Update

Author: corona10

Include/internal/pycore_interp_structs.h

@@ -899,8 +899,6 @@ struct _is {
     struct _stoptheworld_state stoptheworld;
     struct _qsbr_shared qsbr;
 
-    struct _PyUOpInstruction *jit_uop_buffer;
-
 #if defined(Py_GIL_DISABLED)
     struct _mimalloc_interp_state mimalloc;
     struct _brc_state brc;  // biased reference counting state
@@ -952,6 +950,8 @@ struct _is {
     struct callable_cache callable_cache;
     PyObject *common_consts[NUM_COMMON_CONSTANTS];
     bool jit;
+    bool compiling;
+    struct _PyUOpInstruction *jit_uop_buffer;
     struct _PyExecutorObject *executor_list_head;
     struct _PyExecutorObject *executor_deletion_list_head;
     struct _PyExecutorObject *cold_executor;

Python/bytecodes.c

@@ -2961,7 +2961,9 @@ dummy_func(
                     start--;
                 }
                 _PyExecutorObject *executor;
+                assert(!_PyInterpreterState_GET()->compiling);
                 int optimized = _PyOptimizer_Optimize(frame, start, &executor, 0);
+                assert(!_PyInterpreterState_GET()->compiling);
                 if (optimized <= 0) {
                     this_instr[1].counter = restart_backoff_counter(counter);
                     ERROR_IF(optimized < 0);

Python/generated_cases.c.h

@@ -116,7 +116,10 @@ _PyOptimizer_Optimize(
     _PyExecutorObject **executor_ptr, int chain_depth)
 {
     _PyStackRef *stack_pointer = frame->stackpointer;
-    assert(_PyInterpreterState_GET()->jit);
+    PyInterpreterState *interp = _PyInterpreterState_GET();
+    assert(interp->jit);
+    assert(!interp->compiling);
+    interp->compiling = true;
     // The first executor in a chain and the MAX_CHAIN_DEPTH'th executor *must*
     // make progress in order to avoid infinite loops or excessively-long
     // side-exit chains. We can only insert the executor into the bytecode if
@@ -125,12 +128,14 @@ _PyOptimizer_Optimize(
     bool progress_needed = chain_depth == 0;
     PyCodeObject *code = _PyFrame_GetCode(frame);
     assert(PyCode_Check(code));
+    int ret = 0;
     if (progress_needed && !has_space_for_executor(code, start)) {
-        return 0;
+        goto end;
     }
     int err = uop_optimize(frame, start, executor_ptr, (int)(stack_pointer - _PyFrame_Stackbase(frame)), progress_needed);
     if (err <= 0) {
-        return err;
+        ret = err;
+        goto end;
     }
     assert(*executor_ptr != NULL);
     if (progress_needed) {
@@ -143,7 +148,7 @@ _PyOptimizer_Optimize(
              * it might get confused by the executor disappearing,
              * but there is not much we can do about that here. */
             Py_DECREF(*executor_ptr);
-            return 0;
+            goto end;
         }
         insert_executor(code, start, index, *executor_ptr);
     }
@@ -152,7 +157,9 @@ _PyOptimizer_Optimize(
     }
     (*executor_ptr)->vm_data.chain_depth = chain_depth;
     assert((*executor_ptr)->vm_data.valid);
-    return 1;
+end:
+    interp->compiling = false;
+    return ret;
 }
 
 static _PyExecutorObject *
@@ -1281,6 +1288,7 @@ uop_optimize(
     _PyBloomFilter dependencies;
     _Py_BloomFilter_Init(&dependencies);
     PyInterpreterState *interp = _PyInterpreterState_GET();
+    assert(interp->compiling);
     if (interp->jit_uop_buffer == NULL) {
         interp->jit_uop_buffer = (_PyUOpInstruction *)_PyObject_VirtualAlloc(UOP_BUFFER_SIZE);
         if (interp->jit_uop_buffer == NULL) {

Python/optimizer.c

@@ -577,6 +577,7 @@ init_interpreter(PyInterpreterState *interp,
     }
     interp->_code_object_generation = 0;
     interp->jit = false;
+    interp->compiling = false;
     interp->executor_list_head = NULL;
     interp->executor_deletion_list_head = NULL;
     interp->executor_deletion_list_remaining_capacity = 0;