[Python-bugs-list] [ python-Bugs-607092 ] wrong SET_LINENO w/ multi-line func args

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Bugs item #607092, was opened at 2002-09-10 02:18
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https://sourceforge.net/tracker/?func=detail&atid=105470&aid=607092&group_id=5470

Category: Parser/Compiler
Group: Python 2.2.1
Status: Open
Resolution: None
Priority: 5
Submitted By: Inyeol Lee (inyeol)
Assigned to: Michael Hudson (mwh)
Summary: wrong SET_LINENO w/ multi-line func args

Initial Comment:
Python 2.2.1 (#1, Apr 10 2002, 18:25:16) 
[GCC 2.95.3 20010315 (release)] on sunos5
Type "help", "copyright", "credits" or "license" for
more information.
>>> import dis
>>> def f():  # line 1
...   a = [1, # line 2
...     2]
...   b = (1, # line 4
...     2)
...   c(1,    # line 6
...     2)
... 
>>> dis.dis(f)
          0 SET_LINENO               1

          3 SET_LINENO               2
          6 LOAD_CONST               1 (1)
          9 LOAD_CONST               2 (2)
         12 BUILD_LIST               2
         15 STORE_FAST               0 (a)

         18 SET_LINENO               4
         21 LOAD_CONST               1 (1)
         24 LOAD_CONST               2 (2)
         27 BUILD_TUPLE              2
         30 STORE_FAST               1 (b)

         33 SET_LINENO               6
         36 LOAD_GLOBAL              2 (c)
         39 LOAD_CONST               1 (1)

         42 SET_LINENO               7              
<-- Error, should not be here.
         45 LOAD_CONST               2 (2)
         48 CALL_FUNCTION            2
         51 POP_TOP             
         52 LOAD_CONST               0 (None)
         55 RETURN_VALUE        
>>> 

python 2.2.1 generates errornous SET_LINENO instruction
when
function arguments tuple is separated by physical, not
logical newline.
This results in errornous frame.f_lineno.

-Inyeol Lee


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>Comment By: Inyeol Lee (inyeol)
Date: 2002-09-10 18:00

Message:
Logged In: YES 
user_id=595280

I'm making a debugging util which parses current source
line to get argument names. For easy parsing I need the 
starting lineno of current statement (line 1 in your example),
not the phyical lineno of current instruction (line 2). I tested
several multi-line statements with (),{},[],quotes, ... and
they all sets f_lineno as their first line, which the statement
starts, and do not reset/update f_lineno with following
physical line break. The only (as far as I tested ;-) exception
is this fucntion args tuple. For example;

a = """ # line 1
  foo
  """; b = [f(),
  g()]

Above statement sets f_lineno to 1 and use it thruout the
whole statement even though the actual call to f and g
occurs at line 3 and 4.

Even withe function args tuple, it is strange.
f(  #line1
a,b)
generates one 'SET_LINENO 1' and doesn't update it, but
f(a,  #line1
b)
generates both 'SET_LINENO 1', 'SET_LINENO 2', and 
changes f_lineno with the soft newline. I hope it fixed.
Otherwise, I should scan both ways from current f_lineno
to get a statement.

-Inyeol Lee

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Comment By: Michael Hudson (mwh)
Date: 2002-09-10 13:07

Message:
Logged In: YES 
user_id=6656

Why is this a problem?

Execution isn't really on line 6 there.  Think about code like:

f()(1,  # line 1
 c())   # line 2

when "c()" is being evaluated, surely frame.f_lineno should
be 2?  do you think it should go back to 1 when the function
f() returns is called?

----------------------------------------------------------------------

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