Modern compiler design pdf

Date published 

 

Twelve years have passed since the first edition of Modern Compiler Design. The book adds new material to cover the developments in compiler design and. Contribute to germanoa/compiladores development by creating an account on GitHub. Where Can I Find Necessary Files for Creating a Compiler in C?. .. This document is a companion to the textbook Modern Compiler Design by David.

Author:JANINA JORDEN
Language:English, Spanish, Portuguese
Country:Australia
Genre:Politics & Laws
Pages:616
Published (Last):27.10.2015
ISBN:417-3-52597-181-7
Distribution:Free* [*Registration needed]
Uploaded by: ALAINA

47619 downloads 134413 Views 17.87MB PDF Size Report


Modern Compiler Design Pdf

Ten years have passed since the first edition of Modern Compiler Design. For many computer science subjects this would be more than a life. Modern Compiler Design, First Edition For more information, see the Preface ( in PostScript or or in PDF), the Table of Contents (in PostScript or or in PDF). "Modern Compiler Design" makes the topic of compiler design more accessible DRM-free; Included format: PDF; ebooks can be used on all reading devices.

Main article: History of compiler construction A diagram of the operation of a typical multi-language, multi-target compiler Theoretical computing concepts developed by scientists, mathematicians, and engineers formed the basis of digital modern computing development during World War II. Primitive binary languages evolved because digital devices only understand ones and zeros and the circuit patterns in the underlying machine architecture. In the late s, assembly languages were created to offer a more workable abstraction of the computer architectures. Limited memory capacity of early computers led to substantial technical challenges when the first compilers were designed. Therefore, the compilation process needed to be divided into several small programs. The front end programs produce the analysis products used by the back end programs to generate target code. As computer technology provided more resources, compiler designs could align better with the compilation process. It is usually more productive for a programmer to use a high-level language, so the development of high-level languages followed naturally from the capabilities offered by digital computers. High-level languages are formal languages that are strictly defined by their syntax and semantics which form the high-level language architecture. Elements of these formal languages include: Alphabet, any finite set of symbols; String, a finite sequence of symbols; Language, any set of strings on an alphabet. The sentences in a language may be defined by a set of rules called a grammar. While no actual implementation occurred until the s, it presented concepts later seen in APL designed by Ken Iverson in the late s. High-level language design during the formative years of digital computing provided useful programming tools for a variety of applications: FORTRAN Formula Translation for engineering and science applications is considered to be the first high-level language. The compiler could be viewed as a front end to deal with the analysis of the source code and a back end to synthesize the analysis into the target code.

Examples of middle end optimizations are removal of useless dead code elimination or unreachable code reachability analysis , discovery and propagation of constant values constant propagation , relocation of computation to a less frequently executed place e.

Eventually producing the "optimized" IR that is used by the back end. The back end takes the optimized IR from the middle end. It may perform more analysis, transformations and optimizations that are specific for the target CPU architecture. The back end generates the target-dependent assembly code, performing register allocation in the process. The back end performs instruction scheduling , which re-orders instructions to keep parallel execution units busy by filling delay slots.

Although most algorithms for optimization are NP-hard , heuristic techniques are well-developed and currently implemented in production-quality compilers. Typically the output of a back end is machine code specialized for a particular processor and operating system.

Front end[ edit ] Lexer and parser example for C. The latter sequence is transformed by the parser into a syntax tree , which is then treated by the remaining compiler phases. The scanner and parser handles the regular and properly context-free parts of the grammar for C , respectively. The front end analyzes the source code to build an internal representation of the program, called the intermediate representation IR.

It also manages the symbol table , a data structure mapping each symbol in the source code to associated information such as location, type and scope.

While the frontend can be a single monolithic function or program, as in a scannerless parser , it is more commonly implemented and analyzed as several phases, which may execute sequentially or concurrently. This method is favored due to its modularity and separation of concerns. Most commonly today, the frontend is broken into three phases: lexical analysis also known as lexing , syntax analysis also known as scanning or parsing , and semantic analysis.

Lexing and parsing comprise the syntactic analysis word syntax and phrase syntax, respectively , and in simple cases these modules the lexer and parser can be automatically generated from a grammar for the language, though in more complex cases these require manual modification.

The lexical grammar and phrase grammar are usually context-free grammars , which simplifies analysis significantly, with context-sensitivity handled at the semantic analysis phase. The semantic analysis phase is generally more complex and written by hand, but can be partially or fully automated using attribute grammars. These phases themselves can be further broken down: lexing as scanning and evaluating, and parsing as building a concrete syntax tree CST, parse tree and then transforming it into an abstract syntax tree AST, syntax tree.

In some cases additional phases are used, notably line reconstruction and preprocessing, but these are rare. The main phases of the front end include the following: Line reconstruction converts the input character sequence to a canonical form ready for the parser. Languages which strop their keywords or allow arbitrary spaces within identifiers require this phase. The top-down , recursive-descent , table-driven parsers used in the s typically read the source one character at a time and did not require a separate tokenizing phase.

Preprocessing supports macro substitution and conditional compilation. Typically the preprocessing phase occurs before syntactic or semantic analysis; e. However, some languages such as Scheme support macro substitutions based on syntactic forms. Lexical analysis also known as lexing or tokenization breaks the source code text into a sequence of small pieces called lexical tokens.

A token is a pair consisting of a token name and an optional token value.

DOWNLOAD FREE LECTURE NOTES SLIDES PPT PDF EBOOKS: Modern Compiler Design Second Edition PPT Slides

The lexeme syntax is typically a regular language , so a finite state automaton constructed from a regular expression can be used to recognize it. The software doing lexical analysis is called a lexical analyzer.

This may not be a separate step—it can be combined with the parsing step in scannerless parsing , in which case parsing is done at the character level, not the token level. Syntax analysis also known as parsing involves parsing the token sequence to identify the syntactic structure of the program. This phase typically builds a parse tree , which replaces the linear sequence of tokens with a tree structure built according to the rules of a formal grammar which define the language's syntax.

The parse tree is often analyzed, augmented, and transformed by later phases in the compiler. This phase performs semantic checks such as type checking checking for type errors , or object binding associating variable and function references with their definitions , or definite assignment requiring all local variables to be initialized before use , rejecting incorrect programs or issuing warnings.

Semantic analysis usually requires a complete parse tree, meaning that this phase logically follows the parsing phase, and logically precedes the code generation phase, though it is often possible to fold multiple phases into one pass over the code in a compiler implementation. Middle end[ edit ] The middle end, also known as optimizer, performs optimizations on the intermediate representation in order to improve the performance and the quality of the produced machine code.

The main phases of the middle end include the following: Analysis : This is the gathering of program information from the intermediate representation derived from the input; data-flow analysis is used to build use-define chains , together with dependence analysis , alias analysis , pointer analysis , escape analysis , etc.

Accurate analysis is the basis for any compiler optimization. The control flow graph of every compiled function and the call graph of the program are usually also built during the analysis phase. Optimization : the intermediate language representation is transformed into functionally equivalent but faster or smaller forms. Popular optimizations are inline expansion , dead code elimination , constant propagation , loop transformation and even automatic parallelization.

Compiler analysis is the prerequisite for any compiler optimization, and they tightly work together. For example, dependence analysis is crucial for loop transformation. The scope of compiler analysis and optimizations vary greatly; their scope may range from operating within a basic block , to whole procedures, or even the whole program. There is a trade-off between the granularity of the optimizations and the cost of compilation.

For example, peephole optimizations are fast to perform during compilation but only affect a small local fragment of the code, and can be performed independently of the context in which the code fragment appears.

In contrast, interprocedural optimization requires more compilation time and memory space, but enable optimizations which are only possible by considering the behavior of multiple functions simultaneously. The free software GCC was criticized for a long time for lacking powerful interprocedural optimizations, but it is changing in this respect. Another open source compiler with full analysis and optimization infrastructure is Open64 , which is used by many organizations for research and commercial purposes.

Due to the extra time and space needed for compiler analysis and optimizations, some compilers skip them by default. Users have to use compilation options to explicitly tell the compiler which optimizations should be enabled. The back end is responsible for the CPU architecture specific optimizations and for code generation [44].

The main phases of the back end include the following: Machine dependent optimizations: optimizations that depend on the details of the CPU architecture that the compiler targets. Code generation : the transformed intermediate language is translated into the output language, usually the native machine language of the system.

This involves resource and storage decisions, such as deciding which variables to fit into registers and memory and the selection and scheduling of appropriate machine instructions along with their associated addressing modes see also Sethi-Ullman algorithm. Debug data may also need to be generated to facilitate debugging. Main article: Compiler correctness Compiler correctness is the branch of software engineering that deals with trying to show that a compiler behaves according to its language specification.

Compiled versus interpreted languages[ edit ] This section does not cite any sources. October Learn how and when to remove this template message Higher-level programming languages usually appear with a type of translation in mind: either designed as compiled language or interpreted language.

However, in practice there is rarely anything about a language that requires it to be exclusively compiled or exclusively interpreted, although it is possible to design languages that rely on re-interpretation at run time. The categorization usually reflects the most popular or widespread implementations of a language — for instance, BASIC is sometimes called an interpreted language, and C a compiled one, despite the existence of BASIC compilers and C interpreters.

Interpretation does not replace compilation completely. It only hides it from the user and makes it gradual. Even though an interpreter can itself be interpreted, a directly executed program is needed somewhere at the bottom of the stack see machine language.

Further, compilers can contain interpreters for optimization reasons. For example, where an expression can be executed during compilation and the results inserted into the output program, then it prevents it having to be recalculated each time the program runs, which can greatly speed up the final program.

Modern trends toward just-in-time compilation and bytecode interpretation at times blur the traditional categorizations of compilers and interpreters even further. Some language specifications spell out that implementations must include a compilation facility; for example, Common Lisp.

However, there is nothing inherent in the definition of Common Lisp that stops it from being interpreted.

Other languages have features that are very easy to implement in an interpreter, but make writing a compiler much harder; for example, APL , SNOBOL4 , and many scripting languages allow programs to construct arbitrary source code at runtime with regular string operations, and then execute that code by passing it to a special evaluation function.

To implement these features in a compiled language, programs must usually be shipped with a runtime library that includes a version of the compiler itself. Types[ edit ] One classification of compilers is by the platform on which their generated code executes. This is known as the target platform. A native or hosted compiler is one whose output is intended to directly run on the same type of computer and operating system that the compiler itself runs on.

The output of a cross compiler is designed to run on a different platform. Cross compilers are often used when developing software for embedded systems that are not intended to support a software development environment.

The output of a compiler that produces code for a virtual machine VM may or may not be executed on the same platform as the compiler that produced it. For this reason such compilers are not usually classified as native or cross compilers.

The lower level language that is the target of a compiler may itself be a high-level programming language. C, viewed by some as a sort of portable assembly language, is frequently the target language of such compilers. The C code generated by such a compiler is usually not intended to be readable and maintained by humans, so indent style and creating pretty C intermediate code are ignored. Some of the features of C that make it a good target language include the line directive, which can be generated by the compiler to support debugging of the original source, and the wide platform support available with C compilers.

While a common compiler type outputs machine code, there are many other types: Source-to-source compilers are a type of compiler that takes a high-level language as its input and outputs a high-level language. For example, an automatic parallelizing compiler will frequently take in a high-level language program as an input and then transform the code and annotate it with parallel code annotations e. OpenMP or language constructs e.

Bytecode compilers that compile to assembly language of a theoretical machine, like some Prolog implementations This Prolog machine is also known as the Warren Abstract Machine or WAM. Bytecode compilers for Java , Python are also examples of this category.

Just-in-time compilers JIT compiler defer compilation until runtime. A JIT compiler generally runs inside an interpreter. The front end programs produce the analysis products used by the back end programs to generate target code.

As computer technology provided more resources, compiler designs could align better with the compilation process. It is usually more productive for a programmer to use a high-level language, so the development of high-level languages followed naturally from the capabilities offered by digital computers. High-level languages are formal languages that are strictly defined by their syntax and semantics which form the high-level language architecture.

Elements of these formal languages include: Alphabet, any finite set of symbols; String, a finite sequence of symbols; Language, any set of strings on an alphabet. The sentences in a language may be defined by a set of rules called a grammar. While no actual implementation occurred until the s, it presented concepts later seen in APL designed by Ken Iverson in the late s.

High-level language design during the formative years of digital computing provided useful programming tools for a variety of applications: FORTRAN Formula Translation for engineering and science applications is considered to be the first high-level language. The compiler could be viewed as a front end to deal with the analysis of the source code and a back end to synthesize the analysis into the target code. Optimization between the front end and back end could produce more efficient target code.

In , LISP 1. Edwards, a compiler and assembler written by Tim Hart and Mike Levin. In the 60s and early 70s, the use of high-level languages for system programming was still controversial due to resource limitations.

So researchers turned to other development efforts. Unics eventually became spelled Unix. In , a new PDP provided the resource to define extensions to B and rewrite the compiler. The initial design leveraged C language systems programming capabilities with Simula concepts. Object-oriented facilities were added in In many application domains, the idea of using a higher-level language quickly caught on. Because of the expanding functionality supported by newer programming languages and the increasing complexity of computer architectures, compilers became more complex.

PQCC might more properly be referred to as a compiler generator. PQCC research into code generation process sought to build a truly automatic compiler-writing system. The effort discovered and designed the phase structure of the PQC.

The PQCC project investigated techniques of automated compiler construction. The design concepts proved useful in optimizing compilers and compilers for the object-oriented programming language Ada. Initial Ada compiler development by the U. Military Services included the compilers in a complete integrated design environment along the lines of the Stoneman Document. While the projects did not provide the desired results, they did contribute to the overal effort on Ada development.

In the U. VADS provided a set of development tools including a compiler.

You might also like: MODERN QUANTUM MECHANICS PDF

GNAT is free but there is also commercial support, for example, AdaCore, was founded in to provide commercial software solutions for Ada. High-level languages continued to drive compiler research and development. Focus areas included optimization and automatic code generation. Trends in programming languages and development environments influenced compiler technology. The interrelationship and interdependence of technologies grew. The advent of web services promoted growth of web languages and scripting languages.

Scripts trace back to the early days of Command Line Interfaces CLI where the user could enter commands to be executed by the system. User Shell concepts developed with languages to write shell programs. Early Windows designs offered a simple batch programming capability.

The conventional transformation of these language used an interpreter. While not widely used, Bash and Batch compilers have been written. More recently sophisticated interpreted languages became part of the developers tool kit. Lua is widely used in game development. All of these have interpreter and compiler support. The compiler field is increasingly intertwined with other disciplines including computer architecture, programming languages, formal methods, software engineering, and computer security.

Security and parallel computing were cited among the future research targets. This section does not cite any sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. September Learn how and when to remove this template message A compiler implements a formal transformation from a high-level source program to a low-level target program. Compiler design can define an end to end solution or tackle a defined subset that interfaces with other compilation tools e.

Design requirements include rigorously defined interfaces both internally between compiler components and externally between supporting toolsets.

In the early days, the approach taken to compiler design was directly affected by the complexity of the computer language to be processed, the experience of the person s designing it, and the resources available. Resource limitations led to the need to pass through the source code more than once.

A compiler for a relatively simple language written by one person might be a single, monolithic piece of software. However, as the source language grows in complexity the design may be split into a number of interdependent phases. Separate phases provide design improvements that focus development on the functions in the compilation process. One-pass versus multi-pass compilers[ edit ] Classifying compilers by number of passes has its background in the hardware resource limitations of computers.

Compiling involves performing lots of work and early computers did not have enough memory to contain one program that did all of this work.

So compilers were split up into smaller programs which each made a pass over the source or some representation of it performing some of the required analysis and translations. The ability to compile in a single pass has classically been seen as a benefit because it simplifies the job of writing a compiler and one-pass compilers generally perform compilations faster than multi-pass compilers. Thus, partly driven by the resource limitations of early systems, many early languages were specifically designed so that they could be compiled in a single pass e.

In some cases the design of a language feature may require a compiler to perform more than one pass over the source. For instance, consider a declaration appearing on line 20 of the source which affects the translation of a statement appearing on line In this case, the first pass needs to gather information about declarations appearing after statements that they affect, with the actual translation happening during a subsequent pass.

The disadvantage of compiling in a single pass is that it is not possible to perform many of the sophisticated optimizations needed to generate high quality code. It can be difficult to count exactly how many passes an optimizing compiler makes. For instance, different phases of optimization may analyse one expression many times but only analyse another expression once. Splitting a compiler up into small programs is a technique used by researchers interested in producing provably correct compilers.

Proving the correctness of a set of small programs often requires less effort than proving the correctness of a larger, single, equivalent program. Three-stage compiler structure[ edit ] Compiler design Regardless of the exact number of phases in the compiler design, the phases can be assigned to one of three stages. The stages include a front end, a middle end, and a back end. The front end verifies syntax and semantics according to a specific source language.

For statically typed languages it performs type checking by collecting type information. If the input program is syntactically incorrect or has a type error, it generates errors and warnings, highlighting[ dubious — discuss ] them on the source code.

Aspects of the front end include lexical analysis, syntax analysis, and semantic analysis. The front end transforms the input program into an intermediate representation IR for further processing by the middle end.

This IR is usually a lower-level representation of the program with respect to the source code. The middle end performs optimizations on the IR that are independent of the CPU architecture being targeted.

Examples of middle end optimizations are removal of useless dead code elimination or unreachable code reachability analysis , discovery and propagation of constant values constant propagation , relocation of computation to a less frequently executed place e.

Eventually producing the "optimized" IR that is used by the back end. The back end takes the optimized IR from the middle end. It may perform more analysis, transformations and optimizations that are specific for the target CPU architecture. The back end generates the target-dependent assembly code, performing register allocation in the process.

Modern Compiler Design

The back end performs instruction scheduling , which re-orders instructions to keep parallel execution units busy by filling delay slots. Although most algorithms for optimization are NP-hard , heuristic techniques are well-developed and currently implemented in production-quality compilers.

Typically the output of a back end is machine code specialized for a particular processor and operating system. Front end[ edit ] Lexer and parser example for C.

Compiler Design Tutorial

The latter sequence is transformed by the parser into a syntax tree , which is then treated by the remaining compiler phases. The scanner and parser handles the regular and properly context-free parts of the grammar for C , respectively. The front end analyzes the source code to build an internal representation of the program, called the intermediate representation IR.

Similar files:


Copyright © 2019 maroc-evasion.info.
DMCA |Contact Us