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in reply to Re^9: B::Xref buggy?
in thread B::Xref buggy?

Thanks, Dave.

I was aware that OPs do kind of gotos to next-OPs (the ->label at the end of each line).

But it didn't seem logical that the -src option could be offered if B::Concise wasn't respecting the order.*

The solution is that the source lines they are not in order, but the line numbers are still reliable:

D:\tmp>type tst_b_xref3.pl
unless ($var1) {
    $var2++;
}
else {
    $var3++;
}

[download]
(Win Activestate 5.24) 
D:\tmp>perl -MO=Concise,-src tst_b_xref3.pl|find "var"
tst_b_xref3.pl syntax OK
# 1: unless ($var1) {
3              <#> gvsv[*var1] s ->4
# 5:     $var3++;
7                    <#> gvsv[*var3] s ->8
# 2:     $var2++;
d                    <#> gvsv[*var2] s ->e

[download]

So strictly speaking it's still possible to use B::Concise to emulate B::Xref on line number level.

Cheers Rolf
(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery FootballPerl is like chess, only without the dice

*) Interestingly this also depends on the Perl version. Here the vars appear in order: (Ubuntu 5.18)

$ perl -MO=Concise,-src tst_b_xref3.pl|grep var
tst_b_xref3.pl syntax OK
# 1: unless ($var1) {
3                 <#> gvsv[*var1] s ->4
# 2:     $var2++;
8                    <#> gvsv[*var2] s ->9
# 5:     $var3++;
e                    <#> gvsv[*var3] s ->f

[download]

update

and that's the reason why, 5.24 is optimizing the negation away by swapping the branches: 

D:\tmp>perl -MO=Deparse tst_b_xref3.pl
tst_b_xref3.pl syntax OK
if ($var1) {
    ++$var3;
}
else {
    ++$var2;
}

[download]

Replies are listed 'Best First'.
Re^11: B::Xref buggy?
by dave_the_m (Monsignor) on Nov 15, 2018 at 20:15 UTC
    The solution is that the source lines they are not in order, but the line numbers are still reliable:
    (Cough) 
    $ cat /tmp/p
for (
    $var1++;
    $var2++;
    $var3++
) {
    $var4++;
}


$ perl -MO=Concise,-src /tmp/p | grep var
/tmp/p syntax OK
3           <#> gvsv[*var1] s ->4
f                    <#> gvsv[*var2] s ->g
# 6:     $var4++;
9                          <#> gvsv[*var4] s ->a
c                       <#> gvsv[*var3] s ->d

    [download]

    Dave.

[reply]
[d/l]
      well the information is still available, var3 belongs to the tree below the first nextstate

      $ perl -MO=Concise,-src tst_b_xref4.pl|perl -pe 'substr $_, -1, 0, " "
+x(68-length$_) . "  #:$1" if /(^#|nextstate|var\d+)/;'
tst_b_xref4.pl syntax OK
j  <@> leave[1 ref] vKP/REFC ->(end)
1     <0> enter ->2
# 1: for (                                                           #
+:#
2     <;> nextstate(main 3 tst_b_xref4.pl:1) v:{ ->3                 #
+:nextstate
4     <1> preinc[t2] vK/1 ->5
-        <1> ex-rv2sv sKRM/1 ->4
3           <#> gvsv[*var1] s ->4                                    #
+:var1
5     <0> unstack v* ->6
i     <2> leaveloop vK/2 ->j
6        <{> enterloop(next->c last->i redo->7) v ->f
-        <1> null vK/1 ->i
h           <|> and(other->7) vK/1 ->i
g              <1> postinc[t4] sK/1 ->h
-                 <1> ex-rv2sv sKRM/1 ->g
f                    <#> gvsv[*var2] s ->g                           #
+:var2
-              <@> lineseq vK ->-
b                 <@> leave vKP ->c
7                    <0> enter v ->8
# 6:     $var4++;                                                    #
+:#
8                    <;> nextstate(main 1 tst_b_xref4.pl:6) v:{ ->9  #
+:nextstate
a                    <1> preinc[t8] vK/1 ->b
-                       <1> ex-rv2sv sKRM/1 ->a
9                          <#> gvsv[*var4] s ->a                     #
+:var4
d                 <1> preinc[t6] vK/1 ->e
-                    <1> ex-rv2sv sKRM/1 ->d
c                       <#> gvsv[*var3] s ->d                        #
+:var3
e                 <0> unstack v ->f

      [download]

      thanks Dave, I learned a lot! :)

      Cheers Rolf
      (addicted to the Perl Programming Language :)
      Wikisyntax for the Monastery FootballPerl is like chess, only without the dice

[reply]
[d/l]
[reply]

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