This is my patch
[ 587993 ] SET_LINENO killer
Remove SET_LINENO. Tracing is now supported by inspecting co_lnotab.
Many sundry changes to document and adapt to this change.
diff --git a/Python/ceval.c b/Python/ceval.c
index 50ea9c3..6985846 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -51,6 +51,9 @@
static void call_trace_protected(Py_tracefunc, PyObject *,
PyFrameObject *, int);
static void call_exc_trace(Py_tracefunc, PyObject *, PyFrameObject *);
+static void maybe_call_line_trace(int, Py_tracefunc, PyObject *,
+ PyFrameObject *, int *, int *);
+
static PyObject *apply_slice(PyObject *, PyObject *, PyObject *);
static int assign_slice(PyObject *, PyObject *,
PyObject *, PyObject *);
@@ -499,6 +502,16 @@
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;
+
unsigned char *first_instr;
PyObject *names;
PyObject *consts;
@@ -586,7 +599,12 @@
fastlocals = f->f_localsplus;
freevars = f->f_localsplus + f->f_nlocals;
_PyCode_GETCODEPTR(co, &first_instr);
- next_instr = first_instr + f->f_lasti;
+ if (f->f_lasti < 0) {
+ next_instr = first_instr;
+ }
+ else {
+ next_instr = first_instr + f->f_lasti;
+ }
stack_pointer = f->f_stacktop;
assert(stack_pointer != NULL);
f->f_stacktop = NULL; /* remains NULL unless yield suspends frame */
@@ -637,8 +655,9 @@
w = NULL;
for (;;) {
- assert(stack_pointer >= f->f_valuestack); /* else underflow */
- assert(STACK_LEVEL() <= f->f_stacksize); /* else overflow */
+ assert(stack_pointer >= f->f_valuestack); /* else underflow */
+ assert(STACK_LEVEL() <= f->f_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
@@ -658,8 +677,8 @@
#if !defined(HAVE_SIGNAL_H) || defined(macintosh)
/* 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. */
+ have to call PyErr_CheckSignals(). On the
+ Mac and DOS, alas, we have to call it. */
if (PyErr_CheckSignals()) {
why = WHY_EXCEPTION;
goto on_error;
@@ -686,9 +705,7 @@
fast_next_opcode:
/* Extract opcode and argument */
-#if defined(Py_DEBUG) || defined(LLTRACE)
f->f_lasti = INSTR_OFFSET();
-#endif
opcode = NEXTOP();
if (HAS_ARG(opcode))
@@ -708,15 +725,26 @@
if (lltrace) {
if (HAS_ARG(opcode)) {
printf("%d: %d, %d\n",
- (int) (INSTR_OFFSET() - 3),
- opcode, oparg);
+ f->f_lasti, opcode, oparg);
}
else {
printf("%d: %d\n",
- (int) (INSTR_OFFSET() - 1), opcode);
+ f->f_lasti, opcode);
}
}
#endif
+
+ /* line-by-line tracing support */
+
+ if (tstate->c_tracefunc != NULL && !tstate->tracing) {
+ /* see maybe_call_line_trace
+ for expository comments */
+ maybe_call_line_trace(opcode,
+ tstate->c_tracefunc,
+ tstate->c_traceobj,
+ f, &instr_lb, &instr_ub);
+ }
+
/* Main switch on opcode */
switch (opcode) {
@@ -728,26 +756,6 @@
/* case STOP_CODE: this is an error! */
- case SET_LINENO:
-#ifdef LLTRACE
- if (lltrace)
- printf("--- %s:%d \n", filename, oparg);
-#endif
- f->f_lineno = oparg;
- if (tstate->c_tracefunc == NULL || tstate->tracing)
- goto fast_next_opcode;
- /* Trace each line of code reached */
- f->f_lasti = INSTR_OFFSET();
- /* Inline call_trace() for performance: */
- tstate->tracing++;
- tstate->use_tracing = 0;
- err = (tstate->c_tracefunc)(tstate->c_traceobj, f,
- PyTrace_LINE, Py_None);
- tstate->use_tracing = (tstate->c_tracefunc
- || tstate->c_profilefunc);
- tstate->tracing--;
- break;
-
case LOAD_FAST:
x = GETLOCAL(oparg);
if (x != NULL) {
@@ -1504,9 +1512,17 @@
why = WHY_RETURN;
break;
+ case RETURN_NONE:
+ retval = Py_None;
+ Py_INCREF(retval);
+ why = WHY_RETURN;
+ break;
+
case YIELD_VALUE:
retval = POP();
f->f_stacktop = stack_pointer;
+ /* abuse the lasti field: here it points to
+ the *next* instruction */
f->f_lasti = INSTR_OFFSET();
why = WHY_YIELD;
break;
@@ -1954,7 +1970,6 @@
int n = na + 2 * nk;
PyObject **pfunc = stack_pointer - n - 1;
PyObject *func = *pfunc;
- f->f_lasti = INSTR_OFFSET() - 3; /* For tracing */
/* Always dispatch PyCFunction first, because
these are presumed to be the most frequent
@@ -2022,7 +2037,6 @@
n++;
pfunc = stack_pointer - n - 1;
func = *pfunc;
- f->f_lasti = INSTR_OFFSET() - 3; /* For tracing */
if (PyMethod_Check(func)
&& PyMethod_GET_SELF(func) != NULL) {
@@ -2134,7 +2148,8 @@
default:
fprintf(stderr,
"XXX lineno: %d, opcode: %d\n",
- f->f_lineno, opcode);
+ PyCode_Addr2Line(f->f_code, f->f_lasti),
+ opcode);
PyErr_SetString(PyExc_SystemError, "unknown opcode");
why = WHY_EXCEPTION;
break;
@@ -2189,9 +2204,6 @@
/* Log traceback info if this is a real exception */
if (why == WHY_EXCEPTION) {
- f->f_lasti = INSTR_OFFSET() - 1;
- if (HAS_ARG(opcode))
- f->f_lasti -= 2;
PyTraceBack_Here(f);
if (tstate->c_tracefunc != NULL)
@@ -2875,6 +2887,125 @@
return result;
}
+static void
+maybe_call_line_trace(int opcode, Py_tracefunc func, PyObject *obj,
+ PyFrameObject *frame, int *instr_lb, int *instr_ub)
+{
+ /* The theory of SET_LINENO-less tracing.
+
+ In a nutshell, we use the co_lnotab field of the code object
+ to tell when execution has moved onto a different line.
+
+ As mentioned above, the basic idea is so set things up so
+ that
+
+ *instr_lb <= frame->f_lasti < *instr_ub
+
+ is true so long as execution does not change lines.
+
+ This is all fairly simple. Digging the information out of
+ co_lnotab takes some work, but is conceptually clear.
+
+ Somewhat harder to explain is why we don't call the line
+ trace function when executing a POP_TOP or RETURN_NONE
+ opcodes. An example probably serves best.
+
+ Consider this code:
+
+ 1: def f(a):
+ 2: if a:
+ 3: print 1
+ 4: else:
+ 5: print 2
+
+ which compiles to this:
+
+ 2 0 LOAD_FAST 0 (a)
+ 3 JUMP_IF_FALSE 9 (to 15)
+ 6 POP_TOP
+
+ 3 7 LOAD_CONST 1 (1)
+ 10 PRINT_ITEM
+ 11 PRINT_NEWLINE
+ 12 JUMP_FORWARD 6 (to 21)
+ >> 15 POP_TOP
+
+ 5 16 LOAD_CONST 2 (2)
+ 19 PRINT_ITEM
+ 20 PRINT_NEWLINE
+ >> 21 RETURN_NONE
+
+ If a is false, execution will jump to instruction at offset
+ 15 and the co_lnotab will claim that execution has moved to
+ line 3. This is at best misleading. In this case we could
+ associate the POP_TOP with line 4, but that doesn't make
+ sense in all cases (I think).
+
+ On the other hand, if a is true, execution will jump from
+ instruction offset 12 to offset 21. Then the co_lnotab would
+ imply that execution has moved to line 5, which is again
+ misleading.
+
+ This is why it is important that RETURN_NONE is *only* used
+ for the "falling off the end of the function" form of
+ returning None -- using it for code like
+
+ 1: def f():
+ 2: return
+
+ would, once again, lead to misleading tracing behaviour.
+
+ It is also worth mentioning that getting tracing behaviour
+ right is the *entire* motivation for adding the RETURN_NONE
+ opcode.
+ */
+
+ if (opcode != POP_TOP && opcode != RETURN_NONE &&
+ (frame->f_lasti < *instr_lb || frame->f_lasti > *instr_ub)) {
+ PyCodeObject* co = frame->f_code;
+ int size, addr;
+ unsigned char* p;
+
+ call_trace(func, obj, frame, PyTrace_LINE, Py_None);
+
+ size = PyString_Size(co->co_lnotab) / 2;
+ p = (unsigned char*)PyString_AsString(co->co_lnotab);
+
+ /* possible optimization: if f->f_lasti == instr_ub
+ (likely to be a common case) then we already know
+ instr_lb -- if we stored the matching value of p
+ somwhere we could skip the first while loop. */
+
+ addr = 0;
+
+ /* see comments in compile.c for the description of
+ co_lnotab. A point to remember: increments to p
+ should come in pairs -- although we don't care about
+ the line increments here, treating them as byte
+ increments gets confusing, to say the least. */
+
+ while (size >= 0) {
+ if (addr + *p > frame->f_lasti)
+ break;
+ addr += *p++;
+ p++;
+ --size;
+ }
+ *instr_lb = addr;
+ if (size > 0) {
+ while (--size >= 0) {
+ addr += *p++;
+ if (*p++)
+ break;
+ }
+ *instr_ub = addr;
+ }
+ else {
+ *instr_ub = INT_MAX;
+ }
+ }
+}
+
void
PyEval_SetProfile(Py_tracefunc func, PyObject *arg)
{
diff --git a/Python/compile.c b/Python/compile.c
index 5b4e8e6..ff8f4a5 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -407,9 +407,10 @@
/* All about c_lnotab.
-c_lnotab is an array of unsigned bytes disguised as a Python string. In -O
-mode, SET_LINENO opcodes aren't generated, and bytecode offsets are mapped
-to source code line #s (when needed for tracebacks) via c_lnotab instead.
+c_lnotab is an array of unsigned bytes disguised as a Python string. Since
+version 2.3, SET_LINENO opcodes are never generated and bytecode offsets are
+mapped to source code line #s via c_lnotab instead.
+
The array is conceptually a list of
(bytecode offset increment, line number increment)
pairs. The details are important and delicate, best illustrated by example:
@@ -830,11 +831,6 @@
com_addoparg(struct compiling *c, int op, int arg)
{
int extended_arg = arg >> 16;
- if (op == SET_LINENO) {
- com_set_lineno(c, arg);
- if (Py_OptimizeFlag)
- return;
- }
if (extended_arg){
com_addbyte(c, EXTENDED_ARG);
com_addint(c, extended_arg);
@@ -1738,7 +1734,7 @@
break;
if (ch->n_lineno != lineno) {
lineno = ch->n_lineno;
- com_addoparg(c, SET_LINENO, lineno);
+ com_set_lineno(c, lineno);
}
com_argument(c, ch, &keywords);
if (keywords == NULL)
@@ -3168,7 +3164,7 @@
continue;
}
if (i > 0)
- com_addoparg(c, SET_LINENO, ch->n_lineno);
+ com_set_lineno(c, ch->n_lineno);
com_node(c, ch);
com_addfwref(c, JUMP_IF_FALSE, &a);
com_addbyte(c, POP_TOP);
@@ -3195,7 +3191,7 @@
com_addfwref(c, SETUP_LOOP, &break_anchor);
block_push(c, SETUP_LOOP);
c->c_begin = c->c_nexti;
- com_addoparg(c, SET_LINENO, n->n_lineno);
+ com_set_lineno(c, n->n_lineno);
com_node(c, CHILD(n, 1));
com_addfwref(c, JUMP_IF_FALSE, &anchor);
com_addbyte(c, POP_TOP);
@@ -3228,7 +3224,7 @@
com_node(c, CHILD(n, 3));
com_addbyte(c, GET_ITER);
c->c_begin = c->c_nexti;
- com_addoparg(c, SET_LINENO, n->n_lineno);
+ com_set_lineno(c, n->n_lineno);
com_addfwref(c, FOR_ITER, &anchor);
com_push(c, 1);
com_assign(c, CHILD(n, 1), OP_ASSIGN, NULL);
@@ -3339,7 +3335,7 @@
}
except_anchor = 0;
com_push(c, 3); /* tb, val, exc pushed by exception */
- com_addoparg(c, SET_LINENO, ch->n_lineno);
+ com_set_lineno(c, ch->n_lineno);
if (NCH(ch) > 1) {
com_addbyte(c, DUP_TOP);
com_push(c, 1);
@@ -3401,7 +3397,7 @@
com_push(c, 3);
com_backpatch(c, finally_anchor);
ch = CHILD(n, NCH(n)-1);
- com_addoparg(c, SET_LINENO, ch->n_lineno);
+ com_set_lineno(c, ch->n_lineno);
com_node(c, ch);
com_addbyte(c, END_FINALLY);
block_pop(c, END_FINALLY);
@@ -3727,7 +3723,7 @@
case simple_stmt:
/* small_stmt (';' small_stmt)* [';'] NEWLINE */
- com_addoparg(c, SET_LINENO, n->n_lineno);
+ com_set_lineno(c, n->n_lineno);
{
int i;
for (i = 0; i < NCH(n)-1; i += 2)
@@ -3736,7 +3732,7 @@
break;
case compound_stmt:
- com_addoparg(c, SET_LINENO, n->n_lineno);
+ com_set_lineno(c, n->n_lineno);
n = CHILD(n, 0);
goto loop;
@@ -3990,10 +3986,7 @@
c->c_infunction = 1;
com_node(c, CHILD(n, 4));
c->c_infunction = 0;
- com_addoparg(c, LOAD_CONST, com_addconst(c, Py_None));
- com_push(c, 1);
- com_addbyte(c, RETURN_VALUE);
- com_pop(c, 1);
+ com_addbyte(c, RETURN_NONE);
}
static void
@@ -4050,7 +4043,7 @@
static void
compile_node(struct compiling *c, node *n)
{
- com_addoparg(c, SET_LINENO, n->n_lineno);
+ com_set_lineno(c, n->n_lineno);
switch (TYPE(n)) {
@@ -4060,19 +4053,13 @@
n = CHILD(n, 0);
if (TYPE(n) != NEWLINE)
com_node(c, n);
- com_addoparg(c, LOAD_CONST, com_addconst(c, Py_None));
- com_push(c, 1);
- com_addbyte(c, RETURN_VALUE);
- com_pop(c, 1);
+ com_addbyte(c, RETURN_NONE);
c->c_interactive--;
break;
case file_input: /* A whole file, or built-in function exec() */
com_file_input(c, n);
- com_addoparg(c, LOAD_CONST, com_addconst(c, Py_None));
- com_push(c, 1);
- com_addbyte(c, RETURN_VALUE);
- com_pop(c, 1);
+ com_addbyte(c, RETURN_NONE);
break;
case eval_input: /* Built-in function input() */
diff --git a/Python/frozen.c b/Python/frozen.c
index 069ce3c..946d626 100644
--- a/Python/frozen.c
+++ b/Python/frozen.c
@@ -13,12 +13,12 @@
static unsigned char M___hello__[] = {
99,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,
- 0,115,15,0,0,0,127,0,0,127,1,0,100,0,0,71,
- 72,100,1,0,83,40,2,0,0,0,115,14,0,0,0,72,
- 101,108,108,111,32,119,111,114,108,100,46,46,46,78,40,0,
- 0,0,0,40,0,0,0,0,40,0,0,0,0,40,0,0,
- 0,0,115,8,0,0,0,104,101,108,108,111,46,112,121,115,
- 1,0,0,0,63,1,0,0,0,115,0,0,0,0,
+ 0,115,9,0,0,0,100,0,0,71,72,100,1,0,83,40,
+ 2,0,0,0,115,14,0,0,0,72,101,108,108,111,32,119,
+ 111,114,108,100,46,46,46,78,40,0,0,0,0,40,0,0,
+ 0,0,40,0,0,0,0,40,0,0,0,0,115,8,0,0,
+ 0,104,101,108,108,111,46,112,121,115,1,0,0,0,63,1,
+ 0,0,0,115,0,0,0,0,
};
#define SIZE (int)sizeof(M___hello__)
diff --git a/Python/import.c b/Python/import.c
index 6fd05d8..36ca705 100644
--- a/Python/import.c
+++ b/Python/import.c
@@ -49,6 +49,9 @@
algorithm relying on the above scheme. Perhaps we should simply
start counting in increments of 10 from now on ?!
+ MWH, 2002-08-03: Removed SET_LINENO. Couldn't be bothered figuring
+ out the MAGIC schemes, so just incremented it by 10.
+
Known values:
Python 1.5: 20121
Python 1.5.1: 20121
@@ -60,8 +63,9 @@
Python 2.1.2: 60202
Python 2.2: 60717
Python 2.3a0: 62011
+ Python 2.3a0: 62021
*/
-#define MAGIC (62011 | ((long)'\r'<<16) | ((long)'\n'<<24))
+#define MAGIC (62021 | ((long)'\r'<<16) | ((long)'\n'<<24))
/* Magic word as global; note that _PyImport_Init() can change the
value of this global to accommodate for alterations of how the
diff --git a/Python/traceback.c b/Python/traceback.c
index de918f9..27c69b6 100644
--- a/Python/traceback.c
+++ b/Python/traceback.c
@@ -103,8 +103,7 @@
};
static tracebackobject *
-newtracebackobject(tracebackobject *next, PyFrameObject *frame, int lasti,
- int lineno)
+newtracebackobject(tracebackobject *next, PyFrameObject *frame)
{
tracebackobject *tb;
if ((next != NULL && !PyTraceBack_Check(next)) ||
@@ -118,8 +117,9 @@
tb->tb_next = next;
Py_XINCREF(frame);
tb->tb_frame = frame;
- tb->tb_lasti = lasti;
- tb->tb_lineno = lineno;
+ tb->tb_lasti = frame->f_lasti;
+ tb->tb_lineno = PyCode_Addr2Line(frame->f_code,
+ frame->f_lasti);
PyObject_GC_Track(tb);
}
return tb;
@@ -130,8 +130,7 @@
{
PyThreadState *tstate = frame->f_tstate;
tracebackobject *oldtb = (tracebackobject *) tstate->curexc_traceback;
- tracebackobject *tb = newtracebackobject(oldtb,
- frame, frame->f_lasti, frame->f_lineno);
+ tracebackobject *tb = newtracebackobject(oldtb, frame);
if (tb == NULL)
return -1;
tstate->curexc_traceback = (PyObject *)tb;