Fix bad line events

brandtbucher · brandtbucher · commit 70d28d8ab361 · 2023-07-19T09:24:11.000-07:00
diff --git a/Python/bytecodes.c b/Python/bytecodes.c
@@ -2182,7 +2182,14 @@ dummy_func(
             JUMPBY(1-oparg);
             #if ENABLE_SPECIALIZATION
             here[1].cache += (1 << OPTIMIZER_BITS_IN_COUNTER);
-            if (here[1].cache > tstate->interp->optimizer_backedge_threshold) {
+            if (here[1].cache > tstate->interp->optimizer_backedge_threshold &&
+                // Double-check that the opcode isn't instrumented or something:
+                here->op.code == JUMP_BACKWARD &&
+                // _PyOptimizer_BackEdge is going to change frame->prev_instr,
+                // which breaks line event calculations:
+                next_instr->op.code != INSTRUMENTED_LINE
+                )
+            {
                 OBJECT_STAT_INC(optimization_attempts);
                 frame = _PyOptimizer_BackEdge(frame, here, next_instr, stack_pointer);
                 if (frame == NULL) {
diff --git a/Python/generated_cases.c.h b/Python/generated_cases.c.h
diff --git a/Python/optimizer.c b/Python/optimizer.c
@@ -155,6 +155,7 @@ PyUnstable_SetOptimizer(_PyOptimizerObject *optimizer)
 _PyInterpreterFrame *
 _PyOptimizer_BackEdge(_PyInterpreterFrame *frame, _Py_CODEUNIT *src, _Py_CODEUNIT *dest, PyObject **stack_pointer)
 {
+    assert(src->op.code == JUMP_BACKWARD);
     PyCodeObject *code = (PyCodeObject *)frame->f_executable;
     assert(PyCode_Check(code));
     PyInterpreterState *interp = _PyInterpreterState_GET();

Original file line number	Diff line number	Diff line change
`@@ -155,6 +155,7 @@ PyUnstable_SetOptimizer(_PyOptimizerObject *optimizer)`
`155`	`155`	`_PyInterpreterFrame *`
`156`	`156`	`_PyOptimizer_BackEdge(_PyInterpreterFrame frame, _Py_CODEUNIT src, _Py_CODEUNIT dest, PyObject *stack_pointer)`
`157`	`157`	`{`
	`158`	`+ assert(src->op.code == JUMP_BACKWARD);`
`158`	`159`	`PyCodeObject code = (PyCodeObject )frame->f_executable;`
`159`	`160`	`assert(PyCode_Check(code));`
`160`	`161`	`PyInterpreterState *interp = _PyInterpreterState_GET();`