7 Tools Used in Compiler Construction and Why You Should Care

 

A compiler is any program that translates code written in one programming language into code written in another programming language, usually with the intention of being able to execute the translated code on some sort of computer processor. Compilers play an important role in software development, as they allow programmers to use whatever programming language best suits their needs without having to worry about how their code will be executed by computers or whether other developers will be able to run it on their systems. The following are seven tools used in compiler construction and why you should care.

 

Tool 1: Bison

Bison is a general-purpose parser generator that converts an annotated context-free grammar into a deterministic LR or generalized LR (GLR) parser employing LALR(1) parser tables. Generalized LR parsers can recognize all context-free languages, but may run slower than top-down parsers because they perform more lookahead. Bison is useful if you have complex grammars that may not fit into a traditional top-down parser, or if you have a lot of slightly different inputs to parse. For example, it's often used by programming language designers who need to develop multiple similar languages with similar syntax. It also has some error reporting facilities, which many find helpful in debugging their own or others' grammar.

 

Tool 2: Flex

This tool is used to generate lexical analyzers. A lexical analyzer is a program that takes an input character stream as its input and produces as output a set of tokens extracted from that input stream. The lexical analyzer recognizes tokens by finding specific sequences of characters in that input stream. The sequence can be a single character or a group of characters (referred to as an alternative). Flex operates on text files with white space separated lines. It generates C source code for one or more state machines that are responsible for recognizing these tokens from an input stream.

 

Tool 3: Lex

Lex parses source code into tokens, which is a fancy way of saying that it breaks a string of characters into smaller pieces. It does so by looking for defined character combinations that indicate something special—like variable names, strings, or keywords. In some languages (like C), you can declare your own special character combination to mean something else, but you don’t get to do that with all languages (like JavaScript). This makes lex a little less flexible than some other compiler tools.

 

Tool 4: Yacc

Yacc is a tool that will generate code that parses grammar. Grammar is simply a set of rules, usually written in a text file, describing what type of input is allowed (for example, words can be made up of letters and numbers), and what output they are expected to produce. Yacc is often used to compile context-free grammars into programs that parse strings according to those grammars (at least as long as all language elements match their respective rules). This way, people don’t have to worry about writing their own parser, as it's built right into Yacc!

 

Tool 5: C++

C++ has a long history of being used as a systems programming language. Programs like Windows, Mac OS X, Android, and even some game engines are programmed primarily in C++. By using C++ to build your compiler front-end, you get access to many more libraries than you would otherwise have access to. It’s true that there are other ways to do it (Java/C#), but C++ has proven itself to be one of the best solutions for systems programming over many years of production usage. In fact, I wrote an entire book about just these kinds of solutions!

 

Tool 6: LLVM

Low-Level Virtual Machine The LLVM is a compiler framework that provides a toolset for creating compilers. It has everything you need to get started making your own: front end, back end, assembler, disassembler, and more. The most common use of LLVM is as an alternative to using GCC/G++ directly. The benefits are primarily twofold: It's easier to write a language front-end for LLVM than for GCC/G++; several languages have been written using LLVM: OCaml, D, BitC, and Julia.

 

Tool 7: Rust

This is a free, open-source language that's geared toward creating fast, reliable code. It compiles down to machine code, making it easier for developers to write faster applications than if they had used C++ or another more common programming language. But Rust isn't just about performance; it also makes it easier for developers to find errors. As a compiled language, every command you create with Rust is checked before it's run on your machine. Therefore, any potential bugs are found before an application goes live; instead of waiting until they've found one error that crashes everything. This happens all too often when using other languages like C or Python.