**LLVM_ENABLE_EXPENSIVE_CHECKS**:BOOL
Enable additional time/memory expensive checking. Defaults to OFF.
+**LLVM_ENABLE_IDE**:BOOL
+ Tell the build system that an IDE is being used. This in turn disables the
+ creation of certain convenience build system targets, such as the various
+ ``install-*`` and ``check-*`` targets, since IDEs don't always deal well with
+ a large number of targets. This is usually autodetected, but it can be
+ configured manually to explicitly control the generation of those targets. One
+ scenario where a manual override may be desirable is when using Visual Studio
+ 2017's CMake integration, which would not be detected as an IDE otherwise.
+
**LLVM_ENABLE_PIC**:BOOL
Add the ``-fPIC`` flag to the compiler command-line, if the compiler supports
this flag. Some systems, like Windows, do not need this flag. Defaults to ON.