Fortran Preprocessor ignores defined preprocessor variables in VS IDE?

[JantN]

I try to compile software, which was developed in Linux, for Windows. It compiles correctly in Linux. The software contains various preprocessor variables. 

An example from the original source code is:

#if (_DP==0)
use iso_fortran_env,only:output_unit,int32,int64,real32,real64,wp=>real32
#else
use iso_fortran_env,only:output_unit,int32,int64,real32,real64,wp=>real64
#endif

The command line in Visual Studio IDE (Microsoft Visual Studio Community 2022 (64-bit);
Version 17.0.5), which summarises my settings, is:

/nologo /debug:full /Od /fpp /DDP /DPARDISO /DSPAINV /warn:interfaces /module:"x64\Debug\\" /object:"x64\Debug\\" /Fd"x64\Debug\vc170.pdb" /traceback /check:bounds /check:stack /libs:static /threads /dbglibs /Qmkl:parallel /c

The i90 file gives:

use iso_fortran_env,only:output_unit,int32,int64,real32,real64,wp=>real32

So, despite using "/fpp /DDP", fpp evaluates the original source code with DP=0. I also tried /DDP=1, but no difference. There are no #DEFINE preprocessor statements in the source code. In fact, all preprocessor variables are taken as 0.

Any suggestions what I am doing wrong? 

Thanks.

[Arjen_Markus · Accepted solution]

I think you should use: -D_DP instead of -DDP - see the #if line.

[JantN]

Thank you. Embarassingly obvious, but I did not see it. And yes, it works.

[Arjen_Markus]

It happens to everyone from time to time :).