Tom Hayward

Calling Fortran lawyers:
```
integer :: isp
character(len=15), dimension(10) :: species_name
....
associate(spec_name => trim(species_name(isp)))
print *, spec_name
end associate
```
Even without the print statement, gfortran (11.3.0) gives me a SIGABRT at runtime here (though seemingly only if I have read from a namelist file before).
ifort seems happy (different machine).

Is the code legal? gfortran's associate limitations? Am I missing something? Text encoding?
#F90 #Fortran

Aug 9, 2023 at 2:13pmWeb
Show threadMenno Deij - van Rijswijk 🏳️‍🌈Aug 9, 2023

@hattom hmmm, associating with the result of TRIM seems fishy, what about

print *,trim(spec_name)

Show threadTom HaywardAug 9, 2023

@mennodeij

Switching from
```
do isp = 1,nspecies
associate(spec_name => trim(species_name(isp)))
print *, spec_name
end associate
enddo
```
to
```
do isp = 1,nspecies
associate(spec_name => species_name(isp))
print *, trim(spec_name)
end associate
enddo
```
solves the error, but gets rid of approximately 50% of the reason I wanted to use associate in the first place (simplifying strings).

Show threadMenno Deij - van Rijswijk 🏳️‍🌈Aug 9, 2023
@hattom glad that it’s solved; my experience is that strings and Fortran is always awkward, esp. compared to other languages like C++ or Python. Haven’t found a good solution I’m afraid…
Show threadTom HaywardAug 9, 2023
@mennodeij I was still fairly sure it should be allowed. At least I am until convined otherwise.
I'd also like to know why the error goes away if I remove the namelist reading a few lines further up. Seems awfully suspicious.
Show threadTom HaywardAug 9, 2023
@mennodeij Removing the associate entirely (not much point if I can't have the trim() there) was always going to fix it.
I'd just really like to know if this is forbidden by the standard, or an implementation issue.
Show threadarclightAug 9, 2023
@hattom Curious what Compiler Explorer shows for that code: https://godbolt.org/
Compiler Explorer

Compiler Explorer is an interactive online compiler which shows the assembly output of compiled C++, Rust, Go (and many more) code.

Show threadTom HaywardAug 9, 2023
@arclight https://godbolt.org/z/x1zMeYqPj
Compiler Explorer - Fortran (x86-64 gfortran 13.2)

! Type your code here, or load an example. subroutine test_assoc() implicit none integer :: isp character(len=64), dimension(5) :: species_name species_name = "dummy" do isp=1,5 associate(spec_name => trim(species_name(isp))) print *, spec_name end associate enddo end subroutine test_assoc