New directory tree, with preprocessor/ inside interpretor/.

[Faustine.git] / interpretor / preprocessor / faust-0.9.47mr3 / compiler / evaluate / loopDetector.cpp

diff --git a/interpretor/preprocessor/faust-0.9.47mr3/compiler/evaluate/loopDetector.cpp b/interpretor/preprocessor/faust-0.9.47mr3/compiler/evaluate/loopDetector.cpp
new file mode 100644 (file)
index 0000000..a0855aa
--- /dev/null
+++ b/interpretor/preprocessor/faust-0.9.47mr3/compiler/evaluate/loopDetector.cpp
@@ -0,0 +1,28 @@
+#include "loopDetector.hh"
+#include "ppbox.hh"
+
+bool loopDetector::detect(Tree t)
+{
+    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;
+}