Add dump_c_stack

python · pablogsal · Apr 21, 2025 · Dec 21, 2024 · Dec 21, 2024 · Dec 21, 2024
commit 66f2641265dd16a5e71086fef12088745fb0321d
diff --git a/Include/internal/pycore_faulthandler.h b/Include/internal/pycore_faulthandler.h
@@ -56,6 +56,7 @@ struct _faulthandler_runtime_state {
 #ifdef MS_WINDOWS
         void *exc_handler;
 #endif
+        int c_stack;
     } fatal_error;
 
     struct {

diff --git a/Modules/faulthandler.c b/Modules/faulthandler.c
@@ -266,6 +266,13 @@ faulthandler_stack_dump_impl(int fd)
 }
 #endif
 
+static void
+faulthandler_dump_c_stack_nocheck(int fd)
+{
+    PUTS(fd, "Current thread's C stack trace (most recent call first):\n");
+    faulthandler_stack_dump_impl(fd);
+}
+
 static void
 faulthandler_dump_c_stack(int fd)
 {
@@ -276,8 +283,11 @@ faulthandler_dump_c_stack(int fd)
 
     reentrant = 1;
 
-    PUTS(fd, "\nCurrent thread's C stack trace (most recent call first):\n");
-    faulthandler_stack_dump_impl(fd);
+    if (fatal_error.c_stack)
+    {
+        PUTS(fd, "\n");
+        faulthandler_dump_c_stack_nocheck(fd);
+    }
 
     reentrant = 0;
 }
@@ -323,6 +333,32 @@ faulthandler_dump_traceback_py(PyObject *self,
     Py_RETURN_NONE;
 }
 
+static PyObject *
+faulthandler_dump_c_stack_py(PyObject *self,
+                               PyObject *args, PyObject *kwargs)
+{
+    static char *kwlist[] = {"file", NULL};
+    PyObject *file = NULL;
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwargs,
+        "|Op:dump_c_stack", kwlist,
+        &file))
+        return NULL;
+
+    int fd = faulthandler_get_fileno(&file);
+    if (fd < 0) {
+        return NULL;
+    }
+
+    faulthandler_dump_c_stack_nocheck(fd);
+
+    if (PyErr_CheckSignals()) {
+        return NULL;
+    }
+
+    Py_RETURN_NONE;
+}
+
 static void
 faulthandler_disable_fatal_handler(fault_handler_t *handler)
 {
@@ -564,14 +600,15 @@ faulthandler_enable(void)
 static PyObject*
 faulthandler_py_enable(PyObject *self, PyObject *args, PyObject *kwargs)
 {
-    static char *kwlist[] = {"file", "all_threads", NULL};
+    static char *kwlist[] = {"file", "all_threads", "c_stack", NULL};
     PyObject *file = NULL;
     int all_threads = 1;
     int fd;
+    int c_stack = 1;
     PyThreadState *tstate;
 
     if (!PyArg_ParseTupleAndKeywords(args, kwargs,
-        "|Op:enable", kwlist, &file, &all_threads))
+        "|Op:enable", kwlist, &file, &all_threads, &c_stack))
         return NULL;
 
     fd = faulthandler_get_fileno(&file);
@@ -587,6 +624,7 @@ faulthandler_py_enable(PyObject *self, PyObject *args, PyObject *kwargs)
     fatal_error.fd = fd;
     fatal_error.all_threads = all_threads;
     fatal_error.interp = PyThreadState_GetInterpreter(tstate);
+    fatal_error.c_stack = c_stack;
 
     if (faulthandler_enable() < 0) {
         return NULL;
@@ -1277,6 +1315,10 @@ static PyMethodDef module_methods[] = {
      PyDoc_STR("dump_traceback($module, /, file=sys.stderr, all_threads=True)\n--\n\n"
                "Dump the traceback of the current thread, or of all threads "
                "if all_threads is True, into file.")},
+     {"dump_c_stack",
+      _PyCFunction_CAST(faulthandler_dump_c_stack_py), METH_VARARGS|METH_KEYWORDS,
+      PyDoc_STR("dump_c_stack($module, /, file=sys.stderr)\n--\n\n"
+              "Dump the C stack of the current thread.")},
     {"dump_traceback_later",
      _PyCFunction_CAST(faulthandler_dump_traceback_later), METH_VARARGS|METH_KEYWORDS,
      PyDoc_STR("dump_traceback_later($module, /, timeout, repeat=False, file=sys.stderr, exit=False)\n--\n\n"