But Xref is ignoring the whole part inside while (...) and the linenumber is present, I used B::Concise to check.

Looking at the src code for B::Xref, it appears to scan the op tree in execution (op_next) order, noting the current line and file number any time it sees an OP_NEXTSTATE. When it comes to an op that has more than one possible next op (such as loops etc) it recursively follows each branch, without restoring the old file/line number on each return. Thus giving silly results.

Dave.

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}