//=============================================================================
// METHOD : SPELLbytecode::analyze
//=============================================================================
void SPELLbytecode::analyze()
{
assert( m_code != NULL );
// Pointer to initial instruction (used by macros)
unsigned char* first_instr = (unsigned char*) PyString_AS_STRING(m_code->co_code);
// Pointer to current instruction (used by macros)
register unsigned char* next_instr = first_instr;
// Opcode argument
unsigned int oparg;
// Stores the previous line
unsigned int prevLine = 0;
// Stores the last opcode
unsigned int prevOpCode = 0;
// Opcode count in line
unsigned short opcodeCount = 0;
// Will be true when there is no more bytecode to process
bool finished = false;
unsigned int callDepth = 0;
// Try block structure
TryBlock tb;
tb.try_lineno = 0;
tb.end_try_lineno = 0;
tb.except_lineno = 0;
tb.end_except_lineno = 0;
tb.end_lineno = 0;
// Holds the bytecode offset for except and finally statements
unsigned int except_offset = 0;
unsigned int finally_offset = 0;
while(not finished)
{
// Create one BLine info structure per bytecode instruction
BLine info;
// Get the instruction offset
info.offset = INSTR_OFFSET();
// Get the corresponding script line
info.lineno = PyCode_Addr2Line(m_code, info.offset);
// Obtain the opcode
info.opcode = NEXTOP();
// Track the number of opcodes per line in the lnotab.
if ((prevLine>0) && (info.lineno != prevLine))
{
opcodeCount = 0;
}
else
{
opcodeCount++;
}
//////////////////////////////////////////////////////////////////////////////////
// PHASE 1 - UPDATE PREVIOUS LINE INFORMATION (ALREADY STORED) IF NEEDED
//////////////////////////////////////////////////////////////////////////////////
// #1 Detect binary add. This helps us detect lines that shall be executed together
// like when statements spread over several lines with binary add (+\)
if ((opcodeCount == 0)&&(prevOpCode == BINARY_ADD)&&(info.opcode==LOAD_CONST))
{
LineList::iterator it = m_lines.end();
it--;
BLine prev = *it;
m_lines.pop_back();
prev.keepWithNext = true;
m_lines.push_back(prev);
}
//////////////////////////////////////////////////////////////////////////////////
// #2 Special checks for return statements: we may need to update the previous line
if (info.opcode == RETURN_VALUE && ((prevOpCode == LOAD_FAST || prevOpCode == LOAD_CONST)))
{
LineList::iterator it = m_lines.end();
it--;
BLine prev = *it;
m_lines.pop_back();
prev.returnConst = true;
m_lines.push_back(prev);
}
// We will ignore this, for the moment
oparg = 0;
// To decide wether store the bline information or not
bool storeit = false;
if (HAS_ARG(info.opcode)) oparg = NEXTARG();
//////////////////////////////////////////////////////////////////////////////////
// PHASE 2 - BUILD AND STORE NEXT BLINE INFORMATION
//////////////////////////////////////////////////////////////////////////////////
if (( prevLine > 0 ) && ( info.lineno != prevLine ))
{
// Default values
info.executable = false;
info.returnConst = false;
info.keepWithNext = false;
/** \todo
// Depending on the bytecode, either set the block as active,
// or finish the loop (RETURN_VALUE is found at the end of the script)
// This is maybe wrong, need to check if RETURN_VALUE is found
// in function code objects, probably yes... */
switch(info.opcode)
{
case LOAD_NAME:
case LOAD_GLOBAL:
case LOAD_CONST:
callDepth++;
info.executable = true;
break;
case CALL_FUNCTION:
callDepth--;
info.executable = true;
break;
case STORE_NAME:
case IMPORT_NAME:
case JUMP_FORWARD:
case JUMP_IF_FALSE:
case JUMP_IF_TRUE:
case JUMP_ABSOLUTE:
case RETURN_VALUE:
{
info.executable = (callDepth==0);
break;
}
default:
info.executable = true;
break;
}
// Store the info
m_lines.push_back(info);
}
// The very first line is always executable, and needs to be stored explicitly
else if (prevLine == 0)
{
info.executable = true;
// Store the info
m_lines.push_back(info);
}
//////////////////////////////////////////////////////////////////////////////////
// PHASE 3 - ADDITIONAL INFORMATION FOR TRY BLOCKS, LAST ADDRESS, LAST LINE
//////////////////////////////////////////////////////////////////////////////////
switch(info.opcode)
{
case RETURN_VALUE:
m_lastAddr = info.offset;
finished = true;
break;
case SETUP_EXCEPT:
tb.try_lineno = info.lineno;
except_offset = info.offset + oparg + 3; // This is the real destination offset
break;
case SETUP_FINALLY:
finally_offset = info.offset + oparg + 3; // This is the 'finally' destination offset
break;
case END_FINALLY:
if (tb.try_lineno != 0 && tb.end_lineno == 0)
{
tb.end_lineno = info.lineno;
tb.end_except_lineno = info.lineno;
m_tryBlocks.push_back( tb );
tb.try_lineno = 0;
tb.end_try_lineno = 0;
tb.except_lineno = 0;
tb.end_except_lineno = 0;
tb.end_lineno = 0;
}
else
{
// Update the last try block to update it with the finally block
TryBlockList::iterator it = m_tryBlocks.end();
it--;
TryBlock prev = *it;
m_tryBlocks.pop_back();
prev.end_except_lineno = prev.end_lineno;
prev.end_lineno = info.lineno;
m_tryBlocks.push_back( prev );
}
break;
}
// This should always happen between a SETUP_EXCEPT and an END_FINALLY
if ( (tb.try_lineno >0) && (except_offset == info.offset))
{
// The last line before the except
tb.end_try_lineno = prevLine;
// The line of the except
tb.except_lineno = info.lineno;
}
prevLine = info.lineno;
prevOpCode = info.opcode;
m_lastLine = info.lineno;
}
}
static PyObject *
eval_frame(PyFrameObject *f)
{
LOG("> eval_frame\n"); {
PyObject **stack_pointer; /* Next free slot in value stack */
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 *t, *u, *v; /* Temporary objects popped off stack */
register PyObject *w;
register PyObject **fastlocals, **freevars;
PyObject *retval = NULL; /* Return value */
PyThreadState *tstate = PyThreadState_GET();
PyCodeObject *co;
unsigned char *first_instr;
PyObject *names;
PyObject *consts;
/* Tuple access macros */
#define GETITEM(v, i) PyTuple_GET_ITEM((PyTupleObject *)(v), (i))
/* Code access macros */
#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))
/* OpCode prediction macros
Some opcodes tend to come in pairs thus making it possible to predict
the second code when the first is run. For example, COMPARE_OP is often
followed by JUMP_IF_FALSE or JUMP_IF_TRUE. And, those opcodes are often
followed by a POP_TOP.
Verifying the prediction costs a single high-speed test of register
variable against a constant. If the pairing was good, then the
processor has a high likelihood of making its own successful branch
prediction which results in a nearly zero overhead transition to the
next opcode.
A successful prediction saves a trip through the eval-loop including
its two unpredictable branches, the HASARG test and the switch-case.
*/
#define PREDICT(op) if (*next_instr == op) goto PRED_##op
#define PREDICTED(op) PRED_##op: next_instr++
#define PREDICTED_WITH_ARG(op) PRED_##op: oparg = (next_instr[2]<<8) + \
next_instr[1]; next_instr += 3
/* Stack manipulation macros */
#define STACK_LEVEL() (stack_pointer - f->f_valuestack)
#define EMPTY() (STACK_LEVEL() == 0)
#define TOP() (stack_pointer[-1])
#define SECOND() (stack_pointer[-2])
#define THIRD() (stack_pointer[-3])
#define FOURTH() (stack_pointer[-4])
#define SET_TOP(v) (stack_pointer[-1] = (v))
#define SET_SECOND(v) (stack_pointer[-2] = (v))
#define SET_THIRD(v) (stack_pointer[-3] = (v))
#define SET_FOURTH(v) (stack_pointer[-4] = (v))
#define BASIC_STACKADJ(n) (stack_pointer += n)
#define BASIC_PUSH(v) (*stack_pointer++ = (v))
#define BASIC_POP() (*--stack_pointer)
#define PUSH(v) BASIC_PUSH(v)
#define POP() BASIC_POP()
#define STACKADJ(n) BASIC_STACKADJ(n)
/* Local variable macros */
#define GETLOCAL(i) (fastlocals[i])
/* The SETLOCAL() macro must not DECREF the local variable in-place and
then store the new value; it must copy the old value to a temporary
value, then store the new value, and then DECREF the temporary value.
This is because it is possible that during the DECREF the frame is
accessed by other code (e.g. a __del__ method or gc.collect()) and the
variable would be pointing to already-freed memory. */
#define SETLOCAL(i, value) do { PyObject *tmp = GETLOCAL(i); \
GETLOCAL(i) = value; \
Py_XDECREF(tmp); } while (0)
/* Start of code */
if (f == NULL)
return NULL;
/* push frame */
if (++tstate->recursion_depth > recursion_limit) {
--tstate->recursion_depth;
/* ERROR */
tstate->frame = f->f_back;
return NULL;
}
tstate->frame = f;
/* tracing elided */
co = f->f_code;
names = co->co_names;
consts = co->co_consts;
fastlocals = f->f_localsplus;
freevars = f->f_localsplus + f->f_nlocals;
_PyCode_GETCODEPTR(co, &first_instr);
/* An explanation is in order for the next line.
f->f_lasti now refers to the index of the last instruction
executed. You might think this was obvious from the name, but
this wasn't always true before 2.3! PyFrame_New now sets
f->f_lasti to -1 (i.e. the index *before* the first instruction)
and YIELD_VALUE doesn't fiddle with f_lasti any more. So this
does work. Promise. */
next_instr = first_instr + f->f_lasti + 1;
stack_pointer = f->f_stacktop;
f->f_stacktop = NULL; /* remains NULL unless yield suspends frame */
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 (--_Py_Ticker < 0) {
/* @@@ check for SETUP_FINALLY elided */
_Py_Ticker = _Py_CheckInterval;
tstate->tick_counter++;
if (things_to_do) {
if (Py_MakePendingCalls() < 0) {
why = WHY_EXCEPTION;
goto on_error;
}
}
}
fast_next_opcode:
f->f_lasti = INSTR_OFFSET();
/* Extract opcode and argument */
opcode = NEXTOP();
if (HAS_ARG(opcode))
oparg = NEXTARG();
/* 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 LOAD_FAST:
x = GETLOCAL(oparg);
if (x != NULL) {
Py_INCREF(x);
PUSH(x);
goto fast_next_opcode;
}
/* ERROR? */
break;
case STORE_FAST:
v = POP();
SETLOCAL(oparg, v);
continue;
case LOAD_CONST:
x = GETITEM(consts, oparg);
Py_INCREF(x);
PUSH(x);
goto fast_next_opcode;
PREDICTED(POP_TOP);
case POP_TOP:
v = POP();
Py_DECREF(v);
goto fast_next_opcode;
case UNARY_NOT:
v = TOP();
err = PyObject_IsTrue(v);
Py_DECREF(v);
if (err == 0) {
Py_INCREF(Py_True);
SET_TOP(Py_True);
continue;
}
else if (err > 0) {
Py_INCREF(Py_False);
SET_TOP(Py_False);
err = 0;
continue;
}
STACKADJ(-1);
break;
case BINARY_MODULO:
w = POP();
v = TOP();
x = PyNumber_Remainder(v, w);
Py_DECREF(v);
Py_DECREF(w);
SET_TOP(x);
if (x != NULL) continue;
break;
case BINARY_ADD:
w = POP();
v = TOP();
if (PyInt_CheckExact(v) && PyInt_CheckExact(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)
goto slow_add;
x = PyInt_FromLong(i);
}
else {
slow_add:
Py_FatalError("slow add not supported.");
}
Py_DECREF(v);
Py_DECREF(w);
SET_TOP(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 STORE_SUBSCR:
w = POP();
v = POP();
u = POP();
/* v[w] = u */
err = PyObject_SetItem(v, w, u);
Py_DECREF(u);
Py_DECREF(v);
Py_DECREF(w);
if (err == 0) continue;
break;
case BINARY_SUBSCR:
w = POP();
v = TOP();
if (PyList_CheckExact(v) && PyInt_CheckExact(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)) {
/* ERROR */
printf("list index out of range\n");
x = NULL;
}
else {
x = PyList_GET_ITEM(v, i);
Py_INCREF(x);
}
}
else
x = PyObject_GetItem(v, w);
Py_DECREF(v);
Py_DECREF(w);
SET_TOP(x);
if (x != NULL) continue;
break;
case BINARY_AND:
w = POP();
v = TOP();
x = PyNumber_And(v, w);
Py_DECREF(v);
Py_DECREF(w);
SET_TOP(x);
if (x != NULL) continue;
break;
case PRINT_ITEM:
v = POP();
PyObject_Print(v);
Py_DECREF(v);
break;
case PRINT_NEWLINE:
printf("\n");
break;
case RETURN_VALUE:
retval = POP();
why = WHY_RETURN;
break;
case POP_BLOCK:
{
PyTryBlock *b = PyFrame_BlockPop(f);
while (STACK_LEVEL() > b->b_level) {
v = POP();
Py_DECREF(v);
}
}
break;
case STORE_NAME:
w = GETITEM(names, oparg);
v = POP();
if ((x = f->f_locals) == NULL) {
/* ERROR */
printf("STORE_NAME ERROR\n");
break;
}
err = PyDict_SetItem(x, w, v);
Py_DECREF(v);
break;
case LOAD_NAME:
w = GETITEM(names, oparg);
if ((x = f->f_locals) == NULL) {
/* ERROR */
printf("LOAD_NAME ERROR\n");
break;
}
x = PyDict_GetItem(x, w);
if (x == NULL) {
x = PyDict_GetItem(f->f_globals, w);
if (x == NULL) {
x = PyDict_GetItem(f->f_builtins, w);
if (x == NULL) {
printf("can't find %s\n", ((PyStringObject *)w)->ob_sval);
/* format_exc_check_arg */
break;
}
}
}
Py_INCREF(x);
PUSH(x);
break;
case LOAD_GLOBAL:
w = GETITEM(names, oparg);
if (PyString_CheckExact(w)) {
/* Inline the PyDict_GetItem() calls.
WARNING: this is an extreme speed hack.
Do not try this at home. */
long hash = ((PyStringObject *)w)->ob_shash;
if (hash != -1) {
PyDictObject *d;
d = (PyDictObject *)(f->f_globals);
x = d->ma_lookup(d, w, hash)->me_value;
if (x != NULL) {
Py_INCREF(x);
PUSH(x);
continue;
}
d = (PyDictObject *)(f->f_builtins);
x = d->ma_lookup(d, w, hash)->me_value;
if (x != NULL) {
Py_INCREF(x);
PUSH(x);
continue;
}
goto load_global_error;
}
}
/* This is the un-inlined version of the code above */
x = PyDict_GetItem(f->f_globals, w);
if (x == NULL) {
x = PyDict_GetItem(f->f_builtins, w);
if (x == NULL) {
load_global_error:
printf("LOAD_GLOBAL ERROR %s", ((PyStringObject *)w)->ob_sval);
break;
}
}
Py_INCREF(x);
PUSH(x);
break;
case LOAD_ATTR:
w = GETITEM(names, oparg);
v = TOP();
x = PyObject_GetAttr(v, w);
Py_DECREF(v);
SET_TOP(x);
if (x != NULL) continue;
break;
case IMPORT_NAME:
w = GETITEM(names, oparg);
x = PyDict_GetItemString(f->f_builtins, "__import__");
if (x == NULL) {
printf("__import__ not found");
break;
}
u = TOP();
w = Py_BuildValue("(O)", w);
Py_DECREF(u);
if (w == NULL) {
u = POP();
x = NULL;
break;
}
x = PyEval_CallObject(x, w);
Py_DECREF(w);
SET_TOP(x);
if (x != NULL) continue;
break;
case JUMP_FORWARD:
JUMPBY(oparg);
goto fast_next_opcode;
PREDICTED_WITH_ARG(JUMP_IF_FALSE);
case JUMP_IF_FALSE:
w = TOP();
if (w == Py_True) {
PREDICT(POP_TOP);
goto fast_next_opcode;
}
if (w == Py_False) {
JUMPBY(oparg);
goto fast_next_opcode;
}
err = PyObject_IsTrue(w);
if (err > 0)
err = 0;
else if (err == 0)
JUMPBY(oparg);
else
break;
continue;
case JUMP_ABSOLUTE:
JUMPTO(oparg);
continue;
case SETUP_LOOP:
PyFrame_BlockSetup(f, opcode, INSTR_OFFSET() + oparg, STACK_LEVEL());
continue;
case CALL_FUNCTION:
x = call_function(&stack_pointer, oparg);
PUSH(x);
if (x != NULL)
continue;
break;
case MAKE_FUNCTION:
v = POP(); /* code object */
x = PyFunction_New(v, f->f_globals);
Py_DECREF(v);
/* XXX Maybe this should be a separate opcode? */
if (x != NULL && oparg > 0) {
v = PyTuple_New(oparg);
if (v == NULL) {
Py_DECREF(x);
x = NULL;
break;
}
while (--oparg >= 0) {
w = POP();
PyTuple_SET_ITEM(v, oparg, w);
}
err = PyFunction_SetDefaults(x, v);
Py_DECREF(v);
}
PUSH(x);
break;
case SET_LINENO:
break;
default:
printf("opcode: %d\n", opcode);
Py_FatalError("unknown opcode");
} /* switch */
on_error:
if (why == WHY_NOT) {
if (err == 0 && x != NULL) {
continue; /* Normal, fast path */
}
why = WHY_EXCEPTION;
x = Py_None;
err = 0;
}
/* End the loop if we still have an error (or return) */
if (why != WHY_NOT)
break;
} /* main loop */
if (why != WHY_YIELD) {
/* Pop remaining stack entries -- but when yielding */
while (!EMPTY()) {
v = POP();
Py_XDECREF(v);
}
}
if (why != WHY_RETURN && why != WHY_YIELD)
retval = NULL;
/* pop frame */
--tstate->recursion_depth;
tstate->frame = f->f_back;
return retval;
}}
static PyObject *
eval_frame(PyFrameObject *f)
{
LOG("> eval_frame\n");
PyObject **stack_pointer; /* Next free slot in value stack */
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 **fastlocals, **freevars;
PyObject *retval = NULL; /* Return value */
PyThreadState *tstate = PyThreadState_GET();
PyCodeObject *co;
unsigned char *first_instr;
PyObject *names;
PyObject *consts;
/* Tuple access macros */
#define GETITEM(v, i) PyTuple_GET_ITEM((PyTupleObject *)(v), (i))
/* Code access macros */
#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))
/* OpCode prediction macros
Some opcodes tend to come in pairs thus making it possible to predict
the second code when the first is run. For example, COMPARE_OP is often
followed by JUMP_IF_FALSE or JUMP_IF_TRUE. And, those opcodes are often
followed by a POP_TOP.
Verifying the prediction costs a single high-speed test of register
variable against a constant. If the pairing was good, then the
processor has a high likelihood of making its own successful branch
prediction which results in a nearly zero overhead transition to the
next opcode.
A successful prediction saves a trip through the eval-loop including
its two unpredictable branches, the HASARG test and the switch-case.
*/
#define PREDICT(op) if (*next_instr == op) goto PRED_##op
#define PREDICTED(op) PRED_##op: next_instr++
#define PREDICTED_WITH_ARG(op) PRED_##op: oparg = (next_instr[2]<<8) + \
next_instr[1]; next_instr += 3
/* Stack manipulation macros */
#define STACK_LEVEL() (stack_pointer - f->f_valuestack)
#define EMPTY() (STACK_LEVEL() == 0)
#define TOP() (stack_pointer[-1])
#define SECOND() (stack_pointer[-2])
#define THIRD() (stack_pointer[-3])
#define FOURTH() (stack_pointer[-4])
#define SET_TOP(v) (stack_pointer[-1] = (v))
#define SET_SECOND(v) (stack_pointer[-2] = (v))
#define SET_THIRD(v) (stack_pointer[-3] = (v))
#define SET_FOURTH(v) (stack_pointer[-4] = (v))
#define BASIC_STACKADJ(n) (stack_pointer += n)
#define BASIC_PUSH(v) (*stack_pointer++ = (v))
#define BASIC_POP() (*--stack_pointer)
#define PUSH(v) BASIC_PUSH(v)
#define POP() BASIC_POP()
#define STACKADJ(n) BASIC_STACKADJ(n)
/* Local variable macros */
#define GETLOCAL(i) (fastlocals[i])
/* The SETLOCAL() macro must not DECREF the local variable in-place and
then store the new value; it must copy the old value to a temporary
value, then store the new value, and then DECREF the temporary value.
This is because it is possible that during the DECREF the frame is
accessed by other code (e.g. a __del__ method or gc.collect()) and the
variable would be pointing to already-freed memory. */
#define SETLOCAL(i, value) do { PyObject *tmp = GETLOCAL(i); \
GETLOCAL(i) = value; \
Py_XDECREF(tmp); } while (0)
/* Start of code */
if (f == NULL)
return NULL;
/* push frame */
if (++tstate->recursion_depth > recursion_limit) {
--tstate->recursion_depth;
/* ERROR */
tstate->frame = f->f_back;
return NULL;
}
tstate->frame = f;
/* tracing elided */
co = f->f_code;
names = co->co_names;
consts = co->co_consts;
fastlocals = f->f_localsplus;
freevars = f->f_localsplus + f->f_nlocals;
_PyCode_GETCODEPTR(co, &first_instr);
/* An explanation is in order for the next line.
f->f_lasti now refers to the index of the last instruction
executed. You might think this was obvious from the name, but
this wasn't always true before 2.3! PyFrame_New now sets
f->f_lasti to -1 (i.e. the index *before* the first instruction)
and YIELD_VALUE doesn't fiddle with f_lasti any more. So this
does work. Promise. */
next_instr = first_instr + f->f_lasti + 1;
stack_pointer = f->f_stacktop;
f->f_stacktop = NULL; /* remains NULL unless yield suspends frame */
why = WHY_NOT;
err = 0;
x = Py_None; /* Not a reference, just anything non-NULL */
w = NULL;
for (;;) {
/* @@@ pending calls elided */
fast_next_opcode:
f->f_lasti = INSTR_OFFSET();
/* Extract opcode and argument */
opcode = NEXTOP();
if (HAS_ARG(opcode))
oparg = NEXTARG();
/* 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 LOAD_CONST:
x = GETITEM(consts, oparg);
Py_INCREF(x);
PUSH(x);
goto fast_next_opcode;
case BINARY_ADD:
w = POP();
v = TOP();
if (PyInt_CheckExact(v) && PyInt_CheckExact(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)
goto slow_add;
x = PyInt_FromLong(i);
}
else {
slow_add:
Py_FatalError("slow add not supported.");
}
Py_DECREF(v);
Py_DECREF(w);
SET_TOP(x);
if (x != NULL) continue;
break;
case PRINT_ITEM:
v = POP();
PyObject_Print(v);
Py_DECREF(v);
break;
case PRINT_NEWLINE:
printf("\n");
break;
case RETURN_VALUE:
retval = POP();
why = WHY_RETURN;
break;
default:
Py_FatalError("unknown opcode");
} /* switch */
if (why == WHY_NOT) {
if (err == 0 && x != NULL) {
continue; /* Normal, fast path */
}
why = WHY_EXCEPTION;
x = Py_None;
err = 0;
}
/* End the loop if we still have an error (or return) */
if (why != WHY_NOT)
break;
} /* main loop */
if (why != WHY_YIELD) {
/* Pop remaining stack entries -- but when yielding */
while (!EMPTY()) {
v = POP();
Py_XDECREF(v);
}
}
if (why != WHY_RETURN && why != WHY_YIELD)
retval = NULL;
/* pop frame */
--tstate->recursion_depth;
tstate->frame = f->f_back;
return retval;
}
