https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107646
--- Comment #10 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The trunk branch has been updated by Eric Feng <ef...@gcc.gnu.org>: https://gcc.gnu.org/g:597b9ec69bca8acb7a3d65641c0a730de8b27ed4 commit r14-3580-g597b9ec69bca8acb7a3d65641c0a730de8b27ed4 Author: Eric Feng <ef2...@columbia.edu> Date: Wed Aug 30 17:52:24 2023 -0400 analyzer: implement reference count checking for CPython plugin [PR107646] This patch introduces initial support for reference count checking of PyObjects in relation to the Python/C API for the CPython plugin. Additionally, the core analyzer underwent several modifications to accommodate this feature. These include: - Introducing support for callbacks at the end of region_model::pop_frame. This is our current point of validation for the reference count of PyObjects. - An added optional custom stmt_finder parameter to region_model_context::warn. This aids in emitting a diagnostic concerning the reference count, especially when the stmt_finder is NULL, which is currently the case during region_model::pop_frame. The current diagnostic we emit relating to the reference count appears as follows: rc3.c:23:10: warning: expected âitemâ to have reference count: â1â but ob_refcnt field is: â2â 23 | return list; | ^~~~ âcreate_py_objectâ: events 1-4 | | 4 | PyObject* item = PyLong_FromLong(3); | | ^~~~~~~~~~~~~~~~~~ | | | | | (1) when âPyLong_FromLongâ succeeds | 5 | PyObject* list = PyList_New(1); | | ~~~~~~~~~~~~~ | | | | | (2) when âPyList_Newâ succeeds |...... | 14 | PyList_Append(list, item); | | ~~~~~~~~~~~~~~~~~~~~~~~~~ | | | | | (3) when âPyList_Appendâ succeeds, moving buffer |...... | 23 | return list; | | ~~~~ | | | | | (4) here | This is a WIP in several ways: - Currently, functions returning PyObject * are assumed to always produce a new reference. - The validation of reference count is only for PyObjects created within a function body. Verifying reference counts for PyObjects passed as parameters is not supported in this patch. gcc/analyzer/ChangeLog: PR analyzer/107646 * engine.cc (impl_region_model_context::warn): New optional parameter. * exploded-graph.h (class impl_region_model_context): Likewise. * region-model.cc (region_model::pop_frame): New callback feature for region_model::pop_frame. * region-model.h (struct append_regions_cb_data): Likewise. (class region_model): Likewise. (class region_model_context): New optional parameter. (class region_model_context_decorator): Likewise. gcc/testsuite/ChangeLog: PR analyzer/107646 * gcc.dg/plugin/analyzer_cpython_plugin.c: Implements reference count checking for PyObjects. * gcc.dg/plugin/cpython-plugin-test-2.c: Moved to... * gcc.dg/plugin/cpython-plugin-test-PyList_Append.c: ...here (and added more tests). * gcc.dg/plugin/cpython-plugin-test-1.c: Moved to... * gcc.dg/plugin/cpython-plugin-test-no-Python-h.c: ...here (and added more tests). * gcc.dg/plugin/plugin.exp: New tests. * gcc.dg/plugin/cpython-plugin-test-PyList_New.c: New test. * gcc.dg/plugin/cpython-plugin-test-PyLong_FromLong.c: New test. Signed-off-by: Eric Feng <ef2...@columbia.edu>
