cpp behavior?

[Steve Kargl]

% which cpp
/usr/bin/cpp
troutmask:kargl[408] cpp --version
FreeBSD clang version 4.0.0 (tags/RELEASE_400/final 297347) (based on LLVM 4.0.0)
Target: x86_64-unknown-freebsd12.0
Thread model: posix
InstalledDir: /usr/bin
troutmask:kargl[409] cpp --help |grep trad
  -traditional-cpp        Enable some traditional CPP emulation
troutmask:kargl[410] cpp -traditional-cpp boxmuller.F90 
cpp: error: unable to execute command: Executable "gcc" doesn't exist!

OK, so what is the preprocessor for clang?

-- 
Steve
20170425 https://www.youtube.com/watch?v=VWUpyCsUKR4
20161221 https://www.youtube.com/watch?v=IbCHE-hONow