Generate definition file in different qt version

[BigHeadSammy]

Dear all,

I used Qt4.7.3 and mingw4.4 to generate definition file like this

<.def File>
EXPORTS
A@1
B@2
C@3
D@4

Here is my qt pro setting
QMAKE_LFLAGS += -output-def=DefFileNamePath

However, now I use Qt4.8.6 and mingw4.8.2 to generate definition file.
The above method in qt pro setting is not work. (It generate nothing.)
So, I change another way like this in qt pro setting
(https://forum.qt.io/topic/52907/definition-file-with-qt/4)

<.def File>
EXPORTS
_ZTI15DLLE @1 DATA
_ZTI16DLLF @2 DATA
_ZTI17DLLG @3 DATA
_ZTI18DLLH @4 DATA
A@1
B@2
C@3
D@4

Here is my qt pro setting
QMAKE_LFLAGS += -Wl,--output-def,DefFileNamePath

if i use "QMAKE_LFLAGS += -Wl,--output-def,DefFileNamePath" this way to generate definition file,
it will cause unexpected error like crash when i use relate DLL later.

i have two questions:

(1) What difference between "QMAKE_LFLAGS += -output-def=DefFileNamePath" and "QMAKE_LFLAGS += -Wl,--output-def,DefFileNamePath"?

(2) Is there any way to generate the same definition file format whatever in qt4.7.3+mingw4.4 or qt4.8.6+mingw4.8.2 ?

please give me some advice

thanks!