gh-111789: Simplify bytecodes.c by using PyDict_GetItemRef() (GH-111978)

3 files changed, 51 insertions, 140 deletions

diff --git a/Python/bytecodes.c b/Python/bytecodes.c
index d914f27ba9d..bb8123ee0bd 100644
--- a/Python/bytecodes.c
+++ b/Python/bytecodes.c
@@ -643,16 +643,12 @@ dummy_func(
         inst(BINARY_SUBSCR_DICT, (unused/1, dict, sub -- res)) {
             DEOPT_IF(!PyDict_CheckExact(dict));
             STAT_INC(BINARY_SUBSCR, hit);
-            res = PyDict_GetItemWithError(dict, sub);
-            if (res == NULL) {
-                if (!_PyErr_Occurred(tstate)) {
-                    _PyErr_SetKeyError(sub);
-                }
-                DECREF_INPUTS();
-                ERROR_IF(true, error);
+            int rc = PyDict_GetItemRef(dict, sub, &res);
+            if (rc == 0) {
+                _PyErr_SetKeyError(sub);
             }
-            Py_INCREF(res);  // Do this before DECREF'ing dict, sub
             DECREF_INPUTS();
+            ERROR_IF(rc <= 0, error); // not found or error
         }
 
         inst(BINARY_SUBSCR_GETITEM, (unused/1, container, sub -- unused)) {
@@ -1349,14 +1345,10 @@ dummy_func(
                 GOTO_ERROR(error);
             }
             if (v == NULL) {
-                v = PyDict_GetItemWithError(GLOBALS(), name);
-                if (v != NULL) {
-                    Py_INCREF(v);
-                }
-                else if (_PyErr_Occurred(tstate)) {
+                if (PyDict_GetItemRef(GLOBALS(), name, &v) < 0) {
                     GOTO_ERROR(error);
                 }
-                else {
+                if (v == NULL) {
                     if (PyMapping_GetOptionalItem(BUILTINS(), name, &v) < 0) {
                         GOTO_ERROR(error);
                     }
@@ -1383,14 +1375,10 @@ dummy_func(
                 GOTO_ERROR(error);
             }
             if (v == NULL) {
-                v = PyDict_GetItemWithError(GLOBALS(), name);
-                if (v != NULL) {
-                    Py_INCREF(v);
-                }
-                else if (_PyErr_Occurred(tstate)) {
+                if (PyDict_GetItemRef(GLOBALS(), name, &v) < 0) {
                     GOTO_ERROR(error);
                 }
-                else {
+                if (v == NULL) {
                     if (PyMapping_GetOptionalItem(BUILTINS(), name, &v) < 0) {
                         GOTO_ERROR(error);
                     }
@@ -1663,34 +1651,17 @@ dummy_func(
                 ERROR_IF(true, error);
             }
             /* check if __annotations__ in locals()... */
-            if (PyDict_CheckExact(LOCALS())) {
-                ann_dict = _PyDict_GetItemWithError(LOCALS(),
-                                                    &_Py_ID(__annotations__));
-                if (ann_dict == NULL) {
-                    ERROR_IF(_PyErr_Occurred(tstate), error);
-                    /* ...if not, create a new one */
-                    ann_dict = PyDict_New();
-                    ERROR_IF(ann_dict == NULL, error);
-                    err = PyDict_SetItem(LOCALS(), &_Py_ID(__annotations__),
-                                         ann_dict);
-                    Py_DECREF(ann_dict);
-                    ERROR_IF(err, error);
-                }
+            ERROR_IF(PyMapping_GetOptionalItem(LOCALS(), &_Py_ID(__annotations__), &ann_dict) < 0, error);
+            if (ann_dict == NULL) {
+                ann_dict = PyDict_New();
+                ERROR_IF(ann_dict == NULL, error);
+                err = PyObject_SetItem(LOCALS(), &_Py_ID(__annotations__),
+                                       ann_dict);
+                Py_DECREF(ann_dict);
+                ERROR_IF(err, error);
             }
             else {
-                /* do the same if locals() is not a dict */
-                ERROR_IF(PyMapping_GetOptionalItem(LOCALS(), &_Py_ID(__annotations__), &ann_dict) < 0, error);
-                if (ann_dict == NULL) {
-                    ann_dict = PyDict_New();
-                    ERROR_IF(ann_dict == NULL, error);
-                    err = PyObject_SetItem(LOCALS(), &_Py_ID(__annotations__),
-                                           ann_dict);
-                    Py_DECREF(ann_dict);
-                    ERROR_IF(err, error);
-                }
-                else {
-                    Py_DECREF(ann_dict);
-                }
+                Py_DECREF(ann_dict);
             }
         }
 
diff --git a/Python/executor_cases.c.h b/Python/executor_cases.c.h
index 877328a4ab6..ac542a562ea 100644
--- a/Python/executor_cases.c.h
+++ b/Python/executor_cases.c.h
@@ -512,18 +512,13 @@
             dict = stack_pointer[-2];
             DEOPT_IF(!PyDict_CheckExact(dict), BINARY_SUBSCR);
             STAT_INC(BINARY_SUBSCR, hit);
-            res = PyDict_GetItemWithError(dict, sub);
-            if (res == NULL) {
-                if (!_PyErr_Occurred(tstate)) {
-                    _PyErr_SetKeyError(sub);
-                }
-                Py_DECREF(dict);
-                Py_DECREF(sub);
-                if (true) goto pop_2_error_tier_two;
+            int rc = PyDict_GetItemRef(dict, sub, &res);
+            if (rc == 0) {
+                _PyErr_SetKeyError(sub);
             }
-            Py_INCREF(res);  // Do this before DECREF'ing dict, sub
             Py_DECREF(dict);
             Py_DECREF(sub);
+            if (rc <= 0) goto pop_2_error_tier_two;
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
             break;
@@ -1022,14 +1017,10 @@
                 GOTO_ERROR(error);
             }
             if (v == NULL) {
-                v = PyDict_GetItemWithError(GLOBALS(), name);
-                if (v != NULL) {
-                    Py_INCREF(v);
-                }
-                else if (_PyErr_Occurred(tstate)) {
+                if (PyDict_GetItemRef(GLOBALS(), name, &v) < 0) {
                     GOTO_ERROR(error);
                 }
-                else {
+                if (v == NULL) {
                     if (PyMapping_GetOptionalItem(BUILTINS(), name, &v) < 0) {
                         GOTO_ERROR(error);
                     }
@@ -1059,14 +1050,10 @@
                 GOTO_ERROR(error);
             }
             if (v == NULL) {
-                v = PyDict_GetItemWithError(GLOBALS(), name);
-                if (v != NULL) {
-                    Py_INCREF(v);
-                }
-                else if (_PyErr_Occurred(tstate)) {
+                if (PyDict_GetItemRef(GLOBALS(), name, &v) < 0) {
                     GOTO_ERROR(error);
                 }
-                else {
+                if (v == NULL) {
                     if (PyMapping_GetOptionalItem(BUILTINS(), name, &v) < 0) {
                         GOTO_ERROR(error);
                     }
@@ -1404,34 +1391,17 @@
                 if (true) goto error_tier_two;
             }
             /* check if __annotations__ in locals()... */
-            if (PyDict_CheckExact(LOCALS())) {
-                ann_dict = _PyDict_GetItemWithError(LOCALS(),
-                                                    &_Py_ID(__annotations__));
-                if (ann_dict == NULL) {
-                    if (_PyErr_Occurred(tstate)) goto error_tier_two;
-                    /* ...if not, create a new one */
-                    ann_dict = PyDict_New();
-                    if (ann_dict == NULL) goto error_tier_two;
-                    err = PyDict_SetItem(LOCALS(), &_Py_ID(__annotations__),
-                                         ann_dict);
-                    Py_DECREF(ann_dict);
-                    if (err) goto error_tier_two;
-                }
+            if (PyMapping_GetOptionalItem(LOCALS(), &_Py_ID(__annotations__), &ann_dict) < 0) goto error_tier_two;
+            if (ann_dict == NULL) {
+                ann_dict = PyDict_New();
+                if (ann_dict == NULL) goto error_tier_two;
+                err = PyObject_SetItem(LOCALS(), &_Py_ID(__annotations__),
+                                       ann_dict);
+                Py_DECREF(ann_dict);
+                if (err) goto error_tier_two;
             }
             else {
-                /* do the same if locals() is not a dict */
-                if (PyMapping_GetOptionalItem(LOCALS(), &_Py_ID(__annotations__), &ann_dict) < 0) goto error_tier_two;
-                if (ann_dict == NULL) {
-                    ann_dict = PyDict_New();
-                    if (ann_dict == NULL) goto error_tier_two;
-                    err = PyObject_SetItem(LOCALS(), &_Py_ID(__annotations__),
-                                           ann_dict);
-                    Py_DECREF(ann_dict);
-                    if (err) goto error_tier_two;
-                }
-                else {
-                    Py_DECREF(ann_dict);
-                }
+                Py_DECREF(ann_dict);
             }
             break;
         }
diff --git a/Python/generated_cases.c.h b/Python/generated_cases.c.h
index b9a2b227549..6cbc54c8e62 100644
--- a/Python/generated_cases.c.h
+++ b/Python/generated_cases.c.h
@@ -896,18 +896,13 @@
             dict = stack_pointer[-2];
             DEOPT_IF(!PyDict_CheckExact(dict), BINARY_SUBSCR);
             STAT_INC(BINARY_SUBSCR, hit);
-            res = PyDict_GetItemWithError(dict, sub);
-            if (res == NULL) {
-                if (!_PyErr_Occurred(tstate)) {
-                    _PyErr_SetKeyError(sub);
-                }
-                Py_DECREF(dict);
-                Py_DECREF(sub);
-                if (true) goto pop_2_error;
+            int rc = PyDict_GetItemRef(dict, sub, &res);
+            if (rc == 0) {
+                _PyErr_SetKeyError(sub);
             }
-            Py_INCREF(res);  // Do this before DECREF'ing dict, sub
             Py_DECREF(dict);
             Py_DECREF(sub);
+            if (rc <= 0) goto pop_2_error;
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
             DISPATCH();
@@ -1950,14 +1945,10 @@
                 GOTO_ERROR(error);
             }
             if (v == NULL) {
-                v = PyDict_GetItemWithError(GLOBALS(), name);
-                if (v != NULL) {
-                    Py_INCREF(v);
-                }
-                else if (_PyErr_Occurred(tstate)) {
+                if (PyDict_GetItemRef(GLOBALS(), name, &v) < 0) {
                     GOTO_ERROR(error);
                 }
-                else {
+                if (v == NULL) {
                     if (PyMapping_GetOptionalItem(BUILTINS(), name, &v) < 0) {
                         GOTO_ERROR(error);
                     }
@@ -1990,14 +1981,10 @@
                 GOTO_ERROR(error);
             }
             if (v == NULL) {
-                v = PyDict_GetItemWithError(GLOBALS(), name);
-                if (v != NULL) {
-                    Py_INCREF(v);
-                }
-                else if (_PyErr_Occurred(tstate)) {
+                if (PyDict_GetItemRef(GLOBALS(), name, &v) < 0) {
                     GOTO_ERROR(error);
                 }
-                else {
+                if (v == NULL) {
                     if (PyMapping_GetOptionalItem(BUILTINS(), name, &v) < 0) {
                         GOTO_ERROR(error);
                     }
@@ -2422,34 +2409,17 @@
                 if (true) goto error;
             }
             /* check if __annotations__ in locals()... */
-            if (PyDict_CheckExact(LOCALS())) {
-                ann_dict = _PyDict_GetItemWithError(LOCALS(),
-                                                    &_Py_ID(__annotations__));
-                if (ann_dict == NULL) {
-                    if (_PyErr_Occurred(tstate)) goto error;
-                    /* ...if not, create a new one */
-                    ann_dict = PyDict_New();
-                    if (ann_dict == NULL) goto error;
-                    err = PyDict_SetItem(LOCALS(), &_Py_ID(__annotations__),
-                                         ann_dict);
-                    Py_DECREF(ann_dict);
-                    if (err) goto error;
-                }
+            if (PyMapping_GetOptionalItem(LOCALS(), &_Py_ID(__annotations__), &ann_dict) < 0) goto error;
+            if (ann_dict == NULL) {
+                ann_dict = PyDict_New();
+                if (ann_dict == NULL) goto error;
+                err = PyObject_SetItem(LOCALS(), &_Py_ID(__annotations__),
+                                       ann_dict);
+                Py_DECREF(ann_dict);
+                if (err) goto error;
             }
             else {
-                /* do the same if locals() is not a dict */
-                if (PyMapping_GetOptionalItem(LOCALS(), &_Py_ID(__annotations__), &ann_dict) < 0) goto error;
-                if (ann_dict == NULL) {
-                    ann_dict = PyDict_New();
-                    if (ann_dict == NULL) goto error;
-                    err = PyObject_SetItem(LOCALS(), &_Py_ID(__annotations__),
-                                           ann_dict);
-                    Py_DECREF(ann_dict);
-                    if (err) goto error;
-                }
-                else {
-                    Py_DECREF(ann_dict);
-                }
+                Py_DECREF(ann_dict);
             }
             DISPATCH();
         }