LLVM Cookbook

Invoking a driver for parsing

In this recipe, you will learn how to call the parser function from the main function of our TOY parser.

How to do it…

To invoke a driver program to start parsing, define the driver function as shown in the following:

1. Open the toy.cpp file:

   $ vi toy.cpp

2. A Driver function called from the main function, and a parser can now be defined as follows:

   static void Driver() {
     while(1) {
       switch(Current_token) {
       case EOF_TOKEN : return;
       case ';' : next_token(); break;
       case DEF_TOKEN : HandleDefn(); break;
       default : HandleTopExpression(); break;
     }
     }
   }

3. The main() function to run the whole program can be defined as follows:

   int main(int argc, char* argv[]) { LLVMContext &Context = getGlobalContext(); init_precedence(); file = fopen(argv[1], ...