summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorMark Shannon <mark@hotpy.org>2024-07-18 11:47:21 (GMT)
committerGitHub <noreply@github.com>2024-07-18 11:47:21 (GMT)
commit169324c27a39a4d6a4dd7b313b0de6ab2d1f7e6b (patch)
tree89b908cb6b3957a88b567dcc4c44b9873865433f
parent24cf867bed6035f33cd3b38d89d303b7522f12a6 (diff)
downloadcpython-169324c27a39a4d6a4dd7b313b0de6ab2d1f7e6b.zip
cpython-169324c27a39a4d6a4dd7b313b0de6ab2d1f7e6b.tar.gz
cpython-169324c27a39a4d6a4dd7b313b0de6ab2d1f7e6b.tar.bz2
GH-120024: Use pointer for stack pointer (GH-121923)
-rw-r--r--Include/internal/pycore_frame.h45
-rw-r--r--Lib/test/test_sys.py5
-rw-r--r--Objects/frameobject.c24
-rw-r--r--Python/ceval.c2
-rw-r--r--Python/frame.c22
5 files changed, 55 insertions, 43 deletions
diff --git a/Include/internal/pycore_frame.h b/Include/internal/pycore_frame.h
index d5115ad..d3a5be0 100644
--- a/Include/internal/pycore_frame.h
+++ b/Include/internal/pycore_frame.h
@@ -68,7 +68,7 @@ typedef struct _PyInterpreterFrame {
PyObject *f_locals; /* Strong reference, may be NULL. Only valid if not on C stack */
PyFrameObject *frame_obj; /* Strong reference, may be NULL. Only valid if not on C stack */
_Py_CODEUNIT *instr_ptr; /* Instruction currently executing (or about to begin) */
- int stacktop; /* Offset of TOS from localsplus */
+ _PyStackRef *stackpointer;
uint16_t return_offset; /* Only relevant during a function call */
char owner;
/* Locals and stack */
@@ -88,20 +88,20 @@ static inline _PyStackRef *_PyFrame_Stackbase(_PyInterpreterFrame *f) {
}
static inline _PyStackRef _PyFrame_StackPeek(_PyInterpreterFrame *f) {
- assert(f->stacktop > _PyFrame_GetCode(f)->co_nlocalsplus);
- assert(!PyStackRef_IsNull(f->localsplus[f->stacktop-1]));
- return f->localsplus[f->stacktop-1];
+ assert(f->stackpointer > f->localsplus + _PyFrame_GetCode(f)->co_nlocalsplus);
+ assert(!PyStackRef_IsNull(f->stackpointer[-1]));
+ return f->stackpointer[-1];
}
static inline _PyStackRef _PyFrame_StackPop(_PyInterpreterFrame *f) {
- assert(f->stacktop > _PyFrame_GetCode(f)->co_nlocalsplus);
- f->stacktop--;
- return f->localsplus[f->stacktop];
+ assert(f->stackpointer > f->localsplus + _PyFrame_GetCode(f)->co_nlocalsplus);
+ f->stackpointer--;
+ return *f->stackpointer;
}
static inline void _PyFrame_StackPush(_PyInterpreterFrame *f, _PyStackRef value) {
- f->localsplus[f->stacktop] = value;
- f->stacktop++;
+ *f->stackpointer = value;
+ f->stackpointer++;
}
#define FRAME_SPECIALS_SIZE ((int)((sizeof(_PyInterpreterFrame)-1)/sizeof(PyObject *)))
@@ -117,9 +117,12 @@ _PyFrame_NumSlotsForCodeObject(PyCodeObject *code)
static inline void _PyFrame_Copy(_PyInterpreterFrame *src, _PyInterpreterFrame *dest)
{
- assert(src->stacktop >= _PyFrame_GetCode(src)->co_nlocalsplus);
*dest = *src;
- for (int i = 1; i < src->stacktop; i++) {
+ assert(src->stackpointer != NULL);
+ int stacktop = (int)(src->stackpointer - src->localsplus);
+ assert(stacktop >= _PyFrame_GetCode(src)->co_nlocalsplus);
+ dest->stackpointer = dest->localsplus + stacktop;
+ for (int i = 1; i < stacktop; i++) {
dest->localsplus[i] = src->localsplus[i];
}
// Don't leave a dangling pointer to the old frame when creating generators
@@ -141,7 +144,7 @@ _PyFrame_Initialize(
frame->f_builtins = func->func_builtins;
frame->f_globals = func->func_globals;
frame->f_locals = locals;
- frame->stacktop = code->co_nlocalsplus;
+ frame->stackpointer = frame->localsplus + code->co_nlocalsplus;
frame->frame_obj = NULL;
frame->instr_ptr = _PyCode_CODE(code);
frame->return_offset = 0;
@@ -161,22 +164,23 @@ _PyFrame_GetLocalsArray(_PyInterpreterFrame *frame)
return frame->localsplus;
}
-/* Fetches the stack pointer, and sets stacktop to -1.
- Having stacktop <= 0 ensures that invalid
- values are not visible to the cycle GC.
- We choose -1 rather than 0 to assist debugging. */
+/* Fetches the stack pointer, and sets stackpointer to NULL.
+ Having stackpointer == NULL ensures that invalid
+ values are not visible to the cycle GC. */
static inline _PyStackRef*
_PyFrame_GetStackPointer(_PyInterpreterFrame *frame)
{
- _PyStackRef *sp = frame->localsplus + frame->stacktop;
- frame->stacktop = -1;
+ assert(frame->stackpointer != NULL);
+ _PyStackRef *sp = frame->stackpointer;
+ frame->stackpointer = NULL;
return sp;
}
static inline void
_PyFrame_SetStackPointer(_PyInterpreterFrame *frame, _PyStackRef *stack_pointer)
{
- frame->stacktop = (int)(stack_pointer - frame->localsplus);
+ assert(frame->stackpointer == NULL);
+ frame->stackpointer = stack_pointer;
}
/* Determine whether a frame is incomplete.
@@ -304,7 +308,8 @@ _PyFrame_PushTrampolineUnchecked(PyThreadState *tstate, PyCodeObject *code, int
frame->f_globals = NULL;
#endif
frame->f_locals = NULL;
- frame->stacktop = code->co_nlocalsplus + stackdepth;
+ assert(stackdepth <= code->co_stacksize);
+ frame->stackpointer = frame->localsplus + code->co_nlocalsplus + stackdepth;
frame->frame_obj = NULL;
frame->instr_ptr = _PyCode_CODE(code);
frame->owner = FRAME_OWNED_BY_THREAD;
diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
index 81789b2..7e4bc98 100644
--- a/Lib/test/test_sys.py
+++ b/Lib/test/test_sys.py
@@ -1603,7 +1603,8 @@ class SizeofTest(unittest.TestCase):
def func():
return sys._getframe()
x = func()
- check(x, size('3Pi2c2P7P2ic??2P'))
+ INTERPRETER_FRAME = '9PhcP'
+ check(x, size('3PiccPP' + INTERPRETER_FRAME + 'P'))
# function
def func(): pass
check(func, size('16Pi'))
@@ -1620,7 +1621,7 @@ class SizeofTest(unittest.TestCase):
check(bar, size('PP'))
# generator
def get_gen(): yield 1
- check(get_gen(), size('PP4P4c7P2ic??2P'))
+ check(get_gen(), size('6P4c' + INTERPRETER_FRAME + 'P'))
# iterator
check(iter('abc'), size('lP'))
# callable-iterator
diff --git a/Objects/frameobject.c b/Objects/frameobject.c
index 2ef3bea..88093eb 100644
--- a/Objects/frameobject.c
+++ b/Objects/frameobject.c
@@ -1620,8 +1620,10 @@ frame_dealloc(PyFrameObject *f)
Py_CLEAR(frame->f_funcobj);
Py_CLEAR(frame->f_locals);
_PyStackRef *locals = _PyFrame_GetLocalsArray(frame);
- for (int i = 0; i < frame->stacktop; i++) {
- PyStackRef_CLEAR(locals[i]);
+ _PyStackRef *sp = frame->stackpointer;
+ while (sp > locals) {
+ sp--;
+ PyStackRef_CLEAR(*sp);
}
}
Py_CLEAR(f->f_back);
@@ -1656,11 +1658,13 @@ frame_tp_clear(PyFrameObject *f)
/* locals and stack */
_PyStackRef *locals = _PyFrame_GetLocalsArray(f->f_frame);
- assert(f->f_frame->stacktop >= 0);
- for (int i = 0; i < f->f_frame->stacktop; i++) {
- PyStackRef_CLEAR(locals[i]);
+ _PyStackRef *sp = f->f_frame->stackpointer;
+ assert(sp >= locals);
+ while (sp > locals) {
+ sp--;
+ PyStackRef_CLEAR(*sp);
}
- f->f_frame->stacktop = 0;
+ f->f_frame->stackpointer = locals;
Py_CLEAR(f->f_frame->f_locals);
return 0;
}
@@ -1878,8 +1882,9 @@ frame_get_var(_PyInterpreterFrame *frame, PyCodeObject *co, int i,
return 0;
}
- PyObject *value = PyStackRef_AsPyObjectBorrow(frame->localsplus[i]);
- if (frame->stacktop) {
+ PyObject *value = NULL;
+ if (frame->stackpointer == NULL || frame->stackpointer > frame->localsplus + i) {
+ value = PyStackRef_AsPyObjectBorrow(frame->localsplus[i]);
if (kind & CO_FAST_FREE) {
// The cell was set by COPY_FREE_VARS.
assert(value != NULL && PyCell_Check(value));
@@ -1897,9 +1902,6 @@ frame_get_var(_PyInterpreterFrame *frame, PyCodeObject *co, int i,
}
}
}
- else {
- assert(value == NULL);
- }
*pvalue = value;
return 1;
}
diff --git a/Python/ceval.c b/Python/ceval.c
index 026e018..97d4b82 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -764,7 +764,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
#endif
entry_frame.f_executable = Py_None;
entry_frame.instr_ptr = (_Py_CODEUNIT *)_Py_INTERPRETER_TRAMPOLINE_INSTRUCTIONS + 1;
- entry_frame.stacktop = 0;
+ entry_frame.stackpointer = entry_frame.localsplus;
entry_frame.owner = FRAME_OWNED_BY_CSTACK;
entry_frame.return_offset = 0;
/* Push frame */
diff --git a/Python/frame.c b/Python/frame.c
index 9c7e596..25fa282 100644
--- a/Python/frame.c
+++ b/Python/frame.c
@@ -17,10 +17,11 @@ _PyFrame_Traverse(_PyInterpreterFrame *frame, visitproc visit, void *arg)
Py_VISIT(_PyFrame_GetCode(frame));
/* locals */
_PyStackRef *locals = _PyFrame_GetLocalsArray(frame);
- int i = 0;
+ _PyStackRef *sp = frame->stackpointer;
/* locals and stack */
- for (; i <frame->stacktop; i++) {
- Py_VISIT(PyStackRef_AsPyObjectBorrow(locals[i]));
+ while (sp > locals) {
+ sp--;
+ Py_VISIT(PyStackRef_AsPyObjectBorrow(*sp));
}
return 0;
}
@@ -59,10 +60,11 @@ take_ownership(PyFrameObject *f, _PyInterpreterFrame *frame)
assert(frame->owner != FRAME_OWNED_BY_CSTACK);
assert(frame->owner != FRAME_OWNED_BY_FRAME_OBJECT);
assert(frame->owner != FRAME_CLEARED);
- Py_ssize_t size = ((char*)&frame->localsplus[frame->stacktop]) - (char *)frame;
+ Py_ssize_t size = ((char*)frame->stackpointer) - (char *)frame;
Py_INCREF(_PyFrame_GetCode(frame));
memcpy((_PyInterpreterFrame *)f->_f_frame_data, frame, size);
frame = (_PyInterpreterFrame *)f->_f_frame_data;
+ frame->stackpointer = (_PyStackRef *)(((char *)frame) + size);
f->f_frame = frame;
frame->owner = FRAME_OWNED_BY_FRAME_OBJECT;
if (_PyFrame_IsIncomplete(frame)) {
@@ -97,11 +99,13 @@ take_ownership(PyFrameObject *f, _PyInterpreterFrame *frame)
void
_PyFrame_ClearLocals(_PyInterpreterFrame *frame)
{
- assert(frame->stacktop >= 0);
- int stacktop = frame->stacktop;
- frame->stacktop = 0;
- for (int i = 0; i < stacktop; i++) {
- PyStackRef_XCLOSE(frame->localsplus[i]);
+ assert(frame->stackpointer != NULL);
+ _PyStackRef *sp = frame->stackpointer;
+ _PyStackRef *locals = frame->localsplus;
+ frame->stackpointer = locals;
+ while (sp > locals) {
+ sp--;
+ PyStackRef_XCLOSE(*sp);
}
Py_CLEAR(frame->f_locals);
}