[Simh] Compile fail, linux 64 bit vax780 target

[Mark Pizzolato]

On Friday, May 8, 2020 at 4:38 AM, Mark Wickens wrote:
> I'm getting an error  - undeclared type off64_t when I try and compile 
> the vax780 emulator from a clone of the git repository made today. 
> If I edit sim_fio.c and change off64_t to __off64_t I then get implicit 
> declaration warnings for fopen64, fseeko64 and ftello64 and the 
> Hardware Core Test EVKAA core dumps.
> 
> Thanks in advance, Mark.
> 
> msw at hpm:~/tmp/simh/github/simh$ make vax780 CC="gcc -O2 -g -lm -I." 

The man said, "Doctor, It hurts when I do '...'", Doctor says: "DON'T DO '...'".

Nowhere in any simh documentation OR the makefile that is being used 
does it suggest that you mess with putting a CC= on the make command line.  

Maybe, since I see you've got a '-g' on the command line, you're trying to 
produce a debug target.  The makefile explicitly says DEBUG=1 would 
achieve that.  Therefore:

   $ make DEBUG=1 vax780

would be how to generate a debug target for the vax780 simulator.  
If you do this, things will likely work just fine.  

If you're trying to achieve something else with the CC=, please elaborate
and if there is a real problem, create an issue at 
https://github.com/simh/simh/issues

- Mark