Editing Compiler-compiler (section)

{{Short description|Program that generates parsers or compilers}}
{{Distinguish|self-hosting compiler|source-to-source compiler}}
{{more citations needed|date=October 2015}}
{{Use dmy dates|date=January 2020|cs1-dates=y}}

In [[computer science]], a '''compiler-compiler''' or '''compiler generator''' is a programming tool that creates a [[Parsing#Computer_languages|parser]], [[interpreter (computer software)|interpreter]], or [[compiler]] from some form of formal description of a [[programming language]] and machine.

The most common type of compiler-compiler is called a '''parser generator'''.<ref>{{cite book |url=https://www.worldcat.org/oclc/70775643 |title=Compilers : principles, techniques, & tools |date=2007 |others=Alfred V. Aho, Monica S. Lam, Ravi Sethi, Jeffrey D. Ullman, Alfred V. Aho |isbn=978-0-321-48681-3 |edition=Second |location=Boston |page=287 |oclc=70775643}}</ref> It handles only [[syntactic analysis]].

A formal description of a language is usually a [[formal grammar|grammar]] used as an input to a parser generator. It often resembles [[Backus–Naur form]] (BNF), [[extended Backus–Naur form]] (EBNF), or has its own syntax. Grammar files describe a [[Syntax (programming languages)|syntax]] of a generated compiler's target programming language and actions that should be taken against its specific constructs.

[[Source code]] for a parser of the programming language is returned as the parser generator's output. This source code can then be compiled into a parser, which may be either standalone or embedded. The compiled parser then accepts the source code of the target programming language as an input and performs an action or outputs an [[abstract syntax tree]] (AST).

Parser generators do not handle the [[Semantics (computer science)|semantics]] of the AST, or the [[Code generation (compiler)|generation of machine code]] for the target machine.<ref name="name">"A Syntax Directed Compiler for ALGOL 60" Edgar T. Irons, Communications of the ACM Volume 4 Issue 1, Jan. 1961.</ref>

A '''metacompiler''' is a software development tool used mainly in the construction of [[compiler]]s, [[Translator (computing)|translators]], and [[interpreter (computing)|interpreters]] for other programming languages.<ref name="McGraw"/> The input to a metacompiler is a [[computer program]] written in a [[Domain-specific language|specialized]] programming [[metalanguage]] designed mainly for the purpose of constructing compilers.<ref name="McGraw"/><ref name="CWIC" /> The language of the compiler produced is called the object language. The minimal input producing a compiler is a [[Metaprogramming|metaprogram]] specifying the object language grammar and [[Semantics (computer science)|semantic]] transformations into an [[object program]].<ref name="CWIC" /><ref name="TMETA" />