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


use Codecheck::Libraries::InfoSiftr qw(resolveTypedefs);

use constant MAX_NUM => 2;

use constant ERR1 => 'Violation: object "%1" includes more than ' . MAX_NUM . ' levels of indirection (%2 levels).';

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

sub name { '5-0-19 No more than 2 levels of indirection.' }

sub description { '5-0-19 (Required) The declaration of objects should contain no more than 2 levels of pointer indirection.' }

sub detailed_description { <<'END_DESC'
<p><b>Rationale</b><br>
Use  of  more  than  two  levels  of  indirection  can  seriously  impair  the  ability  to  understand  the 
behaviour of the code, and therefore should be avoided.</p>
<b>Example</b><pre style="margin-top:0;padding-top:0;">
typedef int8_t * INTPTR;
struct s { 
   int8_t *   s1;           // Compliant 
   int8_t **  s2;           // Compliant 
   int8_t *** s3;           // Non-compliant 
};
struct s *   ps1;           // Compliant 
struct s **  ps2;           // Compliant 
struct s *** ps3;           // Non-compliant
int8_t **  (  *pfunc1)();   // Compliant 
int8_t **  ( **pfunc2)();   // Compliant 
int8_t **  (***pfunc3)();   // Non-compliant 
int8_t *** ( **pfunc4)();   // Non-compliant
void function( int8_t *   par1,                // Compliant 
               int8_t **  par2,                // Compliant 
               int8_t *** par3,                // Non-compliant 
               INTPTR *   par4,                // Compliant 
               INTPTR *   const * const par5,  // Non-compliant 
               int8_t *   par6[],              // Compliant 
               int8_t **  par7[])              // Non-compliant 
{
   int8_t *   ptr1;                 // Compliant 
   int8_t **  ptr2;                 // Compliant 
   int8_t *** ptr3;                 // Non-compliant 
   INTPTR *   ptr4;                 // Compliant 
   INTPTR *   const * const ptr5;   // Non-compliant 
   int8_t *   ptr6[ 10 ];           // Compliant 
   int8_t **  ptr7[ 10 ];           // Compliant 
}
</pre>
END_DESC
}

sub test_language {
	my $language = shift;
	return $language eq 'C++';
}

sub test_entity { 0 }

sub test_global { 1 }

sub define_options { }


sub check {
	my $check = shift;
	my %typelist;
  
	foreach my $file ($check->get_files) {
		my $type;
		foreach my $ref ($file->filerefs('declare, define', 'object, parameter, function', 0)) {
			if($typelist{$ref->ent->type}){
			$type = $typelist{$ref->ent->type};
			}
			else{
				$type = resolveTypedefs($ref->ent->type, $check->db);
				$typelist{$ref->ent->type} = $type;
			}
			while ($type =~ m! \( (.*?) \) !xg) { # must be a function pointer
				# thus, we must handle the two significant parts separately
				my $contents = $1;
				(my $stars = $1) =~ s![^*\[]!!g;
				my $levels = length $stars;
			
				if ($levels > MAX_NUM) {
					$check->violation($ref->ent, $ref->file, $ref->line, $ref->column, ERR1, $ref->ent->longname, $levels);
			}
			
			$type =~ s! \( \Q$contents\E \) !!xg;
		}
		
		$type =~ s![^*\[]!!g;
		my $levels = length $type;
		
		if ($levels > MAX_NUM) {
			$check->violation($ref->ent, $ref->file, $ref->line, $ref->column, ERR1, $ref->ent->longname, $levels);
		}
	}
	}
	return;
}