C-like compiler

A C-like language compiler written in Java that generates assembly code for the P-machine. This project was done during a university course (Language processors) and finished in July 2015. Most comments are in Spanish.

Feautures of our language:

• Declaration of simple variables and matrix with an arbitrary number of dimensions.
• Nested blocks.
• Predefined, custom and witout name types.
• Types comprobation.
• Infix, prefix and posfix operands.
• Advanced operands: +=, -=, *=, /=, %=, ++, and --.
• Implementation of the mod oerand (%), not avaible in the P-machine.
• Assignment instruction, even for arrays elements.
• If with and without else and while. All of them introduce a new scope.
• Errors are reported including the row and the column. This is done for all kind of errors: lexical, syntactic and semantic errors.
• Functions and methods with any number of params of primitive type. Overloading is not allowed.
• The option to continue the compilation after finding an error.
• Global variables.
• Const modifier to use for constant variables.
• Indexes correction checked in ejecution time.
• The main function can be choosen.
• Nested functions.
• The option to generate the code for the P-machine with labels for a more legible code.
• The syntactic tree it is generated and saved in a .txt.

Lexical Analysis

AnalizadorLexico.jflex - Contains a formal specification of the lexic of the language, in jFlex

AnalizadorLexico.java - Class that implements the lexer. Generated from AnalizadorLexico.jflex

UnidadesLexicas.java - Class with some lexical units (see also /src/sintactico/ClaseLexica.java). Generated from AnalizadorLexico.jflex

Syntactic Analysis

Gramatica.cup - Contains a formal specification of the grammar of the language, in CUP

AnalizadorSintactico.java - Class that implements the parser. Generated from Gramatica.cup

ClaseLexica.java - Class with some syntactic units (see also /src/lexico/UnidadesLexicas.java). Generated from Gramatica.cup

Classes for the language

These classes help to implement the specification of our language. They constitute the nodes of the syntax/semantic tree of the program.

DeclaracionFuncion.java - Represents the declaration of a function

Expresion.java - Implements an expression of the language, consisting of a left-hand side and a right-hand side subexpressions

ExpresionSimple.java - Implements the components of the previous expressions. They can be arithmetical, logical, etc

Identificador.java - Represents an identifier (i.e., the name of a variable)

IdParametro.java - Represents a function parameter's identifier

Instruccion.java - Represents a statement from our language. It can be a compound statement, an expression, a selection statement, a looping statement or a return statement

ListaDecVarFun.java - Represents a list of declarations of functions and/or variables

ListaVariables.java - Represents a list of variables of the same type

Parametros.java - Represents the parameters of a given function

Programa.java - Represents the program, i.e., it is the root node

Tipo.java - It represents a type of a variable/function

VariableParametro.java - Represents a variable or a function parameter

Other classes

GestionExcepciones.java - An exception handler for the errors encountered during the analysis of a source code

TablaSimbolos.java - Contains the data structure used during the analysis of the symbols from the program

Visitor design pattern

The compiler is based on the visitor pattern. The helper class Visitante.java implements the pre/postVisit methods used during the processing of every node from the tree.

Usage of the program

Just simply run Main.java. You'll be prompted to provide the name of the program and its starting point (function) and whether you would like to continue compilation after a first error is found. After the compilation process finishes, if there are no errors the resultant code.p file is generated. In addition, you'll be prompted to provide whether you would like to create a tree.txt file with a tree version of the code and/or a more readable version of the generated code using tags for branching.

Examples

Example 1

The main function has a nested function, which calculates the mirror image of an integer given, declared inside it. The main function calls the nested function with an input value a, initialized to 376, and then returns the output of the function.

Example 2

Declare a matrix with nested structs and access to their fields.

Example 3

Code with lexical and syntactic errors.

Example 4

Code with errors.

Example 5

Tricky code in which the same identifier is used at different scopes.

Example 6

Code in which the local variable is used instead of the global one.

Example 7

Error due to incompatible types.

Example 8

Recursive program to compute the factorial.

Report

report.pdf is a detailed report of the project in Spanish.

Authors

This project was developed by Ana María Martínez Gómez and Víctor Adolfo Gallego Alcalá, except the P-machine which was developed by our teacher Ricardo Peña.

Licence

Code published under MIT License (see LICENSE), except the content of the P-machine folder which has copyright and belongs to Ricardo Peña.