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GH-128682: Mark two more macros as escaping. (GH-129645)
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Expand out SETLOCAL so that code generator can see the decref. Mark Py_CLEAR as escaping
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markshannon authored Feb 4, 2025
1 parent 2effea4 commit 96ff4c2
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Showing 6 changed files with 127 additions and 46 deletions.
25 changes: 18 additions & 7 deletions Python/bytecodes.c
Original file line number Diff line number Diff line change
Expand Up @@ -272,7 +272,6 @@ dummy_func(

inst(LOAD_FAST_AND_CLEAR, (-- value)) {
value = GETLOCAL(oparg);
// do not use SETLOCAL here, it decrefs the old value
GETLOCAL(oparg) = PyStackRef_NULL;
}

Expand Down Expand Up @@ -328,8 +327,10 @@ dummy_func(
}

replicate(8) inst(STORE_FAST, (value --)) {
SETLOCAL(oparg, value);
_PyStackRef tmp = GETLOCAL(oparg);
GETLOCAL(oparg) = value;
DEAD(value);
PyStackRef_XCLOSE(tmp);
}

pseudo(STORE_FAST_MAYBE_NULL, (unused --)) = {
Expand All @@ -339,18 +340,24 @@ dummy_func(
inst(STORE_FAST_LOAD_FAST, (value1 -- value2)) {
uint32_t oparg1 = oparg >> 4;
uint32_t oparg2 = oparg & 15;
SETLOCAL(oparg1, value1);
_PyStackRef tmp = GETLOCAL(oparg1);
GETLOCAL(oparg1) = value1;
DEAD(value1);
value2 = PyStackRef_DUP(GETLOCAL(oparg2));
PyStackRef_XCLOSE(tmp);
}

inst(STORE_FAST_STORE_FAST, (value2, value1 --)) {
uint32_t oparg1 = oparg >> 4;
uint32_t oparg2 = oparg & 15;
SETLOCAL(oparg1, value1);
_PyStackRef tmp = GETLOCAL(oparg1);
GETLOCAL(oparg1) = value1;
DEAD(value1);
SETLOCAL(oparg2, value2);
PyStackRef_XCLOSE(tmp);
tmp = GETLOCAL(oparg2);
GETLOCAL(oparg2) = value2;
DEAD(value2);
PyStackRef_XCLOSE(tmp);
}

pure inst(POP_TOP, (value --)) {
Expand Down Expand Up @@ -1775,7 +1782,9 @@ dummy_func(
);
ERROR_IF(1, error);
}
SETLOCAL(oparg, PyStackRef_NULL);
_PyStackRef tmp = GETLOCAL(oparg);
GETLOCAL(oparg) = PyStackRef_NULL;
PyStackRef_XCLOSE(tmp);
}

inst(MAKE_CELL, (--)) {
Expand All @@ -1786,7 +1795,9 @@ dummy_func(
if (cell == NULL) {
ERROR_NO_POP();
}
SETLOCAL(oparg, PyStackRef_FromPyObjectSteal(cell));
_PyStackRef tmp = GETLOCAL(oparg);
GETLOCAL(oparg) = PyStackRef_FromPyObjectSteal(cell);
PyStackRef_XCLOSE(tmp);
}

inst(DELETE_DEREF, (--)) {
Expand Down
1 change: 1 addition & 0 deletions Python/ceval.c
Original file line number Diff line number Diff line change
Expand Up @@ -194,6 +194,7 @@ lltrace_instruction(_PyInterpreterFrame *frame,
}
fflush(stdout);
}

static void
lltrace_resume_frame(_PyInterpreterFrame *frame)
{
Expand Down
9 changes: 0 additions & 9 deletions Python/ceval_macros.h
Original file line number Diff line number Diff line change
Expand Up @@ -221,15 +221,6 @@ GETITEM(PyObject *v, Py_ssize_t i) {
#define LOCALS_ARRAY (frame->localsplus)
#define GETLOCAL(i) (frame->localsplus[i])

/* The SETLOCAL() macro must not DECREF the local variable in-place and
then store the new value; it must copy the old value to a temporary
value, then store the new value, and then DECREF the temporary value.
This is because it is possible that during the DECREF the frame is
accessed by other code (e.g. a __del__ method or gc.collect()) and the
variable would be pointing to already-freed memory. */
#define SETLOCAL(i, value) do { _PyStackRef tmp = GETLOCAL(i); \
GETLOCAL(i) = value; \
PyStackRef_XCLOSE(tmp); } while (0)

#ifdef Py_STATS
#define UPDATE_MISS_STATS(INSTNAME) \
Expand Down
69 changes: 57 additions & 12 deletions Python/executor_cases.c.h

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