gh-123969: refactor _PyErr_RaiseSyntaxError and _PyErr_EmitSyntaxWarning out of compiler (#123972)

Python/errors.c

@@ -1850,6 +1850,52 @@ PyErr_SyntaxLocationEx(const char *filename, int lineno, int col_offset)
     Py_XDECREF(fileobj);
 }
 
+/* Raises a SyntaxError.
+ * If something goes wrong, a different exception may be raised.
+ */
+void
+_PyErr_RaiseSyntaxError(PyObject *msg, PyObject *filename, int lineno, int col_offset,
+                        int end_lineno, int end_col_offset)
+{
+    PyObject *text = PyErr_ProgramTextObject(filename, lineno);
+    if (text == NULL) {
+        text = Py_NewRef(Py_None);
+    }
+    PyObject *args = Py_BuildValue("O(OiiOii)", msg, filename,
+                                   lineno, col_offset, text,
+                                   end_lineno, end_col_offset);
+    if (args == NULL) {
+        goto exit;
+    }
+    PyErr_SetObject(PyExc_SyntaxError, args);
+ exit:
+    Py_DECREF(text);
+    Py_XDECREF(args);
+}
+
+/* Emits a SyntaxWarning and returns 0 on success.
+   If a SyntaxWarning is raised as error, replaces it with a SyntaxError
+   and returns -1.
+*/
+int
+_PyErr_EmitSyntaxWarning(PyObject *msg, PyObject *filename, int lineno, int col_offset,
+                         int end_lineno, int end_col_offset)
+{
+    if (PyErr_WarnExplicitObject(PyExc_SyntaxWarning, msg, filename,
+                                 lineno, NULL, NULL) < 0)
+    {
+        if (PyErr_ExceptionMatches(PyExc_SyntaxWarning)) {
+            /* Replace the SyntaxWarning exception with a SyntaxError
+               to get a more accurate error report */
+            PyErr_Clear();
+            _PyErr_RaiseSyntaxError(msg, filename, lineno, col_offset,
+                                    end_lineno, end_col_offset);
+        }
+        return -1;
+    }
+    return 0;
+}
+
 /* Attempt to load the line of text that the exception refers to.  If it
    fails, it will return NULL but will not set an exception.