gh-90667: Add specializations of Py_DECREF when types are known (GH-30872)

4 files changed, 39 insertions, 8 deletions

diff --git a/Include/internal/pycore_floatobject.h b/Include/internal/pycore_floatobject.h
index a099f2e..8a65554 100644
--- a/Include/internal/pycore_floatobject.h
+++ b/Include/internal/pycore_floatobject.h
@@ -38,6 +38,8 @@ struct _Py_float_state {
 #endif
 };
 
+void _PyFloat_ExactDealloc(PyObject *op);
+
 
 PyAPI_FUNC(void) _PyFloat_DebugMallocStats(FILE* out);
 
diff --git a/Include/internal/pycore_object.h b/Include/internal/pycore_object.h
index 177b06e..f022f82 100644
--- a/Include/internal/pycore_object.h
+++ b/Include/internal/pycore_object.h
@@ -14,7 +14,6 @@ extern "C" {
 #include "pycore_pystate.h"       // _PyInterpreterState_GET()
 #include "pycore_runtime.h"       // _PyRuntime
 
-
 #define _PyObject_IMMORTAL_INIT(type) \
     { \
         .ob_refcnt = 999999999, \
@@ -26,6 +25,42 @@ extern "C" {
         .ob_size = size, \
     }
 
+PyAPI_FUNC(void) _Py_NO_RETURN _Py_FatalRefcountErrorFunc(
+    const char *func,
+    const char *message);
+
+#define _Py_FatalRefcountError(message) _Py_FatalRefcountErrorFunc(__func__, message)
+
+static inline void
+_Py_DECREF_SPECIALIZED(PyObject *op, const destructor destruct)
+{
+#ifdef Py_REF_DEBUG
+    _Py_RefTotal--;
+#endif
+    if (--op->ob_refcnt != 0) {
+        assert(op->ob_refcnt > 0);
+    }
+    else {
+#ifdef Py_TRACE_REFS
+        _Py_ForgetReference(op);
+#endif
+        destruct(op);
+    }
+}
+
+static inline void
+_Py_DECREF_NO_DEALLOC(PyObject *op)
+{
+#ifdef Py_REF_DEBUG
+    _Py_RefTotal--;
+#endif
+    op->ob_refcnt--;
+#ifdef Py_DEBUG
+    if (op->ob_refcnt <= 0) {
+        _Py_FatalRefcountError("Expected a positive remaining refcount");
+    }
+#endif
+}
 
 PyAPI_FUNC(int) _PyType_CheckConsistency(PyTypeObject *type);
 PyAPI_FUNC(int) _PyDict_CheckConsistency(PyObject *mp, int check_content);
diff --git a/Include/internal/pycore_pyerrors.h b/Include/internal/pycore_pyerrors.h
index e3c445b..66f3794 100644
--- a/Include/internal/pycore_pyerrors.h
+++ b/Include/internal/pycore_pyerrors.h
@@ -100,13 +100,6 @@ extern PyObject* _Py_Offer_Suggestions(PyObject* exception);
 PyAPI_FUNC(Py_ssize_t) _Py_UTF8_Edit_Cost(PyObject *str_a, PyObject *str_b,
                                           Py_ssize_t max_cost);
 
-PyAPI_FUNC(void) _Py_NO_RETURN _Py_FatalRefcountErrorFunc(
-    const char *func,
-    const char *message);
-
-#define _Py_FatalRefcountError(message) _Py_FatalRefcountErrorFunc(__func__, message)
-
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/Include/internal/pycore_unicodeobject.h b/Include/internal/pycore_unicodeobject.h
index 75b9050..4bee241 100644
--- a/Include/internal/pycore_unicodeobject.h
+++ b/Include/internal/pycore_unicodeobject.h
@@ -10,6 +10,7 @@ extern "C" {
 
 #include "pycore_fileutils.h"     // _Py_error_handler
 
+void _PyUnicode_ExactDealloc(PyObject *op);
 
 /* runtime lifecycle */