[Tim, in an earlier msg]
Would be more valuable to rethink the debugger's breakpoint approach so that SET_LINENO is never needed (line-triggered callbacks are expensive because called so frequently, turning each dynamic SET_LINENO into a full-blown Python call;
Ok. In the meantime I think that folding the redundant SET_LINENO doesn't hurt. I ended up with a patchlet that seems to have no side effects, that updates the lnotab as it should and that even makes pdb a bit more clever, IMHO. Consider an extreme case for the function f (listed below). Currently, we get the following: -------------------------------------------
from test import f import dis, pdb dis.dis(f) 0 SET_LINENO 1
3 SET_LINENO 2 6 SET_LINENO 3 9 SET_LINENO 4 12 SET_LINENO 5 15 LOAD_CONST 1 (1) 18 STORE_FAST 0 (a) 21 SET_LINENO 6 24 SET_LINENO 7 27 SET_LINENO 8 30 LOAD_CONST 2 (None) 33 RETURN_VALUE
pdb.runcall(f) test.py(1)f() -> def f(): (Pdb) list 1, 20 1 -> def f(): 2 """Comment about f""" 3 """Another one""" 4 """A third one""" 5 a = 1 6 """Forth""" 7 "and pdb can set a breakpoint on this one (simple quotes)" 8 """but it's intelligent about triple quotes...""" [EOF] (Pdb) step test.py(2)f() -> """Comment about f""" (Pdb) step test.py(3)f() -> """Another one""" (Pdb) step test.py(4)f() -> """A third one""" (Pdb) step test.py(5)f() -> a = 1 (Pdb) step test.py(6)f() -> """Forth""" (Pdb) step test.py(7)f() -> "and pdb can set a breakpoint on this one (simple quotes)" (Pdb) step test.py(8)f() -> """but it's intelligent about triple quotes...""" (Pdb) step --Return-- test.py(8)f()->None -> """but it's intelligent about triple quotes...""" (Pdb)
With folded SET_LINENO, we have this: -------------------------------------------
from test import f import dis, pdb dis.dis(f) 0 SET_LINENO 5 3 LOAD_CONST 1 (1) 6 STORE_FAST 0 (a)
9 SET_LINENO 8 12 LOAD_CONST 2 (None) 15 RETURN_VALUE
pdb.runcall(f) test.py(5)f() -> a = 1 (Pdb) list 1, 20 1 def f(): 2 """Comment about f""" 3 """Another one""" 4 """A third one""" 5 -> a = 1 6 """Forth""" 7 "and pdb can set a breakpoint on this one (simple quotes)" 8 """but it's intelligent about triple quotes...""" [EOF] (Pdb) break 7 Breakpoint 1 at test.py:7 (Pdb) break 8 *** Blank or comment (Pdb) step test.py(8)f() -> """but it's intelligent about triple quotes...""" (Pdb) step --Return-- test.py(8)f()->None -> """but it's intelligent about triple quotes...""" (Pdb)
i.e, pdb stops at (points to) the first real instruction and doesn't step trough the doc strings. Or is there something I'm missing here? -- Vladimir MARANGOZOV | Vladimir.Marangozov@inrialpes.fr http://sirac.inrialpes.fr/~marangoz | tel:(+33-4)76615277 fax:76615252 -------------------------------[ cut here ]--------------------------- *** compile.c-orig Thu Aug 19 19:27:13 1999 --- compile.c Thu Aug 19 19:00:31 1999 *************** *** 615,620 **** --- 615,623 ---- int arg; { if (op == SET_LINENO) { + if (!Py_OptimizeFlag && c->c_last_addr == c->c_nexti - 3) + /* Hack for folding several SET_LINENO in a row. */ + c->c_nexti -= 3; com_set_lineno(c, arg); if (Py_OptimizeFlag) return;