gh-119182: Use public PyUnicodeWriter in Python-ast.c (#129209)

Replace the private _PyUnicodeWriter API with the public
PyUnicodeWriter API.

Use PyUnicodeWriter_WriteRepr() in ast_repr_list().

Author: vstinner

Parser/asdl_c.py

@@ -1462,10 +1462,11 @@ def visitModule(self, mod):
         return PyObject_Repr(list);
     }
 
-    _PyUnicodeWriter writer;
-    _PyUnicodeWriter_Init(&writer);
-    writer.overallocate = 1;
     PyObject *items[2] = {NULL, NULL};
+    PyUnicodeWriter *writer = PyUnicodeWriter_Create(0);
+    if (writer == NULL) {
+        goto error;
+    }
 
     items[0] = PySequence_GetItem(list, 0);
     if (!items[0]) {
@@ -1479,52 +1480,54 @@ def visitModule(self, mod):
     }
 
     bool is_list = PyList_Check(list);
-    if (_PyUnicodeWriter_WriteChar(&writer, is_list ? '[' : '(') < 0) {
+    if (PyUnicodeWriter_WriteChar(writer, is_list ? '[' : '(') < 0) {
         goto error;
     }
 
     for (Py_ssize_t i = 0; i < Py_MIN(length, 2); i++) {
-        PyObject *item = items[i];
-        PyObject *item_repr;
+        if (i > 0) {
+            if (PyUnicodeWriter_WriteUTF8(writer, ", ", 2) < 0) {
+                goto error;
+            }
+        }
 
+        PyObject *item = items[i];
         if (PyType_IsSubtype(Py_TYPE(item), (PyTypeObject *)state->AST_type)) {
+            PyObject *item_repr;
             item_repr = ast_repr_max_depth((AST_object*)item, depth - 1);
-        } else {
-            item_repr = PyObject_Repr(item);
-        }
-        if (!item_repr) {
-            goto error;
-        }
-        if (i > 0) {
-            if (_PyUnicodeWriter_WriteASCIIString(&writer, ", ", 2) < 0) {
+            if (!item_repr) {
+                goto error;
+            }
+            if (PyUnicodeWriter_WriteStr(writer, item_repr) < 0) {
+                Py_DECREF(item_repr);
                 goto error;
             }
-        }
-        if (_PyUnicodeWriter_WriteStr(&writer, item_repr) < 0) {
             Py_DECREF(item_repr);
-            goto error;
+        } else {
+            if (PyUnicodeWriter_WriteRepr(writer, item) < 0) {
+                goto error;
+            }
         }
+
         if (i == 0 && length > 2) {
-            if (_PyUnicodeWriter_WriteASCIIString(&writer, ", ...", 5) < 0) {
-                Py_DECREF(item_repr);
+            if (PyUnicodeWriter_WriteUTF8(writer, ", ...", 5) < 0) {
                 goto error;
             }
         }
-        Py_DECREF(item_repr);
     }
 
-    if (_PyUnicodeWriter_WriteChar(&writer, is_list ? ']' : ')') < 0) {
+    if (PyUnicodeWriter_WriteChar(writer, is_list ? ']' : ')') < 0) {
         goto error;
     }
 
     Py_XDECREF(items[0]);
     Py_XDECREF(items[1]);
-    return _PyUnicodeWriter_Finish(&writer);
+    return PyUnicodeWriter_Finish(writer);
 
 error:
     Py_XDECREF(items[0]);
     Py_XDECREF(items[1]);
-    _PyUnicodeWriter_Dealloc(&writer);
+    PyUnicodeWriter_Discard(writer);
     return NULL;
 }
 
@@ -1568,14 +1571,15 @@ def visitModule(self, mod):
     }
 
     const char* tp_name = Py_TYPE(self)->tp_name;
-    _PyUnicodeWriter writer;
-    _PyUnicodeWriter_Init(&writer);
-    writer.overallocate = 1;
+    PyUnicodeWriter *writer = PyUnicodeWriter_Create(0);
+    if (writer == NULL) {
+        goto error;
+    }
 
-    if (_PyUnicodeWriter_WriteASCIIString(&writer, tp_name, strlen(tp_name)) < 0) {
+    if (PyUnicodeWriter_WriteUTF8(writer, tp_name, -1) < 0) {
         goto error;
     }
-    if (_PyUnicodeWriter_WriteChar(&writer, '(') < 0) {
+    if (PyUnicodeWriter_WriteChar(writer, '(') < 0) {
         goto error;
     }
 
@@ -1610,43 +1614,43 @@ def visitModule(self, mod):
         }
 
         if (i > 0) {
-            if (_PyUnicodeWriter_WriteASCIIString(&writer, ", ", 2) < 0) {
+            if (PyUnicodeWriter_WriteUTF8(writer, ", ", 2) < 0) {
                 Py_DECREF(name);
                 Py_DECREF(value_repr);
                 goto error;
             }
         }
-        if (_PyUnicodeWriter_WriteStr(&writer, name) < 0) {
+        if (PyUnicodeWriter_WriteStr(writer, name) < 0) {
             Py_DECREF(name);
             Py_DECREF(value_repr);
             goto error;
         }
 
         Py_DECREF(name);
 
-        if (_PyUnicodeWriter_WriteChar(&writer, '=') < 0) {
+        if (PyUnicodeWriter_WriteChar(writer, '=') < 0) {
             Py_DECREF(value_repr);
             goto error;
         }
-        if (_PyUnicodeWriter_WriteStr(&writer, value_repr) < 0) {
+        if (PyUnicodeWriter_WriteStr(writer, value_repr) < 0) {
             Py_DECREF(value_repr);
             goto error;
         }
 
         Py_DECREF(value_repr);
     }
 
-    if (_PyUnicodeWriter_WriteChar(&writer, ')') < 0) {
+    if (PyUnicodeWriter_WriteChar(writer, ')') < 0) {
         goto error;
     }
     Py_ReprLeave((PyObject *)self);
     Py_DECREF(fields);
-    return _PyUnicodeWriter_Finish(&writer);
+    return PyUnicodeWriter_Finish(writer);
 
 error:
     Py_ReprLeave((PyObject *)self);
     Py_DECREF(fields);
-    _PyUnicodeWriter_Dealloc(&writer);
+    PyUnicodeWriter_Discard(writer);
     return NULL;
 }