RcppArmadillo code completion

Hello,

RStudio projects using RcppArmadillo do not have code completion because when code completion runs clang, it returns the following error:

error: OpenMP support and version of OpenMP (31, 40 or 45) was disabled in PCH file but is currently enabled

The compilation arguments are as follows on my computer, and they include -fopenmp. How can I change the compilation arguments not to include -fopenmp, so that code completion will work correctly?

Alternatively (and preferably), how do I enable OpenMP support in the PCH file?

COMPILATION ARGUMENTS:
[
"-IC:/Program Files/RStudio/resources/libclang/builtin-headers/5.0.2",
"-IC:/Program Files/RStudio/resources/libclang/builtin-headers/libc++/5.0.2",
"-std=gnu++11",
"-IC:/PROGRA~1/R/R-35~1.3/include",
"-DNDEBUG",
"-I../inst/include",
"-fopenmp",
"-IC:/Users/tprior1/GOOGLE~1/WORKGO~1/R/RWINLI~1/Rv342/Rcpp/include",
"-IC:/Users/tprior1/GOOGLE~1/WORKGO~1/R/RWINLI~1/Rv342/RCPPAR~1/include",
"-IC:/Users/tprior1/GOOGLE~1/WORKGO~1/R/RPROJE~1/TOD818~1",
"-include-pch",
"C:/Users/tprior1/AppData/Local/Temp/RtmpwL8UML/rstudio/libclang/precompiled/Rcpp/4CEAE7E1/1.0.2-x86_64-w64-mingw32-76217-5.0.2/Rcpp-std=gnu++11.pch",
"-v"
]

This seems like an RStudio bug. See also: https://github.com/rstudio/rstudio/issues/4685

Would you mind adding this for extra context on that issue?