Same Target Had been compile Twice with different Compile flags, but the prebuild header file hadn't been recreated.

[lxy9527]

as the title , we meet this problem ,
below ,we will make a example to explain what i meet .
In my CMakeLists, we had build three target , A , B , C
both A and B with depend C .

1. build A , C target , compile flag with -DLE ,
2. build B , C target , compile flag with -DBG
   when we build A C target with -DLE had been successed , we start build B, C target with -DBG
   then the prebuild head file hadn't recreate , so an error had occur as below .
   cc1: warning: xxx_C_prefix.h.gch: not used because `LE' not defined [-Winvalid-pch]

Is there any comman can force recreate the prebuild header file ?

[lxy9527]

I think the _pchFile need depend xxx/flags.make , i will search the depend method in the CMake website ...

[lxy9527]

As I Though ， I did a test that i make _pchFile depend absolute path /xxx/xxx/flags.make, the prebuild header file can be recreate ,
but i don't known the MACRO of this file ,