Better code check before compile?

[pedja089]

If your code can start fire, you are doing something really wrong.
For first run, always use PSU with limited power(at least current limiting) with no load at output. Move actuators if you have them manually to check sensors.
If you are creating PSU controlled by PIC(or any mcu), simulate output voltage by applying voltage on feedback.
Any way you must have HW protections that would prevent code to do catastrophic damage.

As all software in this world PBP can have unsuspected bugs that doesn't manifest all time. I found one few years ago. Other compilers have many more than one.
Also as this is all clock dependent, it can freeze due falling oscillator eg lot of vibration can cause crystal to breaks.

I saw result of using PLC with untested code on 300ton press, and actuating pressing and pulling actuators, it wasn't pretty... And that could be avoided if hydraulics was done correctly to disallow engaging both actuators in opposite directions. Or using relay that would disable inputs to other solenoids, etc...

[Ioannis]

Added to the above, no one can guarantee you that the software will always run, even with faults in it. MCU's can stop anytime and hardware must protect itself in that case.

Now, regarding Subs, it is not easy or feasible at all, to check for correct pairs of gosub-return. It is not the same as open-close of { and } in C for example.

In the case of Returns, you can have one or 100 for the same sub. So, how will the compiler check?

Ioannis

[CuriousOne]

it is simple. Just count number of Subroutines and RETURNs and make sure they match, that's all, and already done 30 years ago.

Regarding what happened - it was huge (about 30 meters) Christmas tree 8 channel light controller. The code enables lights at max power for 0.1 second, to give "blink" effect. It worked for 2 years without any issues, until now, when I added some new programs, and forgot to add RETURN, so lights remain at high power for about 10 minutes, instead of 0.5second. It ended up with 9 pieces of solid state relays fried, until thermal switch cut off the power

[CuriousOne]

Even more simple.

Just add different label for subroutines, say, subroutines should start with SUB statement, after the label. At compile time, do check and that's all.

[pedja089]

Then 80% of my programs wouldn't compile. I often use multiple entry point in same sub. And have only one return at end.

[Ioannis]

Or the reverse. Have one entry and multiple exits:

gosub test

....

test:
if x=1 then
   a=1
   return
endif

if x=2 then
   a=2
   return
endif

return

Ioannis

[CuriousOne]

So you're doing it wrong - same for overlapping for-next cycles