RTTI linking issue, Hydra Cycles render delegate development

Building Blender
1

Hello,

I’m beginning development of a Hydra Cycles render delegate (i.e. from USD library… I’m with Tangent Animation). I want to link libusd_m.lib with bf_intern_cycles library but the following …/intern/cycles/CMakeLists.txt presents an issue when linking the libraries:

if(WITH_CYCLES_OSL)
  # LLVM and OSL need to build without RTTI
  if(WIN32 AND MSVC)
    set(RTTI_DISABLE_FLAGS "/GR- -DBOOST_NO_RTTI -DBOOST_NO_TYPEID")
  elseif(CMAKE_COMPILER_IS_GNUCC OR (CMAKE_C_COMPILER_ID MATCHES "Clang"))
    set(RTTI_DISABLE_FLAGS "-fno-rtti -DBOOST_NO_RTTI -DBOOST_NO_TYPEID")
  endif()
  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${RTTI_DISABLE_FLAGS}")
endif()

I’m compiling and linking with Visual Studio on a Windows 10 box:

cmd.exe /C "cd . && C:\Users\philip.luk\AppData\Local\JetBrains\Toolbox\apps\CLion\ch-0\193.5233.144\bin\cmake\win\bin\cmake.exe -E vs_link_exe --intdir=source\creator\CMakeFiles\blender.dir --rc=C:\PROGRA~2\WI3CF2~1\10\bin\100177~1.0\x86\rc.exe --mt=C:\PROGRA~2\WI3CF2~1\10\bin\100177~1.0\x86\mt.exe --manifests blender.exe.manifest -- C:\PROGRA~2\MICROS~1\2017\COMMUN~1\VC\Tools\MSVC\1416~1.270\bin\Hostx86\x64\link.exe /nologo @CMakeFiles\blender.rsp  /out:bin\blender.exe /implib:bin\blender.lib /pdb:bin\blender.pdb /version:0.0  /machine:x64 /SAFESEH:NO /MACHINE:X64  /SUBSYSTEM:CONSOLE /STACK:2097152 /INCREMENTAL:NO  /ignore:4049 /ignore:4217 /ignore:4221 /debug /INCREMENTAL  /IGNORE:4099 /NODEFAULTLIB:libcmt.lib /NODEFAULTLIB:msvcrt.lib /NODEFAULTLIB:libcmtd.lib /subsystem:console  /DELAYLOAD:vcomp140d.dll delayimp.lib  && cd ."
LINK Pass 1: command "C:\PROGRA~2\MICROS~1\2017\COMMUN~1\VC\Tools\MSVC\1416~1.270\bin\Hostx86\x64\link.exe /nologo @CMakeFiles\blender.rsp /out:bin\blender.exe /implib:bin\blender.lib /pdb:bin\blender.pdb /version:0.0 /machine:x64 /SAFESEH:NO /MACHINE:X64 /SUBSYSTEM:CONSOLE /STACK:2097152 /INCREMENTAL:NO /ignore:4049 /ignore:4217 /ignore:4221 /debug /INCREMENTAL /IGNORE:4099 /NODEFAULTLIB:libcmt.lib /NODEFAULTLIB:msvcrt.lib /NODEFAULTLIB:libcmtd.lib /subsystem:console /DELAYLOAD:vcomp140d.dll delayimp.lib /MANIFEST /MANIFESTFILE:source\creator\CMakeFiles\blender.dir/intermediate.manifest source\creator\CMakeFiles\blender.dir/manifest.res" failed (exit code 1319) with the following output:
bf_intern_cycles.lib(blender_session.cpp.obj) : error LNK2038: mismatch detected for 'boost__type_index__abi': value 'RTTI is off - typeid() is used only for templates' doesn't match value 'RTTI is used' in bf_usd.lib(usd_capi.cc.obj)
   Creating library bin\blender.lib and object bin\blender.exp

Since USD is compiled with RTTI and uses dynamic_cast, typeid, this appears to be an issue with conflicting enabled/disabled RTTI settings. Does anyone have an opinion about how to deal with it?

I’m attempting to enable the following flags when building LLVM and OSL to solve the issue:
LLVM: LLVM_REQUIRES_RTTI =ON
OSL: ENABLERTTI=ON

… but is there a good reason not to do this?

Thanks,
Philip Luk

1 Like
2

Building LLVM and OSL with RTTI enabled is probably fine. They just build without RTTI by default, so we followed that. I couldn’t find information about it why exactly this is done.

Maybe disabling RTTI helps reducing executable size or memory usage? I’ve never tried to check that.

3

Thanks for the feedback. I’ll post to this thread if I discover any performance or related issues from the build.