CONFIG += c++-17 …is in the .pro file. Otherwise the code would not compile with Qt 6.2.2
> Am 27.12.2021 um 23:45 schrieb Lorn Potter <lorn.pot...@gmail.com>: > > Hi, > Emscripten uses clang/LLVM and not gcc, if makes any difference to you. > > Setting /etc/alternatives has no effect on emscripten as essentially we are > cross compiling. > > Perhaps you might try adding > CONFIG += c++17 > If you are using c++-17 ? > > emcc -v > > $> emcc -v > emcc (Emscripten gcc/clang-like replacement + linker emulating GNU ld) 2.0.14 > clang version 13.0.0 > (/opt/s/w/ir/cache/git/chromium.googlesource.com-external-github.com-llvm-llvm--project > 5f3c99085d4c2ebf57fd0586b013b02e32a8e20b) > Target: wasm32-unknown-emscripten > Thread model: posix > > >> On 27/12/2021 9:56 PM, Axel Spoerl wrote: >> I can narrow down the issue as follows: >> The problem at hand occurs on a compile server, compiling desktop >> executables for Qt 5.15.2 (with GCC-7), Qt 6.2.2 (with GCC-9). To make both >> configurations work, QMAKE_CXX=g++-7 / QMAKE_CXX=g++-9 arguments are added >> in the respective Qt Creator build steps (which is necessary for Qt 6.2.2 >> even if g++-9 is specified as compiler in the kit itself). >> Emscripten (intended as a 3rd compile target) has been installed according >> to https://doc.qt.io/qt-6/wasm.html <https://doc.qt.io/qt-6/wasm.html> and >> https://emscripten.org/docs/getting_started/index.html >> <https://emscripten.org/docs/getting_started/index.html> >> The emscripten installation is able to compile the latest openssl pulled >> from github. >> No matter which GCC version is chosen in /etc/alternatives and no matter >> which emscripten version is activated (3.0.1 or 2.0.14): >> .../upstream/emscripten/cache/sysroot/include/c++ only contains the v1 >> directory. >> The server's /usr/include/c++ contains v1, 7 and 9 according to the GCC >> versions installed. This is where my emscripten knowledge ends and I can >> only experiment (e.g. by manually linking the 9 directory into the >> emscripten cache, which is being ignored). >> Compiling basic C++ code with #include <cmath> works for GCC 7 and produces >> the errors mentioned earlier for GCC 9 (i.e. Qt 6.2.2). >> Makefiles are generated by qmake out of a single .pro file. The .pro file >> contains a WASM specific section to link against its own libcrypto and >> libssl. Apart from the compilers used, all Makefiles look almost identical. >> => It appears to me as if emscripten uses a default GCC version, which in >> case of GCC 9 being expected is the wrong one. This leads to the lib >> incompatibility as described by Thiago. I have not found options for em++, >> 'emsdk install' or 'emsdk activate', that provide a GCC selection. That may >> well be attributable to a lack of knowledge on my side. >> > Well, Qt is a bit relevant if the qt-cmake of the Qt 6.2.2 WASM >> > installation >> > results in broken make files. >> > >> > So the question is perhaps: Axel, assuming that you installed emscripten >> > following the instruction and that you can verify that you can compile >> > basic C++ code as Thiago suggested, how do you then generate your make >> > files? >> > >> > Volker >> > >> _______________________________________________ >> Interest mailing list >> Interest@qt-project.org >> https://lists.qt-project.org/listinfo/interest > > -- > Lorn Potter > Freelance Qt Developer. Platform Maintainer Qt WebAssembly, Maintainer > QtSensors > Author, Hands-on Mobile and Embedded Development with Qt 5 > > _______________________________________________ > Interest mailing list > Interest@qt-project.org > https://lists.qt-project.org/listinfo/interest _______________________________________________ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
