1222 lines
37 KiB
C
1222 lines
37 KiB
C
/* Frame object implementation */
|
|
|
|
#include "Python.h"
|
|
#include "pycore_object.h"
|
|
#include "pycore_pystate.h"
|
|
|
|
#include "code.h"
|
|
#include "frameobject.h"
|
|
#include "opcode.h"
|
|
#include "structmember.h"
|
|
|
|
#define OFF(x) offsetof(PyFrameObject, x)
|
|
|
|
static PyMemberDef frame_memberlist[] = {
|
|
{"f_back", T_OBJECT, OFF(f_back), READONLY},
|
|
{"f_code", T_OBJECT, OFF(f_code), READONLY},
|
|
{"f_builtins", T_OBJECT, OFF(f_builtins), READONLY},
|
|
{"f_globals", T_OBJECT, OFF(f_globals), READONLY},
|
|
{"f_lasti", T_INT, OFF(f_lasti), READONLY},
|
|
{"f_trace_lines", T_BOOL, OFF(f_trace_lines), 0},
|
|
{"f_trace_opcodes", T_BOOL, OFF(f_trace_opcodes), 0},
|
|
{NULL} /* Sentinel */
|
|
};
|
|
|
|
static PyObject *
|
|
frame_getlocals(PyFrameObject *f, void *closure)
|
|
{
|
|
if (PyFrame_FastToLocalsWithError(f) < 0)
|
|
return NULL;
|
|
Py_INCREF(f->f_locals);
|
|
return f->f_locals;
|
|
}
|
|
|
|
int
|
|
PyFrame_GetLineNumber(PyFrameObject *f)
|
|
{
|
|
if (f->f_trace)
|
|
return f->f_lineno;
|
|
else
|
|
return PyCode_Addr2Line(f->f_code, f->f_lasti);
|
|
}
|
|
|
|
static PyObject *
|
|
frame_getlineno(PyFrameObject *f, void *closure)
|
|
{
|
|
return PyLong_FromLong(PyFrame_GetLineNumber(f));
|
|
}
|
|
|
|
|
|
/* Given the index of the effective opcode,
|
|
scan back to construct the oparg with EXTENDED_ARG */
|
|
static unsigned int
|
|
get_arg(const _Py_CODEUNIT *codestr, Py_ssize_t i)
|
|
{
|
|
_Py_CODEUNIT word;
|
|
unsigned int oparg = _Py_OPARG(codestr[i]);
|
|
if (i >= 1 && _Py_OPCODE(word = codestr[i-1]) == EXTENDED_ARG) {
|
|
oparg |= _Py_OPARG(word) << 8;
|
|
if (i >= 2 && _Py_OPCODE(word = codestr[i-2]) == EXTENDED_ARG) {
|
|
oparg |= _Py_OPARG(word) << 16;
|
|
if (i >= 3 && _Py_OPCODE(word = codestr[i-3]) == EXTENDED_ARG) {
|
|
oparg |= _Py_OPARG(word) << 24;
|
|
}
|
|
}
|
|
}
|
|
return oparg;
|
|
}
|
|
|
|
typedef struct _codetracker {
|
|
unsigned char *code;
|
|
Py_ssize_t code_len;
|
|
unsigned char *lnotab;
|
|
Py_ssize_t lnotab_len;
|
|
int start_line;
|
|
int offset;
|
|
int line;
|
|
int addr;
|
|
int line_addr;
|
|
} codetracker;
|
|
|
|
/* Reset the mutable parts of the tracker */
|
|
static void
|
|
reset(codetracker *tracker)
|
|
{
|
|
tracker->offset = 0;
|
|
tracker->addr = 0;
|
|
tracker->line_addr = 0;
|
|
tracker->line = tracker->start_line;
|
|
}
|
|
|
|
/* Initialise the tracker */
|
|
static void
|
|
init_codetracker(codetracker *tracker, PyCodeObject *code_obj)
|
|
{
|
|
PyBytes_AsStringAndSize(code_obj->co_code,
|
|
(char **)&tracker->code, &tracker->code_len);
|
|
PyBytes_AsStringAndSize(code_obj->co_lnotab,
|
|
(char **)&tracker->lnotab, &tracker->lnotab_len);
|
|
tracker->start_line = code_obj->co_firstlineno;
|
|
reset(tracker);
|
|
}
|
|
|
|
static void
|
|
advance_tracker(codetracker *tracker)
|
|
{
|
|
tracker->addr += sizeof(_Py_CODEUNIT);
|
|
if (tracker->offset >= tracker->lnotab_len) {
|
|
return;
|
|
}
|
|
while (tracker->offset < tracker->lnotab_len &&
|
|
tracker->addr >= tracker->line_addr + tracker->lnotab[tracker->offset]) {
|
|
tracker->line_addr += tracker->lnotab[tracker->offset];
|
|
tracker->line += (signed char)tracker->lnotab[tracker->offset+1];
|
|
tracker->offset += 2;
|
|
}
|
|
}
|
|
|
|
|
|
static void
|
|
retreat_tracker(codetracker *tracker)
|
|
{
|
|
tracker->addr -= sizeof(_Py_CODEUNIT);
|
|
while (tracker->addr < tracker->line_addr) {
|
|
tracker->offset -= 2;
|
|
tracker->line_addr -= tracker->lnotab[tracker->offset];
|
|
tracker->line -= (signed char)tracker->lnotab[tracker->offset+1];
|
|
}
|
|
}
|
|
|
|
static int
|
|
move_to_addr(codetracker *tracker, int addr)
|
|
{
|
|
while (addr > tracker->addr) {
|
|
advance_tracker(tracker);
|
|
if (tracker->addr >= tracker->code_len) {
|
|
return -1;
|
|
}
|
|
}
|
|
while (addr < tracker->addr) {
|
|
retreat_tracker(tracker);
|
|
if (tracker->addr < 0) {
|
|
return -1;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
first_line_not_before(codetracker *tracker, int line)
|
|
{
|
|
int result = INT_MAX;
|
|
reset(tracker);
|
|
while (tracker->addr < tracker->code_len) {
|
|
if (tracker->line == line) {
|
|
return line;
|
|
}
|
|
if (tracker->line > line && tracker->line < result) {
|
|
result = tracker->line;
|
|
}
|
|
advance_tracker(tracker);
|
|
}
|
|
if (result == INT_MAX) {
|
|
return -1;
|
|
}
|
|
return result;
|
|
}
|
|
|
|
static int
|
|
move_to_nearest_start_of_line(codetracker *tracker, int line)
|
|
{
|
|
if (line > tracker->line) {
|
|
while (line != tracker->line) {
|
|
advance_tracker(tracker);
|
|
if (tracker->addr >= tracker->code_len) {
|
|
return -1;
|
|
}
|
|
}
|
|
}
|
|
else {
|
|
while (line != tracker->line) {
|
|
retreat_tracker(tracker);
|
|
if (tracker->addr < 0) {
|
|
return -1;
|
|
}
|
|
}
|
|
while (tracker->addr > tracker->line_addr) {
|
|
retreat_tracker(tracker);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
typedef struct _blockitem
|
|
{
|
|
unsigned char kind;
|
|
int end_addr;
|
|
int start_line;
|
|
} blockitem;
|
|
|
|
typedef struct _blockstack
|
|
{
|
|
blockitem stack[CO_MAXBLOCKS];
|
|
int depth;
|
|
} blockstack;
|
|
|
|
|
|
static void
|
|
init_blockstack(blockstack *blocks)
|
|
{
|
|
blocks->depth = 0;
|
|
}
|
|
|
|
static void
|
|
push_block(blockstack *blocks, unsigned char kind,
|
|
int end_addr, int start_line)
|
|
{
|
|
assert(blocks->depth < CO_MAXBLOCKS);
|
|
blocks->stack[blocks->depth].kind = kind;
|
|
blocks->stack[blocks->depth].end_addr = end_addr;
|
|
blocks->stack[blocks->depth].start_line = start_line;
|
|
blocks->depth++;
|
|
}
|
|
|
|
static unsigned char
|
|
pop_block(blockstack *blocks)
|
|
{
|
|
assert(blocks->depth > 0);
|
|
blocks->depth--;
|
|
return blocks->stack[blocks->depth].kind;
|
|
}
|
|
|
|
static blockitem *
|
|
top_block(blockstack *blocks)
|
|
{
|
|
assert(blocks->depth > 0);
|
|
return &blocks->stack[blocks->depth-1];
|
|
}
|
|
|
|
static inline int
|
|
is_try_except(unsigned char op, int target_op)
|
|
{
|
|
return op == SETUP_FINALLY && (target_op == DUP_TOP || target_op == POP_TOP);
|
|
}
|
|
|
|
static inline int
|
|
is_async_for(unsigned char op, int target_op)
|
|
{
|
|
return op == SETUP_FINALLY && target_op == END_ASYNC_FOR;
|
|
}
|
|
|
|
static inline int
|
|
is_try_finally(unsigned char op, int target_op)
|
|
{
|
|
return op == SETUP_FINALLY && !is_try_except(op, target_op) && !is_async_for(op, target_op);
|
|
}
|
|
|
|
/* Kind for finding except blocks in the jump to line code */
|
|
#define TRY_EXCEPT 250
|
|
|
|
static int
|
|
block_stack_for_line(codetracker *tracker, int line, blockstack *blocks)
|
|
{
|
|
if (line < tracker->start_line) {
|
|
return -1;
|
|
}
|
|
init_blockstack(blocks);
|
|
reset(tracker);
|
|
while (tracker->addr < tracker->code_len) {
|
|
if (tracker->line == line) {
|
|
return 0;
|
|
}
|
|
if (blocks->depth > 0 && tracker->addr == top_block(blocks)->end_addr) {
|
|
unsigned char kind = pop_block(blocks);
|
|
assert(kind != SETUP_FINALLY);
|
|
if (kind == TRY_EXCEPT) {
|
|
push_block(blocks, POP_EXCEPT, -1, tracker->line);
|
|
}
|
|
if (kind == SETUP_WITH || kind == SETUP_ASYNC_WITH) {
|
|
push_block(blocks, WITH_EXCEPT_START, -1, tracker->line);
|
|
}
|
|
}
|
|
unsigned char op = tracker->code[tracker->addr];
|
|
if (op == SETUP_FINALLY || op == SETUP_ASYNC_WITH || op == SETUP_WITH || op == FOR_ITER) {
|
|
unsigned int oparg = get_arg((const _Py_CODEUNIT *)tracker->code,
|
|
tracker->addr / sizeof(_Py_CODEUNIT));
|
|
int target_addr = tracker->addr + oparg + sizeof(_Py_CODEUNIT);
|
|
int target_op = tracker->code[target_addr];
|
|
if (is_async_for(op, target_op)) {
|
|
push_block(blocks, FOR_ITER, target_addr, tracker->line);
|
|
}
|
|
else if (op == FOR_ITER) {
|
|
push_block(blocks, FOR_ITER, target_addr-sizeof(_Py_CODEUNIT), tracker->line);
|
|
}
|
|
else if (is_try_except(op, target_op)) {
|
|
push_block(blocks, TRY_EXCEPT, target_addr-sizeof(_Py_CODEUNIT), tracker->line);
|
|
}
|
|
else if (is_try_finally(op, target_op)) {
|
|
int addr = tracker->addr;
|
|
// Skip over duplicate 'finally' blocks if line is after body.
|
|
move_to_addr(tracker, target_addr);
|
|
if (tracker->line > line) {
|
|
// Target is in body, rewind to start.
|
|
move_to_addr(tracker, addr);
|
|
push_block(blocks, op, target_addr, tracker->line);
|
|
}
|
|
else {
|
|
// Now in finally block.
|
|
push_block(blocks, RERAISE, -1, tracker->line);
|
|
}
|
|
}
|
|
else {
|
|
push_block(blocks, op, target_addr, tracker->line);
|
|
}
|
|
}
|
|
else if (op == RERAISE) {
|
|
assert(blocks->depth > 0);
|
|
unsigned char kind = top_block(blocks)->kind;
|
|
if (kind == RERAISE || kind == WITH_EXCEPT_START || kind == POP_EXCEPT) {
|
|
pop_block(blocks);
|
|
}
|
|
|
|
}
|
|
advance_tracker(tracker);
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
static void
|
|
frame_stack_pop(PyFrameObject *f)
|
|
{
|
|
PyObject *v = (*--f->f_stacktop);
|
|
Py_DECREF(v);
|
|
}
|
|
|
|
static void
|
|
frame_block_unwind(PyFrameObject *f)
|
|
{
|
|
assert(f->f_iblock > 0);
|
|
f->f_iblock--;
|
|
PyTryBlock *b = &f->f_blockstack[f->f_iblock];
|
|
intptr_t delta = (f->f_stacktop - f->f_valuestack) - b->b_level;
|
|
while (delta > 0) {
|
|
frame_stack_pop(f);
|
|
delta--;
|
|
}
|
|
}
|
|
|
|
|
|
/* Setter for f_lineno - you can set f_lineno from within a trace function in
|
|
* order to jump to a given line of code, subject to some restrictions. Most
|
|
* lines are OK to jump to because they don't make any assumptions about the
|
|
* state of the stack (obvious because you could remove the line and the code
|
|
* would still work without any stack errors), but there are some constructs
|
|
* that limit jumping:
|
|
*
|
|
* o Lines with an 'except' statement on them can't be jumped to, because
|
|
* they expect an exception to be on the top of the stack.
|
|
* o Lines that live in a 'finally' block can't be jumped from or to, since
|
|
* we cannot be sure which state the interpreter was in or would be in
|
|
* during execution of the finally block.
|
|
* o 'try', 'with' and 'async with' blocks can't be jumped into because
|
|
* the blockstack needs to be set up before their code runs.
|
|
* o 'for' and 'async for' loops can't be jumped into because the
|
|
* iterator needs to be on the stack.
|
|
* o Jumps cannot be made from within a trace function invoked with a
|
|
* 'return' or 'exception' event since the eval loop has been exited at
|
|
* that time.
|
|
*/
|
|
static int
|
|
frame_setlineno(PyFrameObject *f, PyObject* p_new_lineno, void *Py_UNUSED(ignored))
|
|
{
|
|
if (p_new_lineno == NULL) {
|
|
PyErr_SetString(PyExc_AttributeError, "cannot delete attribute");
|
|
return -1;
|
|
}
|
|
/* f_lineno must be an integer. */
|
|
if (!PyLong_CheckExact(p_new_lineno)) {
|
|
PyErr_SetString(PyExc_ValueError,
|
|
"lineno must be an integer");
|
|
return -1;
|
|
}
|
|
|
|
/* Upon the 'call' trace event of a new frame, f->f_lasti is -1 and
|
|
* f->f_trace is NULL, check first on the first condition.
|
|
* Forbidding jumps from the 'call' event of a new frame is a side effect
|
|
* of allowing to set f_lineno only from trace functions. */
|
|
if (f->f_lasti == -1) {
|
|
PyErr_Format(PyExc_ValueError,
|
|
"can't jump from the 'call' trace event of a new frame");
|
|
return -1;
|
|
}
|
|
|
|
/* You can only do this from within a trace function, not via
|
|
* _getframe or similar hackery. */
|
|
if (!f->f_trace) {
|
|
PyErr_Format(PyExc_ValueError,
|
|
"f_lineno can only be set by a trace function");
|
|
return -1;
|
|
}
|
|
|
|
/* Forbid jumps upon a 'return' trace event (except after executing a
|
|
* YIELD_VALUE or YIELD_FROM opcode, f_stacktop is not NULL in that case)
|
|
* and upon an 'exception' trace event.
|
|
* Jumps from 'call' trace events have already been forbidden above for new
|
|
* frames, so this check does not change anything for 'call' events. */
|
|
if (f->f_stacktop == NULL) {
|
|
PyErr_SetString(PyExc_ValueError,
|
|
"can only jump from a 'line' trace event");
|
|
return -1;
|
|
}
|
|
|
|
|
|
codetracker tracker;
|
|
init_codetracker(&tracker, f->f_code);
|
|
move_to_addr(&tracker, f->f_lasti);
|
|
int current_line = tracker.line;
|
|
assert(current_line >= 0);
|
|
int new_lineno;
|
|
|
|
{
|
|
/* Fail if the line falls outside the code block and
|
|
select first line with actual code. */
|
|
int overflow;
|
|
long l_new_lineno = PyLong_AsLongAndOverflow(p_new_lineno, &overflow);
|
|
if (overflow
|
|
#if SIZEOF_LONG > SIZEOF_INT
|
|
|| l_new_lineno > INT_MAX
|
|
|| l_new_lineno < INT_MIN
|
|
#endif
|
|
) {
|
|
PyErr_SetString(PyExc_ValueError,
|
|
"lineno out of range");
|
|
return -1;
|
|
}
|
|
new_lineno = (int)l_new_lineno;
|
|
|
|
if (new_lineno < f->f_code->co_firstlineno) {
|
|
PyErr_Format(PyExc_ValueError,
|
|
"line %d comes before the current code block",
|
|
new_lineno);
|
|
return -1;
|
|
}
|
|
|
|
new_lineno = first_line_not_before(&tracker, new_lineno);
|
|
if (new_lineno < 0) {
|
|
PyErr_Format(PyExc_ValueError,
|
|
"line %d comes after the current code block",
|
|
(int)l_new_lineno);
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
if (tracker.code[f->f_lasti] == YIELD_VALUE || tracker.code[f->f_lasti] == YIELD_FROM) {
|
|
PyErr_SetString(PyExc_ValueError,
|
|
"can't jump from a 'yield' statement");
|
|
return -1;
|
|
}
|
|
|
|
/* Find block stack for current line and target line. */
|
|
blockstack current_stack, new_stack;
|
|
block_stack_for_line(&tracker, new_lineno, &new_stack);
|
|
block_stack_for_line(&tracker, current_line, ¤t_stack);
|
|
|
|
/* The trace function is called with a 'return' trace event after the
|
|
* execution of a yield statement. */
|
|
if (tracker.code[tracker.addr] == DUP_TOP || tracker.code[tracker.addr] == POP_TOP) {
|
|
PyErr_SetString(PyExc_ValueError,
|
|
"can't jump to 'except' line as there's no exception");
|
|
return -1;
|
|
}
|
|
|
|
/* Validate change of block stack. */
|
|
if (new_stack.depth > 0) {
|
|
blockitem *current_block_at_new_depth = &(current_stack.stack[new_stack.depth-1]);
|
|
if (new_stack.depth > current_stack.depth ||
|
|
top_block(&new_stack)->start_line != current_block_at_new_depth->start_line) {
|
|
unsigned char target_kind = top_block(&new_stack)->kind;
|
|
const char *msg;
|
|
if (target_kind == POP_EXCEPT) {
|
|
msg = "can't jump into an 'except' block as there's no exception";
|
|
}
|
|
else if (target_kind == RERAISE) {
|
|
msg = "can't jump into a 'finally' block";
|
|
}
|
|
else {
|
|
msg = "can't jump into the middle of a block";
|
|
}
|
|
PyErr_SetString(PyExc_ValueError, msg);
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
/* Check for illegal jumps out of finally or except blocks. */
|
|
for (int depth = new_stack.depth; depth < current_stack.depth; depth++) {
|
|
switch(current_stack.stack[depth].kind) {
|
|
case RERAISE:
|
|
PyErr_SetString(PyExc_ValueError,
|
|
"can't jump out of a 'finally' block");
|
|
return -1;
|
|
case POP_EXCEPT:
|
|
PyErr_SetString(PyExc_ValueError,
|
|
"can't jump out of an 'except' block");
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
/* Unwind block stack. */
|
|
while (current_stack.depth > new_stack.depth) {
|
|
unsigned char kind = pop_block(¤t_stack);
|
|
switch(kind) {
|
|
case FOR_ITER:
|
|
frame_stack_pop(f);
|
|
break;
|
|
case SETUP_FINALLY:
|
|
case TRY_EXCEPT:
|
|
frame_block_unwind(f);
|
|
break;
|
|
case SETUP_WITH:
|
|
case SETUP_ASYNC_WITH:
|
|
frame_block_unwind(f);
|
|
// Pop the exit function
|
|
frame_stack_pop(f);
|
|
break;
|
|
default:
|
|
PyErr_SetString(PyExc_SystemError,
|
|
"unexpected block kind");
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
move_to_addr(&tracker, f->f_lasti);
|
|
move_to_nearest_start_of_line(&tracker, new_lineno);
|
|
|
|
/* Finally set the new f_lineno and f_lasti and return OK. */
|
|
f->f_lineno = new_lineno;
|
|
f->f_lasti = tracker.addr;
|
|
return 0;
|
|
}
|
|
|
|
static PyObject *
|
|
frame_gettrace(PyFrameObject *f, void *closure)
|
|
{
|
|
PyObject* trace = f->f_trace;
|
|
|
|
if (trace == NULL)
|
|
trace = Py_None;
|
|
|
|
Py_INCREF(trace);
|
|
|
|
return trace;
|
|
}
|
|
|
|
static int
|
|
frame_settrace(PyFrameObject *f, PyObject* v, void *closure)
|
|
{
|
|
/* We rely on f_lineno being accurate when f_trace is set. */
|
|
f->f_lineno = PyFrame_GetLineNumber(f);
|
|
|
|
if (v == Py_None)
|
|
v = NULL;
|
|
Py_XINCREF(v);
|
|
Py_XSETREF(f->f_trace, v);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static PyGetSetDef frame_getsetlist[] = {
|
|
{"f_locals", (getter)frame_getlocals, NULL, NULL},
|
|
{"f_lineno", (getter)frame_getlineno,
|
|
(setter)frame_setlineno, NULL},
|
|
{"f_trace", (getter)frame_gettrace, (setter)frame_settrace, NULL},
|
|
{0}
|
|
};
|
|
|
|
/* Stack frames are allocated and deallocated at a considerable rate.
|
|
In an attempt to improve the speed of function calls, we:
|
|
|
|
1. Hold a single "zombie" frame on each code object. This retains
|
|
the allocated and initialised frame object from an invocation of
|
|
the code object. The zombie is reanimated the next time we need a
|
|
frame object for that code object. Doing this saves the malloc/
|
|
realloc required when using a free_list frame that isn't the
|
|
correct size. It also saves some field initialisation.
|
|
|
|
In zombie mode, no field of PyFrameObject holds a reference, but
|
|
the following fields are still valid:
|
|
|
|
* ob_type, ob_size, f_code, f_valuestack;
|
|
|
|
* f_locals, f_trace are NULL;
|
|
|
|
* f_localsplus does not require re-allocation and
|
|
the local variables in f_localsplus are NULL.
|
|
|
|
2. We also maintain a separate free list of stack frames (just like
|
|
floats are allocated in a special way -- see floatobject.c). When
|
|
a stack frame is on the free list, only the following members have
|
|
a meaning:
|
|
ob_type == &Frametype
|
|
f_back next item on free list, or NULL
|
|
f_stacksize size of value stack
|
|
ob_size size of localsplus
|
|
Note that the value and block stacks are preserved -- this can save
|
|
another malloc() call or two (and two free() calls as well!).
|
|
Also note that, unlike for integers, each frame object is a
|
|
malloc'ed object in its own right -- it is only the actual calls to
|
|
malloc() that we are trying to save here, not the administration.
|
|
After all, while a typical program may make millions of calls, a
|
|
call depth of more than 20 or 30 is probably already exceptional
|
|
unless the program contains run-away recursion. I hope.
|
|
|
|
Later, PyFrame_MAXFREELIST was added to bound the # of frames saved on
|
|
free_list. Else programs creating lots of cyclic trash involving
|
|
frames could provoke free_list into growing without bound.
|
|
*/
|
|
|
|
static PyFrameObject *free_list = NULL;
|
|
static int numfree = 0; /* number of frames currently in free_list */
|
|
/* max value for numfree */
|
|
#define PyFrame_MAXFREELIST 200
|
|
|
|
static void _Py_HOT_FUNCTION
|
|
frame_dealloc(PyFrameObject *f)
|
|
{
|
|
PyObject **p, **valuestack;
|
|
PyCodeObject *co;
|
|
|
|
if (_PyObject_GC_IS_TRACKED(f))
|
|
_PyObject_GC_UNTRACK(f);
|
|
|
|
Py_TRASHCAN_SAFE_BEGIN(f)
|
|
/* Kill all local variables */
|
|
valuestack = f->f_valuestack;
|
|
for (p = f->f_localsplus; p < valuestack; p++)
|
|
Py_CLEAR(*p);
|
|
|
|
/* Free stack */
|
|
if (f->f_stacktop != NULL) {
|
|
for (p = valuestack; p < f->f_stacktop; p++)
|
|
Py_XDECREF(*p);
|
|
}
|
|
|
|
Py_XDECREF(f->f_back);
|
|
Py_DECREF(f->f_builtins);
|
|
Py_DECREF(f->f_globals);
|
|
Py_CLEAR(f->f_locals);
|
|
Py_CLEAR(f->f_trace);
|
|
|
|
co = f->f_code;
|
|
if (co->co_zombieframe == NULL)
|
|
co->co_zombieframe = f;
|
|
else if (numfree < PyFrame_MAXFREELIST) {
|
|
++numfree;
|
|
f->f_back = free_list;
|
|
free_list = f;
|
|
}
|
|
else
|
|
PyObject_GC_Del(f);
|
|
|
|
Py_DECREF(co);
|
|
Py_TRASHCAN_SAFE_END(f)
|
|
}
|
|
|
|
static int
|
|
frame_traverse(PyFrameObject *f, visitproc visit, void *arg)
|
|
{
|
|
PyObject **fastlocals, **p;
|
|
Py_ssize_t i, slots;
|
|
|
|
Py_VISIT(f->f_back);
|
|
Py_VISIT(f->f_code);
|
|
Py_VISIT(f->f_builtins);
|
|
Py_VISIT(f->f_globals);
|
|
Py_VISIT(f->f_locals);
|
|
Py_VISIT(f->f_trace);
|
|
|
|
/* locals */
|
|
slots = f->f_code->co_nlocals + PyTuple_GET_SIZE(f->f_code->co_cellvars) + PyTuple_GET_SIZE(f->f_code->co_freevars);
|
|
fastlocals = f->f_localsplus;
|
|
for (i = slots; --i >= 0; ++fastlocals)
|
|
Py_VISIT(*fastlocals);
|
|
|
|
/* stack */
|
|
if (f->f_stacktop != NULL) {
|
|
for (p = f->f_valuestack; p < f->f_stacktop; p++)
|
|
Py_VISIT(*p);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
frame_tp_clear(PyFrameObject *f)
|
|
{
|
|
PyObject **fastlocals, **p, **oldtop;
|
|
Py_ssize_t i, slots;
|
|
|
|
/* Before anything else, make sure that this frame is clearly marked
|
|
* as being defunct! Else, e.g., a generator reachable from this
|
|
* frame may also point to this frame, believe itself to still be
|
|
* active, and try cleaning up this frame again.
|
|
*/
|
|
oldtop = f->f_stacktop;
|
|
f->f_stacktop = NULL;
|
|
f->f_executing = 0;
|
|
|
|
Py_CLEAR(f->f_trace);
|
|
|
|
/* locals */
|
|
slots = f->f_code->co_nlocals + PyTuple_GET_SIZE(f->f_code->co_cellvars) + PyTuple_GET_SIZE(f->f_code->co_freevars);
|
|
fastlocals = f->f_localsplus;
|
|
for (i = slots; --i >= 0; ++fastlocals)
|
|
Py_CLEAR(*fastlocals);
|
|
|
|
/* stack */
|
|
if (oldtop != NULL) {
|
|
for (p = f->f_valuestack; p < oldtop; p++)
|
|
Py_CLEAR(*p);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static PyObject *
|
|
frame_clear(PyFrameObject *f, PyObject *Py_UNUSED(ignored))
|
|
{
|
|
if (f->f_executing) {
|
|
PyErr_SetString(PyExc_RuntimeError,
|
|
"cannot clear an executing frame");
|
|
return NULL;
|
|
}
|
|
if (f->f_gen) {
|
|
_PyGen_Finalize(f->f_gen);
|
|
assert(f->f_gen == NULL);
|
|
}
|
|
(void)frame_tp_clear(f);
|
|
Py_RETURN_NONE;
|
|
}
|
|
|
|
PyDoc_STRVAR(clear__doc__,
|
|
"F.clear(): clear most references held by the frame");
|
|
|
|
static PyObject *
|
|
frame_sizeof(PyFrameObject *f, PyObject *Py_UNUSED(ignored))
|
|
{
|
|
Py_ssize_t res, extras, ncells, nfrees;
|
|
|
|
ncells = PyTuple_GET_SIZE(f->f_code->co_cellvars);
|
|
nfrees = PyTuple_GET_SIZE(f->f_code->co_freevars);
|
|
extras = f->f_code->co_stacksize + f->f_code->co_nlocals +
|
|
ncells + nfrees;
|
|
/* subtract one as it is already included in PyFrameObject */
|
|
res = sizeof(PyFrameObject) + (extras-1) * sizeof(PyObject *);
|
|
|
|
return PyLong_FromSsize_t(res);
|
|
}
|
|
|
|
PyDoc_STRVAR(sizeof__doc__,
|
|
"F.__sizeof__() -> size of F in memory, in bytes");
|
|
|
|
static PyObject *
|
|
frame_repr(PyFrameObject *f)
|
|
{
|
|
int lineno = PyFrame_GetLineNumber(f);
|
|
return PyUnicode_FromFormat(
|
|
"<frame at %p, file %R, line %d, code %S>",
|
|
f, f->f_code->co_filename, lineno, f->f_code->co_name);
|
|
}
|
|
|
|
static PyMethodDef frame_methods[] = {
|
|
{"clear", (PyCFunction)frame_clear, METH_NOARGS,
|
|
clear__doc__},
|
|
{"__sizeof__", (PyCFunction)frame_sizeof, METH_NOARGS,
|
|
sizeof__doc__},
|
|
{NULL, NULL} /* sentinel */
|
|
};
|
|
|
|
PyTypeObject PyFrame_Type = {
|
|
PyVarObject_HEAD_INIT(&PyType_Type, 0)
|
|
"frame",
|
|
sizeof(PyFrameObject),
|
|
sizeof(PyObject *),
|
|
(destructor)frame_dealloc, /* tp_dealloc */
|
|
0, /* tp_vectorcall_offset */
|
|
0, /* tp_getattr */
|
|
0, /* tp_setattr */
|
|
0, /* tp_as_async */
|
|
(reprfunc)frame_repr, /* tp_repr */
|
|
0, /* tp_as_number */
|
|
0, /* tp_as_sequence */
|
|
0, /* tp_as_mapping */
|
|
0, /* tp_hash */
|
|
0, /* tp_call */
|
|
0, /* tp_str */
|
|
PyObject_GenericGetAttr, /* tp_getattro */
|
|
PyObject_GenericSetAttr, /* tp_setattro */
|
|
0, /* tp_as_buffer */
|
|
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */
|
|
0, /* tp_doc */
|
|
(traverseproc)frame_traverse, /* tp_traverse */
|
|
(inquiry)frame_tp_clear, /* tp_clear */
|
|
0, /* tp_richcompare */
|
|
0, /* tp_weaklistoffset */
|
|
0, /* tp_iter */
|
|
0, /* tp_iternext */
|
|
frame_methods, /* tp_methods */
|
|
frame_memberlist, /* tp_members */
|
|
frame_getsetlist, /* tp_getset */
|
|
0, /* tp_base */
|
|
0, /* tp_dict */
|
|
};
|
|
|
|
_Py_IDENTIFIER(__builtins__);
|
|
|
|
PyFrameObject* _Py_HOT_FUNCTION
|
|
_PyFrame_New_NoTrack(PyThreadState *tstate, PyCodeObject *code,
|
|
PyObject *globals, PyObject *locals)
|
|
{
|
|
PyFrameObject *back = tstate->frame;
|
|
PyFrameObject *f;
|
|
PyObject *builtins;
|
|
Py_ssize_t i;
|
|
|
|
#ifdef Py_DEBUG
|
|
if (code == NULL || globals == NULL || !PyDict_Check(globals) ||
|
|
(locals != NULL && !PyMapping_Check(locals))) {
|
|
PyErr_BadInternalCall();
|
|
return NULL;
|
|
}
|
|
#endif
|
|
if (back == NULL || back->f_globals != globals) {
|
|
builtins = _PyDict_GetItemIdWithError(globals, &PyId___builtins__);
|
|
if (builtins) {
|
|
if (PyModule_Check(builtins)) {
|
|
builtins = PyModule_GetDict(builtins);
|
|
assert(builtins != NULL);
|
|
}
|
|
}
|
|
if (builtins == NULL) {
|
|
if (PyErr_Occurred()) {
|
|
return NULL;
|
|
}
|
|
/* No builtins! Make up a minimal one
|
|
Give them 'None', at least. */
|
|
builtins = PyDict_New();
|
|
if (builtins == NULL ||
|
|
PyDict_SetItemString(
|
|
builtins, "None", Py_None) < 0)
|
|
return NULL;
|
|
}
|
|
else
|
|
Py_INCREF(builtins);
|
|
|
|
}
|
|
else {
|
|
/* If we share the globals, we share the builtins.
|
|
Save a lookup and a call. */
|
|
builtins = back->f_builtins;
|
|
assert(builtins != NULL);
|
|
Py_INCREF(builtins);
|
|
}
|
|
if (code->co_zombieframe != NULL) {
|
|
f = code->co_zombieframe;
|
|
code->co_zombieframe = NULL;
|
|
_Py_NewReference((PyObject *)f);
|
|
assert(f->f_code == code);
|
|
}
|
|
else {
|
|
Py_ssize_t extras, ncells, nfrees;
|
|
ncells = PyTuple_GET_SIZE(code->co_cellvars);
|
|
nfrees = PyTuple_GET_SIZE(code->co_freevars);
|
|
extras = code->co_stacksize + code->co_nlocals + ncells +
|
|
nfrees;
|
|
if (free_list == NULL) {
|
|
f = PyObject_GC_NewVar(PyFrameObject, &PyFrame_Type,
|
|
extras);
|
|
if (f == NULL) {
|
|
Py_DECREF(builtins);
|
|
return NULL;
|
|
}
|
|
}
|
|
else {
|
|
assert(numfree > 0);
|
|
--numfree;
|
|
f = free_list;
|
|
free_list = free_list->f_back;
|
|
if (Py_SIZE(f) < extras) {
|
|
PyFrameObject *new_f = PyObject_GC_Resize(PyFrameObject, f, extras);
|
|
if (new_f == NULL) {
|
|
PyObject_GC_Del(f);
|
|
Py_DECREF(builtins);
|
|
return NULL;
|
|
}
|
|
f = new_f;
|
|
}
|
|
_Py_NewReference((PyObject *)f);
|
|
}
|
|
|
|
f->f_code = code;
|
|
extras = code->co_nlocals + ncells + nfrees;
|
|
f->f_valuestack = f->f_localsplus + extras;
|
|
for (i=0; i<extras; i++)
|
|
f->f_localsplus[i] = NULL;
|
|
f->f_locals = NULL;
|
|
f->f_trace = NULL;
|
|
}
|
|
f->f_stacktop = f->f_valuestack;
|
|
f->f_builtins = builtins;
|
|
Py_XINCREF(back);
|
|
f->f_back = back;
|
|
Py_INCREF(code);
|
|
Py_INCREF(globals);
|
|
f->f_globals = globals;
|
|
/* Most functions have CO_NEWLOCALS and CO_OPTIMIZED set. */
|
|
if ((code->co_flags & (CO_NEWLOCALS | CO_OPTIMIZED)) ==
|
|
(CO_NEWLOCALS | CO_OPTIMIZED))
|
|
; /* f_locals = NULL; will be set by PyFrame_FastToLocals() */
|
|
else if (code->co_flags & CO_NEWLOCALS) {
|
|
locals = PyDict_New();
|
|
if (locals == NULL) {
|
|
Py_DECREF(f);
|
|
return NULL;
|
|
}
|
|
f->f_locals = locals;
|
|
}
|
|
else {
|
|
if (locals == NULL)
|
|
locals = globals;
|
|
Py_INCREF(locals);
|
|
f->f_locals = locals;
|
|
}
|
|
|
|
f->f_lasti = -1;
|
|
f->f_lineno = code->co_firstlineno;
|
|
f->f_iblock = 0;
|
|
f->f_executing = 0;
|
|
f->f_gen = NULL;
|
|
f->f_trace_opcodes = 0;
|
|
f->f_trace_lines = 1;
|
|
|
|
return f;
|
|
}
|
|
|
|
PyFrameObject*
|
|
PyFrame_New(PyThreadState *tstate, PyCodeObject *code,
|
|
PyObject *globals, PyObject *locals)
|
|
{
|
|
PyFrameObject *f = _PyFrame_New_NoTrack(tstate, code, globals, locals);
|
|
if (f)
|
|
_PyObject_GC_TRACK(f);
|
|
return f;
|
|
}
|
|
|
|
|
|
/* Block management */
|
|
|
|
void
|
|
PyFrame_BlockSetup(PyFrameObject *f, int type, int handler, int level)
|
|
{
|
|
PyTryBlock *b;
|
|
if (f->f_iblock >= CO_MAXBLOCKS) {
|
|
Py_FatalError("block stack overflow");
|
|
}
|
|
b = &f->f_blockstack[f->f_iblock++];
|
|
b->b_type = type;
|
|
b->b_level = level;
|
|
b->b_handler = handler;
|
|
}
|
|
|
|
PyTryBlock *
|
|
PyFrame_BlockPop(PyFrameObject *f)
|
|
{
|
|
PyTryBlock *b;
|
|
if (f->f_iblock <= 0) {
|
|
Py_FatalError("block stack underflow");
|
|
}
|
|
b = &f->f_blockstack[--f->f_iblock];
|
|
return b;
|
|
}
|
|
|
|
/* Convert between "fast" version of locals and dictionary version.
|
|
|
|
map and values are input arguments. map is a tuple of strings.
|
|
values is an array of PyObject*. At index i, map[i] is the name of
|
|
the variable with value values[i]. The function copies the first
|
|
nmap variable from map/values into dict. If values[i] is NULL,
|
|
the variable is deleted from dict.
|
|
|
|
If deref is true, then the values being copied are cell variables
|
|
and the value is extracted from the cell variable before being put
|
|
in dict.
|
|
*/
|
|
|
|
static int
|
|
map_to_dict(PyObject *map, Py_ssize_t nmap, PyObject *dict, PyObject **values,
|
|
int deref)
|
|
{
|
|
Py_ssize_t j;
|
|
assert(PyTuple_Check(map));
|
|
assert(PyDict_Check(dict));
|
|
assert(PyTuple_Size(map) >= nmap);
|
|
for (j=0; j < nmap; j++) {
|
|
PyObject *key = PyTuple_GET_ITEM(map, j);
|
|
PyObject *value = values[j];
|
|
assert(PyUnicode_Check(key));
|
|
if (deref && value != NULL) {
|
|
assert(PyCell_Check(value));
|
|
value = PyCell_GET(value);
|
|
}
|
|
if (value == NULL) {
|
|
if (PyObject_DelItem(dict, key) != 0) {
|
|
if (PyErr_ExceptionMatches(PyExc_KeyError))
|
|
PyErr_Clear();
|
|
else
|
|
return -1;
|
|
}
|
|
}
|
|
else {
|
|
if (PyObject_SetItem(dict, key, value) != 0)
|
|
return -1;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Copy values from the "locals" dict into the fast locals.
|
|
|
|
dict is an input argument containing string keys representing
|
|
variables names and arbitrary PyObject* as values.
|
|
|
|
map and values are input arguments. map is a tuple of strings.
|
|
values is an array of PyObject*. At index i, map[i] is the name of
|
|
the variable with value values[i]. The function copies the first
|
|
nmap variable from map/values into dict. If values[i] is NULL,
|
|
the variable is deleted from dict.
|
|
|
|
If deref is true, then the values being copied are cell variables
|
|
and the value is extracted from the cell variable before being put
|
|
in dict. If clear is true, then variables in map but not in dict
|
|
are set to NULL in map; if clear is false, variables missing in
|
|
dict are ignored.
|
|
|
|
Exceptions raised while modifying the dict are silently ignored,
|
|
because there is no good way to report them.
|
|
*/
|
|
|
|
static void
|
|
dict_to_map(PyObject *map, Py_ssize_t nmap, PyObject *dict, PyObject **values,
|
|
int deref, int clear)
|
|
{
|
|
Py_ssize_t j;
|
|
assert(PyTuple_Check(map));
|
|
assert(PyDict_Check(dict));
|
|
assert(PyTuple_Size(map) >= nmap);
|
|
for (j=0; j < nmap; j++) {
|
|
PyObject *key = PyTuple_GET_ITEM(map, j);
|
|
PyObject *value = PyObject_GetItem(dict, key);
|
|
assert(PyUnicode_Check(key));
|
|
/* We only care about NULLs if clear is true. */
|
|
if (value == NULL) {
|
|
PyErr_Clear();
|
|
if (!clear)
|
|
continue;
|
|
}
|
|
if (deref) {
|
|
assert(PyCell_Check(values[j]));
|
|
if (PyCell_GET(values[j]) != value) {
|
|
if (PyCell_Set(values[j], value) < 0)
|
|
PyErr_Clear();
|
|
}
|
|
} else if (values[j] != value) {
|
|
Py_XINCREF(value);
|
|
Py_XSETREF(values[j], value);
|
|
}
|
|
Py_XDECREF(value);
|
|
}
|
|
}
|
|
|
|
int
|
|
PyFrame_FastToLocalsWithError(PyFrameObject *f)
|
|
{
|
|
/* Merge fast locals into f->f_locals */
|
|
PyObject *locals, *map;
|
|
PyObject **fast;
|
|
PyCodeObject *co;
|
|
Py_ssize_t j;
|
|
Py_ssize_t ncells, nfreevars;
|
|
|
|
if (f == NULL) {
|
|
PyErr_BadInternalCall();
|
|
return -1;
|
|
}
|
|
locals = f->f_locals;
|
|
if (locals == NULL) {
|
|
locals = f->f_locals = PyDict_New();
|
|
if (locals == NULL)
|
|
return -1;
|
|
}
|
|
co = f->f_code;
|
|
map = co->co_varnames;
|
|
if (!PyTuple_Check(map)) {
|
|
PyErr_Format(PyExc_SystemError,
|
|
"co_varnames must be a tuple, not %s",
|
|
Py_TYPE(map)->tp_name);
|
|
return -1;
|
|
}
|
|
fast = f->f_localsplus;
|
|
j = PyTuple_GET_SIZE(map);
|
|
if (j > co->co_nlocals)
|
|
j = co->co_nlocals;
|
|
if (co->co_nlocals) {
|
|
if (map_to_dict(map, j, locals, fast, 0) < 0)
|
|
return -1;
|
|
}
|
|
ncells = PyTuple_GET_SIZE(co->co_cellvars);
|
|
nfreevars = PyTuple_GET_SIZE(co->co_freevars);
|
|
if (ncells || nfreevars) {
|
|
if (map_to_dict(co->co_cellvars, ncells,
|
|
locals, fast + co->co_nlocals, 1))
|
|
return -1;
|
|
|
|
/* If the namespace is unoptimized, then one of the
|
|
following cases applies:
|
|
1. It does not contain free variables, because it
|
|
uses import * or is a top-level namespace.
|
|
2. It is a class namespace.
|
|
We don't want to accidentally copy free variables
|
|
into the locals dict used by the class.
|
|
*/
|
|
if (co->co_flags & CO_OPTIMIZED) {
|
|
if (map_to_dict(co->co_freevars, nfreevars,
|
|
locals, fast + co->co_nlocals + ncells, 1) < 0)
|
|
return -1;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void
|
|
PyFrame_FastToLocals(PyFrameObject *f)
|
|
{
|
|
int res;
|
|
|
|
assert(!PyErr_Occurred());
|
|
|
|
res = PyFrame_FastToLocalsWithError(f);
|
|
if (res < 0)
|
|
PyErr_Clear();
|
|
}
|
|
|
|
void
|
|
PyFrame_LocalsToFast(PyFrameObject *f, int clear)
|
|
{
|
|
/* Merge f->f_locals into fast locals */
|
|
PyObject *locals, *map;
|
|
PyObject **fast;
|
|
PyObject *error_type, *error_value, *error_traceback;
|
|
PyCodeObject *co;
|
|
Py_ssize_t j;
|
|
Py_ssize_t ncells, nfreevars;
|
|
if (f == NULL)
|
|
return;
|
|
locals = f->f_locals;
|
|
co = f->f_code;
|
|
map = co->co_varnames;
|
|
if (locals == NULL)
|
|
return;
|
|
if (!PyTuple_Check(map))
|
|
return;
|
|
PyErr_Fetch(&error_type, &error_value, &error_traceback);
|
|
fast = f->f_localsplus;
|
|
j = PyTuple_GET_SIZE(map);
|
|
if (j > co->co_nlocals)
|
|
j = co->co_nlocals;
|
|
if (co->co_nlocals)
|
|
dict_to_map(co->co_varnames, j, locals, fast, 0, clear);
|
|
ncells = PyTuple_GET_SIZE(co->co_cellvars);
|
|
nfreevars = PyTuple_GET_SIZE(co->co_freevars);
|
|
if (ncells || nfreevars) {
|
|
dict_to_map(co->co_cellvars, ncells,
|
|
locals, fast + co->co_nlocals, 1, clear);
|
|
/* Same test as in PyFrame_FastToLocals() above. */
|
|
if (co->co_flags & CO_OPTIMIZED) {
|
|
dict_to_map(co->co_freevars, nfreevars,
|
|
locals, fast + co->co_nlocals + ncells, 1,
|
|
clear);
|
|
}
|
|
}
|
|
PyErr_Restore(error_type, error_value, error_traceback);
|
|
}
|
|
|
|
/* Clear out the free list */
|
|
int
|
|
PyFrame_ClearFreeList(void)
|
|
{
|
|
int freelist_size = numfree;
|
|
|
|
while (free_list != NULL) {
|
|
PyFrameObject *f = free_list;
|
|
free_list = free_list->f_back;
|
|
PyObject_GC_Del(f);
|
|
--numfree;
|
|
}
|
|
assert(numfree == 0);
|
|
return freelist_size;
|
|
}
|
|
|
|
void
|
|
_PyFrame_Fini(void)
|
|
{
|
|
(void)PyFrame_ClearFreeList();
|
|
}
|
|
|
|
/* Print summary info about the state of the optimized allocator */
|
|
void
|
|
_PyFrame_DebugMallocStats(FILE *out)
|
|
{
|
|
_PyDebugAllocatorStats(out,
|
|
"free PyFrameObject",
|
|
numfree, sizeof(PyFrameObject));
|
|
}
|
|
|