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C/C++ C/C++ CompilingCompiling

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A Brief History of C A Brief History of C languagelanguage

• In the early 1970s, Dennis Ritchie of Bell Laboratories was engaged in a project to develop new operating system.

• He realized that he needed the use of a programming language that was concise and that produced compact and speedy programs.

• This need led Ritchie to develop the programming language called C.

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A Brief History of C++A Brief History of C++• In the early 1980's, also at Bell Laboratories,

another programming language was created which was based upon the C language.

• This new language was developed by Bjarne Stroustrup and was called C++. According to Stroustrup, the purpose of C++ is to make writing good programs easier and more pleasant for the individual programmer.

• When he designed C++, he added OOP (Object Oriented Programming) features to C without significantly changing the C component. Thus C++ is a "relative" of C, meaning that any valid C program is also a valid C++ program.

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Simple C programSimple C program // Add two numbers and print the result

#include <iostream.h>using namespace std;

void main(){

int firstNum, secondNum, result;cout<< “Please Enter the first Number”<<endl;cin>> firstNum;cout<< “Please Enter the second Number”<<endl;cin>> secondNum;result= firstNum + secondNum;cout<<firstNum<<“ + “<<secondNum<<“ = “<<result<<endl;

}

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C/C++ source files suffixesC/C++ source files suffixes

• .cpp, .cc, .c suffixes are used for C++ programs that are to be preprocessed, compiled and assembled

• .c for C programs that are to be processed, compiled and assembled

• .h or preprocessor (header) files

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File StructureFile Structure• Implementation files (.cpp, .cc, .c)

– Methods are implemented

• Interface files (.h)– Methods and classes are defined– Also called header files

• Implementation files depend on Interface files.– Interface holds prototypes and definitions– Implementation holds actual code

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Compilation DetailsCompilation Details

object.h

object.cpp

main.cpp

object.s

main.s

object.o

main.o

Output

Source code Assembly Machine Code

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Using GNU C CompilerUsing GNU C Compiler• GNU C compiler is one of the compilers installed

on willow server (UM research server)• GCC is the official compiler of the GNU• gcc file1.c command is used to compile and link a C

program on willow with the gcc compiler• g++ file1.c command is used to compile and link a

C++ program on willow with the gcc compiler

• gcc prog.c command creates an executable file known as a.out

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More on gcc commandMore on gcc commandgcc filename [flag]

-c

Compile or assemble the source files, but do not link.

-S

Stop after the stage of compilation proper; do not assemble.

-E

Stop after the preprocessing stage; do not run the compiler proper.

-o newFilename

Place output in file newFilename instead of a.out