Class: Pedant::CheckContainsUnreachableCode

Inherits:
Check
  • Object
show all
Defined in:
lib/pedant/checks/contains_unreachable_code.rb

Instance Attribute Summary

Attributes inherited from Check

#result

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Check

all, depends, #fail, #fatal, friendly_name, inherited, #initialize, initialize!, list, #pass, provides, ready?, #report, run_checks_in_dependency_order, #skip, #warn

Constructor Details

This class inherits a constructor from Pedant::Check

Class Method Details

.requires ⇒ Object 



29
30
31
 
# File 'lib/pedant/checks/contains_unreachable_code.rb', line 29

def self.requires
  super + [:trees]
end

Instance Method Details

#check(file, tree) ⇒ Object 



33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
 
# File 'lib/pedant/checks/contains_unreachable_code.rb', line 33

def check(file, tree)
  def check_statements(file, list)
    list.each do |node|
      # Check if the Node is capable of jumping out of the Block, without
      # resuming where it left off (i.e., Call). The exception is exit(),
      # which is a builtin Function that terminates execution.
      if node.is_a?(Nasl::Break) || node.is_a?(Nasl::Continue) ||
         node.is_a?(Nasl::Return) || (node.is_a?(Nasl::Call) &&
         (node.name.ident.name == 'exit' ||
          node.name.ident.name == 'audit') && node.name.indexes == [])
        # If this is not the final node in the list, then there is
        # absolutely no way for the later nodes to be accessed.
        return node if node != list.last
      end
    end
    return nil
  end

  # Unreachable statements occur only when there are sequential lists of
  # instructions. In layers deeper than the outermost level of indentation,
  # this only occurs in Blocks.
  tree.all(:Block).each do |blk|
    node = check_statements(file, blk.body)
    if not node.nil?
      fail
      report(:error, node.context(blk))
    end
  end

  # The main body of a file is not a Block, so it must be considered
  # separately.
  node = check_statements(file, tree)
  if not node.nil?
    fail
    report(:error, node.context(node))
  end
end

#check_statements(file, list) ⇒ Object 



34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
 
# File 'lib/pedant/checks/contains_unreachable_code.rb', line 34

def check_statements(file, list)
  list.each do |node|
    # Check if the Node is capable of jumping out of the Block, without
    # resuming where it left off (i.e., Call). The exception is exit(),
    # which is a builtin Function that terminates execution.
    if node.is_a?(Nasl::Break) || node.is_a?(Nasl::Continue) ||
       node.is_a?(Nasl::Return) || (node.is_a?(Nasl::Call) &&
       (node.name.ident.name == 'exit' ||
        node.name.ident.name == 'audit') && node.name.indexes == [])
      # If this is not the final node in the list, then there is
      # absolutely no way for the later nodes to be accessed.
      return node if node != list.last
    end
  end
  return nil
end

#run ⇒ Object 



71
72
73
74
75
76
77
 
# File 'lib/pedant/checks/contains_unreachable_code.rb', line 71

def run
  # This check will pass by default.
  pass

  # Run this check on the tree from every file.
  @kb[:trees].each { |file, tree| check(file, tree) }
end