dbadapt / j2c Goto Github PK

What steps will reproduce the problem?
1. install plugin by copying into dropins folder
2. restart Eclipse (tried with 3.7.2 and also more recent Kepler install)
3. right click on project, on package, on file in Java project

I was looking for a "convert to C++" menu item but couldn't find it.

I also tried building the project from source, launching a separate eclipse 
application running the plugin, but still couldn't get the menu to show up.

Is there an eclipse update site for this plugin?  I'm used to installing most 
eclipse plugins that way.

This one is a bit meta.

In the JDK sources we have this:

enum Source {
    private String name;
    private Source(String name) {
        this.name = name;
    }
}

in j2c we have this:

    public static String printEnumCtorParams(Transformer ctx, PrintWriter pw,
            ITypeBinding type, String sep, DepInfo deps) {
        if (type.isEnum()) {
            pw.print(sep + "::java::lang::String* name, int ordinal");
            deps.soft(ctx.resolve(String.class));
            return ", ";
        }

        return sep;
    }


Hence name/ordinal are off limits for member names in java enums. It looks like 
a simple fix.

In Guava there is this line of code:

void 
com::google::common::primitives::UnsignedBytes_LexicographicalComparatorHolder_U
nsafeComparator::clinit() {
...
littleEndian_ = 
npc(::java::nio::ByteOrder::nativeOrder())->equals(::java::nio::ByteOrder::LITTL
E_ENDIAN());
...
}

It makes GCC give this error:

In file included from /usr/include/ctype.h:41:0,
                 from /usr/local/google/home/hearn/gcc-install/include/c++/4.8.1/cctype:42,
                 from /usr/local/google/home/hearn/gcc-install/include/c++/4.8.1/bits/localefwd.h:42,
                 from /usr/local/google/home/hearn/gcc-install/include/c++/4.8.1/ios:41,
                 from /usr/local/google/home/hearn/gcc-install/include/c++/4.8.1/ostream:38,
                 from /usr/local/google/home/hearn/gcc-install/include/c++/4.8.1/iterator:64,
                 from src/SubArray.hpp:3,
                 from src/com/google/common/primitives/UnsignedBytes_LexicographicalComparatorHolder_UnsafeComparator.cpp:26:
src/com/google/common/primitives/UnsignedBytes_LexicographicalComparatorHolder_U
nsafeComparator.cpp: In constructor 
‘com::google::common::primitives::UnsignedBytes_LexicographicalComparatorHolde
r_UnsafeComparator::clinit()::clinit_::clinit_()’:
src/com/google/common/primitives/UnsignedBytes_LexicographicalComparatorHolder_U
nsafeComparator.cpp:178:100: error: expected unqualified-id before numeric 
constant
         littleEndian_ = npc(::java::nio::ByteOrder::nativeOrder())->equals(::java::nio::ByteOrder::LITTLE_ENDIAN());


I'm not sure what about this makes it unhappy but I didn't investigate.

Again in Guava MapMaker class we see this code:

  public <K, V> ConcurrentMap<K, V> makeMap() {
    if (!useCustomMap) {
      return new ConcurrentHashMap<K, V>(getInitialCapacity(), 0.75f, getConcurrencyLevel());
    }
    return (nullRemovalCause == null)
        ? new MapMakerInternalMap<K, V>(this)
        : new NullConcurrentMap<K, V>(this);
  }

The last line is converted to:

    return (nullRemovalCause == nullptr) ? static_cast< ::java::util::AbstractMap* >(new MapMakerInternalMap(this)) : static_cast< ::java::util::AbstractMap* >(new MapMaker_NullConcurrentMap(this));

... the static casts here aren't right and result in compile failures:

src/com/google/common/collect/MapMaker.cpp: In member function ‘virtual 
java::util::concurrent::ConcurrentMap* 
com::google::common::collect::MapMaker::makeMap()’:
src/com/google/common/collect/MapMaker.cpp:241:197: error: cannot convert 
‘java::util::AbstractMap*’ to ‘java::util::concurrent::ConcurrentMap*’ 
in return
     return (nullRemovalCause == nullptr) ? static_cast< ::java::util::AbstractMap* >(new MapMakerInternalMap(this)) : static_cast< ::java::util::AbstractMap* >(new MapMaker_NullConcurrentMap(this));

Guava MapMaker class contains this delightful nugget:

public abstract class GenericMapMaker<K0, V0> {
    // Set by MapMaker, but sits in this class to preserve the type relationship
  @GwtIncompatible("To be supported")
  RemovalListener<K0, V0> removalListener;
}

public final class MapMaker extends GenericMapMaker<Object, Object> {
  @Deprecated
  @GwtIncompatible("To be supported")
  <K, V> GenericMapMaker<K, V> removalListener(RemovalListener<K, V> listener) {
    checkState(this.removalListener == null);

    ....
  }
}

The checkState call is converted to:

::com::google::common::base::Preconditions::checkState(java_cast< 
MapMaker_RemovalListener* >(this->removalListener) == nullptr);

which fails to compile with:

src/com/google/common/collect/MapMaker.cpp: In member function 
‘com::google::common::collect::GenericMapMaker* 
com::google::common::collect::MapMaker::removalListener(com::google::common::col
lect::MapMaker_RemovalListener*)’:
src/com/google/common/collect/MapMaker.cpp:229:120: error: no matching function 
for call to ‘java_cast(<unresolved overloaded function type>)’
     ::com::google::common::base::Preconditions::checkState(java_cast< MapMaker_RemovalListener* >(this->removalListener) == nullptr);
                                                                                                                        ^
src/com/google/common/collect/MapMaker.cpp:229:120: note: candidate is:
src/com/google/common/collect/MapMaker.cpp:32:10: note: template<class T, class 
U> T java_cast(U*)
 static T java_cast(U* u)
          ^
src/com/google/common/collect/MapMaker.cpp:32:10: note:   template argument 
deduction/substitution failed:
src/com/google/common/collect/MapMaker.cpp:229:120: note:   mismatched types 
‘U*’ and ‘com::google::common::collect::GenericMapMaker* 
(com::google::common::collect::MapMaker::*)(com::google::common::collect::MapMak
er_RemovalListener*)’
     ::com::google::common::base::Preconditions::checkState(java_cast< MapMaker_RemovalListener* >(this->removalListener) == nullptr);
                                                                                                                        ^
src/com/google/common/collect/MapMaker.cpp:229:120: note:   could not resolve 
address from overloaded function 
‘((com::google::common::collect::MapMaker*)this)->com::google::common::collect
::MapMaker::removalListener’


I guess the issue is the naming ambiguity between members and methods again.

What steps will reproduce the problem?
1. Put jar into dropins directory
2. Open a Java project in Eclipse 3.7.2
3. Right click the project

What is the expected output? What do you see instead?

The option to convert the project to C++ does not appear in the menu when I 
right click on my projects. I see the regular set of options, but not the 
"Convert to C++" option.

What version of the product are you using? On what operating system?

Eclipse Indigo 3.7.2, latest release, on 64-bit Linux, RHEL6. I also tested it 
with Eclipse Juno.

Please provide any additional information below.

All of my projects are also plug-ins that are used in a large RCP environment. 
Some of them we want to convert to C++.

How can we run the jar file? I have looked for a description but could not find 
one.
Best Regards

What steps will reproduce the problem?
1. hit translate to c++ button
2. waited for the folder "cwilsim-gc" to stop being written to
3. navigated there and ran make

What is the expected output? What do you see instead?
expected it to build


What version of the product are you using? latest from eclipse repo on j2c main 
page
On what operating system? arch linux


Please provide any additional information below.

sirus cwilsim-gc :( $make
Building with "g++ -Isrc -Iext/src -g -pipe -std=gnu++11"
Compile src/CondVar.cpp
Compile src/Controller.cpp
In file included from ext/src/java/awt/Window.hpp:23:0,
                 from ext/src/java/awt/Frame.hpp:13,
                 from ext/src/javax/swing/JFrame.hpp:11,
                 from src/Wilsim.hpp:8,
                 from src/Controller.cpp:20:
ext/src/java/awt/Container.hpp:211:33: error: ‘ContainerListenerArray’ in 
namespace ‘java::awt::event’ does not name a type
     virtual ::java::awt::event::ContainerListenerArray* getContainerListeners();
                                 ^
Makefile:368: recipe for target 'obj/Controller.o' failed
make: *** [obj/Controller.o] Error 1


please let me know of additional files or anything I can help supply.
the project I'm working on is open source and on github so I can supply a uri 
or whatever needed. 

let me know if I need to supply the output of any commands on my system.

What steps will reproduce the problem?
1.
2.
3.

What is the expected output? What do you see instead?


What version of the product are you using? On what operating system?


Please provide any additional information below.

This code:

public <A extends Appendable,
        I extends Object & Iterable<? extends Entry<?, ?>> & Iterator<? extends Entry<?, ?>>>
        A appendTo(A appendable, I entries) throws IOException {
      Iterator<? extends Entry<?, ?>> iterator = entries;
      return appendTo(appendable, iterator);
    }

compiles to:

/* <I extends Object & Iterable<? extends Entry<?,?>> & Iterator<? extends 
Entry<?,?>>> */java::lang::String* 
com::google::common::base::Joiner_MapJoiner::join(::java::lang::Object* 
entries) /* throws(IOException) */
{
    ::java::util::Iterator* iterator = entries;
    return join(static_cast< ::java::util::Iterator* >(iterator));
}

which then fails due to the need to cast Object to Iterator:

    ::java::util::Iterator* iterator = java_cast< ::java::util::Iterator* >(entries);

fixes it.

The type signature of that method is pretty crazy - I don't know why it fails 
to translate though.

What is in init_jvm() external method ? In this method I start a native JVM. Or 
what can I do in this method for JVM.

Hi,
  Is it possible to run this from the commandline?

Cheers

Could it not be a plugin of eclipse so as to convert single java file??

Guava has a class structure like this in AbstractMultimap:

class X implements Y {}

class A {
  class B extends X {
    class C {
      public Y get() {
        return B.this;
      }
    }
  }
}

It gets mistranslated to something like this:

  return A_B_this->A_this;

when the correct translation is

  return A_B_this;

This one could be very hard to fix (or maybe impossible?).

Basically the java protobufs library is a pain in the ass and I think would (in 
c++) require forward declaration of inheritance hierarchies to translate 
naturally.

https://code.google.com/p/protobuf/

I'm not quite sure how to reduce this to a minimal test case.

public abstract class AbstractMessage extends AbstractMessageLite
                                      implements Message {
}

public abstract class AbstractMessageLite implements MessageLite {}

public interface Message extends MessageLite, MessageOrBuilder {
}

public interface MessageLite extends MessageLiteOrBuilder {}

public interface MessageOrBuilder extends MessageLiteOrBuilder {
  // (From MessageLite, re-declared here only for return type covariance.)
  //@Override (Java 1.6 override semantics, but we must support 1.5)
  Message getDefaultInstanceForType();
}

public interface MessageLiteOrBuilder {
  MessageLite getDefaultInstanceForType();
}

So here the MessageOrBuilder interface declares a method that returns a 
Message, but Message itself extends MessageOrBuilder.

In file included from src/com/google/protobuf/Message.hpp:9:0,
                 from src/com/google/protobuf/AbstractMessage.hpp:11,
                 from src/com/google/protobuf/AbstractMessage.cpp:2:
src/com/google/protobuf/MessageOrBuilder.hpp:14:23: error: invalid covariant 
return type for ‘virtual com::google::protobuf::MessageOrBuilder* 
com::google::protobuf::MessageOrBuilder::getDefaultInstanceForType()’
     MessageOrBuilder* getDefaultInstanceForType() = 0;
                       ^
In file included from src/com/google/protobuf/MessageLite.hpp:8:0,
                 from src/com/google/protobuf/AbstractMessageLite.hpp:9,
                 from src/com/google/protobuf/AbstractMessage.hpp:10,
                 from src/com/google/protobuf/AbstractMessage.cpp:2:
src/com/google/protobuf/MessageLiteOrBuilder.hpp:12:26: error:   overriding 
‘virtual com::google::protobuf::MessageLite* 
com::google::protobuf::MessageLiteOrBuilder::getDefaultInstanceForType()’
     virtual MessageLite* getDefaultInstanceForType() = 0;


It's a mess and might be easier if you just grab the library yourself to see 
what's going on :(

j2c looks great, i want to give it a try, but i do not use Eclipse.  Why not 
package this as a normal command line tool?

1. I followed the instruction of README.md. First downloaded the jar, copy it 
to $ECLIPSE_HOME/dropins. Second started the eclipse, it seems no work. 

2. I expected 'Translate to C++' option will appear, but it didn't, there is 
nothing when i right-clicking the project (or a class/package) in the 'Project 
Explorer' or
'Package Explorer' view .

3. The version of the product is as follows and my operating system is Windows 
XP. 
/***********************************************************/
se.arnetheduck.j2c_0.2.2.201207071747.jar

Eclipse SDK

Version: 3.8.0
Build id: I20120608-1200

(c) Copyright Eclipse contributors and others 2000, 2012.  All rights reserved.
Visit http://www.eclipse.org/platform

This product includes software developed by the
Apache Software Foundation http://www.apache.org/

OS : windows xp
/***********************************************************/

That's all, sincerely look forward to your reply.

This gets converted to:

::java::lang::Long::valueOf(0LL)

which is missing a static_cast< int64_t >(0LL), making it ambiguous on 64-bit 
platforms with Long::valueOf(String*)

What steps will reproduce the problem?
1. I convert my Java app to C++ by J2C (that's fine)
2. I compile in CygWin (gcc (GCC) 4.7.3) the C++ version of my App (that's 
fine) 
3. But when I like to link, than raise an error message:

/home/kgy/cgyozo_cntan_baja_J2C/src/java/util/Arrays.cpp:1668:
 undefined reference to `Array<long long>::class_()'

The fwd-CNTAN_BAJA_J2C.hpp file with the next form included into Arrays.cpp: 

// Forward declarations for
#pragma once

#include <stdint.h>
#include <limits>

template<typename T> class Array;
typedef Array<bool> boolArray;
class boolArrayArray;
typedef Array<char16_t> char16_tArray;
class char16_tArrayArray;
class char16_tArrayArrayArray;
typedef Array<double> doubleArray;
class doubleArrayArray;
class doubleArrayArrayArray;
typedef Array<float> floatArray;
class floatArrayArray;
typedef Array<int16_t> int16_tArray;
class int16_tArrayArray;
class int16_tArrayArrayArray;
typedef Array<int32_t> int32_tArray;
class int32_tArrayArray;
class int32_tArrayArrayArray;

typedef Array<int64_t> int64_tArray;

class int64_tArrayArray;
typedef Array<int8_t> int8_tArray;
class int8_tArrayArray;
class int8_tArrayArrayArray;



****************************************************
Arrays.cpp:1668:
****************************************************

if(static_cast< ::java::lang::Object* >(eClass) == 
 static_cast< ::java::lang::Object* >(int8_tArray::class_()))
   npc(buf)->append(toString(java_cast< ::int8_tArray* >(element)));

else if(static_cast< ::java::lang::Object* >(eClass) == 
 static_cast< ::java::lang::Object* >(int16_tArray::class_()))
   npc(buf)->append(toString(java_cast< ::int16_tArray* >(element)));

else if(static_cast< ::java::lang::Object* >(eClass) == 
 static_cast< ::java::lang::Object* >(int32_tArray::class_()))
   npc(buf)->append(toString(java_cast< ::int32_tArray* >(element)));

**********
line 1668
else if(static_cast< ::java::lang::Object* >(eClass) ==  
 static_cast< ::java::lang::Object* >(int64_tArray::class_()))
**********
   npc(buf)->append(toString(java_cast< ::int64_tArray* >(element)));

else if(static_cast< ::java::lang::Object* >(eClass) == 
 static_cast< ::java::lang::Object* >(char16_tArray::class_()))
   npc(buf)->append(toString(java_cast< ::char16_tArray* >(element)));



****************************************************
int64_tArray.cpp
****************************************************
// Generated
#include <Array.hpp>

extern java::lang::Class *class_(const char16_t *c, int n);

template<>
java::lang::Class* int64_tArray::class_()
{
    static ::java::lang::Class* c = ::class_(u"long[]", 6);
    return c;
}

template<>
java::lang::Class* int64_tArray::getClass0()
{
    return class_();
}