refactor __del__ exception handler into PyErr_WriteUnraisable

add sanity check to gc: if an exception occurs during GC, call
PyErr_WriteUnraisable and then call Py_FatalEror.

1 files changed, 11 insertions, 0 deletions

diff --git a/Doc/api/api.tex b/Doc/api/api.tex
index 1f20129..c8731c9 100644
--- a/Doc/api/api.tex
+++ b/Doc/api/api.tex
@@ -972,6 +972,17 @@ alternate base class.  The \var{dict} argument can be used to specify
 a dictionary of class variables and methods.
 \end{cfuncdesc}
 
+\begin{cfuncdesc}{void}{PyErr_WriteUnraisable}{PyObject *obj}
+This utility function prints a warning message to \var{sys.stderr}
+when an exception has been set but it is impossible for the
+interpreter to actually raise the exception.  It is used, for example,
+when an exception occurs in an \member{__del__} method.
+
+The function is called with a single argument \var{obj} that
+identifies where the context in which the unraisable exception
+occurred.  The repr of \var{obj} will be printed in the warning
+message.
+\end{cfuncdesc}
 
 \section{Standard Exceptions \label{standardExceptions}}