To Do for Each Level of C Source Program

Design a grammar and the corresponding parser using yacc/bison for the intermediate representation generated by gcc for each level of C source language programs. This parser has to be augmented further with actions to interpret the IR. For the Machine Description, an interpreter is not possible and we will identity some useful activity to be done with the description. An additional possibility in each case is a syntax directed editor which reads in the IR and allows the user to change it subject to following the syntax. This will require separating the organisational contents (eg. pointer the next node) from the semantic contents (eg. the data contained in a node). Some preliminary semantic checks may also be possible.

• Project :. Identify the types of AST nodes that GCC would use to ``compile'' such a language and write an interpreter for it. The AST interpreter evaluates the tree representation and prints the resulting value.
• Project 2. Identify the GIMPLE and CFG structures that GCC would use to generate an intermediate representation and write an interpreter for it. The GIMPLE interpreter evaluates each statement and returns the result. The returned result must be the same as what the AST interpreter would evaluate.
• Project 3. Identify the RTL IR structures that GCC would use to generate an intermediate representation and write an interpreter for it. The RTL IR interpreter evaluates each RTX in the list and returns the result. Obviously this result should be identical to the one produced by interpreting the AST.

We omit case analysis constructs, explicit type coercion, loop breaks and continues, unrestricted jump, variable argument lists, preprocessing, data structuring mechanisms (structs and unions) and pointers.