#1648: add sys.gettrace() and sys.getprofile().

Doc/library/sys.rst

@@ -392,6 +392,35 @@ always available.
    This function should be used for internal and specialized purposes only.
 
 
+.. function:: getprofile()
+
+   .. index::
+      single: profile function
+      single: profiler
+
+   Get the profiler function as set by :func:`setprofile`.
+
+   .. versionadded:: 2.6
+
+
+.. function:: gettrace()
+
+   .. index::
+      single: trace function
+      single: debugger
+
+   Get the trace function as set by :func:`settrace`.
+
+   .. note::
+
+      The :func:`gettrace` function is intended only for implementing debuggers,
+      profilers, coverage tools and the like. Its behavior is part of the
+      implementation platform, rather than part of the language definition,
+      and thus may not be available in all Python implementations.
+
+   .. versionadded:: 2.6
+
+
 .. function:: getwindowsversion()
 
    Return a tuple containing five components, describing the Windows version

Lib/test/test_profilehooks.py

@@ -4,6 +4,22 @@ import unittest
 
 from test import test_support
 
+class TestGetProfile(unittest.TestCase):
+    def setUp(self):
+        sys.setprofile(None)
+
+    def tearDown(self):
+        sys.setprofile(None)
+
+    def test_empty(self):
+        assert sys.getprofile() == None
+
+    def test_setget(self):
+        def fn(*args):
+            pass
+
+        sys.setprofile(fn)
+        assert sys.getprofile() == fn
 
 class HookWatcher:
     def __init__(self):
@@ -359,6 +375,7 @@ def show_events(callable):
 
 def test_main():
     test_support.run_unittest(
+        TestGetProfile,
         ProfileHookTestCase,
         ProfileSimulatorTestCase
     )

Lib/test/test_trace.py

@@ -268,6 +268,20 @@ class TraceTestCase(unittest.TestCase):
         self.compare_events(func.func_code.co_firstlineno,
                             tracer.events, func.events)
 
+    def set_and_retrieve_none(self):
+        sys.settrace(None)
+        assert sys.gettrace() is None
+
+    def set_and_retrieve_func(self):
+        def fn(*args):
+            pass
+
+        sys.settrace(fn)
+        try:
+            assert sys.gettrace() is fn
+        finally:
+            sys.settrace(None)
+
     def test_01_basic(self):
         self.run_test(basic)
     def test_02_arigo(self):

Misc/NEWS

@@ -1042,6 +1042,8 @@ Library
 Extension Modules
 -----------------
 
+- Patch #1648: added ``sys.getprofile()`` and ``sys.gettrace()``.
+
 - Patch #1663329: added ``os.closerange()`` function to quickly close a range
   of file descriptors without considering errors.
 

Python/sysmodule.c

@@ -397,6 +397,25 @@ Set the global debug tracing function.  It will be called on each\n\
 function call.  See the debugger chapter in the library manual."
 );
 
+static PyObject *
+sys_gettrace(PyObject *self, PyObject *args)
+{
+	PyThreadState *tstate = PyThreadState_GET();
+	PyObject *temp = tstate->c_traceobj;
+
+	if (temp == NULL)
+		temp = Py_None;
+	Py_INCREF(temp);
+	return temp;
+}
+
+PyDoc_STRVAR(gettrace_doc,
+"gettrace()\n\
+\n\
+Return the global debug tracing function set with sys.settrace.\n\
+See the debugger chapter in the library manual."
+);
+
 static PyObject *
 sys_setprofile(PyObject *self, PyObject *args)
 {
@@ -417,6 +436,25 @@ Set the profiling function.  It will be called on each function call\n\
 and return.  See the profiler chapter in the library manual."
 );
 
+static PyObject *
+sys_getprofile(PyObject *self, PyObject *args)
+{
+	PyThreadState *tstate = PyThreadState_GET();
+	PyObject *temp = tstate->c_profileobj;
+
+	if (temp == NULL)
+		temp = Py_None;
+	Py_INCREF(temp);
+	return temp;
+}
+
+PyDoc_STRVAR(getprofile_doc,
+"getprofile()\n\
+\n\
+Return the profiling function set with sys.setprofile.\n\
+See the profiler chapter in the library manual."
+);
+
 static PyObject *
 sys_setcheckinterval(PyObject *self, PyObject *args)
 {
@@ -793,12 +831,14 @@ static PyMethodDef sys_methods[] = {
 	 setdlopenflags_doc},
 #endif
 	{"setprofile",	sys_setprofile, METH_O, setprofile_doc},
+	{"getprofile",	sys_getprofile, METH_NOARGS, getprofile_doc},
 	{"setrecursionlimit", sys_setrecursionlimit, METH_VARARGS,
 	 setrecursionlimit_doc},
 #ifdef WITH_TSC
 	{"settscdump", sys_settscdump, METH_VARARGS, settscdump_doc},
 #endif
 	{"settrace",	sys_settrace, METH_O, settrace_doc},
+	{"gettrace",	sys_gettrace, METH_NOARGS, gettrace_doc},
 	{"call_tracing", sys_call_tracing, METH_VARARGS, call_tracing_doc},
 	{NULL,		NULL}		/* sentinel */
 };
@@ -941,8 +981,10 @@ exc_info() -- return thread-safe information about the current exception\n\
 exc_clear() -- clear the exception state for the current thread\n\
 exit() -- exit the interpreter by raising SystemExit\n\
 getdlopenflags() -- returns flags to be used for dlopen() calls\n\
+getprofile() -- get the global profiling function\n\
 getrefcount() -- return the reference count for an object (plus one :-)\n\
 getrecursionlimit() -- return the max recursion depth for the interpreter\n\
+gettrace() -- get the global debug tracing function\n\
 setcheckinterval() -- control how often the interpreter checks for events\n\
 setdlopenflags() -- set the flags to be used for dlopen() calls\n\
 setprofile() -- set the global profiling function\n\