Message372963
In commit b1cc6ba73 from earlier today, an error-handling path can now read an uninitialized variable.
https://github.com/python/cpython/commit/b1cc6ba73a51d5cc3aeb113b5e7378fb50a0e20a#diff-fa7f27df4c8df1055048e78340f904c4R695-R697
In particular, asdl_c.py is used to generate C source, and when building that code with Clang 10, there is the attached warning.
Likely fix: initialize `fields` to `NULL`. Also, perhaps a CI loop that has `-Werror=sometimes-uninitialized` would help detect these.
Compiler warning:
Python/Python-ast.c:1147:9: warning: variable 'fields' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
if (state == NULL) {
^~~~~~~~~~~~~
Python/Python-ast.c:1210:16: note: uninitialized use occurs here
Py_XDECREF(fields);
^~~~~~
./Include/object.h:520:51: note: expanded from macro 'Py_XDECREF'
#define Py_XDECREF(op) _Py_XDECREF(_PyObject_CAST(op))
^~
./Include/object.h:112:41: note: expanded from macro '_PyObject_CAST'
#define _PyObject_CAST(op) ((PyObject*)(op))
^~
Python/Python-ast.c:1147:5: note: remove the 'if' if its condition is always false
if (state == NULL) {
^~~~~~~~~~~~~~~~~~~~
Python/Python-ast.c:1145:35: note: initialize the variable 'fields' to silence this warning
PyObject *key, *value, *fields;
^
= NULL
1 warning generated. |
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Date |
User |
Action |
Args |
2020-07-03 21:47:00 | blarsen | set | recipients:
+ blarsen, vstinner |
2020-07-03 21:47:00 | blarsen | set | messageid: <1593812820.7.0.967275410849.issue41204@roundup.psfhosted.org> |
2020-07-03 21:47:00 | blarsen | link | issue41204 messages |
2020-07-03 21:47:00 | blarsen | create | |
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