Integrating a new target into the clang frontend

In the previous chapters, we developed the M88k target’s backend implementation within LLVM. To complete the compiler implementation for the M88k target, we will investigate connecting our new target to the frontend by adding a clang implementation for our M88k target.

Implementing the driver integration within clang

Let’s start by adding driver integration into clang for M88k:

1. The first change we will be making is inside the clang/include/clang/Basic/TargetInfo.h file. The BuiltinVaListKind enum lists the different kinds of __builtin_va_list types for each target, which is used for variadic functions support, so a corresponding type for M88k is added:

   enum BuiltinVaListKind {
   . . .
       // typedef struct __va_list_tag {
       //    int __va_arg;
       //    int *__va_stk;
       //   ...