C++ Compiler for MIPS

Overview

A comprehensive, custom-built compiler for a subset of the C++ programming language, optimized for MIPS architecture. This project implements a full compiler pipeline, including:

• Lexical Analysis: Tokenization of C++ code into meaningful symbols.
• Parsing: Robust syntax analysis using LR(1) parsing.
• Semantic Analysis: Validation of syntax trees against C++ language rules.
• Code Generation: Efficient machine code generation for MIPS.

This compiler ensures optimized performance, strict adherence to language rules, and efficient execution.

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Features

Lexical Analysis

• Tokenizes source code into keywords, identifiers, operators, and symbols.
• Ignores whitespace and comments for a clean token stream.
• Supports identifiers (ID), numeric literals (NUM), operators (+ - * / % == != <= >= < >), and keywords (RETURN, IF, ELSE, WHILE).

Parsing

• Implements LR(1) parsing for robust syntax validation.
• Structures programs into procedures, declarations, control structures, and expressions.
• Supports control flow statements: if (mandatory else), while, and return.

Semantic Analysis

• Enforces context-sensitive rules, such as:
  • Unique procedure names.
  • Declaration before use.
  • Type correctness in expressions and assignments.
  • Strict function call conventions.
• Supports recursion, but mutual recursion is not allowed.

Code Generation

• Produces highly optimized MIPS machine code.
• Implements dynamic memory management using new and delete[].
• Ensures efficient execution with a streamlined instruction set.

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Supported Language Specifications

This compiler supports a tailored subset of C++, focusing on fundamental programming concepts:

Variable Declarations

• Supports int and int*.
• Requires initialization with an unsigned integer constant or NULL.

Statements & Expressions

• Includes:
  • Variable names.
  • Memory allocation (new).
  • Unary operators (&, *).
  • Binary operators (+ - * / % == != <= >= < >).

Memory Management

• Supports dynamic allocation with new.
• Implements safe deallocation using delete[].

Function Design

• Mandatory single return statement at the end of each function.
• Functions must have well-defined parameter and return types.

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Compiler Architecture

Lexical Syntax

The compiler follows a rigorous lexical structure, ensuring token clarity and case sensitivity. The lexer converts source code into structured tokens, handling identifiers, keywords, and operators efficiently.

Context-free Grammar

The parsing phase enforces structured C++ grammar, ensuring:

• Proper scoping and nesting of control structures.
• Well-defined function signatures.
• Separation between declarations and statements.

Context-sensitive Rules

• No undeclared variables: Every variable must be declared before use.
• Strict type checking: All expressions must match expected data types.
• Single return statement: Each function requires a single return at the end.

Semantic Validation

This compiler guarantees that valid programs not only meet syntactic rules but also maintain C++-standard semantics, ensuring predictable execution in MIPS environments.

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Source Code

Due to this project being associated with the CS Department at the Unverisity of Waterloo, the code is in a private repository. IF you'd like to see it, please contact me.

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