#This script is designed to run with Understand - CodeCheck
use base ("Understand::Codecheck");
use strict;


use constant ERR1 => 'Octal Constants not allowed: %1';
use constant ERR2 => 'Octal Escape Sequences not allowed: %1';

sub register_tr_text() {
  my $check = shift;
  $check->add_tr_text(ERR1);
  $check->add_tr_text(ERR2);
}

sub name { return "2-13-2 Octal constants and octal escape sequences shall not be used";}

sub description { return "2-13-2 (Required) Octal constants (other than zero) and octal escape sequences(other than \"\\0\") shall not be used.";}

sub detailed_description { return <<"END_DESC"
<p><b>Rationale</b><br>
Any integer constant beginning with a "0" (zero) is treated as octal. Because of this, it is possible 
for a zero-prefxed constant that is intended to be a decimal number to be incorrectly entered as an 
octal number, contrary to developer expectations.</p>
<p>Octal escape sequences can also be problematic because the inadvertent introduction of a decimal 
digit (i.e. "8" or "9") ends the octal escape and introduces another character.
The integer constant zero (written as a single numeric digit), is strictly speaking an octal constant, 
but is a permitted exception to this rule. Additionally, "\\0" is the only permitted octal escape 
sequence.</p>
<p><b>Example</b><br>
The following array initialization for 3-digit decimal bus messages would not behave as 
expected:<br>
code[ 1 ] = 109;   // Compliant     - decimal 109 <br>
code[ 2 ] = 100;   // Compliant     - decimal 100 <br>
code[ 3 ] = 052;   // Non-compliant - equivalent to decimal 42 <br>
code[ 4 ] = 071;   // Non-compliant - equivalent to decimal 57
<p>The  value  of  the frst  expression  in  the  following  example  is  implementation-defned because 
the character constant consists of two characters, "\\10" and "9". The second character constant 
expression contains the single character "\\100".<br>
code[ 5 ] = '\\109';   // Non-compliant - implementation-defined, two character constant <br>
code[ 6 ] = '\\100';   // Non-compliant - set to 64.<br>
</p>
END_DESC
}

sub test_language {
  my $language = shift;
  return $language =~ /C\+\+/; #Handles C and C++
}

sub test_entity { return 1;}

sub test_global { return 0;}

sub define_options{}


sub check {
  my $check = shift; 
  my $file = shift; 
  return unless $file->kind->check("file"); 
  
  my $lexer = $file->lexer;
  return unless $lexer;
  my $scope;
  foreach my $lexeme ($lexer->lexemes){
    $scope = $lexeme->ref->scope if $lexeme->ref;
    $scope = $file unless $scope;
    if($lexeme->token eq "Literal"  &&$lexeme->text =~ /^0\d+$/){
        $check->violation($scope,$file,$lexeme->line_begin,$lexeme->column_begin,ERR1,$lexeme->text);
    }elsif($lexeme->token eq "String" && $lexeme->text =~ /(\\\d\d?\d?)/ && $lexeme->text !~ /\\0[\D]*/ && $lexeme->text !~ /\\\\\d\d?\d?/){
        $check->violation($scope,$file,$lexeme->line_begin,$lexeme->column_begin,ERR2,$1);
    }
  }
}