Life cycle of a computer program
- 1. Presentation On Topic Life cycle of a souce program Presented By - Abhay Kumar MCA IVth Semester
- 2. Life cycle of a souce program • A computer program goes through many phases from its development to execution. From the human readable format (source code) to binary encoded computer instructions (machine code). • In life cycle of a source program the exact procedure behind the compilation task and step by step evaluation of source code are High level languages, Low level languages, Pre-processors, Translators, Compilers, Assembler, Interpreters, Linkers and Loaders.
- 3. Input Translator Linker Loader Target Program Execution by Hardware Pre - processor Sourse Program Output High level language Pure High level language Low level language Executable Code Load the program Execution Process Life cycle of a souce program
- 4. High level language • High level languages are similar to the human language. Unlike low level languages, high level languages are programmers friendly, easy to code, debug and maintain. • High level language provides higher level of abstraction from machine language. They do not interact directly with the hardware. Rather, they focus more on the complex arithmetic operations, optimal program efficiency and easiness in coding. • High level languages are very much closer to English language and uses English structure for program coding. • Examples of high level languages are Visual Basic, PHP, Python, Delphi, FORTRAN, COBOL, C, Pascal, C++, LISP, BASIC etc. High level language Compiled Language Interpreted Language
- 5. Low level languages • Low level languages are languages which can be directly understand by machines. It is programming language having little or no abstraction. These languages are described as close to hardware. • Examples of low level languages are machine languages, binary language, assembly level languages and object code etc. Low level language Assembley Language Machine Language
- 6. Source code • Source code is a plain text file containing computer instructions written in human readable format. It is simple text file written by programmers. • It contain instructions in high-level language that the programmer intended to perform by a program. Source code is later compiled and translated to Object code. # include<stdio.h> #include<conio.h> void maid() { printf(“Hello Abhay”); } getch();
- 7. Object code • Object code is a sequence of computer instructions in an intermediate language. It is generated by compiler after the compilation process. • The compiler reads source code written in high-level language and translates it to an intermediate language. • After translation a file containing instructions encoded in some intermediate language is generated called object code. 101001010010 010101001010 101010001001 001110101001 110010010101 0010011011 # include<stdio.h> #include<conio.h> void maid() { printf(“Hello Abhay”); } getch(); Source Code Object Code Compiler
- 8. Machine code • Machine code is a set of computer instructions written or translated in machine language. • It is the final executable file generated by compiling, assembling or linking several object files together. It is the only code executed by the CPU. 101001010010 010101001010 101010001001 001110101001 110010010101 0010011011 Machine Code
- 9. Pre-processor • Pre-processor is a computer program that manipulates its input data in order to generate output which is ultimately used as input to some other program or compiler. • Input of pre-processor is high level languages and output of pre-processor is pure high level languages. • Pure high level language refers to the language which is having Macros in the program and File Inclusion. • Macro means some set of instructions which can be used repeatedly in the program. • Macro preprocessing task is done by pre- processor. Pre-processor allows user to include header files which may be required by program known as File Inclusion. Assembler Linker/ Loader Pre - processor High level language Pure High level language Assembley Language Executable Code Machine Code Compiler
- 10. Translator • Translator is a program that takes input as a source program and converts it into another form as output. • Translator takes input as a high level language and convert it into low level language. • There are mainly three types of translators - Compilers Assemblers Interpreters High level language Translator Low Level Language Errors
- 11. Compiler • Compiler reads whole program at a time and generate errors (if occurred). Compiler generates intermediate code in order to generate target code. Once the whole program is checked, errors are displayed. • Example of compilers is Borland Compiler, Turbo C Compiler. Generated target code is easy to understand after the process of compilation. • The process of compilation must be done efficiently. There are mainly two parts of compilation process. Source Code Error Message Compiler Target code
- 12. Assembler • Assembler is a translator which takes assembly language as an input and generates machine language as an output. • Output of compiler is input of assembler which is assembly language. Assembly code is mnemonic version of machine code. • Binary codes for operations are replaced by names. Binary language or relocatable machine code is generated from the assembler. • Assembler uses two passes. Pass means one complete scan of the input program. High Leve Language Assembler Compiler Low Level Language Assembley language Machine code
- 13. Interpreter • Interpreter performs the line by line execution of source code. It takes single instruction as an input, reads the statement, analyzes it and executes it. It shows errors immediately if occur . • Interpreter is machine independent andwhich does not produces object code or intermediate code as it directly generates the target code. • Many languages can be implemented using both compilers and interpreters such as BASIC, Python, C#, Pascal, Java, and Lisp etc. • Example of interpreter is UPS Debugger. Source Code Interpreter Target code
- 14. Linker and Loader •Linker combines two or more separate object programs. It combines target program with other library routines. •Linker links the library files and prepares single module or file. Linker also solves the external reference. •Linker allows us tocreate single program from several files. •Loader is utility program which takes object code as input and prepares it for execution. It also loads the object code into executable code. •Loader refers to initializing of execution process. Tasks done by loaders are mentioned below. Allocation Relocation Link editing Loading LinkerAssembler Loader Object Code Executable code Source Code
- 15. Refrences - • http://www.rroij.com/open-access/life-cycle-of-source-program--compiler-design-.pdf • https://codeforwin.org/2017/05/high-level-languages-advantages-disadvantages.html