??????????????C++??????????

???????????? ???????[ 2014/7/2 11:24:38 ] ????????Net ???????

????3. ??????????????????????
????g++???????????????????????????????????????????????????????????????з???????????????point???????沼???
????g++??????????￡?
????[lyt@t468 ~]$ g++ -g -o object object.cpp
????[lyt@t468 ~]$ g++ -g -S -o object.s object.cpp
????object.s???????????????????????????????δ???λ?????????Щ??????????Щ????????????????????????????????????????????????????????????ЩC++???????????????????????????????????
????object???????????gdb?????????????gdb??????????????????λ?????????????з????
????4. ??????point?????????
????C++??????????????????linux?3??ELF???????????????????????????????????????и????????????????????????????????????????????readelf??????????object??????????point?????????з??????????c++filt?????????Щ????????C++?????????????壬???￡?

[lyt@t468 ~]$ readelf -s object | grep point

41: 08048530 10 FUNC WEAK DEFAULT 13 _ZN5point13get_instancesE

49: 0804853a 40 FUNC WEAK DEFAULT 13 _ZN5point4moveEii

56: 080484fa 35 FUNC WEAK DEFAULT 13 _ZN5pointC1Eii

58: 0804851e 18 FUNC WEAK DEFAULT 13 _ZN5pointD1Ev

59: 0804a01c 4 OBJECT GLOBAL DEFAULT 25 _ZN5point7ins_cntE

[lyt@t468 ~]$ c++filt _ZN5point13get_instancesE

point::get_instances

[lyt@t468 ~]$ c++filt _ZN5point4moveEii

point::move(int?? int)

[lyt@t468 ~]$ c++filt _ZN5pointC1Eii

point::point(int?? int)

[lyt@t468 ~]$ c++filt _ZN5pointD1Ev

point::~point()

[lyt@t468 ~]$ c++filt _ZN5point7ins_cntE

point::ins_cnt

????????????????????????point????????????????????move?????????get_instances???????????????????????????????????е?????????point?????????ins_cnt??????????????????????????0804a01c?????????0804a01c ???д????????????ζ???????C++??????д??????????point???????????
????5. point???????沼????????
?????????????????????????????й??????????????????????????????????棬????????????????????????????ν??г????????????????????????????????????沼???
??????????????C++??????????????gdb??point????????????????н??з??????????￡?

(gdb) disassemble /m _ZN5pointC1Eii

Dump of assembler code for function point:

5 point(int x?? int y)

0x080484fa <point+0>: push ebp

0x080484fb <point+1>: mov ebp??esp

6 {

7 this->x = x;

0x080484fd <point+3>: mov eax??DWORD PTR [ebp+0x8]

0x08048500 <point+6>: mov edx??DWORD PTR [ebp+0xc]

0x08048503 <point+9>: mov DWORD PTR [eax]??edx

8 this->y = y;

0x08048505 <point+11>: mov eax??DWORD PTR [ebp+0x8]