C++: accepts invalid export module

[pinskia]

Take:

module
;
export module unexpanded  
 ;

as far I can read P3034R1 this should be invalid as export module is handled during preprocessing and https://eel.is/c++draft/cpp#pre-1 gives module\n; as being an invalid directive too.

[pinskia]

#107168
#90574

[llvmbot]

@llvm/issue-subscribers-clang-modules

Author: Andrew Pinski (pinskia)

Take: ``` module ; export module unexpanded ; ```

as far I can read P3034R1 this should be invalid as export module is handled during preprocessing and https://eel.is/c++draft/cpp#pre-1 gives module\n; as being an invalid directive too.

[llvmbot]

@llvm/issue-subscribers-clang-frontend

Author: Andrew Pinski (pinskia)

Take: ``` module ; export module unexpanded ; ```

as far I can read P3034R1 this should be invalid as export module is handled during preprocessing and https://eel.is/c++draft/cpp#pre-1 gives module\n; as being an invalid directive too.

[anonymouspc]

Approve. I previously reported it to gcc-bugzilla-120845, but finally found that gcc has a correct implemention and it is a bug on clang++ :)

[Bigcheese]

Yes, these are invalid and should be rejected.

[yronglin]

IIUC, this issue will be fixed after P1857R3 landed.