User trace feature.
diff --git a/Python/ceval.c b/Python/ceval.c
index 1d0cdb4..129d743 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -36,7 +36,9 @@
#include "traceback.h"
#ifndef NDEBUG
-#define TRACE
+/* For debugging the interpreter: */
+#define LLTRACE 1 /* Low-level trace feature */
+#define CHECKEXC 1 /* Double-check exception checking */
#endif
/* Forward declarations */
@@ -69,6 +71,7 @@
static int assign_subscript PROTO((object *, object *, object *));
static int assign_slice PROTO((object *, object *, object *, object *));
static int import_from PROTO((object *, object *, object *));
+static object *call_trace PROTO((object *, frameobject *, char *, object *));
static frameobject *current_frame;
@@ -106,12 +109,12 @@
register object *u;
register object *t;
register frameobject *f; /* Current frame */
- int lineno; /* Current line number */
+ object *trace; /* Trace function or NULL */
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;
+#ifdef LLTRACE
+ int lltrace = dictlookup(globals, "__lltrace__") != NULL;
#endif
/* Code access macros */
@@ -134,9 +137,9 @@
#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())
+#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()
@@ -153,9 +156,37 @@
return NULL;
current_frame = f;
+
+ trace = sysget("trace");
+ if (trace != 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. */
+ trace = call_trace(trace, f, "call", arg);
+ if (trace == NULL) {
+ /* Trace function raised an error */
+ sysset("trace", (object *)NULL);
+ current_frame = f->f_back;
+ DECREF(f);
+ return NULL;
+ }
+ if (trace == None) {
+ /* No need to trace this code block */
+ DECREF(trace);
+ trace = NULL;
+ }
+ }
next_instr = GETUSTRINGVALUE(f->f_code->co_code);
-
stack_pointer = f->f_valuestack;
if (arg != NULL) {
@@ -166,7 +197,6 @@
why = WHY_NOT;
err = 0;
x = None; /* Not a reference, just anything non-NULL */
- lineno = -1;
for (;;) {
static int ticker;
@@ -178,7 +208,6 @@
if (intrcheck()) {
err_set(KeyboardInterrupt);
why = WHY_EXCEPTION;
- tb_here(f, INSTR_OFFSET(), lineno);
goto on_error;
}
}
@@ -189,10 +218,10 @@
if (HAS_ARG(opcode))
oparg = NEXTARG();
-#ifdef TRACE
+#ifdef LLTRACE
/* Instruction tracing */
- if (trace) {
+ if (lltrace) {
if (HAS_ARG(opcode)) {
printf("%d: %d, %d\n",
(int) (INSTR_OFFSET() - 3),
@@ -273,6 +302,7 @@
case UNARY_CALL:
v = POP();
+ f->f_lasti = INSTR_OFFSET() - 1; /* For tracing */
x = call_object(v, (object *)NULL);
DECREF(v);
PUSH(x);
@@ -342,6 +372,7 @@
case BINARY_CALL:
w = POP();
v = POP();
+ f->f_lasti = INSTR_OFFSET() - 1; /* For tracing */
x = call_object(v, w);
DECREF(v);
DECREF(w);
@@ -921,17 +952,31 @@
break;
case SET_LINENO:
-#ifdef TRACE
- if (trace)
+#ifdef LLTRACE
+ if (lltrace)
printf("--- Line %d ---\n", oparg);
#endif
- lineno = oparg;
+ f->f_lineno = oparg;
+ if (trace != NULL) {
+ /* Trace each line of code reached */
+ f->f_lasti = INSTR_OFFSET();
+ x = call_trace(trace, f, "line", None);
+ /* The trace function must return itself
+ in order to continue tracing */
+ DECREF(trace);
+ if (x == None) {
+ DECREF(x);
+ trace = NULL;
+ }
+ else
+ trace = x;
+ }
break;
default:
fprintf(stderr,
"XXX lineno: %d, opcode: %d\n",
- lineno, opcode);
+ f->f_lineno, opcode);
err_setstr(SystemError, "eval_code: unknown opcode");
why = WHY_EXCEPTION;
break;
@@ -950,7 +995,7 @@
err = 0;
}
-#ifndef NDEBUG
+#ifndef CHECKEXC
/* Double-check exception status */
if (why == WHY_EXCEPTION || why == WHY_RERAISE) {
@@ -971,10 +1016,49 @@
/* Log traceback info if this is a real exception */
if (why == WHY_EXCEPTION) {
- int lasti = INSTR_OFFSET() - 1;
+ f->f_lasti = INSTR_OFFSET() - 1;
if (HAS_ARG(opcode))
- lasti -= 2;
- tb_here(f, lasti, lineno);
+ f->f_lasti -= 2;
+ tb_here(f);
+
+ if (trace)
+ v = trace;
+ else
+ v = sysget("trace");
+ if (v) {
+ object *type, *value, *traceback, *arg;
+ err_get(&type, &value);
+ traceback = tb_fetch();
+ arg = newtupleobject(3);
+ if (arg == NULL)
+ err_clear();
+ else {
+ settupleitem(arg, 0, type);
+ settupleitem(arg, 1, value);
+ settupleitem(arg, 2, traceback);
+ }
+ v = call_trace(v, f, "exception", arg);
+ if (v == NULL) {
+ /* Trace function raised error */
+ tb_here(f);
+ sysset("trace", (object *)NULL);
+ XDECREF(trace);
+ trace = NULL;
+ }
+ else {
+ /* Restore original exception */
+ err_setval(type, value);
+ tb_store(traceback);
+ if (v == None)
+ DECREF(v);
+ else {
+ /* Set trace function */
+ XDECREF(trace);
+ trace = v;
+ }
+ }
+ XDECREF(arg);
+ }
}
/* For the rest, treat WHY_RERAISE as WHY_EXCEPTION */
@@ -1012,9 +1096,7 @@
Python main loop. Don't do
this for 'finally'. */
if (b->b_type == SETUP_EXCEPT) {
-#if 1 /* Oops, this breaks too many things */
sysset("exc_traceback", v);
-#endif
sysset("exc_value", val);
sysset("exc_type", exc);
err_clear();
@@ -1049,18 +1131,31 @@
XDECREF(v);
}
+ if (why != WHY_RETURN)
+ retval = NULL;
+
+ if (trace) {
+ if (why == WHY_RETURN) {
+ x = call_trace(trace, f, "return", retval);
+ if (x == NULL) {
+ XDECREF(retval);
+ retval = NULL;
+ }
+ else
+ DECREF(x);
+ }
+ DECREF(trace);
+ }
+
/* Restore previous frame and release the current one */
current_frame = f->f_back;
DECREF(f);
- if (why == WHY_RETURN)
- return retval;
- else
- return NULL;
+ return retval;
}
-#ifdef TRACE
+#ifdef LLTRACE
static int
prtrace(v, str)
object *v;
@@ -1073,6 +1168,46 @@
}
#endif
+static object *
+call_trace(trace, f, msg, arg)
+ object *trace;
+ frameobject *f;
+ char *msg;
+ object *arg;
+{
+ object *arglist, *what, *res;
+ static int tracing = 0;
+
+ if (tracing) {
+ /* Don't trace the trace code! */
+ INCREF(None);
+ return None;
+ }
+
+ arglist = newtupleobject(3);
+ if (arglist == NULL)
+ return NULL;
+ what = newstringobject(msg);
+ if (what == NULL) {
+ DECREF(arglist);
+ return NULL;
+ }
+ INCREF(f);
+ if (arg == NULL)
+ arg = None;
+ INCREF(arg);
+ settupleitem(arglist, 0, (object *)f);
+ settupleitem(arglist, 1, what);
+ settupleitem(arglist, 2, arg);
+ tracing++;
+ res = call_object(trace, arglist);
+ tracing--;
+ if (res == NULL)
+ tb_here(f);
+ DECREF(arglist);
+ return res;
+}
+
object *
getlocals()
{
