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 



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

def self.requires
  super + [:trees]
end

Instance Method Details

#check(file, tree) ⇒ Object 



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# File 'lib/pedant/checks/contains_unreachable_code.rb', line 33

def check(file, tree)
  def check_statements(file, list)
    list.each do |node|
      # Is this an exit() call that's used to deprecate the plugin? If so,
      # we'll ignore it and check the rest of the plugin.
      # These look like:
      #   exit(0, "This plugin has been deprecated");
      # Some plugins (like the Slackware plugins) just do: exit(0);
      # But, they are old and have been deprecated forever and will
      # probably never be changed or reenabled.
      next if node.is_a?(Nasl::Call) and
        node.name.ident.name == 'exit' and
        node.args.length == 2 and
        node.args[1].expr.is_a?(Nasl::String) and
        node.args[1].expr.text =~ /plugin has been deprecated|patch has been replaced/i

      # 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 



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# File 'lib/pedant/checks/contains_unreachable_code.rb', line 34

def check_statements(file, list)
  list.each do |node|
    # Is this an exit() call that's used to deprecate the plugin? If so,
    # we'll ignore it and check the rest of the plugin.
    # These look like:
    #   exit(0, "This plugin has been deprecated");
    # Some plugins (like the Slackware plugins) just do: exit(0);
    # But, they are old and have been deprecated forever and will
    # probably never be changed or reenabled.
    next if node.is_a?(Nasl::Call) and
      node.name.ident.name == 'exit' and
      node.args.length == 2 and
      node.args[1].expr.is_a?(Nasl::String) and
      node.args[1].expr.text =~ /plugin has been deprecated|patch has been replaced/i

    # 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 



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# File 'lib/pedant/checks/contains_unreachable_code.rb', line 84

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