Analysis of memory structure of C program code

The internal structure of the program is segmented , It is generally divided into code segments 、 Pile up 、 Stack 、 Data segments, etc . It can be proved by the following code ：

#include <stdio.h>

int globalIntA=10;

void variableInStack()
{
    printf("%s:%d:%s location is %p\n",__FILE__,__LINE__,__FUNCTION__,(void*)&__FUNCTION__);
    printf("%s:%d:%s global globalIntA is %p\n",__FILE__,__LINE__,__FUNCTION__,(void*)&globalIntA);
    int localIntB=100;
    printf("%s:%d:%s local localIntB is %p\n",__FILE__,__LINE__,__FUNCTION__,(void*)&localIntB);
}

void variableInHeap()
{
    printf("%s:%d:%s location is %p\n",__FILE__,__LINE__,__FUNCTION__,(void*)&__FUNCTION__);
    char *description = malloc(10* sizeof(char));
    if( description == NULL )
    {
        fprintf(stderr, "Error - unable to allocate required memory\n");
    }
    else
    {
        strcpy( description, "IN HEAP");
    }
    printf("Description: %s\n", description );

    printf("%s:%d:%s malloc description is %p\n",__FILE__,__LINE__,__FUNCTION__,(void*)&description);
    printf("%s:%d:%s malloc *description is %p\n",__FILE__,__LINE__,__FUNCTION__,&(*description));
    free((void*)description);
    int localIntB=100;
    printf("%s:%d:%s local localIntB is %p\n",__FILE__,__LINE__,__FUNCTION__,(void*)&localIntB);
    static int stcIntC;
    printf("%s:%d:%s static int stcIntC is %p\n",__FILE__,__LINE__,__FUNCTION__,(void*)&stcIntC);
}


int globalIntB;

int main(int argc, char ** argv)
{
    printf("%s:%d:%s process begin @ %p\n",__FILE__,__LINE__,__FUNCTION__,(void*)&__FUNCTION__);
    printf("%s:%d:%s global globalIntB is %p\n",__FILE__,__LINE__,__FUNCTION__,(void*)&globalIntB);
    printf("====================\n");
    variableInStack();
    printf("====================\n");
    variableInHeap();
    return EXIT_SUCCESS;
}

The result of the program execution is as follows ：
/Users/huGuohua/xcode/c_study/c_study/main.c:30:main process begin @ 0x100003f5e
/Users/huGuohua/xcode/c_study/c_study/main.c:31:main global globalIntB is 0x10000810c
====================
/Users/huGuohua/xcode/c_study/c_study/memoryAddress.h:18:variableInStack location is 0x100003e04
/Users/huGuohua/xcode/c_study/c_study/memoryAddress.h:19:variableInStack global globalIntA is 0x1000080d8
/Users/huGuohua/xcode/c_study/c_study/memoryAddress.h:21:variableInStack local localIntB is 0x7ffeefbff42c
====================
/Users/huGuohua/xcode/c_study/c_study/memoryAddress.h:26:variableInHeap location is 0x100003e56
Description: IN HEAP
/Users/huGuohua/xcode/c_study/c_study/memoryAddress.h:38:variableInHeap malloc description is 0x7ffeefbff428
/Users/huGuohua/xcode/c_study/c_study/memoryAddress.h:39:variableInHeap malloc *description is 0x10181e6b0
/Users/huGuohua/xcode/c_study/c_study/memoryAddress.h:42:variableInHeap local localIntB is 0x7ffeefbff424
/Users/huGuohua/xcode/c_study/c_study/memoryAddress.h:44:variableInHeap static int stcIntC is 0x100008108
Program ended with exit code: 0

Based on the above results , The following rules can be found ：
The addresses of functions are together , In the code segment ;
The addresses of variables inside the function are together , On the stack ;
Global variables are placed in data segments , Static variables are also stored in the data segment ;
If a piece of memory is used malloc Created , Then it's in the pile ;

These are the segments of the process in memory ：
Code snippets store executable code 、 String constant 、 const data ;
The data segment stores the initialized global variables 、 Static variables ;
Stack stores local variables 、 Function parameter ;
Heap is used for dynamic memory allocation ;