This directory contains the C and C++ runtime libraries for the LLVM GCC front-ends. It is composed of four distinct pieces: 1. __main and static ctor/dtor support. This is used by both C and C++ codes. 2. Generic EH support routines. This is used by C/C++ programs that use setjmp/longjmp, and by C++ programs that make use of exceptions. 3. setjmp/longjmp EH support. This is used by C/C++ programs that call SJLJ. 4. C++ exception handling runtime support. These four components are compiled together into an archive file, so that applications using a subset of the four do not pull in unnecessary code and dependencies.