/* Execute compiled code */

/* XXX TO DO:

XXX how to pass arguments to profile and trace functions?

XXX speed up searching for keywords by using a dictionary

XXX document it!

*/

#include "Python.h"

#include "compile.h"

#include "frameobject.h"

#include "eval.h"

#include "opcode.h"

#ifdef macintosh

#include "macglue.h"

#endif

#include <ctype.h>

/* Turn this on if your compiler chokes on the big switch: */

/* #define CASE_TOO_BIG 1 */

#ifdef Py_DEBUG

/* For debugging the interpreter: */

#define LLTRACE 1 /* Low-level trace feature */

#define CHECKEXC 1 /* Double-check exception checking */

#endif

typedef PyObject *(*callproc)(PyObject *, PyObject *, PyObject *);

/* Forward declarations */

static PyObject *eval_code2(PyCodeObject *,

PyObject *, PyObject *,

PyObject **, int,

PyObject **, int,

PyObject **, int,

PyObject *);

static PyObject *eval_frame(PyFrameObject *);

static char *get_func_name(PyObject *);

static char *get_func_desc(PyObject *);

static PyObject *call_object(PyObject *, PyObject *, PyObject *);

static PyObject *call_cfunction(PyObject *, PyObject *, PyObject *);

static PyObject *call_instance(PyObject *, PyObject *, PyObject *);

static PyObject *call_method(PyObject *, PyObject *, PyObject *);

static PyObject *call_eval_code2(PyObject *, PyObject *, PyObject *);

static PyObject *fast_function(PyObject *, PyObject ***, int, int, int);

static PyObject *fast_cfunction(PyObject *, PyObject ***, int);

static PyObject *do_call(PyObject *, PyObject ***, int, int);

static PyObject *ext_do_call(PyObject *, PyObject ***, int, int, int);

static PyObject *update_keyword_args(PyObject *, int, PyObject ***,PyObject *);

static PyObject *update_star_args(int, int, PyObject *, PyObject ***);

static PyObject *load_args(PyObject ***, int);

#define CALL_FLAG_VAR 1

#define CALL_FLAG_KW 2

#ifdef LLTRACE

static int prtrace(PyObject *, char *);

#endif

static int call_trace(Py_tracefunc, PyObject *, PyFrameObject *,

int, PyObject *);

static void call_exc_trace(Py_tracefunc, PyObject *, PyFrameObject *);

static PyObject *loop_subscript(PyObject *, PyObject *);

static PyObject *apply_slice(PyObject *, PyObject *, PyObject *);

static int assign_slice(PyObject *, PyObject *,

PyObject *, PyObject *);

static PyObject *cmp_outcome(int, PyObject *, PyObject *);

static PyObject *import_from(PyObject *, PyObject *);

static int import_all_from(PyObject *, PyObject *);

static PyObject *build_class(PyObject *, PyObject *, PyObject *);

static int exec_statement(PyFrameObject *,

PyObject *, PyObject *, PyObject *);

static void set_exc_info(PyThreadState *, PyObject *, PyObject *, PyObject *);

static void reset_exc_info(PyThreadState *);

static void format_exc_check_arg(PyObject *, char *, PyObject *);

#define NAME_ERROR_MSG \

"name '%.200s' is not defined"

#define GLOBAL_NAME_ERROR_MSG \

"global name '%.200s' is not defined"

#define UNBOUNDLOCAL_ERROR_MSG \

"local variable '%.200s' referenced before assignment"

#define UNBOUNDFREE_ERROR_MSG \

"free variable '%.200s' referenced before assignment" \

" in enclosing scope"

/* Dynamic execution profile */

#ifdef DYNAMIC_EXECUTION_PROFILE

#ifdef DXPAIRS

static long dxpairs[257][256];

#define dxp dxpairs[256]

#else

static long dxp[256];

#endif

#endif

staticforward PyTypeObject gentype;

typedef struct {

PyObject_HEAD

/* The gi_ prefix is intended to remind of generator-iterator. */

PyFrameObject *gi_frame;

/* True if generator is being executed. */

int gi_running;

} genobject;

static PyObject *

gen_new(PyFrameObject *f)

{

genobject *gen = PyObject_New(genobject, &gentype);

if (gen == NULL) {

Py_DECREF(f);

return NULL;

}

gen->gi_frame = f;

gen->gi_running = 0;

PyObject_GC_Init(gen);

return (PyObject *)gen;

}

static int

gen_traverse(genobject *gen, visitproc visit, void *arg)

{

return visit((PyObject *)gen->gi_frame, arg);

}

static void

gen_dealloc(genobject *gen)

{

PyObject_GC_Fini(gen);

Py_DECREF(gen->gi_frame);

PyObject_Del(gen);

}

static PyObject *

gen_iternext(genobject *gen)

{

PyThreadState *tstate = PyThreadState_GET();

PyFrameObject *f = gen->gi_frame;

PyObject *result;

if (gen->gi_running) {

PyErr_SetString(PyExc_ValueError,

"generator already executing");

return NULL;

}

if (f->f_stacktop == NULL)

return NULL;

/* Generators always return to their most recent caller, not

* necessarily their creator. */

Py_XINCREF(tstate->frame);

assert(f->f_back == NULL);

f->f_back = tstate->frame;

gen->gi_running = 1;

result = eval_frame(f);

gen->gi_running = 0;

/* Don't keep the reference to f_back any longer than necessary. It

* may keep a chain of frames alive or it could create a reference

* cycle. */

Py_XDECREF(f->f_back);

f->f_back = NULL;

/* If the generator just returned (as opposed to yielding), signal

* that the generator is exhausted. */

if (result == Py_None && f->f_stacktop == NULL) {

Py_DECREF(result);

result = NULL;

}

return result;

}

static PyObject *

gen_next(genobject *gen, PyObject *args)

{

PyObject *result;

if (!PyArg_ParseTuple(args, ":next"))

return NULL;

result = gen_iternext(gen);

if (result == NULL && !PyErr_Occurred()) {

PyErr_SetObject(PyExc_StopIteration, Py_None);

return NULL;

}

return result;

}

static PyObject *

gen_getiter(PyObject *gen)

{

Py_INCREF(gen);

return gen;

}

static struct PyMethodDef gen_methods[] = {

{"next", (PyCFunction)gen_next, METH_VARARGS,

"next() -- get the next value, or raise StopIteration"},

{NULL, NULL} /* Sentinel */

};

static PyObject *

gen_getattr(genobject *gen, char *name)

{

PyObject *result;

if (strcmp(name, "gi_frame") == 0) {

result = (PyObject *)gen->gi_frame;

assert(result != NULL);

Py_INCREF(result);

}

else if (strcmp(name, "gi_running") == 0)

result = (PyObject *)PyInt_FromLong((long)gen->gi_running);

else if (strcmp(name, "__members__") == 0)

result = Py_BuildValue("[ss]", "gi_frame", "gi_running");

else

result = Py_FindMethod(gen_methods, (PyObject *)gen, name);

return result;

}

statichere PyTypeObject gentype = {

PyObject_HEAD_INIT(&PyType_Type)

0, /* ob_size */

"generator", /* tp_name */

sizeof(genobject) + PyGC_HEAD_SIZE, /* tp_basicsize */

0, /* tp_itemsize */

/* methods */

(destructor)gen_dealloc, /* tp_dealloc */

0, /* tp_print */

(getattrfunc)gen_getattr, /* 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 */

0, /* tp_getattro */

0, /* tp_setattro */

0, /* tp_as_buffer */

Py_TPFLAGS_DEFAULT | Py_TPFLAGS_GC, /* tp_flags */

0, /* tp_doc */

(traverseproc)gen_traverse, /* tp_traverse */

0, /* tp_clear */

0, /* tp_richcompare */

0, /* tp_weaklistoffset */

(getiterfunc)gen_getiter, /* tp_iter */

(iternextfunc)gen_iternext, /* tp_iternext */

};

#ifdef WITH_THREAD

#ifndef DONT_HAVE_ERRNO_H

#include <errno.h>

#endif

#include "pythread.h"

extern int _PyThread_Started; /* Flag for Py_Exit */

static PyThread_type_lock interpreter_lock = 0;

static long main_thread = 0;

void

PyEval_InitThreads(void)

{

if (interpreter_lock)

return;

_PyThread_Started = 1;

interpreter_lock = PyThread_allocate_lock();

PyThread_acquire_lock(interpreter_lock, 1);

main_thread = PyThread_get_thread_ident();

}

void

PyEval_AcquireLock(void)

{

PyThread_acquire_lock(interpreter_lock, 1);

}

void

PyEval_ReleaseLock(void)

{

PyThread_release_lock(interpreter_lock);

}

void

PyEval_AcquireThread(PyThreadState *tstate)

{

if (tstate == NULL)

Py_FatalError("PyEval_AcquireThread: NULL new thread state");

PyThread_acquire_lock(interpreter_lock, 1);

if (PyThreadState_Swap(tstate) != NULL)

Py_FatalError(

"PyEval_AcquireThread: non-NULL old thread state");

}

void

PyEval_ReleaseThread(PyThreadState *tstate)

{

if (tstate == NULL)

Py_FatalError("PyEval_ReleaseThread: NULL thread state");

if (PyThreadState_Swap(NULL) != tstate)

Py_FatalError("PyEval_ReleaseThread: wrong thread state");

PyThread_release_lock(interpreter_lock);

}

/* This function is called from PyOS_AfterFork to ensure that newly

created child processes don't hold locks referring to threads which

are not running in the child process. (This could also be done using

pthread_atfork mechanism, at least for the pthreads implementation.) */

void

PyEval_ReInitThreads(void)

{

if (!interpreter_lock)

return;

/*XXX Can't use PyThread_free_lock here because it does too

much error-checking. Doing this cleanly would require

adding a new function to each thread_*.h. Instead, just

create a new lock and waste a little bit of memory */

interpreter_lock = PyThread_allocate_lock();

PyThread_acquire_lock(interpreter_lock, 1);

main_thread = PyThread_get_thread_ident();

}

#endif

/* Functions save_thread and restore_thread are always defined so

dynamically loaded modules needn't be compiled separately for use

with and without threads: */

PyThreadState *

PyEval_SaveThread(void)

{

PyThreadState *tstate = PyThreadState_Swap(NULL);

if (tstate == NULL)

Py_FatalError("PyEval_SaveThread: NULL tstate");

#ifdef WITH_THREAD

if (interpreter_lock)

PyThread_release_lock(interpreter_lock);

#endif

return tstate;

}

void

PyEval_RestoreThread(PyThreadState *tstate)

{

if (tstate == NULL)

Py_FatalError("PyEval_RestoreThread: NULL tstate");

#ifdef WITH_THREAD

if (interpreter_lock) {

int err = errno;

PyThread_acquire_lock(interpreter_lock, 1);

errno = err;

}

#endif

PyThreadState_Swap(tstate);

}

/* Mechanism whereby asynchronously executing callbacks (e.g. UNIX

signal handlers or Mac I/O completion routines) can schedule calls

to a function to be called synchronously.

The synchronous function is called with one void* argument.

It should return 0 for success or -1 for failure -- failure should

be accompanied by an exception.

If registry succeeds, the registry function returns 0; if it fails

(e.g. due to too many pending calls) it returns -1 (without setting

an exception condition).

Note that because registry may occur from within signal handlers,

or other asynchronous events, calling malloc() is unsafe!

#ifdef WITH_THREAD

Any thread can schedule pending calls, but only the main thread

will execute them.

#endif

XXX WARNING! ASYNCHRONOUSLY EXECUTING CODE!

There are two possible race conditions:

(1) nested asynchronous registry calls;

(2) registry calls made while pending calls are being processed.

While (1) is very unlikely, (2) is a real possibility.

The current code is safe against (2), but not against (1).

The safety against (2) is derived from the fact that only one

thread (the main thread) ever takes things out of the queue.

XXX Darn! With the advent of thread state, we should have an array

of pending calls per thread in the thread state! Later...

*/

#define NPENDINGCALLS 32

static struct {

int (*func)(void *);

void *arg;

} pendingcalls[NPENDINGCALLS];

static volatile int pendingfirst = 0;

static volatile int pendinglast = 0;

static volatile int things_to_do = 0;

int

Py_AddPendingCall(int (*func)(void *), void *arg)

{

static int busy = 0;

int i, j;

/* XXX Begin critical section */

/* XXX If you want this to be safe against nested

XXX asynchronous calls, you'll have to work harder! */

if (busy)

return -1;

busy = 1;

i = pendinglast;

j = (i + 1) % NPENDINGCALLS;

if (j == pendingfirst)

return -1; /* Queue full */

pendingcalls[i].func = func;

pendingcalls[i].arg = arg;

pendinglast = j;

things_to_do = 1; /* Signal main loop */

busy = 0;

/* XXX End critical section */

return 0;

}

int

Py_MakePendingCalls(void)

{

static int busy = 0;

#ifdef WITH_THREAD

if (main_thread && PyThread_get_thread_ident() != main_thread)

return 0;

#endif

if (busy)

return 0;

busy = 1;

things_to_do = 0;

for (;;) {

int i;

int (*func)(void *);

void *arg;

i = pendingfirst;

if (i == pendinglast)

break; /* Queue empty */

func = pendingcalls[i].func;

arg = pendingcalls[i].arg;

pendingfirst = (i + 1) % NPENDINGCALLS;

if (func(arg) < 0) {

busy = 0;

things_to_do = 1; /* We're not done yet */

return -1;

}

}

busy = 0;

return 0;

}

/* The interpreter's recursion limit */

static int recursion_limit = 1000;

int

Py_GetRecursionLimit(void)

{

return recursion_limit;

}

void

Py_SetRecursionLimit(int new_limit)

{

recursion_limit = new_limit;

}

/* Status code for main loop (reason for stack unwind) */

enum why_code {

WHY_NOT, /* No error */

WHY_EXCEPTION, /* Exception occurred */

WHY_RERAISE, /* Exception re-raised by 'finally' */

WHY_RETURN, /* 'return' statement */

WHY_BREAK, /* 'break' statement */

WHY_CONTINUE, /* 'continue' statement */

WHY_YIELD, /* 'yield' operator */

};

static enum why_code do_raise(PyObject *, PyObject *, PyObject *);

static int unpack_iterable(PyObject *, int, PyObject **);

PyObject *

PyEval_EvalCode(PyCodeObject *co, PyObject *globals, PyObject *locals)

{

return eval_code2(co,

globals, locals,

(PyObject **)NULL, 0,

(PyObject **)NULL, 0,

(PyObject **)NULL, 0,

NULL);

}

/* Interpreter main loop */

PyObject *

eval_frame(PyFrameObject *f)

{

#ifdef DXPAIRS

int lastopcode = 0;

#endif

PyObject **stack_pointer;

register unsigned char *next_instr;

register int opcode=0; /* Current opcode */

register int oparg=0; /* Current opcode argument, if any */

register enum why_code why; /* Reason for block stack unwind */

register int err; /* Error status -- nonzero if error */

register PyObject *x; /* Result object -- NULL if error */

register PyObject *v; /* Temporary objects popped off stack */

register PyObject *w;

register PyObject *u;

register PyObject *t;

register PyObject *stream = NULL; /* for PRINT opcodes */

register PyObject **fastlocals, **freevars;

PyObject *retval = NULL; /* Return value */

PyThreadState *tstate = PyThreadState_GET();

PyCodeObject *co;

unsigned char *first_instr;

#ifdef LLTRACE

int lltrace;

#endif

#if defined(Py_DEBUG) || defined(LLTRACE)

/* Make it easier to find out where we are with a debugger */

char *filename;

#endif

/* Code access macros */

#define GETCONST(i) Getconst(f, i)

#define GETNAME(i) Getname(f, i)

#define GETNAMEV(i) Getnamev(f, i)

#define INSTR_OFFSET() (next_instr - first_instr)

#define NEXTOP() (*next_instr++)

#define NEXTARG() (next_instr += 2, (next_instr[-1]<<8) + next_instr[-2])

#define JUMPTO(x) (next_instr = first_instr + (x))

#define JUMPBY(x) (next_instr += (x))

/* Stack manipulation macros */

#define STACK_LEVEL() (stack_pointer - f->f_valuestack)

#define EMPTY() (STACK_LEVEL() == 0)

#define TOP() (stack_pointer[-1])

#define BASIC_PUSH(v) (*stack_pointer++ = (v))

#define BASIC_POP() (*--stack_pointer)

#ifdef LLTRACE

#define PUSH(v) (BASIC_PUSH(v), lltrace && prtrace(TOP(), "push"))

#define POP() (lltrace && prtrace(TOP(), "pop"), BASIC_POP())

#else

#define PUSH(v) BASIC_PUSH(v)

#define POP() BASIC_POP()

#endif

/* Local variable macros */

#define GETLOCAL(i) (fastlocals[i])

#define SETLOCAL(i, value) do { Py_XDECREF(GETLOCAL(i)); \

GETLOCAL(i) = value; } while (0)

/* Start of code */

if (f == NULL)

return NULL;

#ifdef USE_STACKCHECK

if (tstate->recursion_depth%10 == 0 && PyOS_CheckStack()) {

PyErr_SetString(PyExc_MemoryError, "Stack overflow");

return NULL;

}

#endif

/* push frame */

if (++tstate->recursion_depth > recursion_limit) {

--tstate->recursion_depth;

PyErr_SetString(PyExc_RuntimeError,

"maximum recursion depth exceeded");

tstate->frame = f->f_back;

return NULL;

}

tstate->frame = f;

co = f->f_code;

fastlocals = f->f_localsplus;

freevars = f->f_localsplus + f->f_nlocals;

_PyCode_GETCODEPTR(co, &first_instr);

next_instr = first_instr + f->f_lasti;

stack_pointer = f->f_stacktop;

assert(stack_pointer != NULL);

f->f_stacktop = NULL;

#ifdef LLTRACE

lltrace = PyDict_GetItemString(f->f_globals,"__lltrace__") != NULL;

#endif

#if defined(Py_DEBUG) || defined(LLTRACE)

filename = PyString_AsString(co->co_filename);

#endif

why = WHY_NOT;

err = 0;

x = Py_None; /* Not a reference, just anything non-NULL */

w = NULL;

for (;;) {

/* Do periodic things. Doing this every time through

the loop would add too much overhead, so we do it

only every Nth instruction. We also do it if

``things_to_do'' is set, i.e. when an asynchronous

event needs attention (e.g. a signal handler or

async I/O handler); see Py_AddPendingCall() and

Py_MakePendingCalls() above. */

if (things_to_do || --tstate->ticker < 0) {

tstate->ticker = tstate->interp->checkinterval;

if (things_to_do) {

if (Py_MakePendingCalls() < 0) {

why = WHY_EXCEPTION;

goto on_error;

}

}

#if !defined(HAVE_SIGNAL_H) || defined(macintosh)

/* If we have true signals, the signal handler

will call Py_AddPendingCall() so we don't

have to call sigcheck(). On the Mac and

DOS, alas, we have to call it. */

if (PyErr_CheckSignals()) {

why = WHY_EXCEPTION;

goto on_error;

}

#endif

#ifdef WITH_THREAD

if (interpreter_lock) {

/* Give another thread a chance */

if (PyThreadState_Swap(NULL) != tstate)

Py_FatalError("ceval: tstate mix-up");

PyThread_release_lock(interpreter_lock);

/* Other threads may run now */

PyThread_acquire_lock(interpreter_lock, 1);

if (PyThreadState_Swap(tstate) != NULL)

Py_FatalError("ceval: orphan tstate");

}

#endif

}

/* Extract opcode and argument */

#if defined(Py_DEBUG) || defined(LLTRACE)

f->f_lasti = INSTR_OFFSET();

#endif

opcode = NEXTOP();

if (HAS_ARG(opcode))

oparg = NEXTARG();

dispatch_opcode:

#ifdef DYNAMIC_EXECUTION_PROFILE

#ifdef DXPAIRS

dxpairs[lastopcode][opcode]++;

lastopcode = opcode;

#endif

dxp[opcode]++;

#endif

#ifdef LLTRACE

/* Instruction tracing */

if (lltrace) {

if (HAS_ARG(opcode)) {

printf("%d: %d, %d\n",

(int) (INSTR_OFFSET() - 3),

opcode, oparg);

}

else {

printf("%d: %d\n",

(int) (INSTR_OFFSET() - 1), opcode);

}

}

#endif

/* Main switch on opcode */

switch (opcode) {

/* BEWARE!

It is essential that any operation that fails sets either

x to NULL, err to nonzero, or why to anything but WHY_NOT,

and that no operation that succeeds does this! */

/* case STOP_CODE: this is an error! */

case POP_TOP:

v = POP();

Py_DECREF(v);

continue;

case ROT_TWO:

v = POP();

w = POP();

PUSH(v);

PUSH(w);

continue;

case ROT_THREE:

v = POP();

w = POP();

x = POP();

PUSH(v);

PUSH(x);

PUSH(w);

continue;

case ROT_FOUR:

u = POP();

v = POP();

w = POP();

x = POP();

PUSH(u);

PUSH(x);

PUSH(w);

PUSH(v);

continue;

case DUP_TOP:

v = TOP();

Py_INCREF(v);

PUSH(v);

continue;

case DUP_TOPX:

switch (oparg) {

case 1:

x = TOP();

Py_INCREF(x);

PUSH(x);

continue;

case 2:

x = POP();

Py_INCREF(x);

w = TOP();

Py_INCREF(w);

PUSH(x);

PUSH(w);

PUSH(x);

continue;

case 3:

x = POP();

Py_INCREF(x);

w = POP();

Py_INCREF(w);

v = TOP();

Py_INCREF(v);

PUSH(w);

PUSH(x);

PUSH(v);

PUSH(w);

PUSH(x);

continue;

case 4:

x = POP();

Py_INCREF(x);

w = POP();

Py_INCREF(w);

v = POP();

Py_INCREF(v);

u = TOP();

Py_INCREF(u);

PUSH(v);

PUSH(w);

PUSH(x);

PUSH(u);

PUSH(v);

PUSH(w);

PUSH(x);

continue;

case 5:

x = POP();

Py_INCREF(x);

w = POP();

Py_INCREF(w);

v = POP();

Py_INCREF(v);

u = POP();

Py_INCREF(u);

t = TOP();

Py_INCREF(t);

PUSH(u);

PUSH(v);

PUSH(w);

PUSH(x);

PUSH(t);

PUSH(u);

PUSH(v);

PUSH(w);

PUSH(x);

continue;

default:

Py_FatalError("invalid argument to DUP_TOPX"

" (bytecode corruption?)");

}

break;

case UNARY_POSITIVE:

v = POP();

x = PyNumber_Positive(v);

Py_DECREF(v);

PUSH(x);

if (x != NULL) continue;

break;

case UNARY_NEGATIVE:

v = POP();

x = PyNumber_Negative(v);

Py_DECREF(v);

PUSH(x);

if (x != NULL) continue;

break;

case UNARY_NOT:

v = POP();

err = PyObject_IsTrue(v);

Py_DECREF(v);

if (err == 0) {

Py_INCREF(Py_True);

PUSH(Py_True);

continue;

}

else if (err > 0) {

Py_INCREF(Py_False);

PUSH(Py_False);

err = 0;

continue;

}

break;

case UNARY_CONVERT:

v = POP();

x = PyObject_Repr(v);

Py_DECREF(v);

PUSH(x);

if (x != NULL) continue;

break;

case UNARY_INVERT:

v = POP();

x = PyNumber_Invert(v);

Py_DECREF(v);

PUSH(x);

if (x != NULL) continue;

break;

case BINARY_POWER:

w = POP();

v = POP();

x = PyNumber_Power(v, w, Py_None);

Py_DECREF(v);

Py_DECREF(w);

PUSH(x);

if (x != NULL) continue;

break;

case BINARY_MULTIPLY:

w = POP();

v = POP();

x = PyNumber_Multiply(v, w);

Py_DECREF(v);

Py_DECREF(w);

PUSH(x);

if (x != NULL) continue;

break;

case BINARY_DIVIDE:

w = POP();

v = POP();

x = PyNumber_Divide(v, w);

Py_DECREF(v);

Py_DECREF(w);

PUSH(x);

if (x != NULL) continue;

break;

case BINARY_MODULO:

w = POP();

v = POP();

x = PyNumber_Remainder(v, w);

Py_DECREF(v);

Py_DECREF(w);

PUSH(x);

if (x != NULL) continue;

break;

case BINARY_ADD:

w = POP();

v = POP();

if (PyInt_Check(v) && PyInt_Check(w)) {

/* INLINE: int + int */

register long a, b, i;

a = PyInt_AS_LONG(v);

b = PyInt_AS_LONG(w);

i = a + b;

if ((i^a) < 0 && (i^b) < 0) {

PyErr_SetString(PyExc_OverflowError,

"integer addition");

x = NULL;

}

else

x = PyInt_FromLong(i);

}

else

x = PyNumber_Add(v, w);

Py_DECREF(v);

Py_DECREF(w);

PUSH(x);

if (x != NULL) continue;

break;

case BINARY_SUBTRACT:

w = POP();

v = POP();

if (PyInt_Check(v) && PyInt_Check(w)) {

/* INLINE: int - int */

register long a, b, i;

a = PyInt_AS_LONG(v);

b = PyInt_AS_LONG(w);

i = a - b;

if ((i^a) < 0 && (i^~b) < 0) {

PyErr_SetString(PyExc_OverflowError,

"integer subtraction");

x = NULL;

}

else

x = PyInt_FromLong(i);

}

else

x = PyNumber_Subtract(v, w);

Py_DECREF(v);

Py_DECREF(w);

PUSH(x);

if (x != NULL) continue;

break;

case BINARY_SUBSCR:

w = POP();

v = POP();

if (PyList_Check(v) && PyInt_Check(w)) {

/* INLINE: list[int] */

long i = PyInt_AsLong(w);

if (i < 0)

i += PyList_GET_SIZE(v);

if (i < 0 ||

i >= PyList_GET_SIZE(v)) {

PyErr_SetString(PyExc_IndexError,

"list index out of range");

x = NULL;

}

else {

x = PyList_GET_ITEM(v, i);

Py_INCREF(x);

}

}

else

x = PyObject_GetItem(v, w);

Py_DECREF(v);

Py_DECREF(w);

PUSH(x);

if (x != NULL) continue;

break;

case BINARY_LSHIFT:

w = POP();

v = POP();

x = PyNumber_Lshift(v, w);

Py_DECREF(v);

Py_DECREF(w);

PUSH(x);

if (x != NULL) continue;

break;