This repository contains several code snippets that I developed to teach the ANTLR compiler generator at Iran University of Science and Technology (UST). Grammars have been written in ANTRL v4 format. For each grammar, the source code of Lexer and Parser is available in Python 3.x. The repository is assumed to be updated regularly. It would be appreciated if you use this repository by forking it. For any question please contact me [email protected] or read documentation.

The following outputs could be generated by code snippets in this repository.

Figure 1 shows how a single pass compiler can generate three address code for assignment statements with minimum numbers of temporary variable, started with T:

Fig 1: Examples of three addresses codes generated by ANTLR for AssignmentStatement grammar.

Figure 2 demonstrates how a single pass compiler can generate abstract syntax three (AST) for assignment statements.

Fig 2: Examples of abstract syntax tree (AST) generated by ANTLR for AssignmentStatement grammar.

The following describes the structure of the repository:

gram1: ANTRL hello world grammar.

Expr1: Simple grammar for handling mathematical expressions without any attribute and action.

Expr2: Simple attributed grammar for handling mathematical expressions with code() attribute.

Expr3: Currently, it is the same Expr2 grammar.

AssignmentStatement1.g4: The grammar to handle multiple assignment statements and mathematical expressions in programming languages like Pascal and C/C++.

AssignmentStatement2.g4: It is the same AssignmentStatement1.g4 grammar with attributes for holding rule code and rule type.

AssignmentStatement3.g4: The grammar to handle multiple assignment statements and mathematical expressions in programming languages like Pascal and C/C++. It provides semantic rules to perform type checking and semantic routines to generate intermediate representation.

AssignmentStatement4.g4: The grammar to handle multiple assignment statements and mathematical expressions in programming languages like Pascal and C/C++. It provides semantic rules to perform type checking and semantic routines to generate intermediate representation. It has been implemented to generate intermediate representation (three addresses codes) with minimum number of "temp" variables.

CPP14_v2: ANTLR grammar for C++14 forked from the official ANTRL website. Some bugs have been fixed and also the rule identifiers have been added to the grammar rules.

EMail.g4: Lexical grammar to validate email addresses.

EMail2.g4: Lexical grammar to validate email addresses, fixing bugs in EMail.g4

The language_apps package currently contains Lexer and Parser codes for each grammar in directory grammars, with a main driver script to demonstrate the type checking and intermediate code generation based on semantic rules and semantic routines.

The termina_batch_script directory contains several batch script to run ANTLR in terminal (Windows) to generate target code in JAVA language. The code snippets in this directory belong to my first experiences with ANTLR.

IUST compiler course official webpage

ANTLR slides: PART 1: Introduction

ANTLR slides: PART 2: Getting started in Java

ANTLR slides: PART 3: Getting started in C#