mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-08-04 00:48:58 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 8

A slight change to SET_LINENO-less tracing.

Browse source 
This makes things a touch more like 2.2.  Read the comments in
Python/ceval.c for more details.
This commit is contained in:
Michael W. Hudson 2002-09-11 15:36:32 +00:00
parent 519a342d79
commit 02ff6a9952
5 changed files with 59 additions and 12 deletions
Download patch file Download diff file Expand all files Collapse all files

23
Python/ceval.c
View file

@ -2909,7 +2909,7 @@ maybe_call_line_trace(int opcode, Py_tracefunc func, PyObject *obj,
>> 21 LOAD_CONST 0 (None)
24 RETURN_VALUE
If a is false, execution will jump to instruction at offset
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
@ -2920,21 +2920,32 @@ maybe_call_line_trace(int opcode, Py_tracefunc func, PyObject *obj,
current instruction offset matches the offset given for the
start of a line by the co_lnotab.
This also takes care of the situation where a is true.
This also takes care of the situation where '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.
Why do we set f_lineno when tracing? Well, consider the code
above when 'a' is true. If stepping through this with 'n' in
pdb, you would stop at line 1 with a "call" type event, then
line events on lines 2 and 3, then a "return" type event -- but
you would be shown line 5 during this event. This is a change
from the behaviour in 2.2 and before, and I've found it
confusing in practice. By setting and using f_lineno when
tracing, one can report a line number different from that
suggested by f_lasti on this one occasion where it's desirable.
*/
if ((frame->f_lasti < *instr_lb || frame->f_lasti >= *instr_ub)) {
PyCodeObject* co = frame->f_code;
int size, addr;
int size, addr, line;
unsigned char* p;
size = PyString_GET_SIZE(co->co_lnotab) / 2;
p = (unsigned char*)PyString_AS_STRING(co->co_lnotab);
addr = 0;
line = co->co_firstlineno;
/* possible optimization: if f->f_lasti == instr_ub
(likely to be a common case) then we already know
@ -2951,12 +2962,14 @@ maybe_call_line_trace(int opcode, Py_tracefunc func, PyObject *obj,
if (addr + *p > frame->f_lasti)
break;
addr += *p++;
p++;
line += *p++;
--size;
}
if (addr == frame->f_lasti)
if (addr == frame->f_lasti) {
frame->f_lineno = line;
call_trace(func, obj, frame,
PyTrace_LINE, Py_None);
}
*instr_lb = addr;
if (size > 0) {
while (--size >= 0) {