New submission from qpatata <qpat...@gmail.com>:
Thanks a lot to all python teams for your excel.lent work.
When latest version of gdbinit macros is used to debug with gdb a python 2.4
session, the result from lineno macro seems one line more than the correct one.
If we compare the gdb macro:
define lineno
set $__continue = 1
set $__co = f->f_code
set $__lasti = f->f_lasti
set $__sz = ((PyStringObject *)$__co->co_lnotab)->ob_size/2
set $__p = (unsigned char *)((PyStringObject *)$__co->co_lnotab)->ob_sval
set $__li = $__co->co_firstlineno
set $__ad = 0
while ($__sz-1 >= 0 && $__continue)
set $__sz = $__sz - 1
set $__ad = $__ad + *$__p
set $__p = $__p + 1
if ($__ad > $__lasti)
set $__continue = 0
end
set $__li = $__li + *$__p
set $__p = $__p + 1
end
printf "%d", $__li
end
with the related C source code in libpython.py
def addr2line(self, addrq):
'''
Get the line number for a given bytecode offset
Analogous to PyCode_Addr2Line; translated from pseudocode in
Objects/lnotab_notes.txt
'''
co_lnotab = self.pyop_field('co_lnotab').proxyval(set())
# Initialize lineno to co_firstlineno as per PyCode_Addr2Line
# not 0, as lnotab_notes.txt has it:
lineno = int_from_int(self.field('co_firstlineno'))
addr = 0
for addr_incr, line_incr in zip(co_lnotab[::2], co_lnotab[1::2]):
addr += ord(addr_incr)
if addr > addrq:
return lineno
lineno += ord(line_incr)
return lineno
we see that if addr is greater than addrq, the python codes returns
immedialty, but the gdb macro adds a new delta of lines before exit the loop.
Kind regards.
----------
messages: 117133
nosy: qpatata
priority: normal
severity: normal
status: open
title: gdbinit lineno result is one line in excess
type: behavior
versions: Python 2.5
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Python tracker <rep...@bugs.python.org>
<http://bugs.python.org/issue9919>
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