The best replacement for clang is gcc.

The best alternatives to clang are rated as following:
★★★★★  gcc
★★★  g++
★★★  llvm
★★  clang++
★  cppcheck
  mingw

Your alternative for clang is not listed? Suggest!
Speaking about clang, one probably shouldn't forget about openmp.

Other search terms related to clang and their ratings are:
★★★★★ openmp
★★★ cmake
★★★ clang
★★ linux kernel
★★ libc++
★★ ide
★ llvm
You have in mind a companion for clang and it is not yet here? Propose!



Google Trends

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clang
gcc
g++