Compiler
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The document discusses the key components and functions of a compiler. A compiler acts as a translator that transforms human-oriented programming languages into machine languages. The major tasks of any compiler are analysis of the source program and synthesis of a machine-language program. A typical compiler consists of several main components - a scanner, parser, semantic routines, code generator, and optimizer. The scanner breaks the source code into tokens. The parser checks the syntax and generates a parse tree. Semantic routines perform analysis and translation to an intermediate representation. The code generator transforms the intermediate code to target machine code, and the optimizer improves the generated code.
![The Structure of a Compiler (4)
7
Scanner Parser
Semantic
Routines
Code
Generator
Optimizer
Source
Program Tokens Syntactic
Structure
Symbol and
Attribute
Tables
(Used by all
Phases of
The Compiler)
Parser
Given a formal syntax specification (typically as a context-
free grammar [CFG] ), the parse reads tokens and groups
them into units as specified by the productions of the CFG
being used.
As syntactic structure is recognized, the parser either calls
corresponding semantic routines directly or builds a
syntax tree.
CFG ( Context-Free Grammar )
GAA ( Grammar Analysis Algorithms )
(Character
Stream)
Intermediate
Representation
Target machine code](https://image.slidesharecdn.com/compilerpresentation-150316003933-conversion-gate01/85/Compiler-7-320.jpg)
![The Structure of a Compiler (8)
11
Scanner
[Lexical Analyzer]
Parser
[Syntax Analyzer]
Semantic Process
[Semantic analyzer]
Code Generator
[Intermediate Code Generator]
Code Optimizer
Tokens
Parse
tree
Abstract Syntax Tree w/
Attributes
Non-optimized Intermediate
Code
Optimized Intermediate Code
Code Optimizer
Target machine code](https://image.slidesharecdn.com/compilerpresentation-150316003933-conversion-gate01/85/Compiler-11-320.jpg)
Compiler
- 1. Date :- 16,jan,2015 Compiler Presented to: Sir Khalid Mehmood Group Name: Tech Routers Members: Muhammad Ahtisham 2813 Nouman Chudhary 2463 Waqas Ahmad 2481 Junaid Pervaiz 2468 Umair Ilyas 2809 Jawad Mian 2490 Sohaib Raza 2497 Muhammad Waqas 2803
- 2. What Do Compilers Do (1) 2 A compiler acts as a translator, transforming human-oriented programming languages into computer-oriented machine languages. Ignore machine-dependent details for programmer Programming Language (Source) Compiler Machine Language (Target)
- 3. 3 Any compiler must perform two major tasks Analysis of the source program Synthesis of a machine-language program The Structure of a Compiler (1) Compiler Analysis Synthesis
- 4. Preprocessors, Compilers, Assemblers, and Linkers Preprocessor Compiler Assembler Linker Skeletal Source Program Source Program Target Assembly Program Relocatable Object Code Absolute Machine Code Libraries and Relocatable Object Files Try for example: gcc -v myprog.c
- 5. The Structure of a Compiler (2) 5 Scanner Parser Semantic Routines Code Generator Optimizer Source Program Tokens Syntactic Structure Symbol and Attribute Tables (Used by all Phases of The Compiler) (Character Stream) Intermediate Representation Target machine code
- 6. The Structure of a Compiler (3) 6 Scanner Parser Semantic Routines Code Generator Optimizer Source Program Tokens Syntactic Structure Symbol and Attribute Tables (Used by all Phases of The Compiler) Scanner The scanner begins the analysis of the source program by reading the input, character by character, and grouping characters into individual words and symbols (tokens) RE ( Regular expression ) NFA ( Non-deterministic Finite Automata ) DFA ( Deterministic Finite Automata ) (Character Stream) Intermediate Representation Target machine code
- 7. The Structure of a Compiler (4) 7 Scanner Parser Semantic Routines Code Generator Optimizer Source Program Tokens Syntactic Structure Symbol and Attribute Tables (Used by all Phases of The Compiler) Parser Given a formal syntax specification (typically as a context- free grammar [CFG] ), the parse reads tokens and groups them into units as specified by the productions of the CFG being used. As syntactic structure is recognized, the parser either calls corresponding semantic routines directly or builds a syntax tree. CFG ( Context-Free Grammar ) GAA ( Grammar Analysis Algorithms ) (Character Stream) Intermediate Representation Target machine code
- 8. The Structure of a Compiler (5) 8 Scanner Parser Semantic Routines Code Generator Optimizer Source Program (Character Stream) Tokens Syntactic Structure Intermediate Representation Symbol and Attribute Tables (Used by all Phases of The Compiler) Semantic Routines Perform two functions Check the static semantics of each construct Do the actual translation The heart of a compiler Syntax Directed Translation Semantic Processing Techniques IR (Intermediate Representation) Target machine code
- 9. The Structure of a Compiler (6) 9 Scanner Parser Semantic Routines Code Generator Optimizer Source Program Tokens Syntactic Structure Symbol and Attribute Tables (Used by all Phases of The Compiler) Optimizer The IR code generated by the semantic routines is analyzed and transformed into functionally equivalent but improved IR code This phase can be very complex and slow loop optimization, register allocation, code scheduling Register and Temporary Management (Character Stream) Intermediate Representation Target machine code
- 10. The Structure of a Compiler (7) 10 Source Program (Character Stream) Scanner Tokens Parser Syntactic Structure Semantic Routines Intermediate Representation Optimizer Code Generator Code Generator Interpretive Code Generation Generating Code from Tree/Dag Grammar-Based Code Generator Target machine code
- 11. The Structure of a Compiler (8) 11 Scanner [Lexical Analyzer] Parser [Syntax Analyzer] Semantic Process [Semantic analyzer] Code Generator [Intermediate Code Generator] Code Optimizer Tokens Parse tree Abstract Syntax Tree w/ Attributes Non-optimized Intermediate Code Optimized Intermediate Code Code Optimizer Target machine code