CMake) em++ : scanning dependencies error (c++ 20)

[hsdk123]

Hi, I set my compiler options like the following:

set(SECORE_EMSCRIPTEN_FLAGS "\
    -sASSERTIONS=1 \
    -sFORCE_FILESYSTEM=1 \
    -sFETCH=1 \
    -sALLOW_MEMORY_GROWTH=1 \
    -sLLD_REPORT_UNDEFINED \
    -sERROR_ON_UNDEFINED_SYMBOLS=0 \
    ")

# required for max memory. reference: https://v8.dev/blog/4gb-wasm-memory
# note: reason for linux-gcc-x86 in CMakeSettings.json
set(SECORE_EMSCRIPTEN_FLAGS "${SECORE_EMSCRIPTEN_FLAGS} -sMAXIMUM_MEMORY=4GB") 

set(SECORE_EMSCRIPTEN_FLAGS "${SECORE_EMSCRIPTEN_FLAGS} -sOFFSCREEN_FRAMEBUFFER=1") 

set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${SECORE_EMSCRIPTEN_FLAGS}")
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${SECORE_EMSCRIPTEN_FLAGS}")

But then when I compile I see:

  [229/968] Building CXX object _deps/magnum-build/src/Magnum/MeshTools/CMakeFiles/MagnumMeshToolsObjects.dir/Tipsify.cpp.o
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\em++ : warning : linker setting ignored during compilation: 'ASSERTIONS' [-Wunused-command-line-argument]
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\em++ : warning : linker setting ignored during compilation: 'FORCE_FILESYSTEM' [-Wunused-command-line-argument]
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\em++ : warning : linker setting ignored during compilation: 'FETCH' [-Wunused-command-line-argument]
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\em++ : warning : linker setting ignored during compilation: 'ALLOW_MEMORY_GROWTH' [-Wunused-command-line-argument]
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\em++ : warning : linker setting ignored during compilation: 'LLD_REPORT_UNDEFINED' [-Wunused-command-line-argument]
  
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\em++ : warning : linker setting ignored during compilation: 'ERROR_ON_UNDEFINED_SYMBOLS' [-Wunused-command-line-argument]
  
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\em++ : warning : linker setting ignored during compilation: 'MAXIMUM_MEMORY' [-Wunused-command-line-argument]
  
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\em++ : warning : linker setting ignored during compilation: 'OFFSCREEN_FRAMEBUFFER' [-Wunused-command-line-argument]

How do I remove these warnings?

[hsdk123]

This seems even problematic as I see a compiler error here:
(c++20 with emscripten 4.0.9)

  [219/968] Scanning C:/Users/daego/Desktop/Projects/Light.vn-core/_deps/pugixml/0c1984d4cfed53cbe7c9c803ce818846acd135aa/src/pugixml.cpp for CXX dependencies
  FAILED: _deps/pugixml-build/CMakeFiles/pugixml-static.dir/src/pugixml.cpp.o.ddi 
  C:\WINDOWS\system32\cmd.exe /C ""C:/Users/daego/Desktop/Projects/emsdk/upstream/emscripten/emscan-deps" -format=p1689 -- C:\Users\daego\Desktop\Projects\emsdk\upstream\emscripten\em++.bat -DAL_LIBTYPE_STATIC -DPUGIXML_WCHAR_MODE -IC:/Users/daego/Desktop/Projects/Light.vn-core/core/extlibs/. -IC:/Users/daego/Desktop/Projects/Light.vn-core/_deps/pugixml/0c1984d4cfed53cbe7c9c803ce818846acd135aa/src -Wno-warn-absolute-paths         -sASSERTIONS=1         -sFORCE_FILESYSTEM=1         -sFETCH=1         -sALLOW_MEMORY_GROWTH=1         -sLLD_REPORT_UNDEFINED         -sERROR_ON_UNDEFINED_SYMBOLS=0          -sMAXIMUM_MEMORY=4GB -sOFFSCREEN_FRAMEBUFFER=1 -DNDEBUG -O3 -flto -O3 -DNDEBUG -std=c++20 -fPIC -x c++ C:/Users/daego/Desktop/Projects/Light.vn-core/_deps/pugixml/0c1984d4cfed53cbe7c9c803ce818846acd135aa/src/pugixml.cpp -c -o _deps\pugixml-build\CMakeFiles\pugixml-static.dir\src\pugixml.cpp.o -resource-dir "C:/Users/daego/Desktop/Projects/emsdk/upstream/lib/clang/21" -MT _deps\pugixml-build\CMakeFiles\pugixml-static.dir\src\pugixml.cpp.o.ddi -MD -MF _deps\pugixml-build\CMakeFiles\pugixml-static.dir\src\pugixml.cpp.o.ddi.d > _deps\pugixml-build\CMakeFiles\pugixml-static.dir\src\pugixml.cpp.o.ddi.tmp && "C:/Program Files/Microsoft Visual Studio/2022/Community/Common7/IDE/CommonExtensions/Microsoft/CMake/CMake/bin/cmake.exe" -E rename _deps\pugixml-build\CMakeFiles\pugixml-static.dir\src\pugixml.cpp.o.ddi.tmp _deps\pugixml-build\CMakeFiles\pugixml-static.dir\src\pugixml.cpp.o.ddi"
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\EXEC : error : unknown argument: '-sASSERTIONS=1'
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\EXEC : error : unknown argument: '-sFORCE_FILESYSTEM=1'
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\EXEC : error : unknown argument: '-sFETCH=1'
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\EXEC : error : unknown argument: '-sALLOW_MEMORY_GROWTH=1'
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\EXEC : error : unknown argument: '-sLLD_REPORT_UNDEFINED'
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\EXEC : error : unknown argument: '-sERROR_ON_UNDEFINED_SYMBOLS=0'
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\EXEC : error : unknown argument: '-sMAXIMUM_MEMORY=4GB'
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\EXEC : error : unknown argument: '-sOFFSCREEN_FRAMEBUFFER=1'
  Error while scanning dependencies for C:/Users/daego/Desktop/Projects/Light.vn-core/_deps/pugixml/0c1984d4cfed53cbe7c9c803ce818846acd135aa/src/pugixml.cpp:
  
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\EXEC : error : unknown argument: '-sASSERTIONS=1'
  
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\EXEC : error : unknown argument: '-sFORCE_FILESYSTEM=1'
  
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\EXEC : error : unknown argument: '-sFETCH=1'
  
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\EXEC : error : unknown argument: '-sALLOW_MEMORY_GROWTH=1'
  
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\EXEC : error : unknown argument: '-sLLD_REPORT_UNDEFINED'
  
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\EXEC : error : unknown argument: '-sERROR_ON_UNDEFINED_SYMBOLS=0'
  
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\EXEC : error : unknown argument: '-sMAXIMUM_MEMORY=4GB'
  
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\EXEC : error : unknown argument: '-sOFFSCREEN_FRAMEBUFFER=1'

[sbc100]

I would recommend passing all those -s flags only the linker.

I think you can do this either via add_link_options or via target_link_options or via https://cmake.org/cmake/help/latest/prop_tgt/LINK_FLAGS.html but I'm not sure that the difference is between them exactly.

[hsdk123]

@sbc100
Thank you, I tried

set(SECORE_EMSCRIPTEN_FLAGS "\
    -sASSERTIONS=1 \
    -sFORCE_FILESYSTEM=1 \
    -sFETCH=1 \
    -sALLOW_MEMORY_GROWTH=1 \
    -sLLD_REPORT_UNDEFINED \
    -sERROR_ON_UNDEFINED_SYMBOLS=0 \
    ")

# required for max memory. reference: https://v8.dev/blog/4gb-wasm-memory
# note: reason for linux-gcc-x86 in CMakeSettings.json
set(SECORE_EMSCRIPTEN_FLAGS "${SECORE_EMSCRIPTEN_FLAGS} -sMAXIMUM_MEMORY=4GB") 

set(SECORE_EMSCRIPTEN_FLAGS "${SECORE_EMSCRIPTEN_FLAGS} -sOFFSCREEN_FRAMEBUFFER=1") 

add_link_options(${SECORE_EMSCRIPTEN_FLAGS})

but now I get the following error:

  [285/296] Linking CXX executable C:\Users\daego\Desktop\Projects\Light.vn-core\core\bin-Emscripten-Release-Clang\LightApp.js
  FAILED: C:/Users/daego/Desktop/Projects/Light.vn-core/core/bin-Emscripten-Release-Clang/LightApp.js 
  C:\WINDOWS\system32\cmd.exe /C "cd . && C:\Users\daego\Desktop\Projects\emsdk\upstream\emscripten\em++.bat -Wno-warn-absolute-paths -DNDEBUG -O3 -flto -O3 -DNDEBUG -s WASM=1 -O3 -flto   "        -sASSERTIONS=1         -sFORCE_FILESYSTEM=1         -sFETCH=1         -sALLOW_MEMORY_GROWTH=1         -sLLD_REPORT_UNDEFINED         -sERROR_ON_UNDEFINED_SYMBOLS=0          -sMAXIMUM_MEMORY=4GB -sOFFSCREEN_FRAMEBUFFER=1" -s USE_WEBGL2=1 @CMakeFiles\LightApp.rsp -o C:\Users\daego\Desktop\Projects\Light.vn-core\core\bin-Emscripten-Release-Clang\LightApp.js && C:\WINDOWS\system32\cmd.exe /C "cd /D C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten && "C:\Program Files\Microsoft Visual Studio\2022\Community\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E copy_if_different C:/Users/daego/Desktop/Projects/Light.vn-core/core/src/Code/Include/Version.h C:/Users/daego/Desktop/Projects/Light.vn-core/core/bin-Emscripten-Release-Clang/Version.txt && cd /D C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten && "C:\Program Files\Microsoft Visual Studio\2022\Community\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E copy_directory_if_different C:/Users/daego/Desktop/Projects/Light.vn-core/core/config/emscripten/scripts C:/Users/daego/Desktop/Projects/Light.vn-core/core/bin-Emscripten-Release-Clang/scripts && "C:\Program Files\Microsoft Visual Studio\2022\Community\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E copy_if_different C:/Users/daego/Desktop/Projects/Light.vn-core/core/config/emscripten/WebCore.css C:/Users/daego/Desktop/Projects/Light.vn-core/core/bin-Emscripten-Release-Clang/WebCore.css && "C:\Program Files\Microsoft Visual Studio\2022\Community\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E copy_if_different C:/Users/daego/Desktop/Projects/Light.vn-core/core/config/emscripten/WebCore.js C:/Users/daego/Desktop/Projects/Light.vn-core/core/bin-Emscripten-Release-Clang/WebCore.js && "C:\Program Files\Microsoft Visual Studio\2022\Community\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E copy_if_different C:/Users/daego/Desktop/Projects/Light.vn-core/core/config/emscripten/index.html C:/Users/daego/Desktop/Projects/Light.vn-core/core/bin-Emscripten-Release-Clang/index.html && "C:\Program Files\Microsoft Visual Studio\2022\Community\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E echo "Copying emscripten files to C:/Users/daego/Desktop/Projects/Light.vn-core/core/bin-Emscripten-Release-Clang" && "C:\Program Files\Microsoft Visual Studio\2022\Community\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E copy C:/Users/daego/Desktop/Projects/Light.vn-core/core/bin-Emscripten-Release-Clang/LightApp.js C:/Users/daego/Desktop/Projects/Light.vn-core/core/../prebuilt/emscripten/LightApp.js && "C:\Program Files\Microsoft Visual Studio\2022\Community\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E copy C:/Users/daego/Desktop/Projects/Light.vn-core/core/bin-Emscripten-Release-Clang/LightApp.wasm C:/Users/daego/Desktop/Projects/Light.vn-core/core/../prebuilt/emscripten/LightApp.wasm && "C:\Program Files\Microsoft Visual Studio\2022\Community\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E copy C:/Users/daego/Desktop/Projects/Light.vn-core/core/src/Code/Include/Version.h C:/Users/daego/Desktop/Projects/Light.vn-core/core/../prebuilt/emscripten/Version.txt && "C:\Program Files\Microsoft Visual Studio\2022\Community\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe" -E echo "Copying emscripten files to C:/Users/daego/Desktop/Projects/Light.vn-core/core/../prebuilt/emscripten"""
C:\Users\daego\Desktop\Projects\Light.vn-core\out\core\build\emscripten\em++ : error : -sASSERTIONS=1         -sFORCE_FILESYSTEM=1         -sFETCH=1         -sALLOW_MEMORY_GROWTH=1         -sLLD_REPORT_UNDEFINED         -sERROR_ON_UNDEFINED_SYMBOLS=0          -sMAXIMUM_MEMORY=4GB -sOFFSCREEN_FRAMEBUFFER=1: No such file or directory ("        -sASSERTIONS=1         -sFORCE_FILESYSTEM=1         -sFETCH=1         -sALLOW_MEMORY_GROWTH=1         -sLLD_REPORT_UNDEFINED         -sERROR_ON_UNDEFINED_SYMBOLS=0          -sMAXIMUM_MEMORY=4GB -sOFFSCREEN_FRAMEBUFFER=1" was expected to be an input file, based on the commandline arguments provided)

[sbc100]

It looks like cmake is adding one big option there. I'm sure there is a way to fix that but maybe just try CMAKE_EXE_LINKER_FLAGS instead.

[hsdk123]

Confirming CMAKE_EXE_LINKER_FLAGS works!
Might want to update the documentation to reflect:
https://emscripten.org/docs/getting_started/FAQ.html#how-do-i-specify-s-options-in-a-cmake-project

[sbc100]

Should be fixed by #24506