Introduction to Compiler Design Structutre, Phases
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This document provides an overview of compilers, including their structure, phases, and functions such as translation, analysis, and optimization. It explains the roles of language processors, compilers, and interpreters, detailing how they convert source code into executable target code. Key components like scanners, parsers, semantic routines, and code generators are also discussed in relation to their responsibilities in the compilation process.
![21
THE STRUCTURE OF A COMPILER (4)
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 )
BNF ( Backus-Naur Form )
GAA ( Grammar Analysis Algorithms )
LL, LR, SLR, LALR Parsers
YACC
(Character Stream)
Intermediate
Representation
Target machine code](https://image.slidesharecdn.com/samplecd-250126134400-54b47277/85/Introduction-to-Compiler-Design-Structutre-Phases-21-320.jpg)
![25
THE STRUCTURE OF A COMPILER (8)
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/samplecd-250126134400-54b47277/85/Introduction-to-Compiler-Design-Structutre-Phases-25-320.jpg)
Introduction to Compiler Design Structutre, Phases
- 2. Syllabus: Translator – Compilation and Interpretation, language processors; The phase of compiler – Errors Encountered in Different Phases, The Grouping of phases; Compiler Construction Tools; Programming Language Basics. SYLLABUS
- 3. TRANSLATOR Translator is a program that takes as input a program written in one programming language (the source language) and produces as output a program in another language (the object or target language).
- 4. COMPILER A compiler is a program that can read a program in one language, the source language, and translate it into an equivalent program in another language - the target language
- 5. If the target program is an executable machine- language program, it can then be called by the user to process inputs and produce outputs; Note:An important role of the compiler is to report any errors in the source program that it detects during the translation process.
- 6. INTERPRETER An interpreter is another common kind of language processor. Instead of producing a target program as a translation, an interpreter appears to directly execute the operations specified in the source program on inputs supplied by the user.
- 7. The machine-language target program produced by a compiler is usually much faster than an interpreter at mapping inputs to outputs . An interpreter, however, can usually give better error diagnostics than a compiler, because it executes the source program statement by statement
- 8. • Java language processors combine compilation and interpretation. • A Java source program may first be compiled into an intermediate form called bytecodes interpreted by virtual machine. compiled on one machine can be interpreted on another machine across a network Achieve faster processing of inputs to outputs: Java compilers, called just-in-time compilers, translate the bytecodes into machine language immediately before they run the intermediate program to process the input
- 11. • A source program may be divided into modules stored in separate files. • The task of collecting the source program is sometimes entrusted to a separate program, called a preprocessor. • The preprocessor may also expand shorthand's, called macros, into source language statements.
- 12. • The modified source program is then fed to a compiler. • The compiler may produce an assembly-language program as its output, because assembly language is easier to produce as output and is easier to debug.
- 13. • The assembly language is then processed by a program called an assembler that produces relocatable machine code as its output. • Large programs are often compiled in pieces, so the relocatable machine code may have to be linked together with other relocatable object files and library files into the code that actually runs on the machine.
- 14. • The linker resolves external memory addresses, where the code in one file may refer to a location in another file. • The loader then puts together all of the executable object files into memory for execution.
- 15. THE STRUCTURE OF A COMPILER • A compiler is treated as a single box that maps a source program into a semantically equivalent target program. • There are two parts to this mapping: analysis part and synthesis part • The analysis part is often called the front end of the compiler; the synthesis part is the back end of the compiler.
- 16. ANALYSIS It breaks up the source program into constituent pieces and imposes a grammatical structure on them. It detects that the source program is either syntactically ill formed or semantically unsound, then it must provide informative messages, so the user can take corrective action This structure to create an intermediate representation of the source program It also collects information about the source program and stores it in a data structure called a symbol table, which is passed along with the intermediate representation to the synthesis part
- 17. SYNTHESIS • In this part, it constructs the desired target program from the intermediate representation and the information in the symbol table
- 18. THE PHASES OF A COMPILER The symbol table, which stores information about the entire source program, is used by all phases of the compiler The purpose of this optimization phase is to perform transformations on the intermediate representation, the backend can produce a better target program
- 19. HOW DOES ITWORKING 19 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
- 20. 20 THE STRUCTURE OF A COMPILER (3) 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 ) LEX (Character Stream) Intermediate Representation Target machine code
- 21. 21 THE STRUCTURE OF A COMPILER (4) 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 ) BNF ( Backus-Naur Form ) GAA ( Grammar Analysis Algorithms ) LL, LR, SLR, LALR Parsers YACC (Character Stream) Intermediate Representation Target machine code
- 22. 22 THE STRUCTURE OF A COMPILER (5) 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
- 23. 23 THE STRUCTURE OF A COMPILER (6) 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 Peephole optimization loop optimization, register allocation, code scheduling Register and Temporary Management Peephole Optimization (Character Stream) Intermediate Representation Target machine code
- 24. 24 THE STRUCTURE OF A COMPILER (7) 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
- 25. 25 THE STRUCTURE OF A COMPILER (8) 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