gh-115011: Improve support of __index__() in setters of members with unsigned integer type (GH-115029)

Setters for members with an unsigned integer type now support
the same range of valid values for objects that has a __index__()
method as for int.

Previously, Py_T_UINT, Py_T_ULONG and Py_T_ULLONG did not support
objects that has a __index__() method larger than LONG_MAX.

Py_T_ULLONG did not support negative ints. Now it supports them and
emits a RuntimeWarning.

1 files changed, 44 insertions, 37 deletions

diff --git a/Python/structmember.c b/Python/structmember.c
index c9f03a4..ba881d1 100644
--- a/Python/structmember.c
+++ b/Python/structmember.c
@@ -2,6 +2,8 @@
 /* Map C struct members to Python object attributes */
 
 #include "Python.h"
+#include "pycore_abstract.h"      // _PyNumber_Index()
+#include "pycore_long.h"          // _PyLong_IsNegative()
 
 
 PyObject *
@@ -200,27 +202,22 @@ PyMember_SetOne(char *addr, PyMemberDef *l, PyObject *v)
     case Py_T_UINT: {
         /* XXX: For compatibility, accept negative int values
            as well. */
-        int overflow;
-        long long_val = PyLong_AsLongAndOverflow(v, &overflow);
-        if (long_val == -1 && PyErr_Occurred()) {
-            return -1;
-        }
-        if (overflow < 0) {
-            PyErr_SetString(PyExc_OverflowError,
-                            "Python int too large to convert to C long");
+        v = _PyNumber_Index(v);
+        if (v == NULL) {
             return -1;
         }
-        else if (!overflow) {
-            *(unsigned int *)addr = (unsigned int)(unsigned long)long_val;
-            if (long_val < 0) {
-                WARN("Writing negative value into unsigned field");
-            }
-            else if ((unsigned long)long_val > UINT_MAX) {
-                WARN("Truncation of value to unsigned short");
+        if (_PyLong_IsNegative((PyLongObject *)v)) {
+            long long_val = PyLong_AsLong(v);
+            Py_DECREF(v);
+            if (long_val == -1 && PyErr_Occurred()) {
+                return -1;
             }
+            *(unsigned int *)addr = (unsigned int)(unsigned long)long_val;
+            WARN("Writing negative value into unsigned field");
         }
         else {
             unsigned long ulong_val = PyLong_AsUnsignedLong(v);
+            Py_DECREF(v);
             if (ulong_val == (unsigned long)-1 && PyErr_Occurred()) {
                 return -1;
             }
@@ -240,24 +237,22 @@ PyMember_SetOne(char *addr, PyMemberDef *l, PyObject *v)
     case Py_T_ULONG: {
         /* XXX: For compatibility, accept negative int values
            as well. */
-        int overflow;
-        long long_val = PyLong_AsLongAndOverflow(v, &overflow);
-        if (long_val == -1 && PyErr_Occurred()) {
-            return -1;
-        }
-        if (overflow < 0) {
-            PyErr_SetString(PyExc_OverflowError,
-                            "Python int too large to convert to C long");
+        v = _PyNumber_Index(v);
+        if (v == NULL) {
             return -1;
         }
-        else if (!overflow) {
-            *(unsigned long *)addr = (unsigned long)long_val;
-            if (long_val < 0) {
-                WARN("Writing negative value into unsigned field");
+        if (_PyLong_IsNegative((PyLongObject *)v)) {
+            long long_val = PyLong_AsLong(v);
+            Py_DECREF(v);
+            if (long_val == -1 && PyErr_Occurred()) {
+                return -1;
             }
+            *(unsigned long *)addr = (unsigned long)long_val;
+            WARN("Writing negative value into unsigned field");
         }
         else {
             unsigned long ulong_val = PyLong_AsUnsignedLong(v);
+            Py_DECREF(v);
             if (ulong_val == (unsigned long)-1 && PyErr_Occurred()) {
                 return -1;
             }
@@ -313,18 +308,30 @@ PyMember_SetOne(char *addr, PyMemberDef *l, PyObject *v)
             return -1;
         break;
         }
-    case Py_T_ULONGLONG:{
-        unsigned long long value;
-        /* ??? PyLong_AsLongLong accepts an int, but PyLong_AsUnsignedLongLong
-            doesn't ??? */
-        if (PyLong_Check(v))
-            *(unsigned long long*)addr = value = PyLong_AsUnsignedLongLong(v);
-        else
-            *(unsigned long long*)addr = value = PyLong_AsLong(v);
-        if ((value == (unsigned long long)-1) && PyErr_Occurred())
+    case Py_T_ULONGLONG: {
+        v = _PyNumber_Index(v);
+        if (v == NULL) {
             return -1;
-        break;
         }
+        if (_PyLong_IsNegative((PyLongObject *)v)) {
+            long long_val = PyLong_AsLong(v);
+            Py_DECREF(v);
+            if (long_val == -1 && PyErr_Occurred()) {
+                return -1;
+            }
+            *(unsigned long long *)addr = (unsigned long long)(long long)long_val;
+            WARN("Writing negative value into unsigned field");
+        }
+        else {
+            unsigned long long ulonglong_val = PyLong_AsUnsignedLongLong(v);
+            Py_DECREF(v);
+            if (ulonglong_val == (unsigned long long)-1 && PyErr_Occurred()) {
+                return -1;
+            }
+            *(unsigned long long*)addr = ulonglong_val;
+        }
+        break;
+    }
     default:
         PyErr_Format(PyExc_SystemError,
                      "bad memberdescr type for %s", l->name);