From 696d0bd002f33410679f0d6f55365094fe490233 Mon Sep 17 00:00:00 2001
From: Dong-hee Na <donghee.na@python.org>
Date: Mon, 30 Aug 2021 00:19:02 +0900
Subject: [PATCH 1/4] bpo-45045: Optimize mapping patterns of structural
 pattern matching

---
 Python/ceval.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/Python/ceval.c b/Python/ceval.c
index 5fec90b10483ab..d77ebb60d852c8 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -859,7 +859,7 @@ match_keys(PyThreadState *tstate, PyObject *map, PyObject *keys)
     if (dummy == NULL) {
         goto fail;
     }
-    values = PyList_New(0);
+    values = PyTuple_New(nkeys);
     if (values == NULL) {
         goto fail;
     }
@@ -873,7 +873,8 @@ match_keys(PyThreadState *tstate, PyObject *map, PyObject *keys)
             }
             goto fail;
         }
-        PyObject *value = PyObject_CallFunctionObjArgs(get, key, dummy, NULL);
+        PyObject *args[] = { key, dummy };
+        PyObject *value = PyObject_Vectorcall(get, args, 2, NULL);
         if (value == NULL) {
             goto fail;
         }
@@ -886,10 +887,8 @@ match_keys(PyThreadState *tstate, PyObject *map, PyObject *keys)
             values = Py_None;
             goto done;
         }
-        PyList_Append(values, value);
-        Py_DECREF(value);
+        PyTuple_SET_ITEM(values, i, value);
     }
-    Py_SETREF(values, PyList_AsTuple(values));
     // Success:
 done:
     Py_DECREF(get);

From c95a7eaf50acffa258cc09cfaa49dca8673b8277 Mon Sep 17 00:00:00 2001
From: Dong-hee Na <donghee.na@python.org>
Date: Mon, 30 Aug 2021 01:51:12 +0900
Subject: [PATCH 2/4] bpo-45045: Address code review

---
 Python/ceval.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/Python/ceval.c b/Python/ceval.c
index d77ebb60d852c8..85c4495ee7cbfc 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -846,7 +846,9 @@ match_keys(PyThreadState *tstate, PyObject *map, PyObject *keys)
     // - Don't cause key creation or resizing in dict subclasses like
     //   collections.defaultdict that define __missing__ (or similar).
     _Py_IDENTIFIER(get);
-    PyObject *get = _PyObject_GetAttrId(map, &PyId_get);
+    PyObject *get_name = _PyUnicode_FromId(&PyId_get); // borrowed
+    PyObject *get = NULL;
+    int meth_found = _PyObject_GetMethod(map, get_name, &get);
     if (get == NULL) {
         goto fail;
     }
@@ -873,8 +875,14 @@ match_keys(PyThreadState *tstate, PyObject *map, PyObject *keys)
             }
             goto fail;
         }
-        PyObject *args[] = { key, dummy };
-        PyObject *value = PyObject_Vectorcall(get, args, 2, NULL);
+        PyObject *args[] = { map, key, dummy };
+        PyObject *value = NULL;
+        if (meth_found) {
+            value = PyObject_Vectorcall(get, args, 3, NULL);
+        }
+        else {
+            value = PyObject_Vectorcall(get, &args[1], 2, NULL);
+        }
         if (value == NULL) {
             goto fail;
         }

From 7a304965599065e168a1aa6b96c53e58e46efc92 Mon Sep 17 00:00:00 2001
From: Dong-hee Na <donghee.na@python.org>
Date: Mon, 30 Aug 2021 02:25:43 +0900
Subject: [PATCH 3/4] bpo-45045 Add unbound method test case

---
 Lib/test/test_patma.py | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/Lib/test/test_patma.py b/Lib/test/test_patma.py
index aa18e29e22548f..57d3b1ec701ca4 100644
--- a/Lib/test/test_patma.py
+++ b/Lib/test/test_patma.py
@@ -2641,6 +2641,19 @@ def f(x):
         self.assertEqual(f((False, range(-1, -11, -1), True)), alts[3])
         self.assertEqual(f((False, range(10, 20), True)), alts[4])
 
+    def test_patma_248(self):
+        class C(dict):
+            @staticmethod
+            def get(key, default=None):
+                return 'bar'
+
+        x = C({'foo': 'bar'})
+        match x:
+            case {'foo': bar}:
+                y = bar
+
+        self.assertEqual(y, 'bar')
+
 
 class TestSyntaxErrors(unittest.TestCase):
 

From 71fe76d9f35fa2a222e0fcf371ae5c23fe7eac43 Mon Sep 17 00:00:00 2001
From: Dong-hee Na <donghee.na@python.org>
Date: Mon, 30 Aug 2021 12:31:27 +0900
Subject: [PATCH 4/4] bpo-45045: nit

---
 Python/ceval.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/Python/ceval.c b/Python/ceval.c
index 85c4495ee7cbfc..0ea85cdc174bde 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -841,13 +841,17 @@ match_keys(PyThreadState *tstate, PyObject *map, PyObject *keys)
     PyObject *seen = NULL;
     PyObject *dummy = NULL;
     PyObject *values = NULL;
+    PyObject *get_name = NULL;
+    PyObject *get = NULL;
     // We use the two argument form of map.get(key, default) for two reasons:
     // - Atomically check for a key and get its value without error handling.
     // - Don't cause key creation or resizing in dict subclasses like
     //   collections.defaultdict that define __missing__ (or similar).
     _Py_IDENTIFIER(get);
-    PyObject *get_name = _PyUnicode_FromId(&PyId_get); // borrowed
-    PyObject *get = NULL;
+    get_name = _PyUnicode_FromId(&PyId_get); // borrowed
+    if (get_name == NULL) {
+        return NULL;
+    }
     int meth_found = _PyObject_GetMethod(map, get_name, &get);
     if (get == NULL) {
         goto fail;