spin2cpp incorrect placement of decrement operator

SRLM

From this source code:

PUB ReadDelta(EncID): DeltaPos
''Read delta position (relative position value since last time read) of EncID.

  DeltaPos := 0 + -(EncID < TotDelta) * -long[Pos][TotEnc+EncID] + (long[Pos][TotEnc+EncID] := long[Pos][EncID])

spin2cpp generates this C++ code (with linebreaks added for readability):

int32_t quadrature_encoder::Readdelta(int32_t Encid)
{
  int32_t Deltapos = 0;
  Deltapos = 
  (0 + (([b]--[/b](Encid < Totdelta)) * (-((int32_t *)Pos)[((*(int32_t *)&dat[196]) + Encid)]))) 
  	+ (((int32_t *)Pos)[((*(int32_t *)&dat[196]) + Encid)] = ((int32_t *)Pos)[Encid]);
  return Deltapos;
}

I get the following error:

quadrature_encoder.cpp:57:41: error: lvalue required as decrement operand

The correct solution is two negation operators or none.

I'm using spin2cpp version 1.04 from the propgcc version alpha_v1_9_0_2042 on Ubuntu 13.04.

ersmith

Thanks for the bug report. I'll fix that. The work-around for now is to split the boolean expression up into pieces (e.g. with a temporary variable).

SRLM

ersmith wrote: »

Thanks for the bug report. I'll fix that. The work-around for now is to split the boolean expression up into pieces (e.g. with a temporary variable).

That's better than my solution: change the negation in the spin to a *-1