interpretor/preprocessor/faust-0.9.47mr3/compiler/evaluate/loopDetector.cpp

   1 #include "loopDetector.hh"
   2 #include "ppbox.hh"
   3
   4 bool loopDetector::detect(Tree t)
   5 {
   6     fPhase++;
   7     int w = fPhase%fBuffersize;
   8     fBuffer[w] = t;
   9     if ((fPhase%fCheckperiod) == 0) {
  10         // time to check for a cycle
  11         for (int i=1; i<fBuffersize; i++) {
  12             int r = w-i; if (r < 0) { r += fBuffersize; }
  13             assert(r>=0);
  14             assert(r<fBuffersize);
  15             assert(r != w);
  16             if (fBuffer[r] == t) {
  17                 cerr    << "ERROR : after "
  18                         << fPhase
  19                         << " evaluation steps, the compiler has detected an endless evaluation cycle of "
  20                         << i
  21                         << " steps"
  22                         << endl;
  23                 exit(1);
  24             }
  25         }
  26     }
  27     return false;
  28 }