This document provides an introduction to compilers. It discusses how compilers bridge the gap between high-level programming languages that are easier for humans to write in and machine languages that computers can actually execute. It describes the various phases of compilation like lexical analysis, syntax analysis, semantic analysis, code generation, and optimization. It also compares compilers to interpreters and discusses different types of translators like compilers, interpreters, and assemblers.
The document discusses lexical analysis in compilers. It describes how the lexical analyzer reads source code characters and divides them into tokens. Regular expressions are used to specify patterns for token recognition. The lexical analyzer generates a finite state automaton to recognize these patterns. Lexical analysis is the first phase of compilation that separates the input into tokens for the parser.
Topics Covered:
Linker: Types of Linker:
Loaders : Types of loader
Example of Translator, Link and Load Time Address
Object Module
Difference between Static and Dynamic Binding
Translator, Link and Load Time Address
Program Relocatability
This document discusses various techniques for optimizing computer code, including:
1. Local optimizations that improve performance within basic blocks, such as constant folding, propagation, and elimination of redundant computations.
2. Global optimizations that analyze control flow across basic blocks, such as common subexpression elimination.
3. Loop optimizations that improve performance of loops by removing invariant data and induction variables.
4. Machine-dependent optimizations like peephole optimizations that replace instructions with more efficient alternatives.
The goal of optimizations is to improve speed and efficiency while preserving program meaning and correctness. Optimizations can occur at multiple stages of development and compilation.
Functions allow programmers to break programs into smaller, reusable parts. There are two types of functions in C: library functions and user-defined functions. User-defined functions make programs easier to understand, debug, test and maintain. Functions are declared with a return type and can accept arguments. Functions can call other functions, allowing for modular and structured program design.
The purpose of types:
To define what the program should do.
e.g. read an array of integers and return a double
To guarantee that the program is meaningful.
that it does not add a string to an integer
that variables are declared before they are used
To document the programmer's intentions.
better than comments, which are not checked by the compiler
To optimize the use of hardware.
reserve the minimal amount of memory, but not more
use the most appropriate machine instructions.
The role of the parser and Error recovery strategies ppt in compiler designSadia Akter
This document summarizes error recovery strategies used by parsers. It discusses the role of parsers in validating syntax based on grammars and producing parse trees. It then describes several error recovery strategies like panic-mode recovery, phrase-level recovery using local corrections, adding error productions to the grammar, and global correction aiming to make minimal changes to parse invalid inputs.
The document provides an introduction to compiler construction including:
1. The objectives of understanding how to build a compiler, use compiler construction tools, understand assembly code and virtual machines, and define grammars.
2. An overview of compilers and interpreters including the analysis-synthesis model of compilation where analysis determines operations from the source program and synthesis translates those operations into the target program.
3. An outline of the phases of compilation including preprocessing, compiling, assembling, and linking source code into absolute machine code using tools like scanners, parsers, syntax-directed translation, and code generators.
The document discusses lexical analysis in compilers. It describes how the lexical analyzer reads source code characters and divides them into tokens. Regular expressions are used to specify patterns for token recognition. The lexical analyzer generates a finite state automaton to recognize these patterns. Lexical analysis is the first phase of compilation that separates the input into tokens for the parser.
Topics Covered:
Linker: Types of Linker:
Loaders : Types of loader
Example of Translator, Link and Load Time Address
Object Module
Difference between Static and Dynamic Binding
Translator, Link and Load Time Address
Program Relocatability
This document discusses various techniques for optimizing computer code, including:
1. Local optimizations that improve performance within basic blocks, such as constant folding, propagation, and elimination of redundant computations.
2. Global optimizations that analyze control flow across basic blocks, such as common subexpression elimination.
3. Loop optimizations that improve performance of loops by removing invariant data and induction variables.
4. Machine-dependent optimizations like peephole optimizations that replace instructions with more efficient alternatives.
The goal of optimizations is to improve speed and efficiency while preserving program meaning and correctness. Optimizations can occur at multiple stages of development and compilation.
Functions allow programmers to break programs into smaller, reusable parts. There are two types of functions in C: library functions and user-defined functions. User-defined functions make programs easier to understand, debug, test and maintain. Functions are declared with a return type and can accept arguments. Functions can call other functions, allowing for modular and structured program design.
The purpose of types:
To define what the program should do.
e.g. read an array of integers and return a double
To guarantee that the program is meaningful.
that it does not add a string to an integer
that variables are declared before they are used
To document the programmer's intentions.
better than comments, which are not checked by the compiler
To optimize the use of hardware.
reserve the minimal amount of memory, but not more
use the most appropriate machine instructions.
The role of the parser and Error recovery strategies ppt in compiler designSadia Akter
This document summarizes error recovery strategies used by parsers. It discusses the role of parsers in validating syntax based on grammars and producing parse trees. It then describes several error recovery strategies like panic-mode recovery, phrase-level recovery using local corrections, adding error productions to the grammar, and global correction aiming to make minimal changes to parse invalid inputs.
The document provides an introduction to compiler construction including:
1. The objectives of understanding how to build a compiler, use compiler construction tools, understand assembly code and virtual machines, and define grammars.
2. An overview of compilers and interpreters including the analysis-synthesis model of compilation where analysis determines operations from the source program and synthesis translates those operations into the target program.
3. An outline of the phases of compilation including preprocessing, compiling, assembling, and linking source code into absolute machine code using tools like scanners, parsers, syntax-directed translation, and code generators.
This document provides information about the CS416 Compiler Design course, including the instructor details, prerequisites, textbook, grading breakdown, course outline, and an overview of the major parts and phases of a compiler. The course will cover topics such as lexical analysis, syntax analysis using top-down and bottom-up parsing, semantic analysis using attribute grammars, intermediate code generation, code optimization, and code generation.
Syntax analysis is the second phase of compiler design after lexical analysis. The parser checks if the input string follows the rules and structure of the formal grammar. It builds a parse tree to represent the syntactic structure. If the input string can be derived from the parse tree using the grammar, it is syntactically correct. Otherwise, an error is reported. Parsers use various techniques like panic-mode, phrase-level, and global correction to handle syntax errors and attempt to continue parsing. Context-free grammars are commonly used with productions defining the syntax rules. Derivations show the step-by-step application of productions to generate the input string from the start symbol.
The document discusses run-time environments and how compilers support program execution through run-time environments. It covers:
1) The compiler cooperates with the OS and system software through a run-time environment to implement language abstractions during execution.
2) The run-time environment handles storage layout/allocation, variable access, procedure linkage, parameter passing and interfacing with the OS.
3) Memory is typically divided into code, static storage, heap and stack areas, with the stack and heap growing towards opposite ends of memory dynamically during execution.
This document discusses compiler design and how compilers work. It begins with prerequisites and definitions of compilers and their origins. It then describes the architecture of compilers, including lexical analysis, parsing, semantic analysis, code optimization, and code generation. It explains how compilers translate high-level code into machine-executable code. In conclusions, it summarizes that compilers translate code without changing meaning and aim to make code efficient. References for further reading on compiler design principles are also provided.
Syntax directed translation allows semantic information to be associated with a formal language by attaching attributes to grammar symbols and defining semantic rules. There are several types of attributes including synthesized and inherited. Syntax directed definitions specify attribute values using semantic rules associated with grammar productions. Evaluation of attributes requires determining an order such as a topological sort of a dependency graph. Syntax directed translation schemes embed program fragments called semantic actions within grammar productions. Actions can be placed inside or at the ends of productions. Various parsing strategies like bottom-up can be used to execute the actions at appropriate times during parsing.
The document discusses stack and heap allocation in a program's memory. The stack grows upwards and stores local variables and temporary data. The heap grows downwards and is used to allocate memory dynamically when the size is unknown. Pointers store the address of dynamically allocated variables on the heap. Arrays can also be allocated on the heap using new and deleted using delete to free up memory. Care must be taken to avoid deleting unallocated pointers or accessing deleted memory.
This produced by straight forward compiling algorithms made to run faster or less space or both. This improvement is achieved by program transformations that are traditionally called optimizations.compiler that apply-code improving transformation are called optimizing compilers.
There are several mechanisms for inter-process communication (IPC) in UNIX systems, including message queues, shared memory, and semaphores. Message queues allow processes to exchange data by placing messages into a queue that can be accessed by other processes. Shared memory allows processes to communicate by declaring a section of memory that can be accessed simultaneously. Semaphores are used to synchronize processes so they do not access critical sections at the same time.
Compiler construction tools were introduced to aid in the development of compilers. These tools include scanner generators, parser generators, syntax-directed translation engines, and automatic code generators. Scanner generators produce lexical analyzers based on regular expressions to recognize tokens. Parser generators take context-free grammars as input to produce syntax analyzers. Syntax-directed translation engines associate translations with parse trees to generate intermediate code. Automatic code generators take intermediate code as input and output machine language. These tools help automate and simplify the compiler development process.
A parser is a program component that breaks input data into smaller elements according to the rules of a formal grammar. It builds a parse tree representing the syntactic structure of the input based on these grammar rules. There are two main types of parsers: top-down parsers start at the root of the parse tree and work downward, while bottom-up parsers start at the leaves and work upward. Parser generators use attributes like First and Follow to build parsing tables for predictive parsers like LL(1) parsers, which parse input from left to right based on a single lookahead token.
This document provides an overview of parallel programming with OpenMP. It discusses how OpenMP allows users to incrementally parallelize serial C/C++ and Fortran programs by adding compiler directives and library functions. OpenMP is based on the fork-join model where all programs start as a single thread and additional threads are created for parallel regions. Core OpenMP elements include parallel regions, work-sharing constructs like #pragma omp for to parallelize loops, and clauses to control data scoping. The document provides examples of using OpenMP for tasks like matrix-vector multiplication and numerical integration. It also covers scheduling, handling race conditions, and other runtime functions.
The document discusses the role and implementation of a lexical analyzer in compilers. A lexical analyzer is the first phase of a compiler that reads source code characters and generates a sequence of tokens. It groups characters into lexemes and determines the tokens based on patterns. A lexical analyzer may need to perform lookahead to unambiguously determine tokens. It associates attributes with tokens, such as symbol table entries for identifiers. The lexical analyzer and parser interact through a producer-consumer relationship using a token buffer.
To make this comparison we need to first consider the problem that both approaches help us to solve. When programming any system you are essentially dealing with data and the code that changes that data. These two fundamental aspects of programming are handled quite differently in procedural systems compared with object oriented systems, and these differences require different strategies in how we think about writing code.
The document provides an overview of compilers by discussing:
1. Compilers translate source code into executable target code by going through several phases including lexical analysis, syntax analysis, semantic analysis, code optimization, and code generation.
2. An interpreter directly executes source code statement by statement while a compiler produces target code as translation. Compiled code generally runs faster than interpreted code.
3. The phases of a compiler include a front end that analyzes the source code and produces intermediate code, and a back end that optimizes and generates the target code.
The document provides information about regular expressions and finite automata. It discusses how regular expressions are used to describe programming language tokens. It explains how regular expressions map to languages and the basic operations used to build regular expressions like concatenation, alternation, and Kleene closure. The document also discusses deterministic finite automata (DFAs), non-deterministic finite automata (NFAs), and algorithms for converting regular expressions to NFAs and DFAs. It covers minimizing DFAs and using finite automata for lexical analysis in scanners.
This document summarizes key topics in intermediate code generation discussed in Chapter 6, including:
1) Variants of syntax trees like DAGs are introduced to share common subexpressions. Three-address code is also discussed where each instruction has at most three operands.
2) Type checking and type expressions are covered, along with translating expressions and statements to three-address code. Control flow statements like if/else are also translated using techniques like backpatching.
3) Backpatching allows symbolic labels in conditional jumps to be resolved by a later pass that inserts actual addresses, avoiding an extra pass. This and other control flow translation topics are covered.
The document discusses the different phases of a compiler: lexical analysis, syntax analysis, semantic analysis, intermediate code generation, code optimization, and code generation. It explains that a compiler takes source code as input and translates it into an equivalent language. The compiler performs analysis and synthesis in multiple phases, with each phase transforming the representation of the source code. Key activities include generating tokens, building a syntax tree, type checking, generating optimized intermediate code, and finally producing target machine code. Symbol tables are also used to store identifier information as the compiler runs.
The document provides an introduction to compiler design, including:
- A compiler converts a program written in a high-level language into machine code. It can run on a different machine than the target.
- Language processing systems like compilers transform high-level code into a form usable by machines through a series of translations.
- A compiler analyzes source code in two main phases - analysis and synthesis. The analysis phase creates an intermediate representation, and the synthesis phase generates target code from that.
The compiler is software that converts source code written in a high-level language into machine code. It works in two major phases - analysis and synthesis. The analysis phase performs lexical analysis, syntax analysis, and semantic analysis to generate an intermediate representation from the source code. The synthesis phase performs code optimization and code generation to create the target machine code from the intermediate representation. The compiler uses various components like a symbol table, parser, and code generator to perform this translation.
This document provides information about the CS416 Compiler Design course, including the instructor details, prerequisites, textbook, grading breakdown, course outline, and an overview of the major parts and phases of a compiler. The course will cover topics such as lexical analysis, syntax analysis using top-down and bottom-up parsing, semantic analysis using attribute grammars, intermediate code generation, code optimization, and code generation.
Syntax analysis is the second phase of compiler design after lexical analysis. The parser checks if the input string follows the rules and structure of the formal grammar. It builds a parse tree to represent the syntactic structure. If the input string can be derived from the parse tree using the grammar, it is syntactically correct. Otherwise, an error is reported. Parsers use various techniques like panic-mode, phrase-level, and global correction to handle syntax errors and attempt to continue parsing. Context-free grammars are commonly used with productions defining the syntax rules. Derivations show the step-by-step application of productions to generate the input string from the start symbol.
The document discusses run-time environments and how compilers support program execution through run-time environments. It covers:
1) The compiler cooperates with the OS and system software through a run-time environment to implement language abstractions during execution.
2) The run-time environment handles storage layout/allocation, variable access, procedure linkage, parameter passing and interfacing with the OS.
3) Memory is typically divided into code, static storage, heap and stack areas, with the stack and heap growing towards opposite ends of memory dynamically during execution.
This document discusses compiler design and how compilers work. It begins with prerequisites and definitions of compilers and their origins. It then describes the architecture of compilers, including lexical analysis, parsing, semantic analysis, code optimization, and code generation. It explains how compilers translate high-level code into machine-executable code. In conclusions, it summarizes that compilers translate code without changing meaning and aim to make code efficient. References for further reading on compiler design principles are also provided.
Syntax directed translation allows semantic information to be associated with a formal language by attaching attributes to grammar symbols and defining semantic rules. There are several types of attributes including synthesized and inherited. Syntax directed definitions specify attribute values using semantic rules associated with grammar productions. Evaluation of attributes requires determining an order such as a topological sort of a dependency graph. Syntax directed translation schemes embed program fragments called semantic actions within grammar productions. Actions can be placed inside or at the ends of productions. Various parsing strategies like bottom-up can be used to execute the actions at appropriate times during parsing.
The document discusses stack and heap allocation in a program's memory. The stack grows upwards and stores local variables and temporary data. The heap grows downwards and is used to allocate memory dynamically when the size is unknown. Pointers store the address of dynamically allocated variables on the heap. Arrays can also be allocated on the heap using new and deleted using delete to free up memory. Care must be taken to avoid deleting unallocated pointers or accessing deleted memory.
This produced by straight forward compiling algorithms made to run faster or less space or both. This improvement is achieved by program transformations that are traditionally called optimizations.compiler that apply-code improving transformation are called optimizing compilers.
There are several mechanisms for inter-process communication (IPC) in UNIX systems, including message queues, shared memory, and semaphores. Message queues allow processes to exchange data by placing messages into a queue that can be accessed by other processes. Shared memory allows processes to communicate by declaring a section of memory that can be accessed simultaneously. Semaphores are used to synchronize processes so they do not access critical sections at the same time.
Compiler construction tools were introduced to aid in the development of compilers. These tools include scanner generators, parser generators, syntax-directed translation engines, and automatic code generators. Scanner generators produce lexical analyzers based on regular expressions to recognize tokens. Parser generators take context-free grammars as input to produce syntax analyzers. Syntax-directed translation engines associate translations with parse trees to generate intermediate code. Automatic code generators take intermediate code as input and output machine language. These tools help automate and simplify the compiler development process.
A parser is a program component that breaks input data into smaller elements according to the rules of a formal grammar. It builds a parse tree representing the syntactic structure of the input based on these grammar rules. There are two main types of parsers: top-down parsers start at the root of the parse tree and work downward, while bottom-up parsers start at the leaves and work upward. Parser generators use attributes like First and Follow to build parsing tables for predictive parsers like LL(1) parsers, which parse input from left to right based on a single lookahead token.
This document provides an overview of parallel programming with OpenMP. It discusses how OpenMP allows users to incrementally parallelize serial C/C++ and Fortran programs by adding compiler directives and library functions. OpenMP is based on the fork-join model where all programs start as a single thread and additional threads are created for parallel regions. Core OpenMP elements include parallel regions, work-sharing constructs like #pragma omp for to parallelize loops, and clauses to control data scoping. The document provides examples of using OpenMP for tasks like matrix-vector multiplication and numerical integration. It also covers scheduling, handling race conditions, and other runtime functions.
The document discusses the role and implementation of a lexical analyzer in compilers. A lexical analyzer is the first phase of a compiler that reads source code characters and generates a sequence of tokens. It groups characters into lexemes and determines the tokens based on patterns. A lexical analyzer may need to perform lookahead to unambiguously determine tokens. It associates attributes with tokens, such as symbol table entries for identifiers. The lexical analyzer and parser interact through a producer-consumer relationship using a token buffer.
To make this comparison we need to first consider the problem that both approaches help us to solve. When programming any system you are essentially dealing with data and the code that changes that data. These two fundamental aspects of programming are handled quite differently in procedural systems compared with object oriented systems, and these differences require different strategies in how we think about writing code.
The document provides an overview of compilers by discussing:
1. Compilers translate source code into executable target code by going through several phases including lexical analysis, syntax analysis, semantic analysis, code optimization, and code generation.
2. An interpreter directly executes source code statement by statement while a compiler produces target code as translation. Compiled code generally runs faster than interpreted code.
3. The phases of a compiler include a front end that analyzes the source code and produces intermediate code, and a back end that optimizes and generates the target code.
The document provides information about regular expressions and finite automata. It discusses how regular expressions are used to describe programming language tokens. It explains how regular expressions map to languages and the basic operations used to build regular expressions like concatenation, alternation, and Kleene closure. The document also discusses deterministic finite automata (DFAs), non-deterministic finite automata (NFAs), and algorithms for converting regular expressions to NFAs and DFAs. It covers minimizing DFAs and using finite automata for lexical analysis in scanners.
This document summarizes key topics in intermediate code generation discussed in Chapter 6, including:
1) Variants of syntax trees like DAGs are introduced to share common subexpressions. Three-address code is also discussed where each instruction has at most three operands.
2) Type checking and type expressions are covered, along with translating expressions and statements to three-address code. Control flow statements like if/else are also translated using techniques like backpatching.
3) Backpatching allows symbolic labels in conditional jumps to be resolved by a later pass that inserts actual addresses, avoiding an extra pass. This and other control flow translation topics are covered.
The document discusses the different phases of a compiler: lexical analysis, syntax analysis, semantic analysis, intermediate code generation, code optimization, and code generation. It explains that a compiler takes source code as input and translates it into an equivalent language. The compiler performs analysis and synthesis in multiple phases, with each phase transforming the representation of the source code. Key activities include generating tokens, building a syntax tree, type checking, generating optimized intermediate code, and finally producing target machine code. Symbol tables are also used to store identifier information as the compiler runs.
The document provides an introduction to compiler design, including:
- A compiler converts a program written in a high-level language into machine code. It can run on a different machine than the target.
- Language processing systems like compilers transform high-level code into a form usable by machines through a series of translations.
- A compiler analyzes source code in two main phases - analysis and synthesis. The analysis phase creates an intermediate representation, and the synthesis phase generates target code from that.
The compiler is software that converts source code written in a high-level language into machine code. It works in two major phases - analysis and synthesis. The analysis phase performs lexical analysis, syntax analysis, and semantic analysis to generate an intermediate representation from the source code. The synthesis phase performs code optimization and code generation to create the target machine code from the intermediate representation. The compiler uses various components like a symbol table, parser, and code generator to perform this translation.
This document provides an overview of the key components and phases of a compiler. It discusses that a compiler translates a program written in a source language into an equivalent program in a target language. The main phases of a compiler are lexical analysis, syntax analysis, semantic analysis, intermediate code generation, code optimization, code generation, and symbol table management. Each phase performs important processing that ultimately results in a program in the target language that is equivalent to the original source program.
Translation of a program written in a source language into a semantically equivalent program written in a target language
It also reports to its users the presence of errors in the source program
The document provides an introduction to compilers, including definitions of key terms like compiler, interpreter, assembler, translator, and phases of compilation like lexical analysis, syntax analysis, semantic analysis, code generation, and optimization. It also discusses compiler types like native compilers, cross compilers, source-to-source compilers, and just-in-time compilers. The phases of a compiler include breaking down a program, generating intermediate code, optimizing, and creating target code.
The document provides an overview of the compilation process and the different phases involved in compiler construction. It can be summarized as follows:
1. A compiler translates a program written in a source language into an equivalent program in a target language. It performs analysis, synthesis and error checking during this translation process.
2. The major phases of a compiler include lexical analysis, syntax analysis, semantic analysis, intermediate code generation, code optimization, code generation and linking. Tools like Lex and Yacc are commonly used to generate lexical and syntax analyzers.
3. Regular expressions are used to specify patterns for tokens during lexical analysis. A lexical analyzer reads the source program and generates a sequence of tokens by matching character sequences to patterns
The document summarizes the key phases of a compiler:
1. The compiler takes source code as input and goes through several phases including lexical analysis, syntax analysis, semantic analysis, code optimization, and code generation to produce machine code as output.
2. Lexical analysis converts the source code into tokens, syntax analysis checks the grammar and produces a parse tree, and semantic analysis validates meanings.
3. Code optimization improves the intermediate code before code generation translates it into machine instructions.
Pros and cons of c as a compiler languageAshok Raj
Computer system is made of hardware and software .The hardware understands instructions in the form of electronic charge or binary language in Software programming. So the programs written in High Level Language are fed into a series of tools and OS components to get the desired machine language.This is known as Language Processing System.
This document provides an introduction to programming concepts such as algorithms, pseudocode, and flowcharts. It defines computer programming as the process of writing code to instruct a computer, and explains that programming languages allow users to communicate instructions to computers. The document outlines different types of computer languages including low-level languages like machine language and assembly language, and high-level languages like procedural, functional, and object-oriented languages. It also discusses specialized languages, translator programs, and program logic design tools for solving problems algorithmically through pseudocode and flowcharts.
This document provides an overview of compilers, including their structure and purpose. It discusses:
- What a compiler is and its main functions of analysis and synthesis.
- The history and need for compilers, from early assembly languages to modern high-level languages.
- The structure of a compiler, including lexical analysis, syntax analysis, semantic analysis, code optimization, and code generation.
- Different types of translators like interpreters, assemblers, and linkers.
- Tools that help in compiler construction like scanner generators, parser generators, and code generators.
We have learnt that any computer system is made of hardware and software.
The hardware understands a language, which humans cannot understand. So we write programs in high-level language, which is easier for us to understand and remember.
These programs are then fed into a series of tools and OS components to get the desired code that can be used by the machine.
This is known as Language Processing System.
This document provides an overview of compiler design and the phases of a compiler. It discusses how compilers translate programs written in high-level languages into machine-executable code. The main phases of a compiler are lexical analysis, syntax analysis, code generation, and optional optimization phases. Lexical analysis breaks the source code into tokens. Syntax analysis checks for errors and determines the program structure. Code generation translates the program into machine code. Optimization aims to improve efficiency. Interpreters execute programs line-by-line rather than generating machine code.
This document provides an introduction to compilers, including definitions of key terms like translator, compiler, interpreter, and assembler. It describes the main phases of compilation as lexical analysis, syntax analysis, semantic analysis, intermediate code generation, code optimization, and code generation. It also discusses related concepts like the front-end and back-end of a compiler, multi-pass compilation, and different types of compilers.
Introduction to programming language (basic)nharsh2308
This document provides an introduction to programming topics including algorithms, pseudocode, flowcharts, programming languages, compilers, interpreters, testing, debugging and documentation. It discusses the basic model of computation involving understanding requirements, inputs/outputs, designing program layout and output, selecting techniques, and testing. Algorithms are defined as ordered sequences of operations to solve a problem. Pseudocode and flowcharts are used to represent program logic without real syntax. Programming languages are categorized as low-level (machine code) or high-level, with compilers and interpreters used to translate high-level languages. Testing and debugging involve inputting data to find and fix errors. Documentation records the development process for users.
Compilers, interpreters, linkers, preprocessors, and virtual machines are tools used in the software development process. Compilers translate source code to machine code while interpreters translate each line to an intermediate form before executing. Linkers combine object files into an executable. Preprocessors modify source code based on directives. Virtual machines run isolated software environments like physical computers through encapsulation and hardware independence. They provide benefits such as portability, security, and allowing multiple environments on one machine.
The document discusses compilers and their role in translating high-level programming languages into machine-readable code. It notes that compilers perform several key functions: lexical analysis, syntax analysis, generation of an intermediate representation, optimization of the intermediate code, and finally generation of assembly or machine code. The compiler allows programmers to write code in a high-level language that is easier for humans while still producing efficient low-level code that computers can execute.
This document provides an overview of compiler design, including:
- The history and importance of compilers in translating high-level code to machine-level code.
- The main components of a compiler including the front-end (analysis), back-end (synthesis), and tools used in compiler construction.
- Key phases of compilation like lexical analysis, syntax analysis, semantic analysis, code optimization, and code generation.
- Types of translators like interpreters, assemblers, cross-compilers and their functions.
- Compiler construction tools that help generate scanners, parsers, translation engines, code generators, and data flow analysis.
The document describes the phases of a compiler. It discusses lexical analysis, syntax analysis, semantic analysis, intermediate code generation, code optimization and code generation.
Lexical analysis scans the source code and returns tokens. Syntax analysis builds an abstract syntax tree from tokens using a context-free grammar. Semantic analysis checks for semantic errors and annotates the tree with types. Intermediate code generation converts the syntax tree to an intermediate representation like 3-address code. Code generation outputs machine or assembly code from the intermediate code.
Cricket management system ptoject report.pdfKamal Acharya
The aim of this project is to provide the complete information of the National and
International statistics. The information is available country wise and player wise. By
entering the data of eachmatch, we can get all type of reports instantly, which will be
useful to call back history of each player. Also the team performance in each match can
be obtained. We can get a report on number of matches, wins and lost.
This is an overview of my current metallic design and engineering knowledge base built up over my professional career and two MSc degrees : - MSc in Advanced Manufacturing Technology University of Portsmouth graduated 1st May 1998, and MSc in Aircraft Engineering Cranfield University graduated 8th June 2007.
Sri Guru Hargobind Ji - Bandi Chor Guru.pdfBalvir Singh
Sri Guru Hargobind Ji (19 June 1595 - 3 March 1644) is revered as the Sixth Nanak.
• On 25 May 1606 Guru Arjan nominated his son Sri Hargobind Ji as his successor. Shortly
afterwards, Guru Arjan was arrested, tortured and killed by order of the Mogul Emperor
Jahangir.
• Guru Hargobind's succession ceremony took place on 24 June 1606. He was barely
eleven years old when he became 6th Guru.
• As ordered by Guru Arjan Dev Ji, he put on two swords, one indicated his spiritual
authority (PIRI) and the other, his temporal authority (MIRI). He thus for the first time
initiated military tradition in the Sikh faith to resist religious persecution, protect
people’s freedom and independence to practice religion by choice. He transformed
Sikhs to be Saints and Soldier.
• He had a long tenure as Guru, lasting 37 years, 9 months and 3 days
Covid Management System Project Report.pdfKamal Acharya
CoVID-19 sprang up in Wuhan China in November 2019 and was declared a pandemic by the in January 2020 World Health Organization (WHO). Like the Spanish flu of 1918 that claimed millions of lives, the COVID-19 has caused the demise of thousands with China, Italy, Spain, USA and India having the highest statistics on infection and mortality rates. Regardless of existing sophisticated technologies and medical science, the spread has continued to surge high. With this COVID-19 Management System, organizations can respond virtually to the COVID-19 pandemic and protect, educate and care for citizens in the community in a quick and effective manner. This comprehensive solution not only helps in containing the virus but also proactively empowers both citizens and care providers to minimize the spread of the virus through targeted strategies and education.
An In-Depth Exploration of Natural Language Processing: Evolution, Applicatio...DharmaBanothu
Natural language processing (NLP) has
recently garnered significant interest for the
computational representation and analysis of human
language. Its applications span multiple domains such
as machine translation, email spam detection,
information extraction, summarization, healthcare,
and question answering. This paper first delineates
four phases by examining various levels of NLP and
components of Natural Language Generation,
followed by a review of the history and progression of
NLP. Subsequently, we delve into the current state of
the art by presenting diverse NLP applications,
contemporary trends, and challenges. Finally, we
discuss some available datasets, models, and
evaluation metrics in NLP.
2. Introduction
• In order to reduce the complexity of designing and
building computers, made to execute relatively simple
commands
• combining these very simple commands into a program in
what is called machine language
• . Since this is a tedious and error-prone process most
programming is, instead, done using a high-level
programming language
• . This language can be very different from the machine
language that the computer can execute, so some means of
bridging the gap is required.
• This is where the compiler comes in.
3. Contd.,
• Using a high-level language for programming has a large impact
on how fast programs can be developed.
• The main reasons for this are:
• Compared to machine language, the notation used by
programming languages is closer to the way humans think about
problems.
• The compiler can spot some obvious programming mistakes.
• Programs written in a high-level language tend to be shorter
than equivalent programs written in machine language.
• Another advantage of using a high-level level language is:
the same program can be compiled to many different machine
languages and, hence, run on many different machines.
4. Translator
• A program written in high-level language is called as
source code. To convert the source code into machine
code, translators are needed.
• A translator takes a program written in source language as
input and converts it into a program in target language as
output.
• It also detects and reports the error during translation.
Roles of translator are:
• Translating the high-level language program input into an
equivalent machine language program.
• Providing diagnostic messages wherever the programmer
violates specification of the high-level language program.
5. Different type of translators
Compiler
Compiler is a translator which is used to convert programs in high-level
language to low-level language. It translates the entire program and also
reports the errors in source program encountered during the translation.
Interpreter
• Interpreter is a translator which is used to convert programs in high-level
language to low-level language. Interpreter translates line by line and
reports the error once it encountered during the translation process.
• It directly executes the operations specified in the source program when the
input is given by the user.
• It gives better error diagnostics than a compiler.
6. • Assembler
Assembler is a translator which is used to
translate the assembly language code into
machine language code.
7. S.No. Compiler Interpreter
1 Performs the translation
of a program as a
whole.
Performs statement by
statement translation.
2 Execution is faster. Execution is slower.
3 Requires more memory
as linking is needed for
the generated
intermediate object
code.
Memory usage is efficient as no
intermediate object code is
generated.
4 Debugging is hard as
the error messages are
generated after scanning
the entire program only.
It stops translation when the first
error is met. Hence, debugging
is easy.
5 Programming languages
like C, C++ uses
compilers.
Programming languages like
Python, BASIC, and Ruby uses
interpreters.
8. Why learn about compilers?
a) It is considered a topic that you should know in order to be
“well-cultured” in computer science.
b) A good craftsman should know his tools, and compilers are
important tools for programmers and computer scientists.
c) The techniques used for constructing a compiler are useful
for other purposes as well.
d) There is a good chance that a programmer or computer
scientist will need to write a compiler or interpreter for a
domain-specific language
9. Compilers and Interpreters
• “Compilation”
– Translation of a program written in a source
language into a semantically equivalent
program written in a target language
Compiler
Error messages
Source
Program
Target
Program
Input
Output
11. The Analysis-Synthesis Model of
Compilation
• There are two parts to compilation:
– Analysis determines the operations implied by
the source program which are recorded in a tree
structure
– Synthesis takes the tree structure and translates
the operations therein into the target program
12. Other Tools that Use the
Analysis-Synthesis Model
• Editors (syntax highlighting)
• Pretty printers (e.g. Doxygen)
• Static checkers (e.g. Lint and Splint)
• Interpreters
• Text formatters (e.g. TeX and LaTeX)
• Silicon compilers (e.g. VHDL)
• Query interpreters/compilers (Databases)
14. Language Processing System
Preprocessor :
• A preprocessor, generally considered as a part of
compiler, is a tool that produces input for compilers.
• It deals with macro-processing, augmentation, file
inclusion, language extension, etc.
Compiler: A compiler, translates high-level language into
low-level machine language
Assembler:
• An assembler translates assembly language programs
into machine code.
• The output of an assembler is called an object file,
which contains a combination of machine
instructions as well as the data required to place
these instructions in memory.
15. Contd.,
Loader:
• Loader is a part of operating system and is
responsible for loading executable files into memory
and execute them.
• It calculates the size of a program instructions and
data and creates memory space for it.
• Cross-compiler: A compiler that runs on platform A
and is capable of generating executable code for
platform B is called a cross-compiler.
• Source-to-source Compiler: A compiler that takes the
source code of one programming language and
translates it into the source code of another
programming language is called a source-to-source
compiler.
16. example
How a program, using C compiler, is executed on
a host machine.
• User writes a program in C language (high-level
language).
• The C compiler, compiles the program and
translates it to assembly program (low-level
language).
• An assembler then translates the assembly
program into machine code (object).
• A linker tool is used to link all the parts of the
program together for execution (executable
machine code).
• A loader loads all of them into memory and
then the program is executed
17. The Grouping of Phases
• Compiler front and back ends:
– Front end: analysis (machine independent)
– Back end: synthesis (machine dependent)
• Compiler passes:
– A collection of phases is done only once (single pass)
or multiple times (multi pass)
• Single pass: usually requires everything to be defined before
being used in source program
• Multi pass: compiler may have to keep entire program
representation in memory
18. Phases of compiler
• Lexical Analysis
A token is a string of characters, categorized according to
the rules as a symbol (e.g. IDENTIFIER,
NUMBER, COMMA, etc.).
The process of forming tokens from an input stream of
characters is called tokenization
and the lexer categorizes them according to symbol
type.
A token can look like anything that is useful for
processing an input text stream or text file.
19. Contd.,
• A lexical analyzer generally does nothing with combinations of
tokens, a task left for a parser. For example, a typical lexical
analyzer recognizes parenthesis as tokens, but does nothing to
ensure that each '(' is matched with a ')'.
• In a compiler, linear analysis is called lexical analysis or scanning.
For example, in lexical analysis
the characters in the assignment statement: Position: = initial + rate ∗ 60
would be grouped into the following tokens:
1. The identifier position.
2. The assignment symbol : =
3. The identifier initial.
4. The plus sign +
5. The identifier 𝐫𝐚𝐭𝐞.
6. The multiplication sign
7. The number 60
The blanks separating the characters of these tokens would be eliminated
20. Syntax Analysis
• Hierarchical analysis is called parsing or syntax
analysis.
• It involves grouping the tokens of the source
program into grammatical phrases that are used by
the compiler to synthesize output.
• Usually, the grammatical phrases of the source
program are represented by a parse tree
21. • The hierarchical structure of a program is usually expressed
by recursive rules.
• For example, we might have the following rules as part of the
definition of expressions:
1. Any identifier is an expression.
2. Any number is an expression.
3. If expression1 and expression2 are expressions, then so are
expression1 + expression2
expression1 ∗ expression2
(expression1)
Rules (1) and (2) are non-recursive basic rules, while (3) defines
expressions in terms of operators applied to other expressions.
Thus, by rule (1), initial and rate are expressions.
By rule (2), 60 is an expression, while by rule (3), we can first
infer that rate∗60 is an expression and finally that initial +
rate∗60 is an expression.
22. Semantic Analysis
• The semantic analysis phase checks the source program for
semantic errors and gathers type information for the subsequent
code-generation phase.
• It uses the hierarchical structure determined by the syntax-analysis
phase to identify the operators and operands of expressions and
statements.
• An important component of semantic analysis is type checking.
• Here the compiler checks that each operator has operands that are
permitted by the source language specification.
• For example, many programming language definitions require a
compiler to report an error every time a real number is used to
index an array.
• However, the language specification may permit some operand
corrections,
• for example, when binary arithmetic operator is applied to an
integer and real.
• In this case, the compiler may need to convert the integer to a real.
25. • The six phases of compilation: lexical analysis, syntax
analysis, semantic analysis, intermediate code
generation, code optimization, and code generation.
• The 6 phases divided into 2 Groups:
1. Front End: Depends on stream of tokens and parse tree
2. Back End: Dependent on Target, Independent of source
code
Symbol-Table Management:
• A symbol table is a data structure containing a record for
each identifier, with fields for the attributes of the
identifier.
• The data structure allows us to find the record for each
identifier quickly and to store or retrieve data from that
record quickly.
• Symbol table is a Data Structure in a Compiler used for
Managing information about variables & their attributes.
26. Error Detection and Reporting
• Each phase can encounter errors.
• However, after detecting an error, a phase must somehow
deal with that error, so that compilation can proceed,
allowing further errors in the source program to be
detected.
• A compiler that stops when it finds the first error is not as
helpful as it could be.
• The syntax and semantic analysis phases usually handle a
large fraction of the errors detectable by the compiler.
• The lexical phase can detect errors where the characters
remaining in the input do not form any token of the
language.
• Errors where the token stream violates the structure rules
(syntax) of the language are determined by the syntax
analysis phase.
27. • Intermediate Code Generations:-
• An intermediate representation of the final machine
language code is produced.
• This phase bridges the analysis and synthesis phases of
translation.
• Code Optimization :-
• This is optional phase described to improve the intermediate
code so that the output runs faster and takes less space.
• Code Generation:-
• The last phase of translation is code generation. A number
of optimizations to reduce the length of machine language
program are carried out during this phase.
• The output of the code generator is the machine language
program of the specified computer.
28.
29. Compiler construction tools
1. Parser generators.
2. Scanner generators.
3. Syntax-directed translation engines.
4. Automatic code generators.
5. Data-flow analysis engines.
6. Compiler-construction toolkits.
Parser Generators
• Input: Grammatical description of a programming
language
Output: Syntax analyzers.
• Parser generator takes the grammatical description
of a programming language and produces a syntax
analyzer.
30. Scanner Generators
• Input: Regular expression description of the tokens of a
language
Output: Lexical analyzers.
• Scanner generator generates lexical analyzers from a regular
expression description of the tokens of a language.
Syntax-directed Translation Engines
• Input: Parse tree.
Output: Intermediate code.
• Syntax-directed translation engines produce collections of
routines that walk a parse tree and generates intermediate
code.
31. Automatic Code Generators
• Input: Intermediate language.
Output: Machine language.
• Code-generator takes a collection of rules that define the translation of each
operation of the intermediate language into the machine language for a
target machine.
Data-flow Analysis Engines
• Data-flow analysis engine gathers the information, that is, the values
transmitted from one part of a program to each of the other parts.
• Data-flow analysis is a key part of code optimization.
Compiler Construction Toolkits
• The toolkits provide integrated set of routines for various phases of compiler.
• Compiler construction toolkits provide an integrated set of routines for
construction of phases of compiler.
32. Cousins of Compiler
• Interpreters: discussed in detail in first lecture
• Preprocessors: They produce input for the compiler. They perform jobs
such as deleting comments, include files, perform macros etc.
• Assemblers: They are translators for Assembly language. Sometimes
the compiler will generate assembly language in symbolic form then
hand it over to assemblers.
• Linkers: Both compilers and assemblers rely on linkers to collect code
separately compiled or assembled in object file into a file that is
directly executable.
• Loaders: It resolves all relocatable addresses to base address
33. Applications of compiler technology
1. Implementation of High-Level Programming
2. Optimizations for Computer Architectures
• Parallelism
• M e m o r y hierarchies
3. Design of New Computer Architectures
• R I S C
• Specialized Architectures
4. Program Translations
• Binary Translation
• Hardware Synthesis
• Database Query Interpreters
• Compiled Simulation
5. Software Productivity Tools
• Type Checking
• Bounds Checking
• Memory – Management Tools
34. Complexity of compiler technology
• A compiler is possibly the most complex
system software
• The complexity arises from the fact that it is
required to map a programmer’s requirements
(in a HLL program) to architectural details
• It uses algorithms and techniques from a very
large number of areas in computer science
• Translates intricate theory into practice -
enables tool building
35. Compiler Algorithms
Makes practical application of
• Greedy algorithms - register allocation
• Heuristic search - list scheduling
• Graph algorithms - dead code elimination, register allocation
• Dynamic programming - instruction selection
• Optimization techniques - instruction scheduling
• Finite automata - lexical analysis
• Pushdown automata - parsing
• Fixed point algorithms - data-flow analysis
• Complex data structures - symbol tables, parse trees, data
dependence graphs
• Computer architecture - machine code generation
36. Context Free Grammars
• Grammars are used to describe the syntax of a
programming language. It specifies the structure of
expression and statements.
• stmt -> if (expr) then stmt
where stmt denotes statements, expr denotes
expressions.
Types of grammar
• Type 0 grammar
• Type 1 grammar
• Type 2 grammar
• Type 3 grammar
• Context free grammar is also called as Type 2
grammar.
37. A context free grammar G is defined by four tuples as,
G=(V,T,P,S)
where,
• G - Grammar
• V - Set of variables
• T - Set of Terminals
• P - Set of productions
• S - Start symbol
• It produces Context Free Language (CFL) which is a collection of
input strings that are terminals, derived from the start symbol of
grammar on multiple steps.
where,
• L-Language
• G- Grammar
• w - Input string
• S - Start symbol
• T - Terminal
38. Conventions
Terminals are symbols from which strings
are formed.
• Lowercase letters i.e., a, b, c.
• Operators i.e.,+,-,*·
• Punctuation symbols i.e., comma, parenthesis.
• Digits i.e. 0, 1, 2, · · · ,9.
• Boldface letters i.e., id, if.
Non-terminals are syntactic variables that denote a set
of strings.
• Uppercase letters i.e., A, B, C.
• Lowercase italic names i.e., expr , stmt.
39. • Start symbol is the head of the production stated first in the
grammar.
• Production is of the form LHS ->RHS (or) head ->
body, where head contains only one non-terminal and body
contains a collection of terminals and non-terminals.
• (eg.) Let G be,
40. Context Free Grammars vs Regular Expressions
• Grammars are more powerful than regular expressions.
• Every construct that can be described by a regular
expression can be described by a grammar but not vice-
versa.
• Every regular language is a context free language but
reverse does not hold.
(eg.)
• RE= (a I b)*abb (set of strings ending with abb).
• Grammar
41. Syntax directed definition
• Syntax directed definition specifies the values of
attributes by associating semantic rules with the
grammar productions.
• It is a context free grammar with attributes and
rules together which are associated with grammar
symbols and productions respectively.
• The process of syntax directed translation is two-
fold:
• Construction of syntax tree
• Computing values of attributes at each node by
visiting the nodes of syntax tree.
42. • Semantic actions
• Semantic actions are fragments of code which are
embedded within production bodies by syntax
directed translation.
• They are usually enclosed within curly braces ({
}).
• It can occur anywhere in a production but usually
at the end of production.
• (eg.)
• E---> E1 + T {print ‘+’}
43. Types of translation
L-attributed translation
• It performs translation during parsing itself.
• No need of explicit tree construction.
• L represents 'left to right'.
•
S-attributed translation
• It is performed in connection with bottom up
parsing.
• 'S' represents synthesized.
44. Types of attributes
Inherited attributes
• It is defined by the semantic rule associated with the
production at the parent of node.
• Attributes values are confined to the parent of node, its
siblings and by itself.
• The non-terminal concerned must be in the body of the
production.
Synthesized attributes
• It is defined by the semantic rule associated with the
production at the node.
• Attributes values are confined to the children of node and by
itself.
• non terminal concerned must be in the head of production.
• Terminals have synthesized attributes which are the lexical
values (denoted by lexval) generated by the lexical analyzer.
45. Syntax directed definition of simple desk calculator
Production Semantic rules
L ---> En L.val = E.val
E ---> E1+ T E.val = E1.val+ T.val
E ---> T E.val = T.val
T---> T1*F T.val = Ti.val x F.val
T ---> F T.val = F.val
F ---> (E) F.val = E.val
F ---> digit F.val = digit.lexval
46. Syntax-directed definition-inherited attributes
Production Semantic Rules
D --->TL L.inh = T.type
T ---> int T.type =integer
T ---> float T.type = float
L ---> L1, id L1.inh = L.inh
addType (id.entry, Linh)
L ---> id addType (id.entry, L.inh)
Symbol T is associated with a synthesized attribute type.
• Symbol L is associated with an inherited attribute inh,
47. Types of Syntax Directed Definitions
• S-attributed Definitions
• Syntax directed definition that involves only synthesized
attributes is called S-attributed.
• Attribute values for the non-terminal at the head is
computed from the attribute values of the symbols at the
body of the production.
• The attributes of a S-attributed SDD can be evaluated in
bottom up order of nodes of the parse tree.
• i.e., by performing post order traversal of the parse tree
and
• evaluating the attributes at a node when the traversal leaves
that node for the last time.
48. Production Semantic rules
L ---> En L.val = E.val
E ---> E1+ T E.val = E1.val+ T.val
E ---> T E.val = T.val
T---> T1*F T.val = Ti.val x F.val
T ---> F T.val = F.val
F ---> (E) F.val = E.val
F ---> digit F.val = digit.lexval
49. • L-attributed Definitions
• The syntax directed definition in which the edges of dependency
graph for the attributes in production body, can go from left to right
and not from right to left is called L-attributed definitions.
• Attributes of L-attributed definitions may either be synthesized or
inherited.
• If the attributes are inherited, it must be computed from:
• Inherited attribute associated with the production head.
• Either by inherited or synthesized attribute associated with the
production located to the left of the attribute which is being computed.
• Either by inherited or synthesized attribute associated with the
attribute under consideration in such a way that no cycles can be
formed by it in dependency graph.
50. Production Semantic Rules
T ---> FT' T '.inh = F.val
T ' ---> *FT1’ T’1.inh =T'.inh x F.val
In production 1, the inherited attribute T' is computed from the value
of F which is to its left.
In production 2, the inherited attributed Tl' is computed from T'. inh
associated with its head and the value of F which appears to its left
in the production.
i.e., for computing inherited attribute it must either use from the
above or from the left information of SDD.