Add sys.set_lazy_imports_filter

Python/clinic/sysmodule.c.h

@@ -1821,6 +1821,92 @@ exit:
     return return_value;
 }
 
+PyDoc_STRVAR(sys_set_lazy_imports_filter__doc__,
+"set_lazy_imports_filter($module, /, filter)\n"
+"--\n"
+"\n"
+"Set the lazy imports filter callback.\n"
+"\n"
+"The filter is a callable which disables lazy imports when they\n"
+"would otherwise be enabled. Returns True if the import is still enabled\n"
+"or False to disable it. The callable is called with:\n"
+"\n"
+"(importing_module_name, imported_module_name, [fromlist])\n"
+"\n"
+"Pass None to clear the filter.");
+
+#define SYS_SET_LAZY_IMPORTS_FILTER_METHODDEF    \
+    {"set_lazy_imports_filter", _PyCFunction_CAST(sys_set_lazy_imports_filter), METH_FASTCALL|METH_KEYWORDS, sys_set_lazy_imports_filter__doc__},
+
+static PyObject *
+sys_set_lazy_imports_filter_impl(PyObject *module, PyObject *filter);
+
+static PyObject *
+sys_set_lazy_imports_filter(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
+{
+    PyObject *return_value = NULL;
+    #if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
+
+    #define NUM_KEYWORDS 1
+    static struct {
+        PyGC_Head _this_is_not_used;
+        PyObject_VAR_HEAD
+        Py_hash_t ob_hash;
+        PyObject *ob_item[NUM_KEYWORDS];
+    } _kwtuple = {
+        .ob_base = PyVarObject_HEAD_INIT(&PyTuple_Type, NUM_KEYWORDS)
+        .ob_hash = -1,
+        .ob_item = { &_Py_ID(filter), },
+    };
+    #undef NUM_KEYWORDS
+    #define KWTUPLE (&_kwtuple.ob_base.ob_base)
+
+    #else  // !Py_BUILD_CORE
+    #  define KWTUPLE NULL
+    #endif  // !Py_BUILD_CORE
+
+    static const char * const _keywords[] = {"filter", NULL};
+    static _PyArg_Parser _parser = {
+        .keywords = _keywords,
+        .fname = "set_lazy_imports_filter",
+        .kwtuple = KWTUPLE,
+    };
+    #undef KWTUPLE
+    PyObject *argsbuf[1];
+    PyObject *filter;
+
+    args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser,
+            /*minpos*/ 1, /*maxpos*/ 1, /*minkw*/ 0, /*varpos*/ 0, argsbuf);
+    if (!args) {
+        goto exit;
+    }
+    filter = args[0];
+    return_value = sys_set_lazy_imports_filter_impl(module, filter);
+
+exit:
+    return return_value;
+}
+
+PyDoc_STRVAR(sys_get_lazy_imports_filter__doc__,
+"get_lazy_imports_filter($module, /)\n"
+"--\n"
+"\n"
+"Get the current lazy imports filter callback.\n"
+"\n"
+"Returns the filter callable or None if no filter is set.");
+
+#define SYS_GET_LAZY_IMPORTS_FILTER_METHODDEF    \
+    {"get_lazy_imports_filter", (PyCFunction)sys_get_lazy_imports_filter, METH_NOARGS, sys_get_lazy_imports_filter__doc__},
+
+static PyObject *
+sys_get_lazy_imports_filter_impl(PyObject *module);
+
+static PyObject *
+sys_get_lazy_imports_filter(PyObject *module, PyObject *Py_UNUSED(ignored))
+{
+    return sys_get_lazy_imports_filter_impl(module);
+}
+
 PyDoc_STRVAR(_jit_is_available__doc__,
 "is_available($module, /)\n"
 "--\n"
@@ -1948,4 +2034,4 @@ exit:
 #ifndef SYS_GETANDROIDAPILEVEL_METHODDEF
     #define SYS_GETANDROIDAPILEVEL_METHODDEF
 #endif /* !defined(SYS_GETANDROIDAPILEVEL_METHODDEF) */
-/*[clinic end generated code: output=449d16326e69dcf6 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=64c56362026c8fcf input=a9049054013a1b77]*/

Python/sysmodule.c

@@ -2772,6 +2772,63 @@ PyAPI_FUNC(int) PyUnstable_CopyPerfMapFile(const char* parent_filename) {
     return 0;
 }
 
+/*[clinic input]
+sys.set_lazy_imports_filter
+
+    filter: object
+
+Set the lazy imports filter callback.
+
+The filter is a callable which disables lazy imports when they
+would otherwise be enabled. Returns True if the import is still enabled
+or False to disable it. The callable is called with:
+
+(importing_module_name, imported_module_name, [fromlist])
+
+Pass None to clear the filter.
+[clinic start generated code]*/
+
+static PyObject *
+sys_set_lazy_imports_filter_impl(PyObject *module, PyObject *filter)
+/*[clinic end generated code: output=10251d49469c278c input=2eb48786bdd4ee42]*/
+{
+    PyObject *current_filter = NULL;
+    if (filter == Py_None) {
+        current_filter = NULL;
+    }
+    else if (!PyCallable_Check(filter)) {
+        PyErr_SetString(PyExc_TypeError, "filter must be callable or None");
+        return NULL;
+    }
+    else {
+        current_filter = filter;
+    }
+
+    PyInterpreterState *interp = _PyInterpreterState_GET();
+    Py_XSETREF(interp->imports.lazy_imports_filter, Py_XNewRef(current_filter));
+    Py_RETURN_NONE;
+}
+
+/*[clinic input]
+sys.get_lazy_imports_filter
+
+Get the current lazy imports filter callback.
+
+Returns the filter callable or None if no filter is set.
+[clinic start generated code]*/
+
+static PyObject *
+sys_get_lazy_imports_filter_impl(PyObject *module)
+/*[clinic end generated code: output=3bf73022892165af input=cf1e07cb8e203c94]*/
+{
+    PyInterpreterState *interp = _PyInterpreterState_GET();
+    PyObject *filter = interp->imports.lazy_imports_filter;
+    if (filter == NULL) {
+        Py_RETURN_NONE;
+    }
+    return Py_NewRef(filter);
+}
+
 
 static PyMethodDef sys_methods[] = {
     /* Might as well keep this in alphabetic order */
@@ -2837,6 +2894,8 @@ static PyMethodDef sys_methods[] = {
     SYS_UNRAISABLEHOOK_METHODDEF
     SYS_GET_INT_MAX_STR_DIGITS_METHODDEF
     SYS_SET_INT_MAX_STR_DIGITS_METHODDEF
+    SYS_GET_LAZY_IMPORTS_FILTER_METHODDEF
+    SYS_SET_LAZY_IMPORTS_FILTER_METHODDEF
     SYS__BASEREPL_METHODDEF
 #ifdef Py_STATS
     SYS__STATS_ON_METHODDEF