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Building Qt Apps to Wasm

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  • D Offline
    D Offline
    DragonOsman
    wrote on last edited by
    #29

    Thanks, I'll try that.

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    • D Offline
      D Offline
      DragonOsman
      wrote on last edited by
      #30

      I launched Python's web server by running python -m http.server, but I get the same exact HTML page as before when I go to notepad.html. It still has that same error on it.

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      • D Offline
        D Offline
        DragonOsman
        wrote on last edited by
        #31

        I get the exact same result with emrun. The error "TypeError: Body has already been read". How do I fix this? Someone please help. This seems like a JavaScript error so maybe I should also consult the Emscripten developers. But it's also something related to Qt and there may be something I need to know about how to run a Wasm module compiled from Qt code.

        lorn.potterL 1 Reply Last reply
        0
        • D DragonOsman

          I get the exact same result with emrun. The error "TypeError: Body has already been read". How do I fix this? Someone please help. This seems like a JavaScript error so maybe I should also consult the Emscripten developers. But it's also something related to Qt and there may be something I need to know about how to run a Wasm module compiled from Qt code.

          lorn.potterL Offline
          lorn.potterL Offline
          lorn.potter
          wrote on last edited by
          #32

          @DragonOsman said in Building Qt Apps to Wasm:

          The error "TypeError: Body has already been read". How do I fix this?

          I have seen that when I configure qt for threads and have forgotten to enable shared memory in the browsers.

          Chrome: chrome://flags "WebAssembly threads support"
          FireFox: about:config "javascript.options.shared_memory"
          

          Freelance Software Engineer, Platform Maintainer QtWebAssembly, Maintainer QtSensors
          Author, Hands-On Mobile and Embedded Development with Qt 5 http://bit.ly/HandsOnMobileEmbedded

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          1
          • D Offline
            D Offline
            DragonOsman
            wrote on last edited by
            #33

            Okay, thanks. I'll have to see how to do that for MS Edge. Thanks for the info on Chrome.

            lorn.potterL 2 Replies Last reply
            0
            • D DragonOsman

              Okay, thanks. I'll have to see how to do that for MS Edge. Thanks for the info on Chrome.

              lorn.potterL Offline
              lorn.potterL Offline
              lorn.potter
              wrote on last edited by
              #34

              @DragonOsman https://wiki.qt.io/Qt_for_WebAssembly

              Freelance Software Engineer, Platform Maintainer QtWebAssembly, Maintainer QtSensors
              Author, Hands-On Mobile and Embedded Development with Qt 5 http://bit.ly/HandsOnMobileEmbedded

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              • D DragonOsman

                Okay, thanks. I'll have to see how to do that for MS Edge. Thanks for the info on Chrome.

                lorn.potterL Offline
                lorn.potterL Offline
                lorn.potter
                wrote on last edited by
                #35

                @DragonOsman said in Building Qt Apps to Wasm:

                Okay, thanks. I'll have to see how to do that for MS Edge. Thanks for the info on Chrome.

                I do not think Edge has re-enabled shared memory:
                https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer

                Freelance Software Engineer, Platform Maintainer QtWebAssembly, Maintainer QtSensors
                Author, Hands-On Mobile and Embedded Development with Qt 5 http://bit.ly/HandsOnMobileEmbedded

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                • D Offline
                  D Offline
                  DragonOsman
                  wrote on last edited by DragonOsman
                  #36

                  I used it in Chrome. The functionality of saving a file doesn't seem to work (may need to let WebAssembly use the filesystem) and the "Select Font" feature is giving me trouble. It opens up two dialogue boxes so I have cancel the second one. On the first one then, the font size selector goes crazy when I try to use it; it keeps going between different sets of two options in really fast succession and I can't choose one at all. Is there a special way to get the Notepad example to work as a Wasm app? These problems only appear in the Wasm app.

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                  • D DragonOsman

                    This is the error I get now when using prebuilt Qt to build the Notepad project:

                    wasm-ld: error: notepad.obj: machine type must be wasm32
                    wasm-ld: error: notepad.js_plugin_import.obj: machine type must be wasm32
                    wasm-ld: error: moc_notepad.obj: machine type must be wasm32
                    wasm-ld: error: qapplication.obj: machine type must be wasm32
                    wasm-ld: error: qwidget.obj: machine type must be wasm32
                    wasm-ld: error: qwasmlocalfileaccess.obj: machine type must be wasm32
                    shared:ERROR: 'C:/emsdk/upstream/bin\wasm-ld.exe -o c:\users\osman\appdata\local\temp\emscripten_temp\notepad.wasm --allow-undefined --lto-O0 main.obj notepad.obj -LC:\emsdk\upstream\emscripten\system\local\lib notepad.js_plugin_import.obj -LC:\emsdk\upstream\emscripten\system\lib moc_notepad.obj -LC:\Users\Osman\.emscripten_cache\wasm-obj C:/Qt/5.13.1/wasm_32/plugins/platforms/libqwasm.a C:/Qt/5.13.1/wasm_32/lib/libQt5EventDispatcherSupport.a C:/Qt/5.13.1/wasm_32/lib/libQt5FontDatabaseSupport.a C:/Qt/5.13.1/wasm_32/lib/libqtfreetype.a C:/Qt/5.13.1/wasm_32/lib/libQt5EglSupport.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqgif.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqicns.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqico.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqjpeg.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqtga.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqtiff.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqwbmp.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqwebp.a C:/Qt/5.13.1/wasm_32/lib/libQt5PrintSupport.a C:/Qt/5.13.1/wasm_32/lib/libQt5Widgets.a C:/Qt/5.13.1/wasm_32/lib/libQt5Gui.a C:/Qt/5.13.1/wasm_32/lib/libqtlibpng.a C:/Qt/5.13.1/wasm_32/lib/libqtharfbuzz.a C:/Qt/5.13.1/wasm_32/lib/libQt5Core.a C:/Qt/5.13.1/wasm_32/lib/libqtpcre2.a C:\Users\Osman\.emscripten_cache\wasm-obj\libc.a C:\Users\Osman\.emscripten_cache\wasm-obj\libcompiler_rt.a C:\Users\Osman\.emscripten_cache\wasm-obj\libc-wasm.a C:\Users\Osman\.emscripten_cache\wasm-obj\libc++-noexcept.a C:\Users\Osman\.emscripten_cache\wasm-obj\libc++abi-noexcept.a --whole-archive C:\Users\Osman\.emscripten_cache\wasm-obj\libembind-rtti.a --no-whole-archive C:\Users\Osman\.emscripten_cache\wasm-obj\libgl-webgl2.a C:\Users\Osman\.emscripten_cache\wasm-obj\libdlmalloc.a C:\Users\Osman\.emscripten_cache\wasm-obj\libpthread_stub.a C:\Users\Osman\.emscripten_cache\wasm-obj\libc_rt_wasm.a --import-memory --import-table -mllvm -combiner-global-alias-analysis=false -mllvm -enable-emscripten-sjlj -mllvm -disable-lsr --export __wasm_call_ctors --export __data_end --export main --export malloc --export free --export setThrew --export __errno_location --export fflush --export _ZSt18uncaught_exceptionv --export __cxa_find_matching_catch --export __cxa_is_pointer_type --export __cxa_can_catch --export emscripten_GetProcAddress --export emscripten_webgl_make_context_current --export emscripten_webgl_get_current_context --export strstr --export emscripten_builtin_memalign --export memalign --export emscripten_builtin_free --export _get_environ --export realloc --export _get_tzname --export _get_daylight --export _get_timezone --export strlen -z stack-size=5242880 --initial-memory=16777216 --no-entry --global-base=1024' failed (1)
                    

                    If I pass -device-option WASM_OBJECT_FILES=1 to Qt configure when building Qt, will that fix this?

                    I checked notepad.obj and notepad.js_plugin_import.obj with wasm-dis.exe before and found that they were Wasm object files. But now when I check again, main.obj does have Wasm code in it but this is what I get for notepad.obj:

                    [parse exception: surprising value (at 0:4)]
                    Fatal: error in parsing wasm binary
                    

                    All three of the ones from my code give the same error. How can I find those three object files from the Qt library so I can check them too?

                    S Offline
                    S Offline
                    steno
                    wrote on last edited by
                    #37

                    @DragonOsman said in Building Qt Apps to Wasm:

                    This is the error I get now when using prebuilt Qt to build the Notepad project:

                    wasm-ld: error: notepad.obj: machine type must be wasm32
                    wasm-ld: error: notepad.js_plugin_import.obj: machine type must be wasm32
                    wasm-ld: error: moc_notepad.obj: machine type must be wasm32
                    wasm-ld: error: qapplication.obj: machine type must be wasm32
                    wasm-ld: error: qwidget.obj: machine type must be wasm32
                    wasm-ld: error: qwasmlocalfileaccess.obj: machine type must be wasm32
                    shared:ERROR: 'C:/emsdk/upstream/bin\wasm-ld.exe -o c:\users\osman\appdata\local\temp\emscripten_temp\notepad.wasm --allow-undefined --lto-O0 main.obj notepad.obj -LC:\emsdk\upstream\emscripten\system\local\lib notepad.js_plugin_import.obj -LC:\emsdk\upstream\emscripten\system\lib moc_notepad.obj -LC:\Users\Osman\.emscripten_cache\wasm-obj C:/Qt/5.13.1/wasm_32/plugins/platforms/libqwasm.a C:/Qt/5.13.1/wasm_32/lib/libQt5EventDispatcherSupport.a C:/Qt/5.13.1/wasm_32/lib/libQt5FontDatabaseSupport.a C:/Qt/5.13.1/wasm_32/lib/libqtfreetype.a C:/Qt/5.13.1/wasm_32/lib/libQt5EglSupport.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqgif.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqicns.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqico.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqjpeg.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqtga.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqtiff.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqwbmp.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqwebp.a C:/Qt/5.13.1/wasm_32/lib/libQt5PrintSupport.a C:/Qt/5.13.1/wasm_32/lib/libQt5Widgets.a C:/Qt/5.13.1/wasm_32/lib/libQt5Gui.a C:/Qt/5.13.1/wasm_32/lib/libqtlibpng.a C:/Qt/5.13.1/wasm_32/lib/libqtharfbuzz.a C:/Qt/5.13.1/wasm_32/lib/libQt5Core.a C:/Qt/5.13.1/wasm_32/lib/libqtpcre2.a C:\Users\Osman\.emscripten_cache\wasm-obj\libc.a C:\Users\Osman\.emscripten_cache\wasm-obj\libcompiler_rt.a C:\Users\Osman\.emscripten_cache\wasm-obj\libc-wasm.a C:\Users\Osman\.emscripten_cache\wasm-obj\libc++-noexcept.a C:\Users\Osman\.emscripten_cache\wasm-obj\libc++abi-noexcept.a --whole-archive C:\Users\Osman\.emscripten_cache\wasm-obj\libembind-rtti.a --no-whole-archive C:\Users\Osman\.emscripten_cache\wasm-obj\libgl-webgl2.a C:\Users\Osman\.emscripten_cache\wasm-obj\libdlmalloc.a C:\Users\Osman\.emscripten_cache\wasm-obj\libpthread_stub.a C:\Users\Osman\.emscripten_cache\wasm-obj\libc_rt_wasm.a --import-memory --import-table -mllvm -combiner-global-alias-analysis=false -mllvm -enable-emscripten-sjlj -mllvm -disable-lsr --export __wasm_call_ctors --export __data_end --export main --export malloc --export free --export setThrew --export __errno_location --export fflush --export _ZSt18uncaught_exceptionv --export __cxa_find_matching_catch --export __cxa_is_pointer_type --export __cxa_can_catch --export emscripten_GetProcAddress --export emscripten_webgl_make_context_current --export emscripten_webgl_get_current_context --export strstr --export emscripten_builtin_memalign --export memalign --export emscripten_builtin_free --export _get_environ --export realloc --export _get_tzname --export _get_daylight --export _get_timezone --export strlen -z stack-size=5242880 --initial-memory=16777216 --no-entry --global-base=1024' failed (1)
                    

                    If I pass -device-option WASM_OBJECT_FILES=1 to Qt configure when building Qt, will that fix this?

                    I checked notepad.obj and notepad.js_plugin_import.obj with wasm-dis.exe before and found that they were Wasm object files. But now when I check again, main.obj does have Wasm code in it but this is what I get for notepad.obj:

                    [parse exception: surprising value (at 0:4)]
                    Fatal: error in parsing wasm binary
                    

                    All three of the ones from my code give the same error. How can I find those three object files from the Qt library so I can check them too?

                    What was your solution for machine type must be wasm32? I have been seeing this as well.

                    lorn.potterL 1 Reply Last reply
                    0
                    • S steno

                      @DragonOsman said in Building Qt Apps to Wasm:

                      This is the error I get now when using prebuilt Qt to build the Notepad project:

                      wasm-ld: error: notepad.obj: machine type must be wasm32
                      wasm-ld: error: notepad.js_plugin_import.obj: machine type must be wasm32
                      wasm-ld: error: moc_notepad.obj: machine type must be wasm32
                      wasm-ld: error: qapplication.obj: machine type must be wasm32
                      wasm-ld: error: qwidget.obj: machine type must be wasm32
                      wasm-ld: error: qwasmlocalfileaccess.obj: machine type must be wasm32
                      shared:ERROR: 'C:/emsdk/upstream/bin\wasm-ld.exe -o c:\users\osman\appdata\local\temp\emscripten_temp\notepad.wasm --allow-undefined --lto-O0 main.obj notepad.obj -LC:\emsdk\upstream\emscripten\system\local\lib notepad.js_plugin_import.obj -LC:\emsdk\upstream\emscripten\system\lib moc_notepad.obj -LC:\Users\Osman\.emscripten_cache\wasm-obj C:/Qt/5.13.1/wasm_32/plugins/platforms/libqwasm.a C:/Qt/5.13.1/wasm_32/lib/libQt5EventDispatcherSupport.a C:/Qt/5.13.1/wasm_32/lib/libQt5FontDatabaseSupport.a C:/Qt/5.13.1/wasm_32/lib/libqtfreetype.a C:/Qt/5.13.1/wasm_32/lib/libQt5EglSupport.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqgif.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqicns.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqico.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqjpeg.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqtga.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqtiff.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqwbmp.a C:/Qt/5.13.1/wasm_32/plugins/imageformats/libqwebp.a C:/Qt/5.13.1/wasm_32/lib/libQt5PrintSupport.a C:/Qt/5.13.1/wasm_32/lib/libQt5Widgets.a C:/Qt/5.13.1/wasm_32/lib/libQt5Gui.a C:/Qt/5.13.1/wasm_32/lib/libqtlibpng.a C:/Qt/5.13.1/wasm_32/lib/libqtharfbuzz.a C:/Qt/5.13.1/wasm_32/lib/libQt5Core.a C:/Qt/5.13.1/wasm_32/lib/libqtpcre2.a C:\Users\Osman\.emscripten_cache\wasm-obj\libc.a C:\Users\Osman\.emscripten_cache\wasm-obj\libcompiler_rt.a C:\Users\Osman\.emscripten_cache\wasm-obj\libc-wasm.a C:\Users\Osman\.emscripten_cache\wasm-obj\libc++-noexcept.a C:\Users\Osman\.emscripten_cache\wasm-obj\libc++abi-noexcept.a --whole-archive C:\Users\Osman\.emscripten_cache\wasm-obj\libembind-rtti.a --no-whole-archive C:\Users\Osman\.emscripten_cache\wasm-obj\libgl-webgl2.a C:\Users\Osman\.emscripten_cache\wasm-obj\libdlmalloc.a C:\Users\Osman\.emscripten_cache\wasm-obj\libpthread_stub.a C:\Users\Osman\.emscripten_cache\wasm-obj\libc_rt_wasm.a --import-memory --import-table -mllvm -combiner-global-alias-analysis=false -mllvm -enable-emscripten-sjlj -mllvm -disable-lsr --export __wasm_call_ctors --export __data_end --export main --export malloc --export free --export setThrew --export __errno_location --export fflush --export _ZSt18uncaught_exceptionv --export __cxa_find_matching_catch --export __cxa_is_pointer_type --export __cxa_can_catch --export emscripten_GetProcAddress --export emscripten_webgl_make_context_current --export emscripten_webgl_get_current_context --export strstr --export emscripten_builtin_memalign --export memalign --export emscripten_builtin_free --export _get_environ --export realloc --export _get_tzname --export _get_daylight --export _get_timezone --export strlen -z stack-size=5242880 --initial-memory=16777216 --no-entry --global-base=1024' failed (1)
                      

                      If I pass -device-option WASM_OBJECT_FILES=1 to Qt configure when building Qt, will that fix this?

                      I checked notepad.obj and notepad.js_plugin_import.obj with wasm-dis.exe before and found that they were Wasm object files. But now when I check again, main.obj does have Wasm code in it but this is what I get for notepad.obj:

                      [parse exception: surprising value (at 0:4)]
                      Fatal: error in parsing wasm binary
                      

                      All three of the ones from my code give the same error. How can I find those three object files from the Qt library so I can check them too?

                      What was your solution for machine type must be wasm32? I have been seeing this as well.

                      lorn.potterL Offline
                      lorn.potterL Offline
                      lorn.potter
                      wrote on last edited by
                      #38

                      @steno said in Building Qt Apps to Wasm:

                      What was your solution for machine type must be wasm32? I have been seeing this as well.

                      If you use the prebuilt binaries, you need to use emscripten version 1.38.27 or 1.38.30 for threaded.

                      ./emsdk install sdk-fastcomp-1.38.27-64bit
                      ./emsdk activate sdk-fastcomp-1.38.27-64bit

                      Freelance Software Engineer, Platform Maintainer QtWebAssembly, Maintainer QtSensors
                      Author, Hands-On Mobile and Embedded Development with Qt 5 http://bit.ly/HandsOnMobileEmbedded

                      1 Reply Last reply
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