C_MAKEFILE

GCC

gcc hello.c -o hello

Course resources 12. Compilation and Makefiles

https://cse.msu.edu/~cse251/

code.c

#include <stdio.h> 
#include <math.h>

#define NumIter 5

int main() {
int i;
for (i=1; i<=NumIter; i++)
     printf("PI^%d is %f\n", i,i);
return 0;
}

Preprocessing

• Removes preprocessor directives (commands that start with #)

• Producescode.i Don’tusedirectly

gcc -E  code.c >  code.i

output: code.i

Compiling

• Convertssourcecodetomachinelanguagewithunresolveddirectives

• Producesthecode.obinary

gcc -o code.o -c code.i

output: code.o

Linking

• Createsmachinelanguageexectutable

• Producesthecodebinarybylinkingwiththemathlibrary(‐lm)

gcc -lm -o code code.o

output: code

-c (Compile only)

i think it equals gcc -E and gcc - o

• Purpose: Tells GCC to compile the source code into an object file (.o or .obj), but not to link it.

• Usage: This is used when you want to compile source files without producing an executable, typically to be linked later in a separate step.

• Example

  :

  bash

  Copy
  gcc -c myfile.c

This will produce an object file 

myfile.o

without linking.

Makefile

https://www.gnu.org/software/make/manual/make.html

Make/make.md · 无限十三年/CPP - Gitee.com

https://www.bilibili.com/video/BV1Bv4y1J7QT

hello.cpp

#include <stdio.h>

int main() {
    // Print "Hello, World!" to the console
    printf("Hello, World!\n");
    return 0;
}

MakeFile

hello: hello.cpp
     g++ hello.cpp -o hello  

make