/* Frame object implementation */ | |
#include "Python.h" | |
#include "code.h" | |
#include "frameobject.h" | |
#include "opcode.h" | |
#include "structmember.h" | |
#undef MIN | |
#undef MAX | |
#define MIN(a, b) ((a) < (b) ? (a) : (b)) | |
#define MAX(a, b) ((a) > (b) ? (a) : (b)) | |
#define OFF(x) offsetof(PyFrameObject, x) | |
static PyMemberDef frame_memberlist[] = { | |
{"f_back", T_OBJECT, OFF(f_back), RO}, | |
{"f_code", T_OBJECT, OFF(f_code), RO}, | |
{"f_builtins", T_OBJECT, OFF(f_builtins),RO}, | |
{"f_globals", T_OBJECT, OFF(f_globals), RO}, | |
{"f_lasti", T_INT, OFF(f_lasti), RO}, | |
{NULL} /* Sentinel */ | |
}; | |
#define WARN_GET_SET(NAME) \ | |
static PyObject * frame_get_ ## NAME(PyFrameObject *f) { \ | |
if (PyErr_WarnPy3k(#NAME " has been removed in 3.x", 2) < 0) \ | |
return NULL; \ | |
if (f->NAME) { \ | |
Py_INCREF(f->NAME); \ | |
return f->NAME; \ | |
} \ | |
Py_RETURN_NONE; \ | |
} \ | |
static int frame_set_ ## NAME(PyFrameObject *f, PyObject *new) { \ | |
if (PyErr_WarnPy3k(#NAME " has been removed in 3.x", 2) < 0) \ | |
return -1; \ | |
if (f->NAME) { \ | |
Py_CLEAR(f->NAME); \ | |
} \ | |
if (new == Py_None) \ | |
new = NULL; \ | |
Py_XINCREF(new); \ | |
f->NAME = new; \ | |
return 0; \ | |
} | |
WARN_GET_SET(f_exc_traceback) | |
WARN_GET_SET(f_exc_type) | |
WARN_GET_SET(f_exc_value) | |
static PyObject * | |
frame_getlocals(PyFrameObject *f, void *closure) | |
{ | |
PyFrame_FastToLocals(f); | |
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 PyInt_FromLong(PyFrame_GetLineNumber(f)); | |
} | |
/* 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 | |
* the END_FINALLY expects to clean up the stack after the 'try' block. | |
* o 'try'/'for'/'while' blocks can't be jumped into because the blockstack | |
* needs to be set up before their code runs, and for 'for' loops the | |
* iterator needs to be on the stack. | |
*/ | |
static int | |
frame_setlineno(PyFrameObject *f, PyObject* p_new_lineno) | |
{ | |
int new_lineno = 0; /* The new value of f_lineno */ | |
int new_lasti = 0; /* The new value of f_lasti */ | |
int new_iblock = 0; /* The new value of f_iblock */ | |
unsigned char *code = NULL; /* The bytecode for the frame... */ | |
Py_ssize_t code_len = 0; /* ...and its length */ | |
unsigned char *lnotab = NULL; /* Iterating over co_lnotab */ | |
Py_ssize_t lnotab_len = 0; /* (ditto) */ | |
int offset = 0; /* (ditto) */ | |
int line = 0; /* (ditto) */ | |
int addr = 0; /* (ditto) */ | |
int min_addr = 0; /* Scanning the SETUPs and POPs */ | |
int max_addr = 0; /* (ditto) */ | |
int delta_iblock = 0; /* (ditto) */ | |
int min_delta_iblock = 0; /* (ditto) */ | |
int min_iblock = 0; /* (ditto) */ | |
int f_lasti_setup_addr = 0; /* Policing no-jump-into-finally */ | |
int new_lasti_setup_addr = 0; /* (ditto) */ | |
int blockstack[CO_MAXBLOCKS]; /* Walking the 'finally' blocks */ | |
int in_finally[CO_MAXBLOCKS]; /* (ditto) */ | |
int blockstack_top = 0; /* (ditto) */ | |
unsigned char setup_op = 0; /* (ditto) */ | |
/* f_lineno must be an integer. */ | |
if (!PyInt_Check(p_new_lineno)) { | |
PyErr_SetString(PyExc_ValueError, | |
"lineno must be an integer"); | |
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" | |
" line trace function"); | |
return -1; | |
} | |
/* Fail if the line comes before the start of the code block. */ | |
new_lineno = (int) PyInt_AsLong(p_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; | |
} | |
else if (new_lineno == f->f_code->co_firstlineno) { | |
new_lasti = 0; | |
new_lineno = f->f_code->co_firstlineno; | |
} | |
else { | |
/* Find the bytecode offset for the start of the given | |
* line, or the first code-owning line after it. */ | |
char *tmp; | |
PyString_AsStringAndSize(f->f_code->co_lnotab, | |
&tmp, &lnotab_len); | |
lnotab = (unsigned char *) tmp; | |
addr = 0; | |
line = f->f_code->co_firstlineno; | |
new_lasti = -1; | |
for (offset = 0; offset < lnotab_len; offset += 2) { | |
addr += lnotab[offset]; | |
line += lnotab[offset+1]; | |
if (line >= new_lineno) { | |
new_lasti = addr; | |
new_lineno = line; | |
break; | |
} | |
} | |
} | |
/* If we didn't reach the requested line, return an error. */ | |
if (new_lasti == -1) { | |
PyErr_Format(PyExc_ValueError, | |
"line %d comes after the current code block", | |
new_lineno); | |
return -1; | |
} | |
/* We're now ready to look at the bytecode. */ | |
PyString_AsStringAndSize(f->f_code->co_code, (char **)&code, &code_len); | |
min_addr = MIN(new_lasti, f->f_lasti); | |
max_addr = MAX(new_lasti, f->f_lasti); | |
/* You can't jump onto a line with an 'except' statement on it - | |
* they expect to have an exception on the top of the stack, which | |
* won't be true if you jump to them. They always start with code | |
* that either pops the exception using POP_TOP (plain 'except:' | |
* lines do this) or duplicates the exception on the stack using | |
* DUP_TOP (if there's an exception type specified). See compile.c, | |
* 'com_try_except' for the full details. There aren't any other | |
* cases (AFAIK) where a line's code can start with DUP_TOP or | |
* POP_TOP, but if any ever appear, they'll be subject to the same | |
* restriction (but with a different error message). */ | |
if (code[new_lasti] == DUP_TOP || code[new_lasti] == POP_TOP) { | |
PyErr_SetString(PyExc_ValueError, | |
"can't jump to 'except' line as there's no exception"); | |
return -1; | |
} | |
/* You can't jump into or out of a 'finally' block because the 'try' | |
* block leaves something on the stack for the END_FINALLY to clean | |
* up. So we walk the bytecode, maintaining a simulated blockstack. | |
* When we reach the old or new address and it's in a 'finally' block | |
* we note the address of the corresponding SETUP_FINALLY. The jump | |
* is only legal if neither address is in a 'finally' block or | |
* they're both in the same one. 'blockstack' is a stack of the | |
* bytecode addresses of the SETUP_X opcodes, and 'in_finally' tracks | |
* whether we're in a 'finally' block at each blockstack level. */ | |
f_lasti_setup_addr = -1; | |
new_lasti_setup_addr = -1; | |
memset(blockstack, '\0', sizeof(blockstack)); | |
memset(in_finally, '\0', sizeof(in_finally)); | |
blockstack_top = 0; | |
for (addr = 0; addr < code_len; addr++) { | |
unsigned char op = code[addr]; | |
switch (op) { | |
case SETUP_LOOP: | |
case SETUP_EXCEPT: | |
case SETUP_FINALLY: | |
blockstack[blockstack_top++] = addr; | |
in_finally[blockstack_top-1] = 0; | |
break; | |
case POP_BLOCK: | |
assert(blockstack_top > 0); | |
setup_op = code[blockstack[blockstack_top-1]]; | |
if (setup_op == SETUP_FINALLY) { | |
in_finally[blockstack_top-1] = 1; | |
} | |
else { | |
blockstack_top--; | |
} | |
break; | |
case END_FINALLY: | |
/* Ignore END_FINALLYs for SETUP_EXCEPTs - they exist | |
* in the bytecode but don't correspond to an actual | |
* 'finally' block. (If blockstack_top is 0, we must | |
* be seeing such an END_FINALLY.) */ | |
if (blockstack_top > 0) { | |
setup_op = code[blockstack[blockstack_top-1]]; | |
if (setup_op == SETUP_FINALLY) { | |
blockstack_top--; | |
} | |
} | |
break; | |
} | |
/* For the addresses we're interested in, see whether they're | |
* within a 'finally' block and if so, remember the address | |
* of the SETUP_FINALLY. */ | |
if (addr == new_lasti || addr == f->f_lasti) { | |
int i = 0; | |
int setup_addr = -1; | |
for (i = blockstack_top-1; i >= 0; i--) { | |
if (in_finally[i]) { | |
setup_addr = blockstack[i]; | |
break; | |
} | |
} | |
if (setup_addr != -1) { | |
if (addr == new_lasti) { | |
new_lasti_setup_addr = setup_addr; | |
} | |
if (addr == f->f_lasti) { | |
f_lasti_setup_addr = setup_addr; | |
} | |
} | |
} | |
if (op >= HAVE_ARGUMENT) { | |
addr += 2; | |
} | |
} | |
/* Verify that the blockstack tracking code didn't get lost. */ | |
assert(blockstack_top == 0); | |
/* After all that, are we jumping into / out of a 'finally' block? */ | |
if (new_lasti_setup_addr != f_lasti_setup_addr) { | |
PyErr_SetString(PyExc_ValueError, | |
"can't jump into or out of a 'finally' block"); | |
return -1; | |
} | |
/* Police block-jumping (you can't jump into the middle of a block) | |
* and ensure that the blockstack finishes up in a sensible state (by | |
* popping any blocks we're jumping out of). We look at all the | |
* blockstack operations between the current position and the new | |
* one, and keep track of how many blocks we drop out of on the way. | |
* By also keeping track of the lowest blockstack position we see, we | |
* can tell whether the jump goes into any blocks without coming out | |
* again - in that case we raise an exception below. */ | |
delta_iblock = 0; | |
for (addr = min_addr; addr < max_addr; addr++) { | |
unsigned char op = code[addr]; | |
switch (op) { | |
case SETUP_LOOP: | |
case SETUP_EXCEPT: | |
case SETUP_FINALLY: | |
delta_iblock++; | |
break; | |
case POP_BLOCK: | |
delta_iblock--; | |
break; | |
} | |
min_delta_iblock = MIN(min_delta_iblock, delta_iblock); | |
if (op >= HAVE_ARGUMENT) { | |
addr += 2; | |
} | |
} | |
/* Derive the absolute iblock values from the deltas. */ | |
min_iblock = f->f_iblock + min_delta_iblock; | |
if (new_lasti > f->f_lasti) { | |
/* Forwards jump. */ | |
new_iblock = f->f_iblock + delta_iblock; | |
} | |
else { | |
/* Backwards jump. */ | |
new_iblock = f->f_iblock - delta_iblock; | |
} | |
/* Are we jumping into a block? */ | |
if (new_iblock > min_iblock) { | |
PyErr_SetString(PyExc_ValueError, | |
"can't jump into the middle of a block"); | |
return -1; | |
} | |
/* Pop any blocks that we're jumping out of. */ | |
while (f->f_iblock > new_iblock) { | |
PyTryBlock *b = &f->f_blockstack[--f->f_iblock]; | |
while ((f->f_stacktop - f->f_valuestack) > b->b_level) { | |
PyObject *v = (*--f->f_stacktop); | |
Py_DECREF(v); | |
} | |
} | |
/* Finally set the new f_lineno and f_lasti and return OK. */ | |
f->f_lineno = new_lineno; | |
f->f_lasti = new_lasti; | |
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) | |
{ | |
PyObject* old_value; | |
/* We rely on f_lineno being accurate when f_trace is set. */ | |
f->f_lineno = PyFrame_GetLineNumber(f); | |
old_value = f->f_trace; | |
Py_XINCREF(v); | |
f->f_trace = v; | |
Py_XDECREF(old_value); | |
return 0; | |
} | |
static PyObject * | |
frame_getrestricted(PyFrameObject *f, void *closure) | |
{ | |
return PyBool_FromLong(PyFrame_IsRestricted(f)); | |
} | |
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}, | |
{"f_restricted",(getter)frame_getrestricted,NULL, NULL}, | |
{"f_exc_traceback", (getter)frame_get_f_exc_traceback, | |
(setter)frame_set_f_exc_traceback, NULL}, | |
{"f_exc_type", (getter)frame_get_f_exc_type, | |
(setter)frame_set_f_exc_type, NULL}, | |
{"f_exc_value", (getter)frame_get_f_exc_value, | |
(setter)frame_set_f_exc_value, 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, | |
f_exc_type, f_exc_value, f_exc_traceback 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 | |
integers are allocated in a special way -- see intobject.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 | |
frame_dealloc(PyFrameObject *f) | |
{ | |
PyObject **p, **valuestack; | |
PyCodeObject *co; | |
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); | |
Py_CLEAR(f->f_exc_type); | |
Py_CLEAR(f->f_exc_value); | |
Py_CLEAR(f->f_exc_traceback); | |
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; | |
int 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); | |
Py_VISIT(f->f_exc_type); | |
Py_VISIT(f->f_exc_value); | |
Py_VISIT(f->f_exc_traceback); | |
/* 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 void | |
frame_clear(PyFrameObject *f) | |
{ | |
PyObject **fastlocals, **p, **oldtop; | |
int 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; | |
Py_CLEAR(f->f_exc_type); | |
Py_CLEAR(f->f_exc_value); | |
Py_CLEAR(f->f_exc_traceback); | |
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); | |
} | |
} | |
static PyObject * | |
frame_sizeof(PyFrameObject *f) | |
{ | |
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 PyInt_FromSsize_t(res); | |
} | |
PyDoc_STRVAR(sizeof__doc__, | |
"F.__sizeof__() -> size of F in memory, in bytes"); | |
static PyMethodDef frame_methods[] = { | |
{"__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_print */ | |
0, /* tp_getattr */ | |
0, /* tp_setattr */ | |
0, /* tp_compare */ | |
0, /* 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_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 */ | |
}; | |
static PyObject *builtin_object; | |
int _PyFrame_Init() | |
{ | |
builtin_object = PyString_InternFromString("__builtins__"); | |
if (builtin_object == NULL) | |
return 0; | |
return 1; | |
} | |
PyFrameObject * | |
PyFrame_New(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_GetItem(globals, builtin_object); | |
if (builtins) { | |
if (PyModule_Check(builtins)) { | |
builtins = PyModule_GetDict(builtins); | |
assert(!builtins || PyDict_Check(builtins)); | |
} | |
else if (!PyDict_Check(builtins)) | |
builtins = NULL; | |
} | |
if (builtins == 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 && PyDict_Check(builtins)); | |
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) { | |
f = PyObject_GC_Resize(PyFrameObject, f, extras); | |
if (f == NULL) { | |
Py_DECREF(builtins); | |
return NULL; | |
} | |
} | |
_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_exc_type = f->f_exc_value = f->f_exc_traceback = 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_tstate = tstate; | |
f->f_lasti = -1; | |
f->f_lineno = code->co_firstlineno; | |
f->f_iblock = 0; | |
_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("XXX 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("XXX 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. | |
Exceptions raised while modifying the dict are silently ignored, | |
because there is no good way to report them. | |
*/ | |
static void | |
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 = nmap; --j >= 0; ) { | |
PyObject *key = PyTuple_GET_ITEM(map, j); | |
PyObject *value = values[j]; | |
assert(PyString_Check(key)); | |
if (deref) { | |
assert(PyCell_Check(value)); | |
value = PyCell_GET(value); | |
} | |
if (value == NULL) { | |
if (PyObject_DelItem(dict, key) != 0) | |
PyErr_Clear(); | |
} | |
else { | |
if (PyObject_SetItem(dict, key, value) != 0) | |
PyErr_Clear(); | |
} | |
} | |
} | |
/* 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 = nmap; --j >= 0; ) { | |
PyObject *key = PyTuple_GET_ITEM(map, j); | |
PyObject *value = PyObject_GetItem(dict, key); | |
assert(PyString_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_XDECREF(values[j]); | |
values[j] = value; | |
} | |
Py_XDECREF(value); | |
} | |
} | |
void | |
PyFrame_FastToLocals(PyFrameObject *f) | |
{ | |
/* Merge fast locals into f->f_locals */ | |
PyObject *locals, *map; | |
PyObject **fast; | |
PyObject *error_type, *error_value, *error_traceback; | |
PyCodeObject *co; | |
Py_ssize_t j; | |
int ncells, nfreevars; | |
if (f == NULL) | |
return; | |
locals = f->f_locals; | |
if (locals == NULL) { | |
locals = f->f_locals = PyDict_New(); | |
if (locals == NULL) { | |
PyErr_Clear(); /* Can't report it :-( */ | |
return; | |
} | |
} | |
co = f->f_code; | |
map = co->co_varnames; | |
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) | |
map_to_dict(map, j, locals, fast, 0); | |
ncells = PyTuple_GET_SIZE(co->co_cellvars); | |
nfreevars = PyTuple_GET_SIZE(co->co_freevars); | |
if (ncells || nfreevars) { | |
map_to_dict(co->co_cellvars, ncells, | |
locals, fast + co->co_nlocals, 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) { | |
map_to_dict(co->co_freevars, nfreevars, | |
locals, fast + co->co_nlocals + ncells, 1); | |
} | |
} | |
PyErr_Restore(error_type, error_value, error_traceback); | |
} | |
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; | |
int 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(); | |
Py_XDECREF(builtin_object); | |
builtin_object = NULL; | |
} |