Use new helpers in the replace handler.

We also refactor that handler and extract the logic for each
exceptions being handled into separate functions.

Author: picnixz

Python/codecs.c

@@ -774,50 +774,72 @@ PyObject *PyCodec_IgnoreErrors(PyObject *exc)
 }
 
 
-PyObject *PyCodec_ReplaceErrors(PyObject *exc)
+// --- handler: 'replace' -----------------------------------------------------
+
+static PyObject *
+_PyCodec_ReplaceUnicodeEncodeError(PyObject *exc)
 {
     Py_ssize_t start, end, slen;
+    if (_PyUnicodeError_GetParams(exc, NULL, NULL,
+                                  &start, &end, &slen, false) < 0) {
+        return NULL;
+    }
+    PyObject *res = PyUnicode_New(slen, '?');
+    if (res == NULL) {
+        return NULL;
+    }
+    assert(PyUnicode_KIND(res) == PyUnicode_1BYTE_KIND);
+    Py_UCS1 *outp = PyUnicode_1BYTE_DATA(res);
+    memset(outp, '?', sizeof(Py_UCS1) * slen);
+    assert(_PyUnicode_CheckConsistency(res, 1));
+    return Py_BuildValue("(Nn)", res, end);
+}
 
-    if (PyObject_TypeCheck(exc, (PyTypeObject *)PyExc_UnicodeEncodeError)) {
-        if (_PyUnicodeError_GetParams(exc, NULL, NULL,
-                                      &start, &end, &slen, false) < 0) {
-            return NULL;
-        }
-        PyObject *res = PyUnicode_New(slen, '?');
-        if (res == NULL) {
-            return NULL;
-        }
-        assert(PyUnicode_KIND(res) == PyUnicode_1BYTE_KIND);
-        Py_UCS1 *outp = PyUnicode_1BYTE_DATA(res);
-        memset(outp, '?', sizeof(Py_UCS1) * slen);
-        assert(_PyUnicode_CheckConsistency(res, 1));
-        return Py_BuildValue("(Nn)", res, end);
+
+static PyObject *
+_PyCodec_ReplaceUnicodeDecodeError(PyObject *exc)
+{
+    Py_ssize_t end;
+    if (PyUnicodeDecodeError_GetEnd(exc, &end) < 0) {
+        return NULL;
     }
-    else if (PyObject_TypeCheck(exc, (PyTypeObject *)PyExc_UnicodeDecodeError)) {
-        if (_PyUnicodeError_GetParams(exc, NULL, NULL,
-                                      NULL, &end, NULL, true) < 0) {
-            return NULL;
-        }
-        return Py_BuildValue("(Cn)",
-                             (int)Py_UNICODE_REPLACEMENT_CHARACTER,
-                             end);
+    // Note: Py_UNICODE_REPLACEMENT_CHARACTER < (2 ** 16) < INT_MAX
+    return Py_BuildValue("(Cn)", (int)Py_UNICODE_REPLACEMENT_CHARACTER, end);
+}
+
+
+static PyObject *
+_PyCodec_ReplaceUnicodeTranslateError(PyObject *exc)
+{
+    Py_ssize_t start, end, slen;
+    if (_PyUnicodeError_GetParams(exc, NULL, NULL,
+                                  &start, &end, &slen, false) < 0) {
+        return NULL;
     }
-    else if (PyObject_TypeCheck(exc, (PyTypeObject *)PyExc_UnicodeTranslateError)) {
-        if (_PyUnicodeError_GetParams(exc, NULL, NULL,
-                                      &start, &end, &slen, false) < 0) {
-            return NULL;
-        }
-        PyObject *res = PyUnicode_New(slen, Py_UNICODE_REPLACEMENT_CHARACTER);
-        if (res == NULL) {
-            return NULL;
-        }
-        assert(slen == 0 || PyUnicode_KIND(res) == PyUnicode_2BYTE_KIND);
-        Py_UCS2 *outp = PyUnicode_2BYTE_DATA(res);
-        for (Py_ssize_t i = 0; i < slen; ++i) {
-            outp[i] = Py_UNICODE_REPLACEMENT_CHARACTER;
-        }
-        assert(_PyUnicode_CheckConsistency(res, 1));
-        return Py_BuildValue("(Nn)", res, end);
+    PyObject *res = PyUnicode_New(slen, Py_UNICODE_REPLACEMENT_CHARACTER);
+    if (res == NULL) {
+        return NULL;
+    }
+    assert(slen == 0 || PyUnicode_KIND(res) == PyUnicode_2BYTE_KIND);
+    Py_UCS2 *outp = PyUnicode_2BYTE_DATA(res);
+    for (Py_ssize_t i = 0; i < slen; ++i) {
+        outp[i] = Py_UNICODE_REPLACEMENT_CHARACTER;
+    }
+    assert(_PyUnicode_CheckConsistency(res, 1));
+    return Py_BuildValue("(Nn)", res, end);
+}
+
+
+PyObject *PyCodec_ReplaceErrors(PyObject *exc)
+{
+    if (_PyIsUnicodeEncodeError(exc)) {
+        return _PyCodec_ReplaceUnicodeEncodeError(exc);
+    }
+    else if (_PyIsUnicodeDecodeError(exc)) {
+        return _PyCodec_ReplaceUnicodeDecodeError(exc);
+    }
+    else if (_PyIsUnicodeTranslateError(exc)) {
+        return _PyCodec_ReplaceUnicodeTranslateError(exc);
     }
     else {
         wrong_exception_type(exc);
@@ -1413,7 +1435,8 @@ ignore_errors(PyObject *Py_UNUSED(self), PyObject *exc)
 }
 
 
-static PyObject *replace_errors(PyObject *self, PyObject *exc)
+static inline PyObject *
+replace_errors(PyObject *Py_UNUSED(self), PyObject *exc)
 {
     return PyCodec_ReplaceErrors(exc);
 }