# Virtual function not declared explicitly with the virtual keyword.

use base ("Understand::Codecheck");
use strict;
use constant ERR1 => "Missing Virtual Keyword";

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

}


sub name {
  return "10-3-2 Each overriding virtual function shall be declared with the virtual keyword.";
}
sub description {
  return "10-3-2 (Required) Each overriding virtual function shall be declared with the virtual keyword.";
}

sub detailed_description {
  return <<"END_DEF"
<p><b>Rationale</b><br>
Declaring overriding virtual functions with the virtual keyword removes the need to check the base class to determine whether a function is virtual.
</p><b>Example</b><pre style="margin-top:0;padding-top:0;">
  class A 
  { 
  public: 
     virtual void g(); 
     virtual void b(); 
  };
  class B1 : public A 
  { 
  public: 
     virtual void g();  // Compliant     - explicitly declared "virtual" 
     void b();          // Non-compliant - implicitly virtual 
  };</pre>
END_DEF
}

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

sub test_entity {
  return 1;
}

sub test_global {
  return 0;
}

sub check {
  my $check = shift;
  my $file = shift;
  return unless $file->kind->check("file ~unresolved ~unknown");
  my $lexer = $file->lexer();
  return unless $lexer;
  foreach my $ref ($file->filerefs("define,declare","function virtual",1)) {
      my $func = $ref->ent();
      # ignore func defs outside of the class body
      next if $ref->kind->check("define") && $func->ref("declarein");
      do_one_ref($check,$lexer,$ref);
  }
}

sub do_one_ref {
    my ($check,$lexer,$ref) = @_;
    my $lexeme = $lexer->lexeme($ref->line(),$ref->column()) or return;
    # walk lexemes backwards until we find 'virtual' or hit something
    # that indicates we've gone too far.
    while ($lexeme) {
        my $text = $lexeme->text();
  return if $text eq "virtual";
  if ($text =~ m/[;{}]/){
    $check->violation($ref->ent,$ref->file,$ref->line,$ref->column,ERR1);
    return;
  }
  $lexeme = $lexeme->previous();
    }
}