Creating a tree data structure (Has to be native) in Perl to represent a call tree that is located in a external file
https://stackoverflow.com/questions/4891453
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28-10-2019 - |
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Here is an example of the file.
powrup.asm POWER_UP
......EXTERNAL_RAM_ADDRESSING_CHECK powrup.asm:461
......EXRAM powrup.asm:490
......INRAM powrup.asm:540
......OUTPUT_TEST powrup.asm:573
............AD_READ douttst.asm:276
............AD_READ douttst.asm:366
......OUTPUT2_TEST powrup.asm:584
............AD_READ douttst2.asm:253
............AD_READ douttst2.asm:342
......OUTPUT3_TEST powrup.asm:599
............AD_READ douttst3.asm:307
............AD_READ douttst3.asm:398
......INPUT_TEST powrup.asm:614
......PROGRAM_PINS2_INPUT powrup.asm:629
......ARINC_TEST powrup.asm:633
............ARINC_LEVEL_TEST artest.asm:178
..................AD_READ arltst.asm:204
..................AD_READ arltst.asm:250
..................AD_READ arltst.asm:300
..................AD_READ arltst.asm:346
..................AD_READ arltst.asm:396
..................AD_READ arltst.asm:442
............ARINC_READ artest.asm:209
............ARINC_WORD_TXRX_TEST artest.asm:221
..................ARINC_OUT artxrx.asm:207
..................ARINC_READ artxrx.asm:221
............ARINC_READ artest.asm:251
............ARINC_WORD_TXRX_TEST artest.asm:263
..................ARINC_OUT artxrx.asm:207
..................ARINC_READ artxrx.asm:221
......PROGRAM_PINS2_INPUT powrup.asm:640
......PROGRAM_PIN_TEST powrup.asm:642
......PT_RCVR_BITE powrup.asm:645
............AD_READ10 ptbite.asm:225
..................AD_READ adread10.asm:141
............AD_READ10 ptbite.asm:308
..................AD_READ adread10.asm:141
............AD_READ10 ptbite.asm:384
..................AD_READ adread10.asm:141
............AD_READ10 ptbite.asm:467
..................AD_READ adread10.asm:141
............AD_READ10 ptbite.asm:542
..................AD_READ adread10.asm:141
............AD_READ10 ptbite.asm:622
..................AD_READ adread10.asm:141
......PROGRAM_PINS2_INPUT powrup.asm:653
......EXEC_INIT powrup.asm:663
The ... represents the call depth. The file name after the line indicates the file name and the line number it was called from in the parent. I can parse the file. What I am trying to do once I have parsed the file is put the data in a n-ary tree. I am doing a Data coupling and Control Coupling analysis and have already collected all the set/use data for the all the variables in the build. I need to now be able to traverse the tree and based on the depth figure out if there are any set before use situations or any set but not used situations. I thought a tree traversal would make the most sense.
Here is an example of the of the collected data:
$hash_DB{'alt_deviation_evaluation.asm->ALT_STATUS'} = [
'alt_deviation_evaluation.asm',
'ALT_STATUS',
'1.1',
1,
"",
"",
"135,188,202,242",
"130,144"
];
'alt_deviation_evaluation.asm->ALT_STATUS' is the file name and variable name.
'alt_deviation_evaluation.asm', File name
'ALT_STATUS', Variable name
'1.1', versions of file
1, indicates has been processed
"", not used (maybe in future)
"", not used (maybe in future)
"135,188,202,242", variable Set line numbers for this fileVariable
"130,144" Variable Use line number for this file/Variable
I also have an array with all the variable names. Shortened example:
our @vars_list = (
'A429_TX_BUFFER_LENGTH',
'A429_TX_INPUT_BUFFER',
'A429_TX_INT_MASK',
'ABS_ALT_DIFF',
'ACTUAL_ALT',
'ADDRESS_FAIL',
'AD_CONV_FAIL',
'AD_CONV_SIGNAL',
'AD_DATA',
'AD_FAIL',
'AD_STATUS',
'AIR_MODE',
'AIR_MODE_COUNT',
'AIR_MODE_LAST',
'ALPHA_COR_SSM',
'ALPHA_EC_SSM',
'ALPHA_GRAD_SSM',
'ALPHA_LE_SSM',
'ALPHA_LG_SSM',
'ALPHA_MAX_MC_SSM'
};
My biggest hurdle is figuring out the proper data structures and algorithms to accomplish this task.
I figured a depth first search of a n-ary tree would give me what I want.
Here is my final solution:
#!/usr/local/bin/perl
# !/usr/bin/perl
use Data::Dumper; #!!!
sub Create_Tree;
sub Treverse;
#for my $node (@TREE) {
# print_node($node[0], 1);
#}
#Main
our @TREE;
Create_Tree("call_tree.small_01.txt");
my $str = Dumper @TREE;
$str =~ s/^(\s+)/' 'x(length($1)>>2)/meg;
#print "\n\n=======================================\n$str"; #!!!
#print "\n\n=======================================\n" . (Dumper @TREE); #!!!
#print "Arr = @TREE, SZ = $#TREE\n\n";
Treverse(\@TREE,1);
sub Create_Tree
{
my ($call_tree) = @_;
my @stack;
my ($old_depth, $p_arr) = (0, \@TREE);
open(IN, "< $call_tree" ) or die "Can not open '$call_tree' for input.\n";
for (<IN>)
{
if (m/^(\s*)(\S+)\s*=>\s*(\S+):(\d+)/ or m/^(\s*)(\S+)()()/)
{
my ($depth, $callee_fn, $caller_fn, $ln, $diff) = ($1, $2, $3, $4, 0);
$depth = int(length($depth) / 6);
$diff = $depth - $old_depth;
if ($diff == 1)
{
push @stack, $p_arr;
$p_arr = \@{$$p_arr[$#{$p_arr}]{children}};
}
elsif ($diff < 0)
{
$p_arr = pop @stack while ++$diff <= 0;
}
elsif ($diff > 1)
{
die "Incorrectly formated call tree:\n $_\n";
}
push @$p_arr, {
caller => $caller_fn,
called_by => $callee_fn,
at_line => $ln
};
$old_depth = $depth;
}
}
close IN;
}
exit;
OUTPUT look like this:
......file1
............file1 101:A
..................XXX.AA 102:AA
........................XXX.AAA 103:AAA
........................XXX.AAB 104:AAB
..............................XXX.AABA 105:AABA
..................XXX.AB 106:AB
........................XXX.ABA 107:ABA
............file1 108:B
..................XXX.BA 109:BA
........................XXX.BAA 110:BAA
........................XXX.BAB 111:BAB
From this call_tree.txt file:
file1
A => file1:101
AA => XXX.AA:102
AAA => XXX.AAA:103
AAB => XXX.AAB:104
AABA => XXX.AABA:105
AB => XXX.AB:106
ABA => XXX.ABA:107
B => file1:108
BA => XXX.BA:109
BAA => XXX.BAA:110
BAB => XXX.BAB:111
Using this subroutine:
sub Treverse
{
my ($p_arr, $level) = @_;
for (my $ind=0; $ind<=$#{$p_arr}; $ind++)
{
print "." x ($level*6);
if ($$p_arr[$ind]{'caller'} ne "") {print "$$p_arr[$ind]{'caller'}" . " " x 4;}
if ($$p_arr[$ind]{'at_line'} ne "") {print "$$p_arr[$ind]{'at_line' }" . ":";}
if ($$p_arr[$ind]{'called_by'} ne "") {print "$$p_arr[$ind]{'called_by'}" . "\n";}
Treverse(\@{$$p_arr[$ind]{children}}, $level +1) if defined $$p_arr[$ind]{children};
}
}
# END of Treverse
Solution
For data structures, one of the biggest powers of perl is arbitrary nesting of structures. Thus, rather than have a single variable that contains all the data for all the notes you can have "subnodes" inside their parents.
Lets say you had a hash for one entry:
%node1 = ( name => 'ALPHA_MAX_MC_SSM', file => 'arltst.asm', line => 42 );
The above code will create a nice simply node to store data in. But you can actually store more data inside that one itself. A "child node":
%node2 = (
name => 'ACTUAL_ALT',
file => 'foo.asm',
line => 2001
);
$node1{children}[0] = \%node2;
Then you have a child node ('children') in the first node that is an array of all it's children. You can access date in the child directly like:
$node1{'children'}[0]{'name'};
To understand this and how it works you need to read up on perl references and the perl data types. It takes a bit as a new perl programmer to get the concepts, but once you get it you can do amazingly powerful quick programs snarfing up complex hierarchical data and processing it.
OTHER TIPS
Here is how to print the structure you built using Wes's answer.
Once processed the data, you end up with something like this:
my @nodes = (
{ name => 'ARINC_TEST', file => 'powrup.asm', line => 633,
children => [
{ name => 'ARINC_LEVEL_TEST', file => 'artest.asm', line => 178,
children => [
{ name => 'AD_READ', file => 'arltst.asm', line => 204 },
{ name => 'AD_READ', file => 'arltst.asm', line => 250 },
{ name => 'AD_READ', file => 'arltst.asm', line => 300 },
{ name => 'AD_READ', file => 'arltst.asm', line => 346 },
{ name => 'AD_READ', file => 'arltst.asm', line => 396 },
{ name => 'AD_READ', file => 'arltst.asm', line => 442 },
],
},
{ name => 'ARINC_READ', file => 'artest.asm', line => 209,
children => [],
},
{ name => 'ARINC_WORD_TXRX_TEST', file => 'artest.asm', line => 221,
children => [
{ name => 'ARINC_OUT', file => 'artxrx.asm', line => 207 },
{ name => 'ARINC_READ', file => 'artxrx.asm', line => 221 },
],
}
]
}
);
The structure is recursive and children key point to arrayref of another hash. To print this out, you need recursive code:
for my $node (@nodes) {
print_node($node, 1);
}
sub print_node {
my ($node, $level) = @_;
# the node itself
print "." x ($level*6)
, $node->{name}, " " x 4
, $node->{file}, ":"
, $node->{line}, "\n";
# recurse for children
if(defined $node->{children}) {
for my $child (@{ $node->{children} }) {
print_node($child, $level + 1);
}
}
}
For data above, the code outputs
......ARINC_TEST powrup.asm:633
............ARINC_LEVEL_TEST artest.asm:178
..................AD_READ arltst.asm:204
..................AD_READ arltst.asm:250
..................AD_READ arltst.asm:300
..................AD_READ arltst.asm:346
..................AD_READ arltst.asm:396
..................AD_READ arltst.asm:442
............ARINC_READ artest.asm:209
............ARINC_WORD_TXRX_TEST artest.asm:221
..................ARINC_OUT artxrx.asm:207
..................ARINC_READ artxrx.asm:221
