轉自：http://blog.csdn.net/magictong/article/details/6105160
1>Linking...
1>msvcrt.lib(ti_inst.obj) : error LNK2005: "private: __thiscall type_info::type_info(class type_info const &)" (??0type_info@@AAE@ABV0@@Z) already defined in LIBCMT.lib(typinfo.obj)
1>msvcrt.lib(ti_inst.obj) : error LNK2005: "private: class type_info & __thiscall type_info::operator=(class type_info const &)" (??4type_info@@AAEAAV0@ABV0@@Z) already defined in LIBCMT.lib(typinfo.obj)
1>msvcrt.lib(MSVCR80.dll) : error LNK2005: _malloc already defined in LIBCMT.lib(malloc.obj)
1>msvcrt.lib(MSVCR80.dll) : error LNK2005: _free already defined in LIBCMT.lib(free.obj)
1>LIBCMT.lib(crt0init.obj) : warning LNK4098: defaultlib 'msvcrt.lib' conflicts with use of other libs; use /NODEFAULTLIB:library
1>../Output/ImpactLib/TSIptLibBuilder.exe : fatal error LNK1169: one or more multiply defined symbols found
神馬玩意？糾結的鏈接報錯，不過看加粗那段，它給了個解決方法……把vc6的工程轉成vs2005的時候經常出現這個問題，原因就是你使用的某些外部靜態庫編譯時使用的標準庫和當前工程使用的標準庫的衝突了。解決方法就是忽略衝突的標準庫，有點蛋疼。其實具體到vc6和vs2005的話，vs2005已經沒有單線程編譯選項了。
vs2005的設置方法如下圖所示：打開工程屬性對話框，選擇鏈接下Input，在Ignore Specific Library裏面輸入要忽略的庫即可（有多個 的話用逗號隔開）。另外具體這裏的話，如果是release版本要忽略LIBCMT.lib，debug版本要忽略LIBCMTD.lib。
到MSDN上搜一下LNK4098（講的很詳細，慢慢看）：
Error Message
defaultlib 'library' conflicts with use of other libs; use /NODEFAULTLIB:library
You are trying to link with incompatible libraries.
 Note |
|---|
|
The run-time libraries now contain directives to prevent mixing different types. You will receive this warning if you try to use different types or debug and non-debug versions of the run-time library in the same program. For example, if you compiled one file to use one kind of run-time library and another file to use another kind (for example, single-threaded versus multithreaded) and tried to link them, you will get this warning. You should compile all source files to use the same run-time library. See the Use Run-Time Library (/MD, /MT, /LD) compiler options for more information. |
You can use the linker's /VERBOSE:LIB switch to determine which libraries the linker is searching. If you receive LNK4098 and want to create an executable file that uses, for example, the single-threaded, non-debug run-time libraries, use the /VERBOSE:LIB option to find out which libraries the linker is searching. The linker should print LIBC.lib and not LIBCMT.lib, MSVCRT.lib, LIBCD.lib, LIBCMTD.lib, or MSVCRTD.lib as the libraries searched. You can tell the linker to ignore the incorrect run-time libraries by using/NODEFAULTLIB for each library you want to ignore.
The table below shows which libraries should be ignored depending on which run-time library you want to use.
| To use this run-time library | Ignore these libraries |
|---|---|
|
Single-threaded (libc.lib) |
libcmt.lib, msvcrt.lib, libcd.lib, libcmtd.lib, msvcrtd.lib |
|
Multithreaded (libcmt.lib) |
libc.lib, msvcrt.lib, libcd.lib, libcmtd.lib, msvcrtd.lib |
|
Multithreaded using DLL (msvcrt.lib) |
libc.lib, libcmt.lib, libcd.lib, libcmtd.lib, msvcrtd.lib |
|
Debug Single-threaded (libcd.lib) |
libc.lib, libcmt.lib, msvcrt.lib, libcmtd.lib, msvcrtd.lib |
|
Debug Multithreaded (libcmtd.lib) |
libc.lib, libcmt.lib, msvcrt.lib, libcd.lib, msvcrtd.lib |
|
Debug Multithreaded using DLL (msvcrtd.lib) |
libc.lib, libcmt.lib, msvcrt.lib, libcd.lib, libcmtd.lib |
For example, if you received this warning and you want to create an executable file that uses the non-debug, single-threaded version of the run-time libraries, you could use the following options with the linker: