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cpython/Python/ceval.c

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/* Execute compiled code */
#include "allobjects.h"
#include "import.h"
#include "sysmodule.h"
#include "compile.h"
#include "frameobject.h"
#include "ceval.h"
#include "opcode.h"
#include "builtinmodule.h"
#include "traceback.h"
#ifndef NDEBUG
#define TRACE
#endif
#ifdef TRACE
static int
prtrace(v, str)
object *v;
char *str;
{
printf("%s ", str);
printobject(v, stdout, 0);
printf("\n");
}
#endif
static frameobject *current_frame;
object *
getlocals()
{
if (current_frame == NULL)
return NULL;
else
return current_frame->f_locals;
}
object *
getglobals()
{
if (current_frame == NULL)
return NULL;
else
return current_frame->f_globals;
}
void
printtraceback(fp)
FILE *fp;
{
object *v = tb_fetch();
if (v != NULL) {
fprintf(fp, "Stack backtrace (innermost last):\n");
tb_print(v, fp);
DECREF(v);
}
}
/* XXX Mixing "print ...," and direct file I/O on stdin/stdout
XXX has some bad consequences. The needspace flag should
XXX really be part of the file object. */
static int needspace;
void
flushline()
{
FILE *fp = sysgetfile("stdout", stdout);
if (needspace) {
fprintf(fp, "\n");
needspace = 0;
}
}
/* Test a value used as condition, e.g., in a for or if statement */
static int
testbool(v)
object *v;
{
if (is_intobject(v))
return getintvalue(v) != 0;
if (is_floatobject(v))
return getfloatvalue(v) != 0.0;
if (v->ob_type->tp_as_sequence != NULL)
return (*v->ob_type->tp_as_sequence->sq_length)(v) != 0;
if (v->ob_type->tp_as_mapping != NULL)
return (*v->ob_type->tp_as_mapping->mp_length)(v) != 0;
if (v == None)
return 0;
/* All other objects are 'true' */
return 1;
}
static object *
add(v, w)
object *v, *w;
{
if (v->ob_type->tp_as_number != NULL)
v = (*v->ob_type->tp_as_number->nb_add)(v, w);
else if (v->ob_type->tp_as_sequence != NULL)
v = (*v->ob_type->tp_as_sequence->sq_concat)(v, w);
else {
err_setstr(TypeError, "+ not supported by operands");
return NULL;
}
return v;
}
static object *
sub(v, w)
object *v, *w;
{
if (v->ob_type->tp_as_number != NULL)
return (*v->ob_type->tp_as_number->nb_subtract)(v, w);
err_setstr(TypeError, "bad operand type(s) for -");
return NULL;
}
static object *
mul(v, w)
object *v, *w;
{
typeobject *tp;
if (is_intobject(v) && w->ob_type->tp_as_sequence != NULL) {
/* int*sequence -- swap v and w */
object *tmp = v;
v = w;
w = tmp;
}
tp = v->ob_type;
if (tp->tp_as_number != NULL)
return (*tp->tp_as_number->nb_multiply)(v, w);
if (tp->tp_as_sequence != NULL) {
if (!is_intobject(w)) {
err_setstr(TypeError,
"can't multiply sequence with non-int");
return NULL;
}
if (tp->tp_as_sequence->sq_repeat == NULL) {
err_setstr(TypeError, "sequence does not support *");
return NULL;
}
return (*tp->tp_as_sequence->sq_repeat)
(v, (int)getintvalue(w));
}
err_setstr(TypeError, "bad operand type(s) for *");
return NULL;
}
static object *
divide(v, w)
object *v, *w;
{
if (v->ob_type->tp_as_number != NULL)
return (*v->ob_type->tp_as_number->nb_divide)(v, w);
err_setstr(TypeError, "bad operand type(s) for /");
return NULL;
}
static object *
rem(v, w)
object *v, *w;
{
if (v->ob_type->tp_as_number != NULL)
return (*v->ob_type->tp_as_number->nb_remainder)(v, w);
err_setstr(TypeError, "bad operand type(s) for %");
return NULL;
}
static object *
neg(v)
object *v;
{
if (v->ob_type->tp_as_number != NULL)
return (*v->ob_type->tp_as_number->nb_negative)(v);
err_setstr(TypeError, "bad operand type(s) for unary -");
return NULL;
}
static object *
pos(v)
object *v;
{
if (v->ob_type->tp_as_number != NULL)
return (*v->ob_type->tp_as_number->nb_positive)(v);
err_setstr(TypeError, "bad operand type(s) for unary +");
return NULL;
}
static object *
not(v)
object *v;
{
int outcome = testbool(v);
object *w = outcome == 0 ? True : False;
INCREF(w);
return w;
}
static object *
call_builtin(func, arg)
object *func;
object *arg;
{
if (is_methodobject(func)) {
method meth = getmethod(func);
object *self = getself(func);
return (*meth)(self, arg);
}
if (is_classobject(func)) {
if (arg != NULL) {
err_setstr(TypeError,
"classobject() allows no arguments");
return NULL;
}
return newclassmemberobject(func);
}
err_setstr(TypeError, "call of non-function");
return NULL;
}
static object *
call_function(func, arg)
object *func;
object *arg;
{
object *newarg = NULL;
object *newlocals, *newglobals;
object *co, *v;
if (is_classmethodobject(func)) {
object *self = classmethodgetself(func);
func = classmethodgetfunc(func);
if (arg == NULL) {
arg = self;
}
else {
newarg = newtupleobject(2);
if (newarg == NULL)
return NULL;
INCREF(self);
INCREF(arg);
settupleitem(newarg, 0, self);
settupleitem(newarg, 1, arg);
arg = newarg;
}
}
else {
if (!is_funcobject(func)) {
err_setstr(TypeError, "call of non-function");
return NULL;
}
}
co = getfunccode(func);
if (co == NULL) {
XDECREF(newarg);
return NULL;
}
if (!is_codeobject(co)) {
fprintf(stderr, "XXX Bad code\n");
abort();
}
newlocals = newdictobject();
if (newlocals == NULL) {
XDECREF(newarg);
return NULL;
}
newglobals = getfuncglobals(func);
INCREF(newglobals);
v = eval_code((codeobject *)co, newglobals, newlocals, arg);
DECREF(newlocals);
DECREF(newglobals);
XDECREF(newarg);
return v;
}
static object *
apply_subscript(v, w)
object *v, *w;
{
typeobject *tp = v->ob_type;
if (tp->tp_as_sequence == NULL && tp->tp_as_mapping == NULL) {
err_setstr(TypeError, "unsubscriptable object");
return NULL;
}
if (tp->tp_as_sequence != NULL) {
int i;
if (!is_intobject(w)) {
err_setstr(TypeError, "sequence subscript not int");
return NULL;
}
i = getintvalue(w);
return (*tp->tp_as_sequence->sq_item)(v, i);
}
return (*tp->tp_as_mapping->mp_subscript)(v, w);
}
static object *
loop_subscript(v, w)
object *v, *w;
{
sequence_methods *sq = v->ob_type->tp_as_sequence;
int i, n;
if (sq == NULL) {
err_setstr(TypeError, "loop over non-sequence");
return NULL;
}
i = getintvalue(w);
n = (*sq->sq_length)(v);
if (i >= n)
return NULL; /* End of loop */
return (*sq->sq_item)(v, i);
}
static int
slice_index(v, isize, pi)
object *v;
int isize;
int *pi;
{
if (v != NULL) {
if (!is_intobject(v)) {
err_setstr(TypeError, "slice index must be int");
return -1;
}
*pi = getintvalue(v);
if (*pi < 0)
*pi += isize;
}
return 0;
}
static object *
apply_slice(u, v, w) /* return u[v:w] */
object *u, *v, *w;
{
typeobject *tp = u->ob_type;
int ilow, ihigh, isize;
if (tp->tp_as_sequence == NULL) {
err_setstr(TypeError, "only sequences can be sliced");
return NULL;
}
ilow = 0;
isize = ihigh = (*tp->tp_as_sequence->sq_length)(u);
if (slice_index(v, isize, &ilow) != 0)
return NULL;
if (slice_index(w, isize, &ihigh) != 0)
return NULL;
return (*tp->tp_as_sequence->sq_slice)(u, ilow, ihigh);
}
static int
assign_subscript(w, key, v) /* w[key] = v */
object *w;
object *key;
object *v;
{
typeobject *tp = w->ob_type;
sequence_methods *sq;
mapping_methods *mp;
int (*func)();
if ((sq = tp->tp_as_sequence) != NULL &&
(func = sq->sq_ass_item) != NULL) {
if (!is_intobject(key)) {
err_setstr(TypeError,
"sequence subscript must be integer");
return -1;
}
else
return (*func)(w, (int)getintvalue(key), v);
}
else if ((mp = tp->tp_as_mapping) != NULL &&
(func = mp->mp_ass_subscript) != NULL) {
return (*func)(w, key, v);
}
else {
err_setstr(TypeError,
"can't assign to this subscripted object");
return -1;
}
}
static int
assign_slice(u, v, w, x) /* u[v:w] = x */
object *u, *v, *w, *x;
{
sequence_methods *sq = u->ob_type->tp_as_sequence;
int ilow, ihigh, isize;
if (sq == NULL) {
err_setstr(TypeError, "assign to slice of non-sequence");
return -1;
}
if (sq == NULL || sq->sq_ass_slice == NULL) {
err_setstr(TypeError, "unassignable slice");
return -1;
}
ilow = 0;
isize = ihigh = (*sq->sq_length)(u);
if (slice_index(v, isize, &ilow) != 0)
return -1;
if (slice_index(w, isize, &ihigh) != 0)
return -1;
return (*sq->sq_ass_slice)(u, ilow, ihigh, x);
}
static int
cmp_exception(err, v)
object *err, *v;
{
if (is_tupleobject(v)) {
int i, n;
n = gettuplesize(v);
for (i = 0; i < n; i++) {
if (err == gettupleitem(v, i))
return 1;
}
return 0;
}
return err == v;
}
static int
cmp_member(v, w)
object *v, *w;
{
int i, n, cmp;
object *x;
sequence_methods *sq;
/* Special case for char in string */
if (is_stringobject(w)) {
register char *s, *end;
register char c;
if (!is_stringobject(v) || getstringsize(v) != 1) {
err_setstr(TypeError,
"string member test needs char left operand");
return -1;
}
c = getstringvalue(v)[0];
s = getstringvalue(w);
end = s + getstringsize(w);
while (s < end) {
if (c == *s++)
return 1;
}
return 0;
}
sq = w->ob_type->tp_as_sequence;
if (sq == NULL) {
err_setstr(TypeError,
"'in' or 'not in' needs sequence right argument");
return -1;
}
n = (*sq->sq_length)(w);
for (i = 0; i < n; i++) {
x = (*sq->sq_item)(w, i);
cmp = cmpobject(v, x);
XDECREF(x);
if (cmp == 0)
return 1;
}
return 0;
}
static object *
cmp_outcome(op, v, w)
enum cmp_op op;
register object *v;
register object *w;
{
register int cmp;
register int res = 0;
switch (op) {
case IS:
case IS_NOT:
res = (v == w);
if (op == IS_NOT)
res = !res;
break;
case IN:
case NOT_IN:
res = cmp_member(v, w);
if (res < 0)
return NULL;
if (op == NOT_IN)
res = !res;
break;
case EXC_MATCH:
res = cmp_exception(v, w);
break;
default:
cmp = cmpobject(v, w);
switch (op) {
case LT: res = cmp < 0; break;
case LE: res = cmp <= 0; break;
case EQ: res = cmp == 0; break;
case NE: res = cmp != 0; break;
case GT: res = cmp > 0; break;
case GE: res = cmp >= 0; break;
/* XXX no default? (res is initialized to 0 though) */
}
}
v = res ? True : False;
INCREF(v);
return v;
}
static int
import_from(locals, v, name)
object *locals;
object *v;
char *name;
{
object *w, *x;
w = getmoduledict(v);
if (name[0] == '*') {
int i;
int n = getdictsize(w);
for (i = 0; i < n; i++) {
name = getdictkey(w, i);
if (name == NULL || name[0] == '_')
continue;
x = dictlookup(w, name);
if (x == NULL) {
/* XXX can't happen? */
err_setstr(NameError, name);
return -1;
}
if (dictinsert(locals, name, x) != 0)
return -1;
}
return 0;
}
else {
x = dictlookup(w, name);
if (x == NULL) {
err_setstr(NameError, name);
return -1;
}
else
return dictinsert(locals, name, x);
}
}
static object *
build_class(v, w)
object *v; /* None or tuple containing base classes */
object *w; /* dictionary */
{
if (is_tupleobject(v)) {
int i;
for (i = gettuplesize(v); --i >= 0; ) {
object *x = gettupleitem(v, i);
if (!is_classobject(x)) {
err_setstr(TypeError,
"base is not a class object");
return NULL;
}
}
}
else {
v = NULL;
}
if (!is_dictobject(w)) {
err_setstr(SystemError, "build_class with non-dictionary");
return NULL;
}
return newclassobject(v, w);
}
/* 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 */
};
/* Interpreter main loop */
object *
eval_code(co, globals, locals, arg)
codeobject *co;
object *globals;
object *locals;
object *arg;
{
register unsigned char *next_instr;
register int opcode; /* Current opcode */
register int oparg; /* Current opcode argument, if any */
register object **stack_pointer;
register enum why_code why; /* Reason for block stack unwind */
register int err; /* Error status -- nonzero if error */
register object *x; /* Result object -- NULL if error */
register object *v; /* Temporary objects popped off stack */
register object *w;
register object *u;
register object *t;
register frameobject *f; /* Current frame */
int lineno; /* Current line number */
object *retval; /* Return value iff why == WHY_RETURN */
char *name; /* Name used by some instructions */
FILE *fp; /* Used by print operations */
#ifdef TRACE
int trace = dictlookup(globals, "__trace__") != NULL;
#endif
/* Code access macros */
#define GETCONST(i) Getconst(f, i)
#define GETNAME(i) Getname(f, i)
#define FIRST_INSTR() (GETUSTRINGVALUE(f->f_code->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 TRACE
#define PUSH(v) (BASIC_PUSH(v), trace && prtrace(TOP(), "push"))
#define POP() (trace && prtrace(TOP(), "pop"), BASIC_POP())
#else
#define PUSH(v) BASIC_PUSH(v)
#define POP() BASIC_POP()
#endif
f = newframeobject(
current_frame, /*back*/
co, /*code*/
globals, /*globals*/
locals, /*locals*/
50, /*nvalues*/
20); /*nblocks*/
if (f == NULL)
return NULL;
current_frame = f;
next_instr = GETUSTRINGVALUE(f->f_code->co_code);
stack_pointer = f->f_valuestack;
if (arg != NULL) {
INCREF(arg);
PUSH(arg);
}
why = WHY_NOT;
err = 0;
x = None; /* Not a reference, just anything non-NULL */
lineno = -1;
for (;;) {
static ticker;
/* Do periodic things */
if (--ticker < 0) {
ticker = 100;
if (intrcheck()) {
err_set(KeyboardInterrupt);
why = WHY_EXCEPTION;
tb_here(f, INSTR_OFFSET(), lineno);
break;
}
}
/* Extract opcode and argument */
opcode = NEXTOP();
if (HAS_ARG(opcode))
oparg = NEXTARG();
#ifdef TRACE
/* Instruction tracing */
if (trace) {
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();
DECREF(v);
break;
case ROT_TWO:
v = POP();
w = POP();
PUSH(v);
PUSH(w);
break;
case ROT_THREE:
v = POP();
w = POP();
x = POP();
PUSH(v);
PUSH(x);
PUSH(w);
break;
case DUP_TOP:
v = TOP();
INCREF(v);
PUSH(v);
break;
case UNARY_POSITIVE:
v = POP();
x = pos(v);
DECREF(v);
PUSH(x);
break;
case UNARY_NEGATIVE:
v = POP();
x = neg(v);
DECREF(v);
PUSH(x);
break;
case UNARY_NOT:
v = POP();
x = not(v);
DECREF(v);
PUSH(x);
break;
case UNARY_CONVERT:
v = POP();
x = reprobject(v);
DECREF(v);
PUSH(x);
break;
case UNARY_CALL:
v = POP();
if (is_classmethodobject(v) || is_funcobject(v))
x = call_function(v, (object *)NULL);
else
x = call_builtin(v, (object *)NULL);
DECREF(v);
PUSH(x);
break;
case BINARY_MULTIPLY:
w = POP();
v = POP();
x = mul(v, w);
DECREF(v);
DECREF(w);
PUSH(x);
break;
case BINARY_DIVIDE:
w = POP();
v = POP();
x = divide(v, w);
DECREF(v);
DECREF(w);
PUSH(x);
break;
case BINARY_MODULO:
w = POP();
v = POP();
x = rem(v, w);
DECREF(v);
DECREF(w);
PUSH(x);
break;
case BINARY_ADD:
w = POP();
v = POP();
x = add(v, w);
DECREF(v);
DECREF(w);
PUSH(x);
break;
case BINARY_SUBTRACT:
w = POP();
v = POP();
x = sub(v, w);
DECREF(v);
DECREF(w);
PUSH(x);
break;
case BINARY_SUBSCR:
w = POP();
v = POP();
x = apply_subscript(v, w);
DECREF(v);
DECREF(w);
PUSH(x);
break;
case BINARY_CALL:
w = POP();
v = POP();
if (is_classmethodobject(v) || is_funcobject(v))
x = call_function(v, w);
else
x = call_builtin(v, w);
DECREF(v);
DECREF(w);
PUSH(x);
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);
DECREF(u);
XDECREF(v);
XDECREF(w);
PUSH(x);
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 */
DECREF(t);
DECREF(u);
XDECREF(v);
XDECREF(w);
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, (object *)NULL);
/* del u[v:w] */
DECREF(u);
XDECREF(v);
XDECREF(w);
break;
case STORE_SUBSCR:
w = POP();
v = POP();
u = POP();
/* v[w] = u */
err = assign_subscript(v, w, u);
DECREF(u);
DECREF(v);
DECREF(w);
break;
case DELETE_SUBSCR:
w = POP();
v = POP();
/* del v[w] */
err = assign_subscript(v, w, (object *)NULL);
DECREF(v);
DECREF(w);
break;
case PRINT_EXPR:
v = POP();
fp = sysgetfile("stdout", stdout);
/* Print value except if procedure result */
if (v != None) {
flushline();
printobject(v, fp, 0);
fprintf(fp, "\n");
}
DECREF(v);
break;
case PRINT_ITEM:
v = POP();
fp = sysgetfile("stdout", stdout);
if (needspace)
fprintf(fp, " ");
if (is_stringobject(v)) {
char *s = getstringvalue(v);
int len = getstringsize(v);
fwrite(s, 1, len, fp);
if (len > 0 && s[len-1] == '\n')
needspace = 0;
else
needspace = 1;
}
else {
printobject(v, fp, 0);
needspace = 1;
}
DECREF(v);
break;
case PRINT_NEWLINE:
fp = sysgetfile("stdout", stdout);
fprintf(fp, "\n");
needspace = 0;
break;
case BREAK_LOOP:
why = WHY_BREAK;
break;
case RAISE_EXCEPTION:
v = POP();
w = POP();
if (!is_stringobject(w))
err_setstr(TypeError,
"exceptions must be strings");
else
err_setval(w, v);
DECREF(v);
DECREF(w);
why = WHY_EXCEPTION;
break;
case LOAD_LOCALS:
v = f->f_locals;
INCREF(v);
PUSH(v);
break;
case RETURN_VALUE:
retval = POP();
why = WHY_RETURN;
break;
case REQUIRE_ARGS:
if (EMPTY()) {
err_setstr(TypeError,
"function expects argument(s)");
why = WHY_EXCEPTION;
}
break;
case REFUSE_ARGS:
if (!EMPTY()) {
err_setstr(TypeError,
"function expects no argument(s)");
why = WHY_EXCEPTION;
}
break;
case BUILD_FUNCTION:
v = POP();
x = newfuncobject(v, f->f_globals);
DECREF(v);
PUSH(x);
break;
case POP_BLOCK:
{
block *b = pop_block(f);
while (STACK_LEVEL() > b->b_level) {
v = POP();
DECREF(v);
}
}
break;
case END_FINALLY:
v = POP();
if (is_intobject(v)) {
why = (enum why_code) getintvalue(v);
if (why == WHY_RETURN)
retval = POP();
}
else if (is_stringobject(v)) {
w = POP();
err_setval(v, w);
DECREF(w);
w = POP();
tb_store(w);
DECREF(w);
why = WHY_RERAISE;
}
else if (v != None) {
err_setstr(SystemError,
"'finally' pops bad exception");
why = WHY_EXCEPTION;
}
DECREF(v);
break;
case BUILD_CLASS:
w = POP();
v = POP();
x = build_class(v, w);
PUSH(x);
DECREF(v);
DECREF(w);
break;
case STORE_NAME:
name = GETNAME(oparg);
v = POP();
err = dictinsert(f->f_locals, name, v);
DECREF(v);
break;
case DELETE_NAME:
name = GETNAME(oparg);
if ((err = dictremove(f->f_locals, name)) != 0)
err_setstr(NameError, name);
break;
case UNPACK_TUPLE:
v = POP();
if (!is_tupleobject(v)) {
err_setstr(TypeError, "unpack non-tuple");
why = WHY_EXCEPTION;
}
else if (gettuplesize(v) != oparg) {
err_setstr(RuntimeError,
"unpack tuple of wrong size");
why = WHY_EXCEPTION;
}
else {
for (; --oparg >= 0; ) {
w = gettupleitem(v, oparg);
INCREF(w);
PUSH(w);
}
}
DECREF(v);
break;
case UNPACK_LIST:
v = POP();
if (!is_listobject(v)) {
err_setstr(TypeError, "unpack non-list");
why = WHY_EXCEPTION;
}
else if (getlistsize(v) != oparg) {
err_setstr(RuntimeError,
"unpack list of wrong size");
why = WHY_EXCEPTION;
}
else {
for (; --oparg >= 0; ) {
w = getlistitem(v, oparg);
INCREF(w);
PUSH(w);
}
}
DECREF(v);
break;
case STORE_ATTR:
name = GETNAME(oparg);
v = POP();
u = POP();
err = setattr(v, name, u); /* v.name = u */
DECREF(v);
DECREF(u);
break;
case DELETE_ATTR:
name = GETNAME(oparg);
v = POP();
err = setattr(v, name, (object *)NULL);
/* del v.name */
DECREF(v);
break;
case LOAD_CONST:
x = GETCONST(oparg);
INCREF(x);
PUSH(x);
break;
case LOAD_NAME:
name = GETNAME(oparg);
x = dictlookup(f->f_locals, name);
if (x == NULL) {
x = dictlookup(f->f_globals, name);
if (x == NULL)
x = getbuiltin(name);
}
if (x == NULL)
err_setstr(NameError, name);
else
INCREF(x);
PUSH(x);
break;
case BUILD_TUPLE:
x = newtupleobject(oparg);
if (x != NULL) {
for (; --oparg >= 0;) {
w = POP();
err = settupleitem(x, oparg, w);
if (err != 0)
break;
}
PUSH(x);
}
break;
case BUILD_LIST:
x = newlistobject(oparg);
if (x != NULL) {
for (; --oparg >= 0;) {
w = POP();
err = setlistitem(x, oparg, w);
if (err != 0)
break;
}
PUSH(x);
}
break;
case BUILD_MAP:
x = newdictobject();
PUSH(x);
break;
case LOAD_ATTR:
name = GETNAME(oparg);
v = POP();
x = getattr(v, name);
DECREF(v);
PUSH(x);
break;
case COMPARE_OP:
w = POP();
v = POP();
x = cmp_outcome((enum cmp_op)oparg, v, w);
DECREF(v);
DECREF(w);
PUSH(x);
break;
case IMPORT_NAME:
name = GETNAME(oparg);
x = import_module(name);
XINCREF(x);
PUSH(x);
break;
case IMPORT_FROM:
name = GETNAME(oparg);
v = TOP();
err = import_from(f->f_locals, v, name);
break;
case JUMP_FORWARD:
JUMPBY(oparg);
break;
case JUMP_IF_FALSE:
if (!testbool(TOP()))
JUMPBY(oparg);
break;
case JUMP_IF_TRUE:
if (testbool(TOP()))
JUMPBY(oparg);
break;
case JUMP_ABSOLUTE:
JUMPTO(oparg);
break;
case FOR_LOOP:
/* for v in s: ...
On entry: stack contains s, i.
On exit: stack contains s, i+1, s[i];
but if loop exhausted:
s, i are popped, and we jump */
w = POP(); /* Loop index */
v = POP(); /* Sequence object */
u = loop_subscript(v, w);
if (u != NULL) {
PUSH(v);
x = newintobject(getintvalue(w)+1);
PUSH(x);
DECREF(w);
PUSH(u);
}
else {
DECREF(v);
DECREF(w);
/* A NULL can mean "s exhausted"
but also an error: */
if (err_occurred())
why = WHY_EXCEPTION;
else
JUMPBY(oparg);
}
break;
case SETUP_LOOP:
case SETUP_EXCEPT:
case SETUP_FINALLY:
setup_block(f, opcode, INSTR_OFFSET() + oparg,
STACK_LEVEL());
break;
case SET_LINENO:
#ifdef TRACE
if (trace)
printf("--- Line %d ---\n", oparg);
#endif
lineno = oparg;
break;
default:
fprintf(stderr,
"XXX lineno: %d, opcode: %d\n",
lineno, opcode);
err_setstr(SystemError, "eval_code: unknown opcode");
why = WHY_EXCEPTION;
break;
} /* switch */
/* Quickly continue if no error occurred */
if (why == WHY_NOT) {
if (err == 0 && x != NULL)
continue; /* Normal, fast path */
why = WHY_EXCEPTION;
x = None;
err = 0;
}
#ifndef NDEBUG
/* Double-check exception status */
if (why == WHY_EXCEPTION || why == WHY_RERAISE) {
if (!err_occurred()) {
fprintf(stderr, "XXX ghost error\n");
err_setstr(SystemError, "ghost error");
why = WHY_EXCEPTION;
}
}
else {
if (err_occurred()) {
fprintf(stderr, "XXX undetected error\n");
why = WHY_EXCEPTION;
}
}
#endif
/* Log traceback info if this is a real exception */
if (why == WHY_EXCEPTION) {
int lasti = INSTR_OFFSET() - 1;
if (HAS_ARG(opcode))
lasti -= 2;
tb_here(f, lasti, lineno);
}
/* For the rest, treat WHY_RERAISE as WHY_EXCEPTION */
if (why == WHY_RERAISE)
why = WHY_EXCEPTION;
/* Unwind stacks if a (pseudo) exception occurred */
while (why != WHY_NOT && f->f_iblock > 0) {
block *b = pop_block(f);
while (STACK_LEVEL() > b->b_level) {
v = POP();
XDECREF(v);
}
if (b->b_type == SETUP_LOOP && why == WHY_BREAK) {
why = WHY_NOT;
JUMPTO(b->b_handler);
break;
}
if (b->b_type == SETUP_FINALLY ||
b->b_type == SETUP_EXCEPT &&
why == WHY_EXCEPTION) {
if (why == WHY_EXCEPTION) {
object *exc, *val;
err_get(&exc, &val);
if (val == NULL) {
val = None;
INCREF(val);
}
v = tb_fetch();
/* Make the raw exception data
available to the handler,
so a program can emulate the
Python main loop. Don't do
this for 'finally'. */
if (b->b_type == SETUP_EXCEPT) {
#if 0 /* Oops, this breaks too many things */
sysset("exc_traceback", v);
#endif
sysset("exc_value", val);
sysset("exc_type", exc);
err_clear();
}
PUSH(v);
PUSH(val);
PUSH(exc);
}
else {
if (why == WHY_RETURN)
PUSH(retval);
v = newintobject((long)why);
PUSH(v);
}
why = WHY_NOT;
JUMPTO(b->b_handler);
break;
}
} /* unwind stack */
/* End the loop if we still have an error (or return) */
if (why != WHY_NOT)
break;
} /* main loop */
/* Pop remaining stack entries */
while (!EMPTY()) {
v = POP();
XDECREF(v);
}
/* Restore previous frame and release the current one */
current_frame = f->f_back;
DECREF(f);
if (why == WHY_RETURN)
return retval;
else
return NULL;
}
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