lib/brakeman/processors/lib/call_conversion_helper.rb
module Brakeman
module CallConversionHelper
# Join two array literals into one.
def join_arrays lhs, rhs, original_exp = nil
if array? lhs and array? rhs
result = Sexp.new(:array)
result.line(lhs.line || rhs.line || 1)
result.concat lhs[1..-1]
result.concat rhs[1..-1]
result
else
original_exp
end
end
STRING_LENGTH_LIMIT = 50
# Join two string literals into one.
def join_strings lhs, rhs, original_exp = nil
if string? lhs and string? rhs
if (lhs.value.length + rhs.value.length > STRING_LENGTH_LIMIT)
# Avoid gigantic strings
lhs
else
result = Sexp.new(:str).line(lhs.line)
result.value = lhs.value + rhs.value
result
end
elsif call? lhs and lhs.method == :+ and string? lhs.first_arg and string? rhs
joined = join_strings lhs.first_arg, rhs
lhs.first_arg = joined
lhs
elsif safe_literal? lhs or safe_literal? rhs
safe_literal(lhs.line)
else
original_exp
end
rescue Encoding::CompatibilityError => e
# If the two strings are different encodings, we can't join them.
Brakeman.debug e.inspect
original_exp
end
def math_op op, lhs, rhs, original_exp = nil
if number? lhs and number? rhs
if op == :/ and rhs.value == 0 and not lhs.value.is_a? Float
# Avoid division by zero
return original_exp
else
value = lhs.value.send(op, rhs.value)
Sexp.new(:lit, value).line(lhs.line)
end
elsif call? lhs and lhs.method == :+ and number? lhs.first_arg and number? rhs
# (x + 1) + 2 -> (x + 3)
lhs.first_arg = Sexp.new(:lit, lhs.first_arg.value + rhs.value).line(lhs.first_arg.line)
lhs
elsif safe_literal? lhs or safe_literal? rhs
safe_literal(lhs.line)
else
original_exp
end
end
# Process single integer access to an array.
#
# Returns the value inside the array, if possible.
def process_array_access array, args, original_exp = nil
if args.length == 1 and integer? args.first
index = args.first.value
#Have to do this because first element is :array and we have to skip it
array[1..-1][index] or original_exp
elsif all_literals? array
safe_literal(array.line)
else
original_exp
end
end
# Process hash access by returning the value associated
# with the given argument.
def process_hash_access hash, index, original_exp = nil
if value = hash_access(hash, index)
value # deep_clone?
elsif all_literals? hash, :hash
safe_literal(hash.line)
else
original_exp
end
end
# You must check the return value for `nil`s -
# which indicate a key could not be found.
def hash_values_at hash, keys
values = keys.map do |key|
process_hash_access hash, key
end
Sexp.new(:array).concat(values).line(hash.line)
end
end
end