diff options
Diffstat (limited to 'Python')
| -rw-r--r-- | Python/ceval.c | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/Python/ceval.c b/Python/ceval.c index 6364c3f..362cd0b 100644 --- a/Python/ceval.c +++ b/Python/ceval.c @@ -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) { |