bpo-37999: Simplify the conversion code for %c, %d, %x, etc. (GH-20437)

Since PyLong_AsLong() no longer use __int__, explicit call
of PyNumber_Index() before it is no longer needed.

Author: serhiy-storchaka

Objects/bytearrayobject.c

@@ -22,22 +22,15 @@ char _PyByteArray_empty_string[] = "";
 static int
 _getbytevalue(PyObject* arg, int *value)
 {
-    long face_value;
+    int overflow;
+    long face_value = PyLong_AsLongAndOverflow(arg, &overflow);
 
-    if (PyLong_Check(arg)) {
-        face_value = PyLong_AsLong(arg);
-    } else {
-        PyObject *index = PyNumber_Index(arg);
-        if (index == NULL) {
-            *value = -1;
-            return 0;
-        }
-        face_value = PyLong_AsLong(index);
-        Py_DECREF(index);
+    if (face_value == -1 && PyErr_Occurred()) {
+        *value = -1;
+        return 0;
     }
-
     if (face_value < 0 || face_value >= 256) {
-        /* this includes the OverflowError in case the long is too large */
+        /* this includes an overflow in converting to C long */
         PyErr_SetString(PyExc_ValueError, "byte must be in range(0, 256)");
         *value = -1;
         return 0;

Objects/bytesobject.c

@@ -510,17 +510,14 @@ formatlong(PyObject *v, int flags, int prec, int type)
             iobj = _PyNumber_Index(v);
         else
             iobj = PyNumber_Long(v);
-        if (iobj == NULL) {
-            if (!PyErr_ExceptionMatches(PyExc_TypeError))
-                return NULL;
-        }
-        else if (!PyLong_Check(iobj))
-            Py_CLEAR(iobj);
         if (iobj != NULL) {
+            assert(PyLong_Check(iobj));
             result = _PyUnicode_FormatLong(iobj, flags & F_ALT, prec, type);
             Py_DECREF(iobj);
             return result;
         }
+        if (!PyErr_ExceptionMatches(PyExc_TypeError))
+            return NULL;
     }
     PyErr_Format(PyExc_TypeError,
         "%%%c format: %s is required, not %.200s", type,
@@ -542,26 +539,16 @@ byte_converter(PyObject *arg, char *p)
         return 1;
     }
     else {
-        PyObject *iobj;
-        long ival;
         int overflow;
-        /* make sure number is a type of integer */
-        if (PyLong_Check(arg)) {
-            ival = PyLong_AsLongAndOverflow(arg, &overflow);
-        }
-        else {
-            iobj = PyNumber_Index(arg);
-            if (iobj == NULL) {
-                if (!PyErr_ExceptionMatches(PyExc_TypeError))
-                    return 0;
+        long ival = PyLong_AsLongAndOverflow(arg, &overflow);
+        if (ival == -1 && PyErr_Occurred()) {
+            if (PyErr_ExceptionMatches(PyExc_TypeError)) {
                 goto onError;
             }
-            ival = PyLong_AsLongAndOverflow(iobj, &overflow);
-            Py_DECREF(iobj);
+            return 0;
         }
-        if (!overflow && ival == -1 && PyErr_Occurred())
-            goto onError;
-        if (overflow || !(0 <= ival && ival <= 255)) {
+        if (!(0 <= ival && ival <= 255)) {
+            /* this includes an overflow in converting to C long */
             PyErr_SetString(PyExc_OverflowError,
                             "%c arg not in range(256)");
             return 0;

Objects/unicodeobject.c

@@ -14641,19 +14641,14 @@ mainformatlong(PyObject *v,
     if (!PyLong_Check(v)) {
         if (type == 'o' || type == 'x' || type == 'X') {
             iobj = _PyNumber_Index(v);
-            if (iobj == NULL) {
-                if (PyErr_ExceptionMatches(PyExc_TypeError))
-                    goto wrongtype;
-                return -1;
-            }
         }
         else {
             iobj = PyNumber_Long(v);
-            if (iobj == NULL ) {
-                if (PyErr_ExceptionMatches(PyExc_TypeError))
-                    goto wrongtype;
-                return -1;
-            }
+        }
+        if (iobj == NULL ) {
+            if (PyErr_ExceptionMatches(PyExc_TypeError))
+                goto wrongtype;
+            return -1;
         }
         assert(PyLong_Check(iobj));
     }
@@ -14736,24 +14731,17 @@ formatchar(PyObject *v)
         goto onError;
     }
     else {
-        PyObject *iobj;
-        long x;
-        /* make sure number is a type of integer */
-        if (!PyLong_Check(v)) {
-            iobj = PyNumber_Index(v);
-            if (iobj == NULL) {
+        int overflow;
+        long x = PyLong_AsLongAndOverflow(v, &overflow);
+        if (x == -1 && PyErr_Occurred()) {
+            if (PyErr_ExceptionMatches(PyExc_TypeError)) {
                 goto onError;
             }
-            x = PyLong_AsLong(iobj);
-            Py_DECREF(iobj);
-        }
-        else {
-            x = PyLong_AsLong(v);
+            return (Py_UCS4) -1;
         }
-        if (x == -1 && PyErr_Occurred())
-            goto onError;
 
         if (x < 0 || x > MAX_UNICODE) {
+            /* this includes an overflow in converting to C long */
             PyErr_SetString(PyExc_OverflowError,
                             "%c arg not in range(0x110000)");
             return (Py_UCS4) -1;