Python: CG trace: Handle LOAD_DEREF

python/tools/recorded-call-graph-metrics/example/problem-2.py

@@ -0,0 +1,25 @@
+def func(func_arg):
+    print("func")
+
+    def func2():
+        print("func2")
+        return func_arg()
+
+    func2()
+
+
+def nop():
+    print("nop")
+    pass
+
+
+func(nop)
+
+
+"""
+Needs handling of LOAD_DEREF. Disassembled bytecode looks like:
+
+  6           8 LOAD_DEREF               0 (func_arg)
+             10 CALL_FUNCTION            0
+             12 RETURN_VALUE
+"""

python/tools/recorded-call-graph-metrics/src/cg_trace/bytecode_reconstructor.py

@@ -143,7 +143,7 @@ def expr_from_instruction(instructions: List[Instruction], index: int) -> Byteco
 
     LOGGER.debug(f"expr_from_instruction: {inst} {index=}")
 
-    if inst.opname in ["LOAD_GLOBAL", "LOAD_FAST", "LOAD_NAME"]:
+    if inst.opname in ["LOAD_GLOBAL", "LOAD_FAST", "LOAD_NAME", "LOAD_DEREF"]:
         return BytecodeVariableName(inst.argval)
 
     elif inst.opname in ["LOAD_CONST"]: