c语言:基于函数指针的两个示例分析

后来别人通过反汇编发现的情况:
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如下红色的几行，main与strcmp此时为常量（你也会发现没有.data段），在汇编代码中他是把这两个常量写入函数堆栈，然后调用函数，作出对比，然后输出。而你所说的 f ，也就是函数参数，实际上它只作为预分配的参考（汇编代码中，你是找不到 f 的）。
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.file "1.c"
.text
.globl main
.type main, @function
main:
leal 4(%esp), %ecx
andl $-16, %esp
pushl -4(%ecx)
pushl %ebp
movl %esp, %ebp
pushl %ecx
subl $4, %esp
movl $strcmp, (%esp)
call tell_me
movl $main, %eax
movl %eax, (%esp)
call tell_me
movl $0, %eax
addl $4, %esp
popl %ecx
popl %ebp
leal -4(%ecx), %esp
ret
.size main, .-main
.section .rodata
.LC0:
.string "Address of strcmp(): %p\n"
.LC1:
.string "Function address: %p\n"
.text
.globl tell_me
.type tell_me, @function
tell_me:
pushl %ebp
movl %esp, %ebp
subl $8, %esp
cmpl $strcmp, 8(%ebp)
jne .L4
movl 8(%ebp), %eax
movl %eax, 4(%esp)
movl $.LC0, (%esp)
call printf
jmp .L6
.L4:
movl 8(%ebp), %eax
movl %eax, 4(%esp)
movl $.LC1, (%esp)
call printf
.L6:
leave
ret
.size tell_me, .-tell_me
.ident "GCC: (Ubuntu 4.3.3-5ubuntu4) 4.3.3"
.section .note.GNU-stack,"",@progbits
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00401090 push ebp //第一题的反汇编
00401091 mov ebp,esp
00401093 sub esp,40h
00401096 push ebx
00401097 push esi
00401098 push edi
00401099 lea edi,[ebp-40h]
0040109C mov ecx,10h
004010A1 mov eax,0CCCCCCCCh //应该说在函数传递时，f与strcmp的地址都相同
004010A6 rep stos dword ptr [edi]
13: printf("%0x\t%0x\n",f,strcmp); //看这里，输出f与strcmp的地址是相同的
004010A8 push offset strcmp (004011a0)
004010AD mov eax,dword ptr [ebp+8]
004010B0 push eax
004010B1 push offset string "%0x\t%0x\n" (0042201c)
004010B6 call printf (00401120)
004010BB add esp,0Ch
14: if (f == strcmp) /* <-----我不理解这里*/ //比较后，输出的地址同样是一样的，
004010BE cmp dword ptr [ebp+8],offset strcmp (004011a0)
004010C5 jne tell_me+4Ah (004010da)
15: printf("Address of strcmp(): %0x\n", f);
004010C7 mov ecx,dword ptr [ebp+8]
004010CA push ecx
004010CB push offset string "Address of strcmp(): %0x\n" (00422044)
004010D0 call printf (00401120)
004010D5 add esp,8
16: else
004010D8 jmp tell_me+5Bh (004010eb)
17: printf("Function address: %p\n", f);
004010DA mov edx,dword ptr [ebp+8]
004010DD push edx
004010DE push offset string "Function address: %p\n" (00422028)
004010E3 call printf (00401120)
004010E8 add esp,8=======================================================

第二个:
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