Building on Linux

[define-private-public]

I've been trying to get QtSharp working for a bit now and I still keep on having issues with getting it working on Linux.

I got to the point where I had to tell the QtSharp.CLI.exe app where my qmake and make utilities are stored. I supplied the application with the full path, but when trying to do that, I got this error:

Calling /home/me/Qt/5.5/clang_64/bin/qmake caused an exception: ApplicationName='/home/ben/Qt/5.5/clang_64/bin/qmake', CommandLine='-query QT_INSTALL_BINS', CurrentDirectory='', Native error= Cannot find the specified file.

[ddobrev]

Could you please run the same command in the terminal to see if it works properly?

[define-private-public]

It was run in the terminal.

[ddobrev]

I assume you build CppSharp yourself because the binaries in the repo are (for now) Windows-only. In turn, this means you built QtSharp too. With this in mind, please debug the call. It's performed by a method called ProcessHelper.Run at https://github.com/ddobrev/QtSharp/blob/master/QtSharp.CLI/Program.cs#L110 . When you debug it, you'll be able to see if the qmake executable you pass exists, as well as check for any other irregularities.

[define-private-public]

I did some poking, so the path /home/me/Qt/5.5/clang_64/bin/qmake doesn't exist, instead /home/me/Qt/5.5/gcc_64/bin/qmake does.

When I ran via the terminal again, I got this error:

Unhandled Exception:
System.TypeInitializationException: The type initializer for '<Module>' threw an exception. ---> System.NotImplementedException: The method or operation is not implemented.
  at <Module>.___CxxCallUnwindDtor (System.MonoFNPtrFakeClass pDtor, System.Void* pThis) <0x40d1e250 + 0x00037> in <filename unknown>:0 
  at <Module>..cctor () <0x40d1df50 + 0x0004b> in <filename unknown>:0 
  --- End of inner exception stack trace ---
  at QtSharp.CLI.Program.GetDependencies (QtSharp.CLI.QtVersion qt) <0x40d1d930 + 0x0009f> in <filename unknown>:0 
  at QtSharp.CLI.Program.Main (System.String[] args) <0x41f41fd0 + 0x001d3> in <filename unknown>:0 
[ERROR] FATAL UNHANDLED EXCEPTION: System.TypeInitializationException: The type initializer for '<Module>' threw an exception. ---> System.NotImplementedException: The method or operation is not implemented.
  at <Module>.___CxxCallUnwindDtor (System.MonoFNPtrFakeClass pDtor, System.Void* pThis) <0x40d1e250 + 0x00037> in <filename unknown>:0 
  at <Module>..cctor () <0x40d1df50 + 0x0004b> in <filename unknown>:0 
  --- End of inner exception stack trace ---
  at QtSharp.CLI.Program.GetDependencies (QtSharp.CLI.QtVersion qt) <0x40d1d930 + 0x0009f> in <filename unknown>:0 
  at QtSharp.CLI.Program.Main (System.String[] args) <0x41f41fd0 + 0x001d3> in <filename unknown>:0 

I also tried to run in the debugger, It kept on running until it hit this line: https://github.com/ddobrev/QtSharp/blob/master/QtSharp.CLI/Program.cs#L202

Where Monodevelop told me that it lost connection with the debugger.

[ddobrev]

I think you didn't update the binary references. They are only for Windows. For Linux you need to build https://github.com/mono/CppSharp yourself because while we have Linux CI for it at https://travis-ci.org/mono/CppSharp/jobs/123573796, we do not upload binaries yet. Once you have, you need to replace the references to CppSharp with your build and this error is going to disappear.

[define-private-public]

I'm sorry for not being more attentive with this. I'm finishing up school right now, I should be able to revisit this in less than a month.

Also, if I were to port some of the Qt examples to C#, would you be willing to merge them into this repo?

[ddobrev]

I won't be willing but happy to. :) Please just have in mind that API-s which require support for templates, such as QObjectList QObject::children(), are not available yet. I've been working on it and I hope I'll have it done in a month.

[define-private-public]

I've tried to take the release .dlls and include them in a MonoDevelop project on Ubuntu Linux. I was able to build the following small program, when when constructing the QColor, it throws a System.DllNotFoundException.

using System;
using QtGui;
using QtCore;
using QtWidgets;

namespace First
{
    class MainClass
    {
        public static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");

            QColor clr = new QColor("red");
            Console.WriteLine(clr.Red);
            Console.WriteLine(clr.Green);
            Console.WriteLine(clr.Blue);
        }
    }
}

Here are the details of the error:

Unhandled Exception:
System.DllNotFoundException: Qt5Core
  at (wrapper managed-to-native) QtCore.QString+__Internal:FromUtf16_0 (intptr,uint16*,int)
  at QtCore.QString.FromUtf16 (System.UInt16& unicode, System.Int32 size) [0x00015] in <036aaf2feb0a47fba24c3cd1d557c6a8>:0 
  at QtGui.QColor..ctor (System.String name) [0x00053] in <3304e7a86acf4bebbe03fee2a9776156>:0 
  at First.MainClass.Main (System.String[] args) [0x0000b] in <8c0c07057a4f469a91e489d47e7acc37>:0 
[ERROR] FATAL UNHANDLED EXCEPTION: System.DllNotFoundException: Qt5Core
  at (wrapper managed-to-native) QtCore.QString+__Internal:FromUtf16_0 (intptr,uint16*,int)
  at QtCore.QString.FromUtf16 (System.UInt16& unicode, System.Int32 size) [0x00015] in <036aaf2feb0a47fba24c3cd1d557c6a8>:0 
  at QtGui.QColor..ctor (System.String name) [0x00053] in <3304e7a86acf4bebbe03fee2a9776156>:0 
  at First.MainClass.Main (System.String[] args) [0x0000b] in <8c0c07057a4f469a91e489d47e7acc37>:0 

[tritao]

I think you will need to compile your own version of Qt# for Linux, the releases are specific to Windows.

I got it to compile on OSX a few months ago, so making it work on Linux shouldn't be too much work.

@define-private-public What step are you stuck on when compiling Qt# from source code?

[define-private-public]

I was hoping that the .dll would world on a whim. Guess not. : P

Looking at the Qt Sharp build documentation, that's where I'm getting confused. If you would be able to document what you did step by step to get QtSharp built on OS X, that would be the best thing you could do for me.

[tritao]

Well, the way I did it was by using Premake. You can find the build scripts on the build folder.

First you need to compile CppSharp from scratch, by following the guide on the repository: https://github.com/mono/CppSharp/blob/master/docs/GettingStarted.md#building-from-source

After you have that built, you can call CppSharp's premake5-linux-64 binary to generate QtSharp project make files for Linux.

You can also generate project files for Xamarin Studio, by invoking with the VS action, something like: premake5-linux-64 --file=/path/to/QtSharp/build/premake5.lua --os=macosx vs2015.

Give it a try and I will try to help if you get stuck on any step.

Once you get QtSharp generator compiled, then we look into generate the Linux bindings from the Qt source files.

[define-private-public]

I'm at the last part of this document: https://github.com/mono/CppSharp/blob/master/docs/GettingStarted.md#compiling-on-linux

Where I run make -C gmake config=release_x64. I'm getting this error:

me@hostmachine:build$ make -C gmake config=release_x64
make: Entering directory '/home/me/Desktop/qt_sharp/CppSharp/build/gmake'
==== Building CppSharp (release_x64) ====
make[1]: Nothing to be done for 'all'.
==== Building CppSharp.AST (release_x64) ====
make[1]: Nothing to be done for 'all'.
==== Building CppSharp.CppParser (release_x64) ====
==== Building CppSharp.Runtime (release_x64) ====
make[1]: Nothing to be done for 'all'.
==== Building CppSharp.Parser.CSharp (release_x64) ====
make[1]: Nothing to be done for 'all'.
==== Building CppSharp.Parser (release_x64) ====
make[1]: Nothing to be done for 'all'.
==== Building CppSharp.Generator (release_x64) ====
make[1]: Nothing to be done for 'all'.
==== Building CppSharp.Parser.Gen (release_x64) ====
make[1]: Nothing to be done for 'all'.
==== Building CppSharp.Generator.Tests (release_x64) ====
make[1]: Nothing to be done for 'all'.
==== Building CSharp.Native (release_x64) ====
==== Building CSharp.Gen (release_x64) ====
make[1]: Nothing to be done for 'all'.
==== Building CSharp.CSharp (release_x64) ====
Running prebuild commands
mono --debug "../lib/Release_x64/CSharp.Gen.exe"
Stacktrace:

  at <unknown> <0xffffffff>
  at CppSharp.ConsoleDriver.Run (CppSharp.ILibrary) [0x00027] in /home/ben/Desktop/qt_sharp/CppSharp/src/Generator/Driver.cs:476
  at CppSharp.Tests.CSharpTestsGenerator.Main (string[]) [0x00007] in /home/ben/Desktop/qt_sharp/CppSharp/tests/CSharp/CSharp.cs:185
  at (wrapper runtime-invoke) <Module>.runtime_invoke_void_object (object,intptr,intptr,intptr) <IL 0x00051, 0x000c8>

Native stacktrace:

    mono() [0x4accca]
    mono() [0x5040fe]
    mono() [0x4275d7]
    /lib/x86_64-linux-gnu/libpthread.so.0(+0x113d0) [0x7ffaa05e43d0]
    mono() [0x657efc]
    mono() [0x657f91]
    mono() [0x4b124b]
    mono() [0x4254cb]
    mono() [0x50d831]
    mono() [0x50f96e]
    mono() [0x510253]
    mono() [0x425efc]
    mono() [0x4af809]
    mono() [0x4b0117]
    [0x41c6368c]

Debug info from gdb:

[New LWP 4129]
[New LWP 4130]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
0x00007ffaa05e3fbb in __waitpid (pid=4131, stat_loc=0x7ffaa111811c, options=0) at ../sysdeps/unix/sysv/linux/waitpid.c:29
29  ../sysdeps/unix/sysv/linux/waitpid.c: No such file or directory.
  Id   Target Id         Frame 
* 1    Thread 0x7ffaa110a740 (LWP 4128) "Main" 0x00007ffaa05e3fbb in __waitpid (pid=4131, stat_loc=0x7ffaa111811c, options=0) at ../sysdeps/unix/sysv/linux/waitpid.c:29
  2    Thread 0x7ffa9efff700 (LWP 4129) "SGen worker" pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
  3    Thread 0x7ffa9cc34700 (LWP 4130) "Finalizer" 0x00007ffaa05e2867 in futex_abstimed_wait_cancelable (private=0, abstime=0x0, expected=0, futex_word=0x97c100) at ../sysdeps/unix/sysv/linux/futex-internal.h:205

Thread 3 (Thread 0x7ffa9cc34700 (LWP 4130)):
#0  0x00007ffaa05e2867 in futex_abstimed_wait_cancelable (private=0, abstime=0x0, expected=0, futex_word=0x97c100) at ../sysdeps/unix/sysv/linux/futex-internal.h:205
#1  do_futex_wait (sem=sem@entry=0x97c100, abstime=0x0) at sem_waitcommon.c:111
#2  0x00007ffaa05e2914 in __new_sem_wait_slow (sem=0x97c100, abstime=0x0) at sem_waitcommon.c:181
#3  0x00007ffaa05e29ba in __new_sem_wait (sem=<optimized out>) at sem_wait.c:29
#4  0x00000000005bb8f9 in ?? ()
#5  0x000000000059c68c in ?? ()
#6  0x0000000000653b4c in ?? ()
#7  0x00007ffaa05da6fa in start_thread (arg=0x7ffa9cc34700) at pthread_create.c:333
#8  0x00007ffaa00fab5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7ffa9efff700 (LWP 4129)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x0000000000623a27 in ?? ()
#2  0x00007ffaa05da6fa in start_thread (arg=0x7ffa9efff700) at pthread_create.c:333
#3  0x00007ffaa00fab5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7ffaa110a740 (LWP 4128)):
#0  0x00007ffaa05e3fbb in __waitpid (pid=4131, stat_loc=0x7ffaa111811c, options=0) at ../sysdeps/unix/sysv/linux/waitpid.c:29
#1  0x00000000004acd59 in ?? ()
#2  0x00000000005040fe in ?? ()
#3  0x00000000004275d7 in ?? ()
#4  <signal handler called>
#5  0x0000000000657efc in ?? ()
#6  0x0000000000657f91 in ?? ()
#7  0x00000000004b124b in ?? ()
#8  0x00000000004254cb in ?? ()
#9  0x000000000050d831 in ?? ()
#10 0x000000000050f96e in ?? ()
#11 0x0000000000510253 in ?? ()
#12 0x0000000000425efc in ?? ()
#13 0x00000000004af809 in ?? ()
#14 0x00000000004b0117 in ?? ()
#15 0x0000000041c6368c in ?? ()
#16 0x00007ffaa110a700 in ?? ()
#17 0x00000000018bc765 in ?? ()
#18 0x000000004158b76b in ?? ()
#19 0x0000000000000000 in ?? ()

=================================================================
Got a SIGSEGV while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries 
used by your application.
=================================================================

Aborted (core dumped)
CSharp.CSharp.make:140: recipe for target 'prebuild' failed
make[1]: *** [prebuild] Error 134
Makefile:272: recipe for target 'CSharp.CSharp' failed
make: *** [CSharp.CSharp] Error 2
make: Leaving directory '/home/me/Desktop/qt_sharp/CppSharp/build/gmake'

[tritao]

I suspect you're hitting this issue.

mono/CppSharp#655 (comment)

The issue has been fixed but the build scripts have not been yet fixed to auto-detect recent GCC versions and choose the correct triple.

Try to change the triple in the build files and re-generate the project files to try a new build.