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/* Execute compiled code */
/* XXX TO DO:
XXX speed up searching for keywords by using a dictionary
XXX document it!
*/
/* enable more aggressive intra-module optimizations, where available */
#define PY_LOCAL_AGGRESSIVE
#include "Python.h"
#include "code.h"
#include "frameobject.h"
#include "eval.h"
#include "opcode.h"
#include "structmember.h"
#include <ctype.h>
#ifndef WITH_TSC
#define READ_TIMESTAMP(var)
#else
typedef unsigned long long uint64;
#if defined(__ppc__) /* <- Don't know if this is the correct symbol; this
section should work for GCC on any PowerPC
platform, irrespective of OS.
POWER? Who knows :-) */
#define READ_TIMESTAMP(var) ppc_getcounter(&var)
static void
ppc_getcounter(uint64 *v)
{
register unsigned long tbu, tb, tbu2;
loop:
asm volatile ("mftbu %0" : "=r" (tbu) );
asm volatile ("mftb %0" : "=r" (tb) );
asm volatile ("mftbu %0" : "=r" (tbu2));
if (__builtin_expect(tbu != tbu2, 0)) goto loop;
/* The slightly peculiar way of writing the next lines is
compiled better by GCC than any other way I tried. */
((long*)(v))[0] = tbu;
((long*)(v))[1] = tb;
}
#else /* this is for linux/x86 (and probably any other GCC/x86 combo) */
#define READ_TIMESTAMP(val) \
__asm__ __volatile__("rdtsc" : "=A" (val))
#endif
void dump_tsc(int opcode, int ticked, uint64 inst0, uint64 inst1,
uint64 loop0, uint64 loop1, uint64 intr0, uint64 intr1)
{
uint64 intr, inst, loop;
PyThreadState *tstate = PyThreadState_Get();
if (!tstate->interp->tscdump)
return;
intr = intr1 - intr0;
inst = inst1 - inst0 - intr;
loop = loop1 - loop0 - intr;
fprintf(stderr, "opcode=%03d t=%d inst=%06lld loop=%06lld\n",
opcode, ticked, inst, loop);
}
#endif
/* 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 */
#ifdef WITH_TSC
static PyObject * call_function(PyObject ***, int, uint64*, uint64*);
#else
static PyObject * call_function(PyObject ***, int);
#endif
static PyObject * fast_function(PyObject *, PyObject ***, int, int, 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 lltrace;
static int prtrace(PyObject *, char *);
#endif
static int call_trace(Py_tracefunc, PyObject *, PyFrameObject *,
int, PyObject *);
static int call_trace_protected(Py_tracefunc, PyObject *,
PyFrameObject *, int, PyObject *);
static void call_exc_trace(Py_tracefunc, PyObject *, PyFrameObject *);
static int maybe_call_line_trace(Py_tracefunc, PyObject *,
PyFrameObject *, int *, int *, int *);
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 *);
static PyObject * string_concatenate(PyObject *, PyObject *,
PyFrameObject *, unsigned char *);
static PyObject * kwd_as_string(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
/* Function call profile */
#ifdef CALL_PROFILE
#define PCALL_NUM 11
static int pcall[PCALL_NUM];
#define PCALL_ALL 0
#define PCALL_FUNCTION 1
#define PCALL_FAST_FUNCTION 2
#define PCALL_FASTER_FUNCTION 3
#define PCALL_METHOD 4
#define PCALL_BOUND_METHOD 5
#define PCALL_CFUNCTION 6
#define PCALL_TYPE 7
#define PCALL_GENERATOR 8
#define PCALL_OTHER 9
#define PCALL_POP 10
/* Notes about the statistics
PCALL_FAST stats
FAST_FUNCTION means no argument tuple needs to be created.
FASTER_FUNCTION means that the fast-path frame setup code is used.
If there is a method call where the call can be optimized by changing
the argument tuple and calling the function directly, it gets recorded
twice.
As a result, the relationship among the statistics appears to be
PCALL_ALL == PCALL_FUNCTION + PCALL_METHOD - PCALL_BOUND_METHOD +
PCALL_CFUNCTION + PCALL_TYPE + PCALL_GENERATOR + PCALL_OTHER
PCALL_FUNCTION > PCALL_FAST_FUNCTION > PCALL_FASTER_FUNCTION
PCALL_METHOD > PCALL_BOUND_METHOD
*/
#define PCALL(POS) pcall[POS]++
PyObject *
PyEval_GetCallStats(PyObject *self)
{
return Py_BuildValue("iiiiiiiiiii",
pcall[0], pcall[1], pcall[2], pcall[3],
pcall[4], pcall[5], pcall[6], pcall[7],
pcall[8], pcall[9], pcall[10]);
}
#else
#define PCALL(O)
PyObject *
PyEval_GetCallStats(PyObject *self)
{
Py_INCREF(Py_None);
return Py_None;
}
#endif
#ifdef WITH_THREAD
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#include "pythread.h"
static PyThread_type_lock interpreter_lock = 0; /* This is the GIL */
static PyThread_type_lock pending_lock = 0; /* for pending calls */
static long main_thread = 0;
int
PyEval_ThreadsInitialized(void)
{
return interpreter_lock != 0;
}
void
PyEval_InitThreads(void)
{
if (interpreter_lock)
return;
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");
/* Check someone has called PyEval_InitThreads() to create the lock */
assert(interpreter_lock);
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)
{
PyObject *threading, *result;
PyThreadState *tstate;
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();
pending_lock = PyThread_allocate_lock();
PyThread_acquire_lock(interpreter_lock, 1);
main_thread = PyThread_get_thread_ident();
/* Update the threading module with the new state.
*/
tstate = PyThreadState_GET();
threading = PyMapping_GetItemString(tstate->interp->modules,
"threading");
if (threading == NULL) {
/* threading not imported */
PyErr_Clear();
return;
}
result = PyObject_CallMethod(threading, "_after_fork", NULL);
if (result == NULL)
PyErr_WriteUnraisable(threading);
else
Py_DECREF(result);
Py_DECREF(threading);
}
#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.
There is no facility to schedule calls to a particular thread, but
that should be easy to change, should that ever be required. In
that case, the static variables here should go into the python
threadstate.
#endif
*/
#ifdef WITH_THREAD
/* The WITH_THREAD implementation is thread-safe. It allows
scheduling to be made from any thread, and even from an executing
callback.
*/
#define NPENDINGCALLS 32
static struct {
int (*func)(void *);
void *arg;
} pendingcalls[NPENDINGCALLS];
static int pendingfirst = 0;
static int pendinglast = 0;
static volatile int pendingcalls_to_do = 1; /* trigger initialization of lock */
static char pendingbusy = 0;
int
Py_AddPendingCall(int (*func)(void *), void *arg)
{
int i, j, result=0;
PyThread_type_lock lock = pending_lock;
/* try a few times for the lock. Since this mechanism is used
* for signal handling (on the main thread), there is a (slim)
* chance that a signal is delivered on the same thread while we
* hold the lock during the Py_MakePendingCalls() function.
* This avoids a deadlock in that case.
* Note that signals can be delivered on any thread. In particular,
* on Windows, a SIGINT is delivered on a system-created worker
* thread.
* We also check for lock being NULL, in the unlikely case that
* this function is called before any bytecode evaluation takes place.
*/
if (lock != NULL) {
for (i = 0; i<100; i++) {
if (PyThread_acquire_lock(lock, NOWAIT_LOCK))
break;
}
if (i == 100)
return -1;
}
i = pendinglast;
j = (i + 1) % NPENDINGCALLS;
if (j == pendingfirst) {
result = -1; /* Queue full */
} else {
pendingcalls[i].func = func;
pendingcalls[i].arg = arg;
pendinglast = j;
}
/* signal main loop */
_Py_Ticker = 0;
pendingcalls_to_do = 1;
if (lock != NULL)
PyThread_release_lock(lock);
return result;
}
int
Py_MakePendingCalls(void)
{
int i;
int r = 0;
if (!pending_lock) {
/* initial allocation of the lock */
pending_lock = PyThread_allocate_lock();
if (pending_lock == NULL)
return -1;
}
/* only service pending calls on main thread */
if (main_thread && PyThread_get_thread_ident() != main_thread)
return 0;
/* don't perform recursive pending calls */
if (pendingbusy)
return 0;
pendingbusy = 1;
/* perform a bounded number of calls, in case of recursion */
for (i=0; i<NPENDINGCALLS; i++) {
int j;
int (*func)(void *);
void *arg = NULL;
/* pop one item off the queue while holding the lock */
PyThread_acquire_lock(pending_lock, WAIT_LOCK);
j = pendingfirst;
if (j == pendinglast) {
func = NULL; /* Queue empty */
} else {
func = pendingcalls[j].func;
arg = pendingcalls[j].arg;
pendingfirst = (j + 1) % NPENDINGCALLS;
}
pendingcalls_to_do = pendingfirst != pendinglast;
PyThread_release_lock(pending_lock);
/* having released the lock, perform the callback */
if (func == NULL)
break;
r = func(arg);
if (r)
break;
}
pendingbusy = 0;
return r;
}
#else /* if ! defined WITH_THREAD */
/*
WARNING! ASYNCHRONOUSLY EXECUTING CODE!
This code is used for signal handling in python that isn't built
with WITH_THREAD.
Don't use this implementation when Py_AddPendingCalls() can happen
on a different thread!
There are two possible race conditions:
(1) nested asynchronous calls to Py_AddPendingCall()
(2) AddPendingCall() calls made while pending calls are being processed.
(1) is very unlikely because typically signal delivery
is blocked during signal handling. So it should be impossible.
(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 is present, interrupted by signals, and that the critical
section is protected with the "busy" variable. On Windows, which
delivers SIGINT on a system thread, this does not hold and therefore
Windows really shouldn't use this version.
The two threads could theoretically wiggle around the "busy" variable.
*/
#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 pendingcalls_to_do = 0;
int
Py_AddPendingCall(int (*func)(void *), void *arg)
{
static volatile int busy = 0;
int i, j;
/* XXX Begin critical section */
if (busy)
return -1;
busy = 1;
i = pendinglast;
j = (i + 1) % NPENDINGCALLS;
if (j == pendingfirst) {
busy = 0;
return -1; /* Queue full */
}
pendingcalls[i].func = func;
pendingcalls[i].arg = arg;
pendinglast = j;
_Py_Ticker = 0;
pendingcalls_to_do = 1; /* Signal main loop */
busy = 0;
/* XXX End critical section */
return 0;
}
int
Py_MakePendingCalls(void)
{
static int busy = 0;
if (busy)
return 0;
busy = 1;
pendingcalls_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;
pendingcalls_to_do = 1; /* We're not done yet */
return -1;
}
}
busy = 0;
return 0;
}
#endif /* WITH_THREAD */
/* The interpreter's recursion limit */
#ifndef Py_DEFAULT_RECURSION_LIMIT
#define Py_DEFAULT_RECURSION_LIMIT 1000
#endif
static int recursion_limit = Py_DEFAULT_RECURSION_LIMIT;
int _Py_CheckRecursionLimit = Py_DEFAULT_RECURSION_LIMIT;
int
Py_GetRecursionLimit(void)
{
return recursion_limit;
}
void
Py_SetRecursionLimit(int new_limit)
{
recursion_limit = new_limit;
_Py_CheckRecursionLimit = recursion_limit;
}
/* the macro Py_EnterRecursiveCall() only calls _Py_CheckRecursiveCall()
if the recursion_depth reaches _Py_CheckRecursionLimit.
If USE_STACKCHECK, the macro decrements _Py_CheckRecursionLimit
to guarantee that _Py_CheckRecursiveCall() is regularly called.
Without USE_STACKCHECK, there is no need for this. */
int
_Py_CheckRecursiveCall(char *where)
{
PyThreadState *tstate = PyThreadState_GET();
#ifdef USE_STACKCHECK
if (PyOS_CheckStack()) {
--tstate->recursion_depth;
PyErr_SetString(PyExc_MemoryError, "Stack overflow");
return -1;
}
#endif
if (tstate->recursion_depth > recursion_limit) {
--tstate->recursion_depth;
PyErr_Format(PyExc_RuntimeError,
"maximum recursion depth exceeded%s",
where);
return -1;
}
_Py_CheckRecursionLimit = recursion_limit;
return 0;
}
/* Status code for main loop (reason for stack unwind) */
enum why_code {
WHY_NOT = 0x0001, /* No error */
WHY_EXCEPTION = 0x0002, /* Exception occurred */
WHY_RERAISE = 0x0004, /* Exception re-raised by 'finally' */
WHY_RETURN = 0x0008, /* 'return' statement */
WHY_BREAK = 0x0010, /* 'break' statement */
WHY_CONTINUE = 0x0020, /* 'continue' statement */
WHY_YIELD = 0x0040 /* 'yield' operator */
};
static enum why_code do_raise(PyObject *, PyObject *, PyObject *);
static int unpack_iterable(PyObject *, int, PyObject **);
/* Records whether tracing is on for any thread. Counts the number of
threads for which tstate->c_tracefunc is non-NULL, so if the value
is 0, we know we don't have to check this thread's c_tracefunc.
This speeds up the if statement in PyEval_EvalFrameEx() after
fast_next_opcode*/
static int _Py_TracingPossible = 0;
/* for manipulating the thread switch and periodic "stuff" - used to be
per thread, now just a pair o' globals */
int _Py_CheckInterval = 100;
volatile int _Py_Ticker = 0; /* so that we hit a "tick" first thing */
PyObject *
PyEval_EvalCode(PyCodeObject *co, PyObject *globals, PyObject *locals)
{
return PyEval_EvalCodeEx(co,
globals, locals,
(PyObject **)NULL, 0,
(PyObject **)NULL, 0,
(PyObject **)NULL, 0,
NULL);
}
/* Interpreter main loop */
PyObject *
PyEval_EvalFrame(PyFrameObject *f) {
/* This is for backward compatibility with extension modules that
used this API; core interpreter code should call
PyEval_EvalFrameEx() */
return PyEval_EvalFrameEx(f, 0);
}
PyObject *
PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
{
#ifdef DXPAIRS
int lastopcode = 0;
#endif
register PyObject **stack_pointer; /* Next free slot in value stack */
register unsigned char *next_instr;
register int opcode; /* Current opcode */
register int oparg; /* 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;
/* when tracing we set things up so that
not (instr_lb <= current_bytecode_offset < instr_ub)
is true when the line being executed has changed. The
initial values are such as to make this false the first
time it is tested. */
int instr_ub = -1, instr_lb = 0, instr_prev = -1;
unsigned char *first_instr;
PyObject *names;
PyObject *consts;
#if defined(Py_DEBUG) || defined(LLTRACE)
/* Make it easier to find out where we are with a debugger */
char *filename;
#endif
/* Tuple access macros */
#ifndef Py_DEBUG
#define GETITEM(v, i) PyTuple_GET_ITEM((PyTupleObject *)(v), (i))
#else
#define GETITEM(v, i) PyTuple_GetItem((v), (i))
#endif
#ifdef WITH_TSC
/* Use Pentium timestamp counter to mark certain events:
inst0 -- beginning of switch statement for opcode dispatch
inst1 -- end of switch statement (may be skipped)
loop0 -- the top of the mainloop
loop1 -- place where control returns again to top of mainloop
(may be skipped)
intr1 -- beginning of long interruption
intr2 -- end of long interruption
Many opcodes call out to helper C functions. In some cases, the
time in those functions should be counted towards the time for the
opcode, but not in all cases. For example, a CALL_FUNCTION opcode
calls another Python function; there's no point in charge all the
bytecode executed by the called function to the caller.
It's hard to make a useful judgement statically. In the presence
of operator overloading, it's impossible to tell if a call will
execute new Python code or not.
It's a case-by-case judgement. I'll use intr1 for the following
cases:
EXEC_STMT
IMPORT_STAR
IMPORT_FROM
CALL_FUNCTION (and friends)
*/
uint64 inst0, inst1, loop0, loop1, intr0 = 0, intr1 = 0;
int ticked = 0;
READ_TIMESTAMP(inst0);
READ_TIMESTAMP(inst1);
READ_TIMESTAMP(loop0);
READ_TIMESTAMP(loop1);
/* shut up the compiler */
opcode = 0;
#endif
/* Code access macros */
#define INSTR_OFFSET() ((int)(next_instr - first_instr))
#define NEXTOP() (*next_instr++)
#define NEXTARG() (next_instr += 2, (next_instr[-1]<<8) + next_instr[-2])
#define PEEKARG() ((next_instr[2]<<8) + next_instr[1])
#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 a register
variable against a constant. If the pairing was good, then the
processor's own internal branch predication has a high likelihood of
success, resulting 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 HAS_ARG test and the
switch-case. Combined with the processor's internal branch prediction,
a successful PREDICT has the effect of making the two opcodes run as if
they were a single new opcode with the bodies combined.
If collecting opcode statistics, your choices are to either keep the
predictions turned-on and interpret the results as if some opcodes
had been combined or turn-off predictions so that the opcode frequency
counter updates for both opcodes.
*/
#ifdef DYNAMIC_EXECUTION_PROFILE
#define PREDICT(op) if (0) goto PRED_##op
#else
#define PREDICT(op) if (*next_instr == op) goto PRED_##op
#endif
#define PREDICTED(op) PRED_##op: next_instr++
#define PREDICTED_WITH_ARG(op) PRED_##op: oparg = PEEKARG(); next_instr += 3
/* Stack manipulation macros */
/* The stack can grow at most MAXINT deep, as co_nlocals and
co_stacksize are ints. */
#define STACK_LEVEL() ((int)(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)
#ifdef LLTRACE
#define PUSH(v) { (void)(BASIC_PUSH(v), \
lltrace && prtrace(TOP(), "push")); \
assert(STACK_LEVEL() <= co->co_stacksize); }
#define POP() ((void)(lltrace && prtrace(TOP(), "pop")), \
BASIC_POP())
#define STACKADJ(n) { (void)(BASIC_STACKADJ(n), \
lltrace && prtrace(TOP(), "stackadj")); \
assert(STACK_LEVEL() <= co->co_stacksize); }
#define EXT_POP(STACK_POINTER) ((void)(lltrace && \
prtrace((STACK_POINTER)[-1], "ext_pop")), \
*--(STACK_POINTER))
#else
#define PUSH(v) BASIC_PUSH(v)
#define POP() BASIC_POP()
#define STACKADJ(n) BASIC_STACKADJ(n)
#define EXT_POP(STACK_POINTER) (*--(STACK_POINTER))
#endif
/* 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 (Py_EnterRecursiveCall(""))
return NULL;
tstate->frame = f;
if (tstate->use_tracing) {
if (tstate->c_tracefunc != NULL) {
/* tstate->c_tracefunc, 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 is also called
whenever an exception is detected. */
if (call_trace_protected(tstate->c_tracefunc,
tstate->c_traceobj,
f, PyTrace_CALL, Py_None)) {
/* Trace function raised an error */
goto exit_eval_frame;
}
}
if (tstate->c_profilefunc != NULL) {
/* Similar for c_profilefunc, except it needn't
return itself and isn't called for "line" events */
if (call_trace_protected(tstate->c_profilefunc,
tstate->c_profileobj,
f, PyTrace_CALL, Py_None)) {
/* Profile function raised an error */
goto exit_eval_frame;
}
}
}
co = f->f_code;
names = co->co_names;
consts = co->co_consts;
fastlocals = f->f_localsplus;
freevars = f->f_localsplus + co->co_nlocals;
first_instr = (unsigned char*) PyString_AS_STRING(co->co_code);
/* 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.
When the PREDICT() macros are enabled, some opcode pairs follow in
direct succession without updating f->f_lasti. A successful
prediction effectively links the two codes together as if they
were a single new opcode; accordingly,f->f_lasti will point to
the first code in the pair (for instance, GET_ITER followed by
FOR_ITER is effectively a single opcode and f->f_lasti will point
at to the beginning of the combined pair.)
*/
next_instr = first_instr + f->f_lasti + 1;
stack_pointer = f->f_stacktop;
assert(stack_pointer != NULL);
f->f_stacktop = NULL; /* remains NULL unless yield suspends frame */
#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;
if (throwflag) { /* support for generator.throw() */
why = WHY_EXCEPTION;
goto on_error;
}
for (;;) {
#ifdef WITH_TSC
if (inst1 == 0) {
/* Almost surely, the opcode executed a break
or a continue, preventing inst1 from being set
on the way out of the loop.
*/
READ_TIMESTAMP(inst1);
loop1 = inst1;
}
dump_tsc(opcode, ticked, inst0, inst1, loop0, loop1,
intr0, intr1);
ticked = 0;
inst1 = 0;
intr0 = 0;
intr1 = 0;
READ_TIMESTAMP(loop0);
#endif
assert(stack_pointer >= f->f_valuestack); /* else underflow */
assert(STACK_LEVEL() <= co->co_stacksize); /* else overflow */
/* 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
``pendingcalls_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) {
if (*next_instr == SETUP_FINALLY) {
/* Make the last opcode before
a try: finally: block uninterruptable. */
goto fast_next_opcode;
}
_Py_Ticker = _Py_CheckInterval;
tstate->tick_counter++;
#ifdef WITH_TSC
ticked = 1;
#endif
if (pendingcalls_to_do) {
if (Py_MakePendingCalls() < 0) {
why = WHY_EXCEPTION;
goto on_error;
}
if (pendingcalls_to_do)
/* MakePendingCalls() didn't succeed.
Force early re-execution of this
"periodic" code, possibly after
a thread switch */
_Py_Ticker = 0;
}
#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");