Deal with instrumentation deleting locals

Author: msimacek

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/bytecode/PBytecodeRootNode.java

@@ -3336,7 +3336,7 @@ public Frame getLocalFrame(VirtualFrame frame) {
     @TruffleBoundary
     private static Object doInvokeTraceFunction(PythonContext.TraceEvent event, PFrame pyFrame, Object traceFn, Object nonNullArg) {
         // Force locals dict sync, so that we can sync them back later
-        GetFrameLocalsNode.executeUncached(pyFrame, false);
+        GetFrameLocalsNode.executeUncached(pyFrame, true);
         pyFrame.setLocalsAccessed(false);
         return CallTernaryMethodNode.getUncached().execute(null, traceFn, pyFrame, event.pythonName, nonNullArg);
     }

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/bytecode_dsl/PBytecodeDSLRootNode.java

@@ -629,7 +629,7 @@ private void invokeTraceFunction(VirtualFrame virtualFrame, BytecodeNode locatio
             }
 
             // Force locals dict sync, so that we can sync them back later
-            GetFrameLocalsNode.executeUncached(pyFrame, false);
+            GetFrameLocalsNode.executeUncached(pyFrame, true);
             Object result = doInvokeProfileOrTraceFunction(virtualFrame, location, threadState, traceFn, pyFrame, event.pythonName, nonNullArg);
             syncLocalsBackToFrame(virtualFrame, pyFrame, location);
             // https://github.com/python/cpython/issues/104232

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/frame/GetFrameLocalsNode.java

@@ -41,6 +41,7 @@
 package com.oracle.graal.python.nodes.frame;
 
 import com.oracle.graal.python.PythonLanguage;
+import com.oracle.graal.python.builtins.objects.PNone;
 import com.oracle.graal.python.builtins.objects.cell.PCell;
 import com.oracle.graal.python.builtins.objects.common.HashingStorage;
 import com.oracle.graal.python.builtins.objects.common.HashingStorageNodes.HashingStorageDelItem;
@@ -218,6 +219,10 @@ private static void copyLocalsArray(Frame localFrame, PDict localsDict, Bytecode
                     PCell cell = (PCell) bytecodeNode.getLocalValue(0, localFrame, offset + i);
                     cell.setRef(value);
                 } else {
+                    if (value == null) {
+                        value = PNone.NONE;
+                        // TODO warn: "assigning None to unbound local %s"
+                    }
                     bytecodeNode.setLocalValue(0, localFrame, offset + i, value);
                 }
             }
@@ -229,6 +234,10 @@ private static void copyLocalsArray(Frame localFrame, PDict localsDict, Bytecode
                     PCell cell = (PCell) localFrame.getObject(offset + i);
                     cell.setRef(value);
                 } else {
+                    if (value == null) {
+                        value = PNone.NONE;
+                        // TODO warn: "assigning None to unbound local %s"
+                    }
                     localFrame.setObject(offset + i, value);
                 }
             }