Preliminaries

You will also learn a lot by studying last year's project (the MOOL language) which was proposed as Assignment 3. Observe that the archive yacc.tar.gz contains samples of different steps in the development of a MOOL compiler.

mool-0.y

generates a parser for MOOL programs restricted to classes declarations, themselves restricted to attributes declarations.

mool-1.y

generates a parser similar to mool-0.y but provides animation to figure out in which order YACC actions are performed.

mool-2.y

generates a parser similar to mool-1.y. In addition, stores the names of the defined classes. Hence, this is a preliminary stage for symbol table computations.

mool-3.y

generates a parser similar to mool-2.y. In addition, stores the names of the defined attributes. It performs also some little checks.

mool-4.y

is similar to mool-3.y except that it uses an external C file mool-aux.c for C code.

You are strongly suggested to proceed in the same way, carefully step by step:

1. Realize a first parser that will parse only category definitions (i.e. no domain definitions, no main definitions).
2. Realize a second parser from the previous one that will parse category and domain definitions with very limited statements, say just assignments (i.e. no alternatives, no loops, no arithmetic/boolean expressions, ...).
3. Your third parser will recognize arithmetic/boolean expressions.
4. The fourth will add statements,
5. Finally, enhance this parser with the construction of symbol tables. Here again, you can proceed step by step:
   1. a symbol table for the whole program that will only store category and domain names,
   2. a symbol table for each category that will store function declarations,
   3. a symbol table for each domain that will store its category and its attributes,
   4. a symbol table for each function definition that will store the domain it belongs to, its local variables, ...