Difference between revisions of "Compiler"
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| − | :'''Lexical analysis''': convert source code into sequence of tokens, such as variable names, keywords, numbers, and special symbols such as '+'. | + | :'''Lexical analysis''': convert the source code into a sequence of tokens, such as variable names, keywords, numbers, and special symbols such as '+'. |
| − | :'''Syntax analysis''' or '''parsing''': | + | :'''Syntax analysis''' or '''parsing''': arrange the tokens into a parse tree or syntax tree which represents the structure of the program. |
| − | :'''Semantic analysis''': annotate parse tree with semantic actions, and perform various consistency checks. | + | :'''Semantic analysis''': annotate the parse tree with semantic actions, and perform various consistency checks. |
:'''Intermediate code generation''': use the annotated parse tree to generate code in some simple machine-independent intermediate language. | :'''Intermediate code generation''': use the annotated parse tree to generate code in some simple machine-independent intermediate language. | ||
Revision as of 19:37, March 20, 2012
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.
Outline of the compilation process
In the freely available online book "Basics of Compiler Design"[1], Professor Torben Mogensen identifies seven phases within a compiler, with the various phases being performed in one or more passes over the program. A diagram illustrating these (and other optional optimisation) phases is shown on the last page of Professor Frank Pfenning's "Lecture Notes on Compiler Design: Overview"[2]
- Lexical analysis: convert the source code into a sequence of tokens, such as variable names, keywords, numbers, and special symbols such as '+'.
- Syntax analysis or parsing: arrange the tokens into a parse tree or syntax tree which represents the structure of the program.
- Semantic analysis: annotate the parse tree with semantic actions, and perform various consistency checks.
- Intermediate code generation: use the annotated parse tree to generate code in some simple machine-independent intermediate language.
- Register allocation: map the symbolic names used in the intermediate code on to the registers available in the target machine code.
- 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.
References
- ↑ Basics of Compiler Design. Retrieved on 2012-03-19.
- ↑ Lecture Notes on Compiler Design: Overview (pdf). Retrieved on 2012-03-19.
