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


use constant ERR1 => '<cstring> included in file %1';

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

sub name { return "18-0-5 The unbounded functions of library <cstring> shall not be used";}

sub description { return "18-0-5 (Required) The unbounded functions of library <cstring> shall not be used";}

sub detailed_description { return <<"END_DESC"
<p><b>Rationale</b><br>
The <i>strcpy, strcmp, strcat, strchr, strspn, strcspn, strpbrk, strrchr, strstr, strtok</i> and <i>strlen</i> functions
within the &lt;<i>cstring</i>&gt; library can read or write beyond the end of a buffer, resulting in <i>undefined
behaviour</i>.<br>
Ideally, a safe string handling library should be used.
</p>
<b>Example</b><pre style="margin-top:0;padding-top:0;">
#include <ctime> 
#include <cstring>
void fn ( const char_t * pChar )
{
  char_t array [ 10 ];
  strcpy ( array, pChar ); // Non-compliant
}
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{}
 our %seen;
sub check {
  my $check = shift; 
  my $file = shift;
  return unless $file->kind->check("file ~unknown ~unresolved");
 	foreach my $libFuncs($file->filerefs(" ","Function")){
 		if($libFuncs->ent->name eq "strcpy" || $libFuncs->ent->name eq "strcmp" || $libFuncs->ent->name eq "strcat" || 
       $libFuncs->ent->name eq "strchr" || $libFuncs->ent->name eq "strspn" || $libFuncs->ent->name eq "strcspn" ||
       $libFuncs->ent->name eq "strpbrk" || $libFuncs->ent->name eq "strrchr" || $libFuncs->ent->name eq "strstr" ||
       $libFuncs->ent->name eq "strtok" || $libFuncs->ent->name eq "strlen"){
 			my $libUsed = includeCheck($file);
      if($libUsed){
        $check->violation($libFuncs->ent,$file,$libFuncs->line,$libFuncs->column,ERR1,$file->name,$libFuncs->ent->name);
      }
    }
 	}
}

sub includeCheck {
  my $file = shift;
 
  if ($seen{$file->id}){
    return 0;
  }
  $seen{$file->id}=1;
  if($file->name eq "cstring"){
    return 1;
  }
  my @refs = $file->refs("include","file",1);
  foreach my $ref (@refs){
    return 1 if includeCheck($ref->ent);
  }
}