[flang] preprocessor issue with openmp conditional code

[shivaramaarao]

consider the following example

program main
integer NDIR
#define BLANKMACRO

BLANKMACRO !$ NDIR=0
end program main

flang ignores the conditional code

$flang -fopenmp -E -fopenmp -ffree-form t2.f90

flang-21: warning: OpenMP support in flang is still experimental [-Wexperimental-option]
#line "./t2.f90" 4
end program

[llvmbot]

@llvm/issue-subscribers-flang-frontend

Author: None (shivaramaarao)

consider the following example

program main
integer NDIR
#define BLANKMACRO

BLANKMACRO !$ NDIR=0
end program main

flang ignores the conditional code

$flang -fopenmp -E -fopenmp -ffree-form t2.f90

flang-21: warning: OpenMP support in flang is still experimental [-Wexperimental-option]
#line "./t2.f90" 4
end program

[eugeneepshteyn]

Yes, seems to be a bug. OpenMP 6.0 spec says the following: "The sentinel can appear in any column as long as it is preceded only by white space."