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A '''compiler''' is a computer program which translates source code written in a high-level [[programming language]] into executable machine code.  The act of doing this is called [[compilation]].

A '''compiler''' is a computer program which translates source code written in a high-level [[programming language]] into executable machine code.  The act of doing this is called [[compilation]].

Most compilers perform the following actions, sometimes in a single pass over the source code, and sometimes in several passes.  Program optimisation may take place before and during the 'code generation' stage.

==Outline of the compilation process==

| accessdate = 2012-03-19}}</ref>, Professor Torben Mogensen identifies seven phases within a compiler, with the various phases being performed in one or more passes over the program.

:'''Lexical analysis''': convert source code into sequence of tokens.

:'''Lexical analysis''': convert source code into sequence of tokens, such as variable names, keywords, numbers, and special symbols such as '+'.

:'''Syntactic analysis''': structure tokens into parse tree.

:'''Syntax analysis''' or '''parsing''': structure tokens into parse tree or syntax tree which represents the structure of the program.

:'''Semantic analysis''': annotate parse tree with semantic actions.

:'''Semantic analysis''': annotate parse tree with semantic actions, and perform various consistency checks.

:'''Code generation''': produce the final machine code.

:'''Intermediate code generation''': use the annotated parse tree to generate code in some simple machine-independent intermediate language.

 

 

:'''Assembly code generation''': translate the intermediate code into assembly language for the target machine.

 

:'''Assembly and linking''': translate the assembly language into executable machine code.

 

[[Category:Computer Science]]

[[Category:Computer Science]]