栈区、堆区、静态区、常量区、代码区演示

这是老问题了，今天被同事问到，因此写了一个demo，代码如下：

#include <stdio.h> #include <string.h> #include <stdlib.h> #define MAX_LENGTH 32 struct node { void *address; char area[16]; char desc[128]; }; typedef struct node Node; Node array[MAX_LENGTH]; int size = 0; void add_item(void *addr, const char *area, const char *desc) { array[size].address = addr; strcpy(array[size].area, area); strcpy(array[size].desc, desc); size++; } void print_item() { int i; for ( i = 0; i < size; i++ ) { printf("%p\t%s\t%s\n", array[i].address, array[i].area, array[i].desc); } } void swap_item(Node *a, Node *b) { void *t = (*a).address; (*a).address = (*b).address; (*b).address = t; char s[128]; strcpy(s, (*a).area); strcpy((*a).area, (*b).area); strcpy((*b).area, s); strcpy(s, (*a).desc); strcpy((*a).desc, (*b).desc); strcpy((*b).desc, s); } void sort_item(Node *array, int n) { float factor = 1.3; int g = n; int swapped = 1; while ( g>1 || swapped ) { g = (g>1) ? g/factor : g; swapped = 0; int i = 0; while ( g+i < n ) { if ( array[i].address < array[g+i].address ) { swap_item(&array[i], &array[g+i]); swapped = 1; } i++; } } } char *a() { static int dummya = 0; add_item((void *)&dummya, "STATIC", "address of dummy a"); printf("a() addr of a() in CODE area : %p\n", a); add_item((void *)a, "CODE", "address of a()"); //printf("a() addr of main() is %p\n", main); // this is error, main undeclared char p[] = "hello, everyone!"; printf("a() pointing to a STACK area : %p\n", p); add_item((void *)p, "STACK", "address of p in a()"); printf("a() it's content : %s\n", p); printf("a() addr of the const value : %p\n", "hello, everyone!"); return p; } char *b() { static int dummyb = 0; add_item((void *)&dummyb, "STATIC", "address of dummy b"); printf("b() addr of b() in CODE area : %p\n", b); add_item((void *)b, "CODE", "address of b()"); //printf("b() addr of c() : %p\n", c); // this is error, c undeclared char *p = "hello, everyone!"; printf("b() pointing to a CONST area : %p\n", p); add_item((void *)p, "CONST", "address of p in b()"); printf("b() it's content : %s\n", p); printf("b() addr of the const value : %p\n", "hello, everyone!"); return p; } char *c() { static int dummyc = 0; add_item((void *)&dummyc, "STATIC", "address of dummy c"); printf("c() addr of c() in CODE area : %p\n", c); add_item((void *)c, "CODE", "address of c()"); char *p = malloc(100); strcpy(p, "hello, everyone!"); printf("c() pointing to a HEAP area : %p\n", p); add_item((void *)p, "HEAP", "address of p in c()"); printf("c() it's content : %s\n", p); printf("c() addr of the const value : %p\n", "hello, everyone!"); return p; } int main() { static int dummym = 0; add_item((void *)&dummym, "STATIC", "address of dummy main"); char *r1 = a(); printf("main() addr of a() : %p\n", a); printf("main() pointer recv from a() : %p\n", r1); printf("main() content recv from a() : %s\n", r1); printf("-----------------\n"); char *r2 = b(); printf("main() addr of b() : %p\n", b); printf("main() pointer recv from b() : %p\n", r2); printf("main() content recv from b() : %s\n", r2); printf("-----------------\n"); char *r3 = c(); printf("main() addr of c() : %p\n", c); printf("main() pointer recv from c() : %p\n", r3); printf("main() content recv from c() : %s\n", r3); printf("-----------------\n"); free(r3); printf("main() addr of the const value: %p\n", "hello, everyone!"); add_item((void *)"hello, everyone!", "CONST", "address of const string"); printf("main() addr of main() in CODE area : %p\n", main); add_item((void *)main, "CODE", "address of main()"); add_item((void *)array, "STATIC", "address of GLOBAL array"); add_item((void *)&size, "STATIC", "address of GLOBAL size"); printf("-----------------\n"); printf("sorted result:\n"); int i = 0; add_item((void *)&i, "STACK", "address of i in main()"); sort_item(array, size); print_item(); return 0; }

在各平台的执行结果如下，可以看出各段的位置差异：

Windows 2000

a() addr of a() in CODE area : 004016B3 a() pointing to a STACK area : 0022FEFF a() it's content : hello, everyone! a() addr of the const value : 00404124 main() addr of a() : 004016B3 main() pointer recv from a() : 0022FEFF main() content recv from a() : w ----------------- b() addr of b() in CODE area : 0040177D b() pointing to a CONST area : 00404124 b() it's content : hello, everyone! b() addr of the const value : 00404124 main() addr of b() : 0040177D main() pointer recv from b() : 00404124 main() content recv from b() : hello, everyone! ----------------- c() addr of c() in CODE area : 00401830 c() pointing to a HEAP area : 00474C40 c() it's content : hello, everyone! c() addr of the const value : 00404124 main() addr of c() : 00401830 main() pointer recv from c() : 00474C40 main() content recv from c() : hello, everyone! ----------------- main() addr of the const value: 00404124 main() addr of main() in CODE area : 00401906 ----------------- sorted result: 00474C40 HEAP address of p in c() 004060E0 STATIC address of GLOBAL array 00406030 STATIC address of dummy a 0040602C STATIC address of dummy b 00406028 STATIC address of dummy c 00406024 STATIC address of dummy main 00406020 STATIC address of GLOBAL size 00404124 CONST address of p in b() 00404124 CONST address of const string 00401906 CODE address of main() 00401830 CODE address of c() 0040177D CODE address of b() 004016B3 CODE address of a() 0022FF40 STACK address of i in main() 0022FEFF STACK address of p in a()

Linux

a() addr of a() in CODE area : 0x40091d a() pointing to a STACK area : 0x7fff82eaf840 a() it's content : hello, everyone! a() addr of the const value : 0x400edc main() addr of a() : 0x40091d main() pointer recv from a() : 0x7fff82eaf840 main() content recv from a() : hello, everyone! ----------------- b() addr of b() in CODE area : 0x4009d4 b() pointing to a CONST area : 0x400edc b() it's content : hello, everyone! b() addr of the const value : 0x400edc main() addr of b() : 0x4009d4 main() pointer recv from b() : 0x400edc main() content recv from b() : hello, everyone! ----------------- c() addr of c() in CODE area : 0x400a73 c() pointing to a HEAP area : 0x1448d010 c() it's content : hello, everyone! c() addr of the const value : 0x400edc main() addr of c() : 0x400a73 main() pointer recv from c() : 0x1448d010 main() content recv from c() : hello, everyone! ----------------- main() addr of the const value: 0x400edc main() addr of main() in CODE area : 0x400b3b ----------------- sorted result: 0x7fff82eaf874 STACK address of i in main() 0x7fff82eaf840 STACK address of p in a() 0x1448d010 HEAP address of p in c() 0x601700 STATIC address of GLOBAL array 0x6016fc STATIC address of dummy main 0x6016f8 STATIC address of dummy c 0x6016f4 STATIC address of dummy b 0x6016f0 STATIC address of dummy a 0x6016ec STATIC address of GLOBAL size 0x400edc CONST address of p in b() 0x400edc CONST address of const string 0x400b3b CODE address of main() 0x400a73 CODE address of c() 0x4009d4 CODE address of b() 0x40091d CODE address of a()

Tru64

a() addr of a() in CODE area : 120001840 a() pointing to a STACK area : 11fffbfa8 a() it's content : hello, everyone! a() addr of the const value : 140000100 main() addr of a() : 120001840 main() pointer recv from a() : 11fffbfa8 main() content recv from a() : ----------------- b() addr of b() in CODE area : 120001950 b() pointing to a CONST area : 140000168 b() it's content : hello, everyone! b() addr of the const value : 140000210 main() addr of b() : 120001950 main() pointer recv from b() : 140000168 main() content recv from b() : hello, everyone! ----------------- c() addr of c() in CODE area : 120001a40 c() pointing to a HEAP area : 140004100 c() it's content : hello, everyone! c() addr of the const value : 140000320 main() addr of c() : 120001a40 main() pointer recv from c() : 140004100 main() content recv from c() : hello, everyone! ----------------- main() addr of the const value: 140000510 main() addr of main() in CODE area : 120001b70 ----------------- sorted result: 140004100 HEAP address of p in c() 140000870 STATIC address of GLOBAL array 14000072c STATIC address of dummy main 140000728 STATIC address of dummy a 140000724 STATIC address of dummy b 140000720 STATIC address of dummy c 1400006a0 STATIC address of GLOBAL size 140000528 CONST address of const string 140000168 CONST address of p in b() 120001b70 CODE address of main() 120001a40 CODE address of c() 120001950 CODE address of b() 120001840 CODE address of a() 11fffbfe0 STACK address of i in main() 11fffbfa8 STACK address of p in a()

Solaris

a() addr of a() in CODE area : 10c68 a() pointing to a STACK area : ffbfece0 a() it's content : hello, everyone! a() addr of the const value : 112a8 main() addr of a() : 10c68 main() pointer recv from a() : ffbfece0 main() content recv from a() : ÿ¿í ----------------- b() addr of b() in CODE area : 10d64 b() pointing to a CONST area : 112a8 b() it's content : hello, everyone! b() addr of the const value : 112a8 main() addr of b() : 10d64 main() pointer recv from b() : 112a8 main() content recv from b() : hello, everyone! ----------------- c() addr of c() in CODE area : 10e38 c() pointing to a HEAP area : 22c08 c() it's content : hello, everyone! c() addr of the const value : 112a8 main() addr of c() : 10e38 main() pointer recv from c() : 22c08 main() content recv from c() : hello, everyone! ----------------- main() addr of the const value: 112a8 main() addr of main() in CODE area : 10f28 ----------------- sorted result: ffbfed68 STACK address of i in main() ffbfece0 STACK address of p in a() 22c08 HEAP address of p in c() 2197c STATIC address of GLOBAL array 21978 STATIC address of dummy main 21974 STATIC address of dummy c 21970 STATIC address of dummy b 2196c STATIC address of dummy a 21968 STATIC address of GLOBAL size 112a8 CONST address of p in b() 112a8 CONST address of const string 10f28 CODE address of main() 10e38 CODE address of c() 10d64 CODE address of b() 10c68 CODE address of a()

HP-UX

a() addr of a() in CODE area : 777daa80 a() pointing to a STACK area : 7fffe7d0 a() it's content : hello, everyone! a() addr of the const value : 40010020 main() addr of a() : 777daa80 main() pointer recv from a() : 7fffe7d0 main() content recv from a() : ----------------- b() addr of b() in CODE area : 777daa90 b() pointing to a CONST area : 40010040 b() it's content : hello, everyone! b() addr of the const value : 40010060 main() addr of b() : 777daa90 main() pointer recv from b() : 40010040 main() content recv from b() : hello, everyone! ----------------- c() addr of c() in CODE area : 777daaa0 c() pointing to a HEAP area : 400157d0 c() it's content : hello, everyone! c() addr of the const value : 40010080 main() addr of c() : 777daaa0 main() pointer recv from c() : 400157d0 main() content recv from c() : hello, everyone! ----------------- main() addr of the const value: 400100a0 main() addr of main() in CODE area : 777daab0 ----------------- sorted result: 7fffe800 STACK address of i in main() 7fffe7d0 STACK address of p in a() 777daab0 CODE address of main() 777daaa0 CODE address of c() 777daa90 CODE address of b() 777daa80 CODE address of a() 400157d0 HEAP address of p in c() 40010190 STATIC address of GLOBAL array 40010170 STATIC address of GLOBAL size 4001016c STATIC address of dummy main 40010168 STATIC address of dummy c 40010164 STATIC address of dummy b 40010160 STATIC address of dummy a 400100c0 CONST address of const string 40010040 CONST address of p in b()