto_ptr_ref<_Tp1>() [with _Tp1 = 
> Opencxx::MetacompilerConfiguration::IteratorIface, _Tp = 
> Opencxx::MetacompilerConfiguration::IteratorIface]' discards qualifiers
>
> The problem is that in gcc 3.4.x std::auto_ptrs can't be swapped with 
> std::swap. I assume this is a bug in the STL, and not a feature. The 
> reason for the problem is that std::swap has a const tmp variable; 
> i.e. (from bits/stl_algobase.h):
>
>   template<typename _Tp>
>     inline void
>     swap(_Tp& __a, _Tp& __b)
>     {
>       // concept requirements
>       __glibcxx_function_requires(_SGIAssignableConcept<_Tp>)
>
>       const _Tp __tmp = __a; // <---THIS CAUSES std::auto_ptr PROBLEMS
>       __a = __b;
>       __b = __tmp;
>     }
>
> And std::auto_ptr's auto_ptr_ref operator, which is called in the 
> const line above, is a non-const method; i.e. (from memory.h):
>
>   template<typename _Tp>
>     class auto_ptr
>     {
>       ...
>       template<typename _Tp1>
>         operator auto_ptr_ref<_Tp1>() throw()
>         { return auto_ptr_ref<_Tp1>(this->release()); }
>       ...
>
> My solution to the problem was add my own swap function to the OpenC++ 
> code, and  use it to swap std::auto_ptrs. To accomplish this, I edited 
> the MetacompilerConfiguration.h file in the OpenC++ source. I added 
> this function definition near the top of the file just under "class 
> ErrorLog":
>
>   template<class T>
>   inline void
>   MYswap(std::auto_ptr<T>& a, std::auto_ptr<T>& b)
>   {
>     std::auto_ptr<T> c = a;
>     a = b;
>     b = c;
>   }
>
> Next (in the same file), I changed class 
> MetacompilerConfiguration::Iterator (found in the public section of 
> class MetacompilerConfiguration), so that its operator= went from:
>
>         Iterator& operator=(Iterator iter)
>         {
>             std::swap(impl_, iter.impl_);
>             return *this;
>         }
>
> To:
>
>         Iterator& operator=(Iterator iter)
>         {
>             MYswap(impl_, iter.impl_);
>             return *this;
>         }
>
> And this solved the problem for me, and I expect it will for you as well.
>
> Now, I must warn you that there is another problem you will encounter 
> with OpenC++ once you have built it. There is a mistake in the grammar 
> that OpenC++'s parser expects. Prior to GCC 3.4, this was never a 
> problem, but since GCC 3.4, the STL library uses the syntax that the 
> broken grammar doesn't accept. In particular OpenC++ expects template 
> declarations to look like this:
>
>   template<typename T>...
>
> With an identifier like "T" following typename, but in fact the 
> following is legal C++:
>
>   template<typename>...
>
> This causes occ to issue errors whenever it parses the GCC library 
> files that include the latter syntax (e.g., bits/cpp_type_traits.h). I 
> fixed the problem by changing the Parser::rTempArgDeclaration member 
> function definition in parser/Parser.cc. I changed this line (roughly 
> the third line in the function):
>
>     if(t0 == CLASS && lex->LookAhead(1) == Identifier){
>
> To this:
>
>     if(t0 == CLASS && !(lex->LookAhead(1) == Identifier)){
>         lex->GetToken(tk1);
>         decl = PtreeUtil::List(new Leaf(tk1));
>     }
>     else if(t0 == CLASS && lex->LookAhead(1) == Identifier){
>
> I am not positive that my Ptree representation for the template 
> argument declaration (temp.arg.declaration) is exactly what the 
> OpenC++ maintainers would want, but it seemed to make sense to me.
>
> Anyway, I hope these fixes help you get OpenC++ running. I've been 
> using it for a couple of years, and it's really a lovely tool.
> Cheers, Scott
>
> PS: There is one other fix that you will probably want to apply, found 
> in:
>
>     http://sourceforge.net/mailarchive/message.php?msg_id=9785370
>
>
>
> Jonathan Gdalevich wrote:
>
>> Dear OpenC++ users,
>>
>> I am trying to make the latest version of OpenC++ (2.8) in Cygwin with
>> gcc (3.4.4) and all latest updates and getting an error during make. 
>> Attached are my configure and make log files along with the Makefile.
>>
>> Sincerely,
>>
>>
>
>
> -------------------------------------------------------
> SF.Net email is Sponsored by the Better Software Conference & EXPO
> September 19-22, 2005 * San Francisco, CA * Development Lifecycle 
> Practices
> Agile & Plan-Driven Development * Managing Projects & Teams * Testing 
> & QA
> Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf
> _______________________________________________
> Opencxx-users mailing list
> Ope...@li...
> https://lists.sourceforge.net/lists/listinfo/opencxx-users