Re^4: B::Xref buggy?

Thanks Dave.

I'm no expert on OP-Codes but that doesn't seem to be always the case.

On a simpler example the insides of while are parsed but the following line-number is wrong

(manually added #:markers)

D:\tmp>more tst_b_xref2.pl
use strict;
use warnings;
my $sth;

while ( my @row =$sth->fetchrow) {    #:5 intro
    print "@row";                     #:6 used
}
[download]

activating debug options

D:\tmp>perl -MO=Xref,-r,-d,-DO tst_b_xref2.pl
OP (0x163e650) enter
COP (0x10fcdd8) nextstate
OP (0x10fce38) padsv
tst_b_xref2.pl   (main)           3 (lexical)       $ sth             
+ intro
COP (0x163e698) nextstate
LOOP (0x163e740) enterloop
OP (0x16579c8) pushmark
OP (0x1657a50) pushmark
PADOP (0x1657b48) gvsv
tst_b_xref2.pl   (main)           5 main            $ "               
+ used
OP (0x1657ad0) padav
tst_b_xref2.pl   (main)           5 (lexical)       @ row             
+ used  #:used?
LISTOP (0x1657a88) join
LISTOP (0x1657a08) print
OP (0x163e870) unstack
OP (0x1657bd0) pushmark
OP (0x1657d60) pushmark
OP (0x10fcd18) padsv
tst_b_xref2.pl   (main)           5 (lexical)       $ sth             
+ used     
METHOP (0x1657d18) method_named
UNOP (0x1657cd0) entersub
tst_b_xref2.pl   (main)           5 (lexical)       $ sth             
+ subused
OP (0x1657c50) pushmark
OP (0x10fcd58) padav
tst_b_xref2.pl   (main)           5 (lexical)       @ row             
+ intro #:5?intro?
BINOP (0x1657b88) aassign
LOGOP (0x163e7e0) and
BINOP (0x163e6f8) leaveloop
LISTOP (0x10fcd90) leave
tst_b_xref2.pl syntax OK
[download]

It's worth noting that B::Concise and B::Deparse are getting the line-numbers right:

D:\tmp>perl -MO=Concise,-src tst_b_xref2.pl
n  <@> leave[1 ref] vKP/REFC ->(end)
1     <0> enter ->2
# 3: my $sth;
2     <;> nextstate(main 3 tst_b_xref2.pl:3) v:*,&,{,x*,x&,x$,$ ->3
3     <0> padsv[$sth:3,9] vM/LVINTRO ->4
# 5: while ( my @row =$sth->fetchrow) {                             #:
+line 5
4     <;> nextstate(main 4 tst_b_xref2.pl:5) v:*,&,{,x*,x&,x$,$ ->5
m     <2> leaveloop vK/2 ->n
5        <{> enterloop(next->c last->m redo->6) v ->d
-        <1> null vK/1 ->m
l           <|> and(other->6) vK/1 ->m
k              <2> aassign[t4] sKS/COM_AGG ->l
-                 <1> ex-list lK ->i
d                    <0> pushmark s ->e
h                    <1> entersub[t3] lKS/TARG,STRICT ->i
e                       <0> pushmark s ->f
f                       <0> padsv[$sth:3,9] sM ->g
g                       <.> method_named[PV "fetchrow"] l ->h
-                 <1> ex-list lK ->k
i                    <0> pushmark s ->j
j                    <0> padav[@row:5,8] lRM*/LVINTRO ->k           #:
+@row intro
-              <@> lineseq vK ->-
-                 <@> scope vK ->c
# 6:     print "@row";                                              #:
+line 6
-                    <;> ex-nextstate(main 7 tst_b_xref2.pl:6) v:*,&,x
+*,x&,x$,$ ->6
b                    <@> print vK ->c
6                       <0> pushmark s ->7
a                       <@> join[t6] sK/2 ->b
7                          <0> pushmark s ->8
-                          <1> ex-rv2sv sK/STRICT,1 ->9
8                             <#> gvsv[*"] s ->9
9                          <0> padav[@row:5,8] l ->a                #:
+@row used
c                 <0> unstack v ->d
tst_b_xref2.pl syntax OK
[download]

So probably B::Xref is better implemented by extending B::Concise ?

Cheers Rolf
_{(addicted to the Perl Programming Language :)

Wikisyntax for the Monastery
FootballPerl is like chess, only without the dice}

Comment on Re^4: B::Xref buggy? Select or Download Code

Replies are listed 'Best First'.
Re^5: B::Xref buggy? by dave_the_m (Monsignor) on Nov 15, 2018 at 15:52 UTC
I'm no expert on OP-Codes but that doesn't seem to be always the case. Nothing you've shown me contradicts what I think is the problem. So probably B::Xref is better implemented by extending B::Concise ? That doesn't really make any sense. Both are implemented on top of of B.pm, which presents an op tree as a a connected collection of perl node objects which can be interrogated by suitable perl code. Concise does minimal work, just dumping the nodes in depth-first or execution order. Xref scans the same structure but does more clever things, which involves trying to keep track of the current line number. Xref needs fixing by being smarter when scanning sub-nodes associated with nodes which have multiple execution paths. Dave.	[reply]
Re^6: B::Xref buggy? by LanX (Saint) on Nov 15, 2018 at 15:57 UTC
> That doesn't really make any sense. Let me elaborate: It's possible to apply a callback to Concise to handle the logic with B::Concise::add_callback This would make debugging much easier and more intuitive. I'll try as soon as I have closed other projects in the pipeline. Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery FootballPerl is like chess, only without the dice}	[reply]
Re^7: B::Xref buggy? by dave_the_m (Monsignor) on Nov 15, 2018 at 16:28 UTC
It's possible to apply a callback to Concise to handle the logic with B::Concise::add_callback That still doesn't make any sense. That just allows a per-node callback to affect how Concise dumps nodes. It doesn't help with scanning the op tree in the correct order to keep track of line numbers. Concise doesn't track line numbers, nor does it allow you to customise the order in which nodes are scanned. Xref has all the logic to do that, it just needs tweaking. Dave.	[reply]
Re^8: B::Xref buggy? by LanX (Saint) on Nov 15, 2018 at 16:42 UTC
Re^9: B::Xref buggy? by dave_the_m (Monsignor) on Nov 15, 2018 at 17:25 UTC
Some notes below your chosen depth have not been shown here
Re^5: B::Xref buggy? by ikegami (Patriarch) on Nov 16, 2018 at 20:12 UTC
It's worth noting that B::Concise and B::Deparse are getting the line-numbers right: uh, concise doesn't list a line number for the op in question.	[reply]
Re^6: B::Xref buggy? by LanX (Saint) on Nov 16, 2018 at 20:15 UTC
sorry? `v # 5: while ( my @row =$sth->fetchrow) { #: +line 5 4 <;> nextstate(main 4 tst_b_xref2.pl:5) v:,&,{,x,x&,x$,$ ->5 ^` [download] Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery FootballPerl is like chess, only without the dice}	[reply] [d/l]
Re^7: B::Xref buggy? by ikegami (Patriarch) on Nov 16, 2018 at 21:27 UTC
That's not the op in question. The problem is with the `padav[@row:x,x] lRM*/LVINTRO` op.	[reply] [d/l]
Re^8: B::Xref buggy? by LanX (Saint) on Nov 16, 2018 at 22:11 UTC
Re^9: B::Xref buggy? by ikegami (Patriarch) on Nov 17, 2018 at 01:28 UTC
Some notes below your chosen depth have not been shown here