web assembly error

maxwell31 · wrote on 1 Apr 2019, 09:04

Hi,
I tried to use webassembly for a small project. In my project source dir I run

~/work/TestWeb$ ~/Qt/5.13.0/wasm_32/bin/qmake
Info: creating stash file /home/maxwell/work/TestWeb/.qmake.stash
~/work/TestWeb$ make

and then get the error

Exception in thread Thread-3:
Traceback (most recent call last):
  File "/usr/lib/python2.7/threading.py", line 801, in __bootstrap_inner
    self.run()
  File "/usr/lib/python2.7/threading.py", line 754, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/usr/lib/python2.7/multiprocessing/pool.py", line 392, in _handle_results
    task = get()
TypeError: __init__() takes at least 3 arguments (1 given)

How can I make this work?

maxwell31 · wrote on 1 Apr 2019, 11:09

I should note that I don't think this is specific to my project. Basically I am trying to compile the QtQuick Empty Application template with the wasm toolkit which is shipped together with the Qt513 Preview

maxwell31 · wrote on 1 Apr 2019, 12:50

The Ubuntu emscripten package seems to be to old. Installing emscripten from https://github.com/emscripten-core/emsdk seems to fix the above error. Now it starts compiling and crashs with the following error

in   ret double 0x7FF4000000000000 in _ZL7qt_snanv() 
emcc: warning: cannot represent a NaN literal '0x26f2c060' with custom bit pattern in NaN-canonicalizing JS engines (e.g. Firefox and Safari) without erasing bits!
in   ret double 0x7FF4000000000000 in _ZL7qt_snanv.38141() 
error: undefined symbol: _ZN10QArrayData10deallocateEPS_jj
warning: To disable errors for undefined symbols use `-s ERROR_ON_UNDEFINED_SYMBOLS=0`
error: undefined symbol: _ZN11Preparation7changedEv
error: undefined symbol: _ZN9SuitEntry15selectedChangedEv
error: undefined symbol: _ZNSt3__14stoiERKNS_12basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEEEPji
error: undefined symbol: _ZNSt3__16localeC1Ev
error: undefined symbol: _ZNSt3__16localeD1Ev
error: undefined symbol: _ZNSt3__18ios_base4initEPv
error: undefined symbol: _ZNSt3__18ios_base5clearEj
error: undefined symbol: _ZNSt3__18ios_baseD2Ev
error: undefined symbol: _Znwj
error: undefined symbol: __atomic_fetch_add_4
error: undefined symbol: __atomic_fetch_sub_4
error: undefined symbol: __atomic_load_4
error: undefined symbol: __atomic_store_4
error: undefined symbol: _ZTINSt3__18ios_baseE
error: undefined symbol: _ZTV10GuiHandler
error: undefined symbol: _ZTV11Preparation
error: undefined symbol: _ZTV16ProtocolQuestion
error: undefined symbol: _ZTV9SuitEntry
Error: Aborting compilation due to previous errors
shared:ERROR: '/home/maxwell/tools/emsdk/node/8.9.1_64bit/bin/node /home/maxwell/tools/emsdk/emscripten/1.38.30/src/compiler.js /tmp/tmpK_IO2U.txt /home/maxwell/tools/emsdk/emscripten/1.38.30/src/embind/emval.js /home/maxwell/tools/emsdk/emscripten/1.38.30/src/embind/embind.js /home/maxwell/tools/emsdk/emscripten/1.38.30/src/library_pthread_stub.js' failed (1)
Makefile:213: recipe for target 'TestWeb.js' failed

maxwell31 · 4 Jan 2019, 13:22

Ok, the problem seems to be that I did not set the HEADERS field in the .pro file (I am usually using cmake instead). Now it compiles

Izza · wrote on 15 Apr 2019, 12:02

Hi , i am having the same error can you please help me hpow did you update your .pro file to resolve this.

maxwell31 · wrote on 15 Apr 2019, 13:26

I simply forgot to add the following entry into the .pro file, so my header files which have macros like Q_OBJECT were not processed:

HEADERS = guihandler.h question.h entry.h