Enhance and rewrite traceback dump C functions

Issue #26564:

* Expose _Py_DumpASCII() and _Py_DumpDecimal() in traceback.h
* Change the type of the second _Py_DumpASCII() parameter from int to unsigned
  long
* Rewrite _Py_DumpDecimal() and dump_hexadecimal() to write directly characters
  in the expected order, avoid the need of reversing the string.
* dump_hexadecimal() limits width to the size of the buffer
* _Py_DumpASCII() does nothing if the object is not a Unicode string
* dump_frame() wrtites "???" as the line number if the line number is negative

1 files changed, 18 insertions, 0 deletions

diff --git a/Include/traceback.h b/Include/traceback.h
index 891000c8fe..7c630e33df 100644
--- a/Include/traceback.h
+++ b/Include/traceback.h
@@ -67,6 +67,24 @@ PyAPI_DATA(const char*) _Py_DumpTracebackThreads(
     PyThreadState *current_thread);
 
 
+#ifndef Py_LIMITED_API
+
+/* Write a Unicode object into the file descriptor fd. Encode the string to
+   ASCII using the backslashreplace error handler.
+
+   Do nothing if text is not a Unicode object. The function accepts Unicode
+   string which is not ready (PyUnicode_WCHAR_KIND).
+
+   This function is signal safe. */
+PyAPI_FUNC(void) _Py_DumpASCII(int fd, PyObject *text);
+
+/* Format an integer as decimal into the file descriptor fd.
+
+   This function is signal safe. */
+PyAPI_FUNC(void) _Py_DumpDecimal(int fd, unsigned long value);
+
+#endif   /* !Py_LIMITED_API */
+
 #ifdef __cplusplus
 }
 #endif