#include <loopDetector.hh>

Public Member Functions
	loopDetector (int buffersize, int checkperiod)
bool	detect (Tree t)
Private Attributes
const int	fBuffersize
const int	fCheckperiod
vector< Tree >	fBuffer
int	fPhase

Detailed Description

Definition at line 41 of file loopDetector.hh.

Constructor & Destructor Documentation

loopDetector::loopDetector	(	int	buffersize,
		int	checkperiod
	)		`[inline]`

Definition at line 49 of file loopDetector.hh.

: fBuffersize(buffersize), fCheckperiod(checkperiod), fBuffer(buffersize), fPhase(0) {}

Member Function Documentation

bool loopDetector::detect ( Tree t )

Definition at line 4 of file loopDetector.cpp.

References fBuffer, fBuffersize, fCheckperiod, and fPhase.

Referenced by eval().

{
    fPhase++;
    int w = fPhase%fBuffersize;
    fBuffer[w] = t;
    if ((fPhase%fCheckperiod) == 0) {
        // time to check for a cycle
        for (int i=1; i<fBuffersize; i++) {
            int r = w-i; if (r < 0) { r += fBuffersize; }
            assert(r>=0);
            assert(r<fBuffersize);
            assert(r != w);
            if (fBuffer[r] == t) {
                cerr    << "ERROR : after "
                        << fPhase
                        << " evaluation steps, the compiler has detected an endless evaluation cycle of "
                        << i
                        << " steps"
                        << endl;
                exit(1);
            }
        }
    }
    return false;
}