/***********************************************************

Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,

The Netherlands.

All Rights Reserved

Permission to use, copy, modify, and distribute this software and its

documentation for any purpose and without fee is hereby granted,

provided that the above copyright notice appear in all copies and that

both that copyright notice and this permission notice appear in

supporting documentation, and that the names of Stichting Mathematisch

Centrum or CWI or Corporation for National Research Initiatives or

CNRI not be used in advertising or publicity pertaining to

distribution of the software without specific, written prior

permission.

While CWI is the initial source for this software, a modified version

is made available by the Corporation for National Research Initiatives

(CNRI) at the Internet address ftp://ftp.python.org.

STICHTING MATHEMATISCH CENTRUM AND CNRI DISCLAIM ALL WARRANTIES WITH

REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF

MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH

CENTRUM OR CNRI BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL

DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR

PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER

TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR

PERFORMANCE OF THIS SOFTWARE.

******************************************************************/

/* Execute compiled code */

/* XXX TO DO:

XXX how to pass arguments to call_trace?

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"

#include "graminit.h"

#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

/* Forward declarations */

static PyObject *eval_code2 Py_PROTO((PyCodeObject *,

PyObject *, PyObject *,

PyObject **, int,

PyObject **, int,

PyObject **, int,

PyObject *));

#ifdef LLTRACE

static int prtrace Py_PROTO((PyObject *, char *));

#endif

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

static int call_trace

Py_PROTO((PyObject **, PyObject **, PyFrameObject *, char *, PyObject *));

static PyObject *add Py_PROTO((PyObject *, PyObject *));

static PyObject *sub Py_PROTO((PyObject *, PyObject *));

static PyObject *powerop Py_PROTO((PyObject *, PyObject *));

static PyObject *mul Py_PROTO((PyObject *, PyObject *));

static PyObject *divide Py_PROTO((PyObject *, PyObject *));

static PyObject *mod Py_PROTO((PyObject *, PyObject *));

static PyObject *neg Py_PROTO((PyObject *));

static PyObject *pos Py_PROTO((PyObject *));

static PyObject *not Py_PROTO((PyObject *));

static PyObject *invert Py_PROTO((PyObject *));

static PyObject *lshift Py_PROTO((PyObject *, PyObject *));

static PyObject *rshift Py_PROTO((PyObject *, PyObject *));

static PyObject *and Py_PROTO((PyObject *, PyObject *));

static PyObject *xor Py_PROTO((PyObject *, PyObject *));

static PyObject *or Py_PROTO((PyObject *, PyObject *));

static PyObject *call_builtin Py_PROTO((PyObject *, PyObject *, PyObject *));

static PyObject *call_function Py_PROTO((PyObject *, PyObject *, PyObject *));

static PyObject *apply_subscript Py_PROTO((PyObject *, PyObject *));

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

static int slice_index Py_PROTO((PyObject *, int, int *));

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

static int assign_subscript Py_PROTO((PyObject *, PyObject *, PyObject *));

static int assign_slice Py_PROTO((PyObject *, PyObject *, PyObject *, PyObject *));

static int cmp_exception Py_PROTO((PyObject *, PyObject *));

static int cmp_member Py_PROTO((PyObject *, PyObject *));

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

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

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

static int exec_statement Py_PROTO((PyObject *, PyObject *, PyObject *));

static PyObject *find_from_args Py_PROTO((PyFrameObject *, int));

/* 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

/* Pointer to current frame, used to link new frames to */

static PyFrameObject *current_frame;

#ifdef WITH_THREAD

#include <errno.h>

#include "thread.h"

static type_lock interpreter_lock = 0;

static long main_thread = 0;

void

PyEval_InitThreads()

{

if (interpreter_lock)

return;

interpreter_lock = allocate_lock();

acquire_lock(interpreter_lock, 1);

main_thread = 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: */

PyObject *

PyEval_SaveThread()

{

#ifdef WITH_THREAD

if (interpreter_lock) {

PyObject *res;

res = (PyObject *)current_frame;

current_frame = NULL;

release_lock(interpreter_lock);

return res;

}

#endif

return NULL;

}

void

PyEval_RestoreThread(x)

PyObject *x;

{

#ifdef WITH_THREAD

if (interpreter_lock) {

int err;

err = errno;

acquire_lock(interpreter_lock, 1);

errno = err;

current_frame = (PyFrameObject *)x;

}

#endif

}

/* 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.

*/

static int ticker = 0; /* main loop counter to do periodic things */

#define NPENDINGCALLS 32

static struct {

int (*func) Py_PROTO((ANY *));

ANY *arg;

} pendingcalls[NPENDINGCALLS];

static volatile int pendingfirst = 0;

static volatile int pendinglast = 0;

int

Py_AddPendingCall(func, arg)

int (*func) Py_PROTO((ANY *));

ANY *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;

ticker = 0; /* Signal main loop */

busy = 0;

/* XXX End critical section */

return 0;

}

int

Py_MakePendingCalls()

{

static int busy = 0;

#ifdef WITH_THREAD

if (main_thread && get_thread_ident() != main_thread) {

ticker = 0; /* We're not done yet */

return 0;

}

#endif

if (busy) {

ticker = 0; /* We're not done yet */

return 0;

}

busy = 1;

for (;;) {

int i;

int (*func) Py_PROTO((ANY *));

ANY *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;

ticker = 0; /* We're not done yet */

return -1;

}

}

busy = 0;

return 0;

}

/* 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 */

};

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

/* Backward compatible interface */

PyObject *

PyEval_EvalCode(co, globals, locals)

PyCodeObject *co;

PyObject *globals;

PyObject *locals;

{

return eval_code2(co,

globals, locals,

(PyObject **)NULL, 0,

(PyObject **)NULL, 0,

(PyObject **)NULL, 0,

(PyObject *)NULL);

}

/* Interpreter main loop */

#ifndef MAX_RECURSION_DEPTH

#define MAX_RECURSION_DEPTH 10000

#endif

static int recursion_depth = 0;

static PyObject *

eval_code2(co, globals, locals,

args, argcount, kws, kwcount, defs, defcount, owner)

PyCodeObject *co;

PyObject *globals;

PyObject *locals;

PyObject **args;

int argcount;

PyObject **kws; /* length: 2*kwcount */

int kwcount;

PyObject **defs;

int defcount;

PyObject *owner;

{

#ifdef DXPAIRS

int lastopcode = 0;

#endif

register unsigned char *next_instr;

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

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

register PyObject **stack_pointer;

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 PyFrameObject *f; /* Current frame */

register PyObject **fastlocals = NULL;

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

#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 = PyString_AsString(co->co_filename);

#endif

/* Code access macros */

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

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

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

#define FIRST_INSTR() (GETUSTRINGVALUE(co->co_code))

#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)

#ifdef USE_STACKCHECK

if (recursion_depth%10 == 0 && PyOS_CheckStack()) {

PyErr_SetString(PyExc_MemoryError, "Stack overflow");

return NULL;

}

#endif

if (globals == NULL) {

PyErr_SetString(PyExc_SystemError, "eval_code2: NULL globals");

return NULL;

}

#ifdef LLTRACE

lltrace = PyDict_GetItemString(globals, "__lltrace__") != NULL;

#endif

f = PyFrame_New(

current_frame, /*back*/

co, /*code*/

globals, /*globals*/

locals); /*locals*/

if (f == NULL)

return NULL;

current_frame = f;

fastlocals = f->f_localsplus;

if (co->co_argcount > 0 ||

co->co_flags & (CO_VARARGS | CO_VARKEYWORDS)) {

int i;

int n = argcount;

PyObject *kwdict = NULL;

if (co->co_flags & CO_VARKEYWORDS) {

kwdict = PyDict_New();

if (kwdict == NULL)

goto fail;

i = co->co_argcount;

if (co->co_flags & CO_VARARGS)

i++;

SETLOCAL(i, kwdict);

}

if (argcount > co->co_argcount) {

if (!(co->co_flags & CO_VARARGS)) {

PyErr_SetString(PyExc_TypeError, "too many arguments");

goto fail;

}

n = co->co_argcount;

}

for (i = 0; i < n; i++) {

x = args[i];

Py_INCREF(x);

SETLOCAL(i, x);

}

if (co->co_flags & CO_VARARGS) {

u = PyTuple_New(argcount - n);

if (u == NULL)

goto fail;

SETLOCAL(co->co_argcount, u);

for (i = n; i < argcount; i++) {

x = args[i];

Py_INCREF(x);

PyTuple_SET_ITEM(u, i-n, x);

}

}

for (i = 0; i < kwcount; i++) {

PyObject *keyword = kws[2*i];

PyObject *value = kws[2*i + 1];

int j;

/* XXX slow -- speed up using dictionary? */

for (j = 0; j < co->co_argcount; j++) {

PyObject *nm = PyTuple_GET_ITEM(co->co_varnames, j);

if (PyObject_Compare(keyword, nm) == 0)

break;

}

if (j >= co->co_argcount) {

if (kwdict == NULL) {

PyErr_Format(PyExc_TypeError,

"unexpected keyword argument: %.400s",

PyString_AsString(keyword));

goto fail;

}

PyDict_SetItem(kwdict, keyword, value);

}

else {

if (GETLOCAL(j) != NULL) {

PyErr_SetString(PyExc_TypeError,

"keyword parameter redefined");

goto fail;

}

Py_INCREF(value);

SETLOCAL(j, value);

}

}

if (argcount < co->co_argcount) {

int m = co->co_argcount - defcount;

for (i = argcount; i < m; i++) {

if (GETLOCAL(i) == NULL) {

PyErr_SetString(PyExc_TypeError,

"not enough arguments");

goto fail;

}

}

if (n > m)

i = n - m;

else

i = 0;

for (; i < defcount; i++) {

if (GETLOCAL(m+i) == NULL) {

PyObject *def = defs[i];

Py_INCREF(def);

SETLOCAL(m+i, def);

}

}

}

}

else {

if (argcount > 0 || kwcount > 0) {

PyErr_SetString(PyExc_TypeError, "no arguments expected");

goto fail;

}

}

if (_PySys_TraceFunc != NULL) {

/* sys_trace, if defined, is a function that will

be called on *every* entry to a code block.

Its return value, if not None, is a function that

will be called at the start of each executed line

of code. (Actually, the function must return

itself in order to continue tracing.)

The trace functions are called with three arguments:

a pointer to the current frame, a string indicating

why the function is called, and an argument which

depends on the situation. The global trace function

(sys.trace) is also called whenever an exception

is detected. */

if (call_trace(&_PySys_TraceFunc, &f->f_trace, f, "call",

Py_None/*XXX how to compute arguments now?*/)) {

/* Trace function raised an error */

goto fail;

}

}

if (_PySys_ProfileFunc != NULL) {

/* Similar for sys_profile, except it needn't return

itself and isn't called for "line" events */

if (call_trace(&_PySys_ProfileFunc, (PyObject**)0, f, "call",

Py_None/*XXX*/)) {

goto fail;

}

}

if (++recursion_depth > MAX_RECURSION_DEPTH) {

--recursion_depth;

PyErr_SetString(PyExc_RuntimeError, "Maximum recursion depth exceeded");

current_frame = f->f_back;

Py_DECREF(f);

return NULL;

}

next_instr = GETUSTRINGVALUE(co->co_code);

stack_pointer = f->f_valuestack;

why = WHY_NOT;

err = 0;

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

for (;;) {

/* Do periodic things.

Doing this every time through the loop would add

too much overhead (a function call per instruction).

So we do it only every Nth instruction.

The ticker is reset to zero if there are pending

calls (see Py_AddPendingCall() and

Py_MakePendingCalls() above). */

if (--ticker < 0) {

ticker = _PySys_CheckInterval;

if (pendingfirst != pendinglast) {

if (Py_MakePendingCalls() < 0) {

why = WHY_EXCEPTION;

goto on_error;

}

}

#ifdef macintosh

#undef HAVE_SIGNAL_H

#endif

#ifndef HAVE_SIGNAL_H /* Is this the right #define? */

/* 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 */

current_frame = NULL;

release_lock(interpreter_lock);

/* Other threads may run now */

acquire_lock(interpreter_lock, 1);

current_frame = f;

}

#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();

#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 DUP_TOP:

v = TOP();

Py_INCREF(v);

PUSH(v);

continue;

case UNARY_POSITIVE:

v = POP();

x = pos(v);

Py_DECREF(v);

PUSH(x);

if (x != NULL) continue;

break;

case UNARY_NEGATIVE:

v = POP();

x = neg(v);

Py_DECREF(v);

PUSH(x);

if (x != NULL) continue;

break;

case UNARY_NOT:

v = POP();

x = not(v);

Py_DECREF(v);

PUSH(x);

if (x != NULL) 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 = invert(v);

Py_DECREF(v);

PUSH(x);

if (x != NULL) continue;

break;

case BINARY_POWER:

w = POP();

v = POP();

x = powerop(v, w);

Py_DECREF(v);

Py_DECREF(w);

PUSH(x);

if (x != NULL) continue;

break;

case BINARY_MULTIPLY:

w = POP();

v = POP();

x = mul(v, w);

Py_DECREF(v);

Py_DECREF(w);

PUSH(x);

if (x != NULL) continue;

break;

case BINARY_DIVIDE:

w = POP();

v = POP();

x = divide(v, w);

Py_DECREF(v);

Py_DECREF(w);

PUSH(x);

if (x != NULL) continue;

break;

case BINARY_MODULO:

w = POP();

v = POP();

x = mod(v, w);

Py_DECREF(v);

Py_DECREF(w);

PUSH(x);

if (x != NULL) continue;

break;

case BINARY_ADD:

w = POP();

v = POP();

x = add(v, w);

Py_DECREF(v);

Py_DECREF(w);

PUSH(x);

if (x != NULL) continue;

break;

case BINARY_SUBTRACT:

w = POP();

v = POP();

x = sub(v, w);

Py_DECREF(v);

Py_DECREF(w);

PUSH(x);

if (x != NULL) continue;

break;

case BINARY_SUBSCR:

w = POP();

v = POP();

x = apply_subscript(v, w);

Py_DECREF(v);

Py_DECREF(w);

PUSH(x);

if (x != NULL) continue;

break;

case BINARY_LSHIFT:

w = POP();

v = POP();

x = lshift(v, w);

Py_DECREF(v);

Py_DECREF(w);

PUSH(x);

if (x != NULL) continue;

break;

case BINARY_RSHIFT:

w = POP();

v = POP();

x = rshift(v, w);

Py_DECREF(v);

Py_DECREF(w);

PUSH(x);

if (x != NULL) continue;

break;

case BINARY_AND:

w = POP();

v = POP();

x = and(v, w);

Py_DECREF(v);

Py_DECREF(w);

PUSH(x);

if (x != NULL) continue;

break;

case BINARY_XOR:

w = POP();

v = POP();

x = xor(v, w);

Py_DECREF(v);

Py_DECREF(w);

PUSH(x);

if (x != NULL) continue;

break;

case BINARY_OR:

w = POP();

v = POP();

x = or(v, w);

Py_DECREF(v);

Py_DECREF(w);

PUSH(x);

if (x != NULL) continue;

break;

case SLICE+0:

case SLICE+1:

case SLICE+2:

case SLICE+3:

if ((opcode-SLICE) & 2)

w = POP();

else

w = NULL;

if ((opcode-SLICE) & 1)

v = POP();

else

v = NULL;

u = POP();

x = apply_slice(u, v, w);

Py_DECREF(u);

Py_XDECREF(v);

Py_XDECREF(w);

PUSH(x);

if (x != NULL) continue;

break;

case STORE_SLICE+0:

case STORE_SLICE+1:

case STORE_SLICE+2:

case STORE_SLICE+3:

if ((opcode-STORE_SLICE) & 2)

w = POP();

else

w = NULL;

if ((opcode-STORE_SLICE) & 1)

v = POP();

else

v = NULL;

u = POP();

t = POP();

err = assign_slice(u, v, w, t); /* u[v:w] = t */

Py_DECREF(t);

Py_DECREF(u);

Py_XDECREF(v);

Py_XDECREF(w);

if (err == 0) continue;

break;

case DELETE_SLICE+0:

case DELETE_SLICE+1:

case DELETE_SLICE+2:

case DELETE_SLICE+3:

if ((opcode-DELETE_SLICE) & 2)

w = POP();

else

w = NULL;

if ((opcode-DELETE_SLICE) & 1)

v = POP();

else

v = NULL;

u = POP();

err = assign_slice(u, v, w, (PyObject *)NULL);

/* del u[v:w] */

Py_DECREF(u);

Py_XDECREF(v);

Py_XDECREF(w);

if (err == 0) continue;

break;

case STORE_SUBSCR:

w = POP();

v = POP();

u = POP();

/* v[w] = u */

err = assign_subscript(v, w, u);

Py_DECREF(u);

Py_DECREF(v);

Py_DECREF(w);

if (err == 0) continue;

break;

case DELETE_SUBSCR:

w = POP();

v = POP();

/* del v[w] */

err = assign_subscript(v, w, (PyObject *)NULL);

Py_DECREF(v);

Py_DECREF(w);

if (err == 0) continue;

break;

case PRINT_EXPR:

v = POP();

/* Print value except if procedure result */

/* Before printing, also assign to '_' */

if (v != Py_None &&

(err = PyDict_SetItemString(f->f_builtins, "_", v)) == 0 &&

!Py_SuppressPrintingFlag) {

Py_FlushLine();

x = PySys_GetObject("stdout");

err = PyFile_WriteObject(v, x, 0);

PyFile_SoftSpace(x, 1);

Py_FlushLine();

}

Py_DECREF(v);

break;

case PRINT_ITEM:

v = POP();

w = PySys_GetObject("stdout");

if (PyFile_SoftSpace(w, 1))

PyFile_WriteString(" ", w);

err = PyFile_WriteObject(v, w, Py_PRINT_RAW);

if (err == 0 && PyString_Check(v)) {

/* XXX move into writeobject() ? */

char *s = PyString_AsString(v);

int len = PyString_Size(v);

if (len > 0 &&

isspace(Py_CHARMASK(s[len-1])) &&

s[len-1] != ' ')

PyFile_SoftSpace(w, 0);

}

Py_DECREF(v);

if (err == 0) continue;

break;

case PRINT_NEWLINE:

x = PySys_GetObject("stdout");

if (x == NULL)

PyErr_SetString(PyExc_RuntimeError, "lost sys.stdout");

else {

PyFile_WriteString("\n", x);

PyFile_SoftSpace(x, 0);

}

break;

case BREAK_LOOP:

why = WHY_BREAK;

break;

case RAISE_VARARGS:

u = v = w = NULL;

switch (oparg) {

case 3:

u = POP(); /* traceback */

/* Fallthrough */

case 2:

v = POP(); /* value */

/* Fallthrough */

case 1:

w = POP(); /* exc */

why = do_raise(w, v, u);

break;

default:

PyErr_SetString(PyExc_SystemError,

"bad RAISE_VARARGS oparg");

why = WHY_EXCEPTION;

break;

}

break;

case LOAD_LOCALS:

if ((x = f->f_locals) == NULL) {

PyErr_SetString(PyExc_SystemError, "no locals");

break;

}

Py_INCREF(x);

PUSH(x);

break;

case RETURN_VALUE:

retval = POP();

why = WHY_RETURN;

break;