From 244567398370bfa62a332676762bb1db395c02fc Mon Sep 17 00:00:00 2001 From: Quentin Peter Date: Tue, 31 Oct 2023 17:24:54 +0100 Subject: gh-102249: Expand sys.call_tracing documentation (#102806) Co-authored-by: C.A.M. Gerlach --- Doc/library/sys.rst | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst index 5ef6f83..4d24606 100644 --- a/Doc/library/sys.rst +++ b/Doc/library/sys.rst @@ -175,7 +175,11 @@ always available. Call ``func(*args)``, while tracing is enabled. The tracing state is saved, and restored afterwards. This is intended to be called from a debugger from - a checkpoint, to recursively debug some other code. + a checkpoint, to recursively debug or profile some other code. + + Tracing is suspended while calling a tracing function set by + :func:`settrace` or :func:`setprofile` to avoid infinite recursion. + :func:`!call_tracing` enables explicit recursion of the tracing function. .. data:: copyright @@ -1473,13 +1477,16 @@ always available. its return value is not used, so it can simply return ``None``. Error in the profile function will cause itself unset. + .. note:: + The same tracing mechanism is used for :func:`!setprofile` as :func:`settrace`. + To trace calls with :func:`!setprofile` inside a tracing function + (e.g. in a debugger breakpoint), see :func:`call_tracing`. + Profile functions should have three arguments: *frame*, *event*, and *arg*. *frame* is the current stack frame. *event* is a string: ``'call'``, ``'return'``, ``'c_call'``, ``'c_return'``, or ``'c_exception'``. *arg* depends on the event type. - .. audit-event:: sys.setprofile "" sys.setprofile - The events have the following meaning: ``'call'`` @@ -1501,6 +1508,9 @@ always available. ``'c_exception'`` A C function has raised an exception. *arg* is the C function object. + .. audit-event:: sys.setprofile "" sys.setprofile + + .. function:: setrecursionlimit(limit) Set the maximum depth of the Python interpreter stack to *limit*. This limit @@ -1560,6 +1570,10 @@ always available. If there is any error occurred in the trace function, it will be unset, just like ``settrace(None)`` is called. + .. note:: + Tracing is disabled while calling the trace function (e.g. a function set by + :func:`!settrace`). For recursive tracing see :func:`call_tracing`. + The events have the following meaning: ``'call'`` -- cgit v0.12