Re: [Opencxx-users] unable to compile

[Scott D. F. <sd...@ms...>]

Hi John,
I have found that there are 3 patches that must be applied to the 
OpenC++ 2.8 release (numbered 1-3 below). 1 and 3 have been added to the 
OpenC++ CVS repository, but 2 has yet to be added. Here is a link to the 
latest CVS snapshot as of now:

   http://opencxx.sourceforge.net/snapshots/opencxx-20050912.tar.gz


PATCH #1
--------

The problem is that in gcc 3.4.x std::auto_ptrs can't be swapped with 
std::swap. 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.


PATCH #2
--------

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.


PATCH #3
--------

This patch solves the problem of -I flags not being passed to gcc/g++, 
and was originally reported in:

   http://sourceforge.net/mailarchive/message.php?msg_id=9785370

I will copy the relevant portions of that message here for convenience:

My patch does the following:

  - Add a method to get the CC options to OpencxxConfiguration

  - In file driver2.cc method RunPreprocessor, inserts the CC options
    after argv.push_back(compiler)

diff -ur opencxx-2.8/opencxx/driver2.cc opencxx-patched/opencxx/driver2.cc
--- opencxx-2.8/opencxx/driver2.cc	2004-08-10 09:48:05.000000000 +0200
+++ opencxx-patched/opencxx/driver2.cc	2004-10-14 14:49:27.870216699 +0200
@@ -241,9 +241,11 @@
      string compiler = config.CompilerCommand();

      vector<string> argv;
-
+
      argv.push_back(compiler);

+    argv.insert(argv.end(), config.CppOptions().begin(), 
config.CppOptions().end());
+
      if(config.RecognizeOccExtensions())
  	argv.push_back("-D__opencxx");

diff -ur opencxx-2.8/opencxx/MetacompilerConfiguration.h
opencxx-patched/opencxx/MetacompilerConfiguration.h
  --- opencxx-2.8/opencxx/MetacompilerConfiguration.h	2004-08-10 
09:48:05.000000000 +0200
+++ opencxx-patched/opencxx/MetacompilerConfiguration.h	2004-10-14 
14:42:21.060422444 +0200
@@ -20,6 +20,7 @@
  #include <opencxx/defs.h>
  #include <string>
  #include <memory>
+#include <vector>

  namespace Opencxx
  {
@@ -95,7 +96,7 @@
      virtual Opencxx::ErrorLog& ErrorLog() const = 0;

      virtual Iterator CcOptions() const = 0;
-
+    virtual const std::vector<std::string>& CppOptions() const = 0;
      virtual Iterator Metaclasses() const = 0;
  };

diff -ur opencxx-2.8/opencxx/OpencxxConfiguration.h
opencxx-patched/opencxx/OpencxxConfiguration.h
--- opencxx-2.8/opencxx/OpencxxConfiguration.h	2004-08-10 
09:48:05.000000000 +0200
+++ opencxx-patched/opencxx/OpencxxConfiguration.h	2004-10-14 
14:42:32.511592506 +0200
@@ -117,6 +117,9 @@
      {
          cc2Options_.push_back(option);
      }
+    const std::vector<std::string>& CppOptions() const {
+      return cc2Options_;
+    }
      void SetDoPreprocess(bool v) { doPreprocess_ = v; }
      bool DoPreprocess() const { return doPreprocess_; }


Hope this helps.
Cheers, Scott


John Altidor wrote:
> Hello,
>  
> Whenever I try to compile a metaclass, I get the following error message:
>  
> /courses/cs400/cs491s/jaltidor/opencxx-2.8/opencxx/parser/Ptree.h:47: 
> error: `metaclass' does not name a type
>  
> I entered this command to attempt to compile my files:
>  
> g++ -I. -I../opencxx-2.8 -D__opencxx JNIClass.ii -shared -o JNIClass.so 
> *.o /courses/cs400/cs491s/jaltidor/opencxx-2.8/libs/libocc.0
>  
> I tried using the OpenC++ script (occ) to compile my metaclass but the 
> script would never use my include flags (-I<path>) so the compiler would 
> never find any of the OpenC++ headers.
>  
> Does anyone know what is wrong?
>  
> John