| /* 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; |
| } |
| |
| |
| /* 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', '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)) |
| { |
| int new_lineno = 0; /* The new value of f_lineno */ |
| long l_new_lineno; |
| int overflow; |
| int new_lasti = 0; /* The new value of f_lasti */ |
| 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 delta_iblock = 0; /* Scanning the SETUPs and POPs */ |
| int delta = 0; |
| int blockstack[CO_MAXBLOCKS]; /* Walking the 'finally' blocks */ |
| int blockstack_top = 0; /* (ditto) */ |
| |
| 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; |
| } |
| |
| /* Fail if the line comes before the start of the code block. */ |
| 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; |
| } |
| 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; |
| PyBytes_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 += (signed char)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. */ |
| PyBytes_AsStringAndSize(f->f_code->co_code, (char **)&code, &code_len); |
| |
| /* The trace function is called with a 'return' trace event after the |
| * execution of a yield statement. */ |
| assert(f->f_lasti != -1); |
| if (code[f->f_lasti] == YIELD_VALUE || code[f->f_lasti] == YIELD_FROM) { |
| PyErr_SetString(PyExc_ValueError, |
| "can't jump from a yield statement"); |
| return -1; |
| } |
| |
| /* 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. |
| * 'blockstack' is a stack of the bytecode addresses of the starts of |
| * the 'finally' blocks. */ |
| memset(blockstack, '\0', sizeof(blockstack)); |
| blockstack_top = 0; |
| unsigned char prevop = NOP; |
| for (addr = 0; addr < code_len; addr += sizeof(_Py_CODEUNIT)) { |
| unsigned char op = code[addr]; |
| switch (op) { |
| case SETUP_FINALLY: |
| case SETUP_WITH: |
| case SETUP_ASYNC_WITH: |
| case FOR_ITER: { |
| unsigned int oparg = get_arg((const _Py_CODEUNIT *)code, |
| addr / sizeof(_Py_CODEUNIT)); |
| int target_addr = addr + oparg + sizeof(_Py_CODEUNIT); |
| assert(target_addr < code_len); |
| /* 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. */ |
| int first_in = addr < f->f_lasti && f->f_lasti < target_addr; |
| int second_in = addr < new_lasti && new_lasti < target_addr; |
| if (!first_in && second_in) { |
| PyErr_SetString(PyExc_ValueError, |
| "can't jump into the middle of a block"); |
| return -1; |
| } |
| int in_for_loop = op == FOR_ITER || code[target_addr] == END_ASYNC_FOR; |
| if (first_in && !second_in) { |
| if (!delta_iblock) { |
| if (in_for_loop) { |
| /* Pop the iterators of any 'for' and 'async for' loop |
| * we're jumping out of. */ |
| delta++; |
| } |
| else if (prevop == LOAD_CONST) { |
| /* Pops None pushed before SETUP_FINALLY. */ |
| delta++; |
| } |
| } |
| if (!in_for_loop) { |
| delta_iblock++; |
| } |
| } |
| if (!in_for_loop) { |
| blockstack[blockstack_top++] = target_addr; |
| } |
| break; |
| } |
| |
| case END_FINALLY: { |
| assert(blockstack_top > 0); |
| int target_addr = blockstack[--blockstack_top]; |
| assert(target_addr <= addr); |
| int first_in = target_addr <= f->f_lasti && f->f_lasti <= addr; |
| int second_in = target_addr <= new_lasti && new_lasti <= addr; |
| if (first_in != second_in) { |
| op = code[target_addr]; |
| PyErr_Format(PyExc_ValueError, |
| "can't jump %s %s block", |
| second_in ? "into" : "out of", |
| (op == DUP_TOP || op == POP_TOP) ? |
| "an 'except'" : "a 'finally'"); |
| return -1; |
| } |
| break; |
| } |
| } |
| prevop = op; |
| } |
| |
| /* Verify that the blockstack tracking code didn't get lost. */ |
| assert(blockstack_top == 0); |
| |
| /* Pop any blocks that we're jumping out of. */ |
| if (delta_iblock > 0) { |
| f->f_iblock -= delta_iblock; |
| PyTryBlock *b = &f->f_blockstack[f->f_iblock]; |
| delta += (int)(f->f_stacktop - f->f_valuestack) - b->b_level; |
| if (b->b_type == SETUP_FINALLY && |
| code[b->b_handler] == WITH_CLEANUP_START) |
| { |
| /* Pop the exit function. */ |
| delta++; |
| } |
| } |
| while (delta > 0) { |
| PyObject *v = (*--f->f_stacktop); |
| Py_DECREF(v); |
| delta--; |
| } |
| |
| /* 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) |
| { |
| /* 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("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. |
| */ |
| |
| 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)); |
| } |
| |