karishma bhasin

8/8/2019 karishma bhasin

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H IGH LEVEL L ANGUAGESCOMPILER

INTERPRETERL INKER

A SSEMBLER


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A high-level programming language isan advance programming language withstrong abstraction from the details of the

computer .

Examples : BASIC,FORTAN,C,PASCAL A,C++, etc

H IGH L EVEL L ANGUAGE


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ADVANTAGES OF HIGH LEVELLANGUAGES

Machine independence

Easy to learn and use

Fewer errors

Lower program preparationEasy to maintain


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LIMITATIONS OF HIGH LEVELLANGUAGES

LOWER EFFICIENCY : High level language result inmultiple machine language instructions that may not be optimized,taking more time to execute and requiring more main memory space.

LESS FLEXIBILITY : High level languages are less flexiblebecause they normally do not have mechanism to control acomputers CPU , memory and registers.


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TYPES OF LANGUAGE PROCESSORS


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COMPILER

A compiler is a translator program that

translates(converts) a high-levellanguage program (source program)into its equivalent machine-languageprogram (object program).

Examples : FORTR A N COMPILER, COBOLCOMPILER, C COMPILER.. etc.


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B ASIS OF REQUIREMENT OF A COMPILER

Compiler for L1

Compiler for L2

Program P1 in highlevel language L1

Program P2 in highlevel language

L2

Machine code for P1

Machine code for P2


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T RANSLATION P ROCESSO F A C OMPILER

COMPILERINPUT OUTPUTHIGH LEVELLANGUAGEPROGRAM

MACHINELANGUAGEPROGRAM

(Source Program) (Object Program)One to many correspondence


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Executed oncomputer A

Compiler forlanguage L1

on computer A

Compiler forlanguage L1

on computer BExecuted oncomputer B

Machine codefor P1 thatwill run oncomputer A

Machinecode for P1that will runoncomputer B

Program P1and high-levellanguage L1

Same resultsobtained


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W ORKING OF A C OMPILER

W hen a source program is to be translated, the compiler and thesource program are copied from secondary storage into the mainmemory of the computer .

The compiler, being a program is then executed with the sourceprogram as its input data .

It generates the equivalent object program as its output which isnormally saved in a file on secondary storage .

W henever there is a need to execute the program the objectprogram is copied from secondary storage in to the mainmemory of the computer and executed .


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S ECONDARY F UNCTION O F A C OMPILER

Compilers also detect and indicate certain typesof errors in source programs, these errors arecalled Syntax Errors.

Some typical syntax errors-Illegal charactersIllegal combination of characters

Improper sequencing of instructions in aprogramUse of undefined variable names


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RECOMPILATION OF A SOURCE PROGRAM

START

Edit source program

Compile sourceprogram

Syntaxerrors

detected?

Generate list of coded

error messages

Generate object

program

STOP Y es

No

Source program

Object program


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INTERPRETER

An interpreter is a type of translator that translatesprograms written in high level languages into machine

language.

An interpreter takes one statement of the sourceprogram , translates it into machine language

instructions and then immediately executes the

resulting machine language instructions before takingthe next statement for translation.

Examples: Basic interpreter , Java script interpreter


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ROLE OF AN INTERPRETER

High levellanguageprogram(Source

Program)

INPUT

INTERPRETER(translates and

executes statement-by-statement)

OUTPUTResult of program

execution

There is a need to repeat the interpretation process

every time you wish to execute the program


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A DVANTAGES OF AN I NTERPRETER

Interpreters are easy to write

Less complex

A syntax error in a program statement isdetected and brought to the attention of theprogrammer as soon as the program statement is

interpreted.

Require less memory space for execution.


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D ISADVANTAGES O F A N I NTERPRETER

REPEATED INTERPRETATION : Since duringinterpretation ,no object program is saved for future use,repeated interpretation (translation + execution) is

necessary for its repeated execution.

SPEED : Interpreters are slow while running a finishedprogram because each statement is translated everytime it is executed from the source program.


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B ASIS OFDISTINCTION

COMPILER INTERPRETER

OUTPUTThe resulting object program is

permanently saved for futureuse.

No object program is savedfor future use.

REPETITIONRepeated compilation is not

necessary for repeatedexecution of program.

Repeated interpretation isnecessary for repeatedexecution of program .

DETECTION OFS Y NTAX ERROR

Syntax error is not detectedearly.

Syntax error is detected assoon as the program

statement is interpreted.

CHARACTERISTIC They are complex to write. They are easier to write.

TIMECONSUMPTION

It is less time consuming to runa program under the

compiler as it is faster.

It is slow while running afinished program.


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L INKER

A Linker or Link Editor is a program that takesone or more object program files generated by

a compiler and combines them into asingle executable program which is called a loadmodule .


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W H Y IS L INKER REQUIRED ?... P ART 1 ADAPTATION OF MODULAR APPROACH : A Modular

approach is adapted to develop reasonably sized softwarebecause.

A software often consists of several millions of lines of programcode which cant be stored in a single source program file.

The large size of the file would make it very difficult to workwith.e.g.it is impossible to load the file for compilation on acomputer with limited main memory capacity.

It would make it difficult to deploy multiple programmers to workconcurrently towards the development of the software for completingit within a specified time limit.

Any change in the source program would require the entiresource program to be recompiled.


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ASSEMBLER

An Assembler is a utility translator program whichconverts (translates) assembly language program into its

equivalent machine language program , before it can beexecuted on the computer.

An Assembler also assembles the machine languageprogram in the main memory of the computer and

makes it ready for execution.

Examples: Go A sm,T A SM(Turbo A ssembler Software),M A SM,X86(-64),MIPSetc.


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B ASIS OFDISTINCTION

ASSEM B LER INTERPRETER

PRIMARYFUNCTION

It converts assembly languageprogram into its equivalent

machine language program.

It translates high-levellanguage program into its

equivalent machinelanguage program .

SECONDARYFUNCTION

It assembles the machinelanguage program in the mainmemory of the computer andmakes it ready for execution .

It immediately executesresulting machine language

instructions

MEMORY SPACE Require more memory space for execution.

Doesnt require memoryspace for execution .

OUTPUT The output given by assembler isthe object program.

The output given byinterpreter is the result of the program execution .


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BRIEF RECAPITULATION

A Compiler is a translator program which translates a high-level languageprogram (source code) into its equivalent machine-language program (object

program).

A n Interpreter is a translator program ,which translates a high-level languageprogram into its equivalent machine-language program .It takes one statement of the source program,translates it into machine-language instructions,and thenimmediately executes the resulting machine language instructions before takingthe next statement for translation.

A Linker is a program , which takes multiple object programfiles (modules) of a software , and fits them together toassemble them into the programs final executable form.

A n Assembler is a utility translator program whichconverts (translates) assembly language program into itsequivalent machine language program , before it can beexecuted on the computer.


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MADE B Y:

PALAK AGGARWAL (9956)

KARISHMA BHASIN (9957)

DISHA KHANNA (9958)

karishma bhasin

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