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# frozen_string_literal: true
module YARP
# This represents a source of Ruby code that has been parsed. It is used in
# conjunction with locations to allow them to resolve line numbers and source
# ranges.
class Source
attr_reader :source, :offsets
def initialize(source, offsets = compute_offsets(source))
@source = source
@offsets = offsets
end
def slice(offset, length)
source.byteslice(offset, length)
end
def line(value)
offsets.bsearch_index { |offset| offset > value } || offsets.length
end
def column(value)
value - offsets[line(value) - 1]
end
private
def compute_offsets(code)
offsets = [0]
code.b.scan("\n") { offsets << $~.end(0) }
offsets
end
end
# This represents a location in the source.
class Location
# A Source object that is used to determine more information from the given
# offset and length.
private attr_reader :source
# The byte offset from the beginning of the source where this location
# starts.
attr_reader :start_offset
# The length of this location in bytes.
attr_reader :length
def initialize(source, start_offset, length)
@source = source
@start_offset = start_offset
@length = length
end
def inspect
"#<YARP::Location @start_offset=#{@start_offset} @length=#{@length}>"
end
# The source code that this location represents.
def slice
source.slice(start_offset, length)
end
# The byte offset from the beginning of the source where this location ends.
def end_offset
start_offset + length
end
# The line number where this location starts.
def start_line
source.line(start_offset)
end
# The line number where this location ends.
def end_line
source.line(end_offset - 1)
end
# The column number in bytes where this location starts from the start of
# the line.
def start_column
source.column(start_offset)
end
# The column number in bytes where this location ends from the start of the
# line.
def end_column
source.column(end_offset - 1)
end
def deconstruct_keys(keys)
{ start_offset: start_offset, end_offset: end_offset }
end
def pretty_print(q)
q.text("(#{start_offset}...#{end_offset})")
end
def ==(other)
other.is_a?(Location) &&
other.start_offset == start_offset &&
other.end_offset == end_offset
end
def self.null
new(0, 0)
end
end
# This represents a comment that was encountered during parsing.
class Comment
TYPES = [:inline, :embdoc, :__END__]
attr_reader :type, :location
def initialize(type, location)
@type = type
@location = location
end
def deconstruct_keys(keys)
{ type: type, location: location }
end
end
# This represents an error that was encountered during parsing.
class ParseError
attr_reader :message, :location
def initialize(message, location)
@message = message
@location = location
end
def deconstruct_keys(keys)
{ message: message, location: location }
end
end
# This represents a warning that was encountered during parsing.
class ParseWarning
attr_reader :message, :location
def initialize(message, location)
@message = message
@location = location
end
def deconstruct_keys(keys)
{ message: message, location: location }
end
end
# A class that knows how to walk down the tree. None of the individual visit
# methods are implemented on this visitor, so it forces the consumer to
# implement each one that they need. For a default implementation that
# continues walking the tree, see the Visitor class.
class BasicVisitor
def visit(node)
node&.accept(self)
end
def visit_all(nodes)
nodes.map { |node| visit(node) }
end
def visit_child_nodes(node)
visit_all(node.child_nodes)
end
end
class Visitor < BasicVisitor
end
# This represents the result of a call to ::parse or ::parse_file. It contains
# the AST, any comments that were encounters, and any errors that were
# encountered.
class ParseResult
attr_reader :value, :comments, :errors, :warnings, :source
def initialize(value, comments, errors, warnings, source)
@value = value
@comments = comments
@errors = errors
@warnings = warnings
@source = source
end
def deconstruct_keys(keys)
{ value: value, comments: comments, errors: errors, warnings: warnings }
end
def success?
errors.empty?
end
def failure?
!success?
end
# Keep in sync with Java MarkNewlinesVisitor
class MarkNewlinesVisitor < YARP::Visitor
def initialize(newline_marked)
@newline_marked = newline_marked
end
def visit_block_node(node)
old_newline_marked = @newline_marked
@newline_marked = Array.new(old_newline_marked.size, false)
begin
super(node)
ensure
@newline_marked = old_newline_marked
end
end
alias_method :visit_lambda_node, :visit_block_node
def visit_if_node(node)
node.set_newline_flag(@newline_marked)
super(node)
end
alias_method :visit_unless_node, :visit_if_node
def visit_statements_node(node)
node.body.each do |child|
child.set_newline_flag(@newline_marked)
end
super(node)
end
end
private_constant :MarkNewlinesVisitor
def mark_newlines
newline_marked = Array.new(1 + @source.offsets.size, false)
visitor = MarkNewlinesVisitor.new(newline_marked)
value.accept(visitor)
value
end
end
# This represents a token from the Ruby source.
class Token
attr_reader :type, :value, :location
def initialize(type, value, location)
@type = type
@value = value
@location = location
end
def deconstruct_keys(keys)
{ type: type, value: value, location: location }
end
def pretty_print(q)
q.group do
q.text(type.to_s)
self.location.pretty_print(q)
q.text("(")
q.nest(2) do
q.breakable("")
q.pp(value)
end
q.breakable("")
q.text(")")
end
end
def ==(other)
other.is_a?(Token) &&
other.type == type &&
other.value == value
end
end
# This represents a node in the tree.
class Node
attr_reader :location
def newline?
@newline ? true : false
end
def set_newline_flag(newline_marked)
line = location.start_line
unless newline_marked[line]
newline_marked[line] = true
@newline = true
end
end
# Slice the location of the node from the source.
def slice
location.slice
end
def pretty_print(q)
q.group do
q.text(self.class.name.split("::").last)
location.pretty_print(q)
q.text("[Li:#{location.start_line}]") if newline?
q.text("(")
q.nest(2) do
deconstructed = deconstruct_keys([])
deconstructed.delete(:location)
q.breakable("")
q.seplist(deconstructed, lambda { q.comma_breakable }, :each_value) { |value| q.pp(value) }
end
q.breakable("")
q.text(")")
end
end
end
# Load the serialized AST using the source as a reference into a tree.
def self.load(source, serialized)
Serialize.load(source, serialized)
end
# This module is used for testing and debugging and is not meant to be used by
# consumers of this library.
module Debug
class ISeq
attr_reader :parts
def initialize(parts)
@parts = parts
end
def type
parts[0]
end
def local_table
parts[10]
end
def instructions
parts[13]
end
def each_child
instructions.each do |instruction|
# Only look at arrays. Other instructions are line numbers or
# tracepoint events.
next unless instruction.is_a?(Array)
instruction.each do |opnd|
# Only look at arrays. Other operands are literals.
next unless opnd.is_a?(Array)
# Only look at instruction sequences. Other operands are literals.
next unless opnd[0] == "YARVInstructionSequence/SimpleDataFormat"
yield ISeq.new(opnd)
end
end
end
end
# For the given source, compiles with CRuby and returns a list of all of the
# sets of local variables that were encountered.
def self.cruby_locals(source)
verbose = $VERBOSE
$VERBOSE = nil
begin
locals = []
stack = [ISeq.new(RubyVM::InstructionSequence.compile(source).to_a)]
while (iseq = stack.pop)
if iseq.type != :once
names = iseq.local_table
# CRuby will push on a special local variable when there are keyword
# arguments. We get rid of that here.
names = names.grep_v(Integer)
# TODO: We don't support numbered local variables yet, so we get rid
# of those here.
names = names.grep_v(/^_\d$/)
# Now push them onto the list of locals.
locals << names
end
iseq.each_child { |child| stack << child }
end
locals
ensure
$VERBOSE = verbose
end
end
# For the given source, parses with YARP and returns a list of all of the
# sets of local variables that were encountered.
def self.yarp_locals(source)
locals = []
stack = [YARP.parse(source).value]
while (node = stack.pop)
case node
when BlockNode, DefNode, LambdaNode
names = node.locals
params = node.parameters
params = params&.parameters unless node.is_a?(DefNode)
# YARP places parameters in the same order that they appear in the
# source. CRuby places them in the order that they need to appear
# according to their own internal calling convention. We mimic that
# order here so that we can compare properly.
if params
sorted = [
*params.requireds.grep(RequiredParameterNode).map(&:constant_id),
*params.optionals.map(&:constant_id),
*((params.rest.name ? params.rest.name.to_sym : :*) if params.rest && params.rest.operator != ","),
*params.posts.grep(RequiredParameterNode).map(&:constant_id),
*params.keywords.reject(&:value).map { |param| param.name.chomp(":").to_sym },
*params.keywords.select(&:value).map { |param| param.name.chomp(":").to_sym }
]
# TODO: When we get a ... parameter, we should be pushing * and &
# onto the local list. We don't do that yet, so we need to add them
# in here.
if params.keyword_rest.is_a?(ForwardingParameterNode)
sorted.push(:*, :&, :"...")
end
# Recurse down the parameter tree to find any destructured
# parameters and add them after the other parameters.
param_stack = params.requireds.concat(params.posts).grep(RequiredDestructuredParameterNode).reverse
while (param = param_stack.pop)
case param
when RequiredDestructuredParameterNode
param_stack.concat(param.parameters.reverse)
when RequiredParameterNode
sorted << param.constant_id
when SplatNode
sorted << param.expression.constant_id if param.expression
end
end
names = sorted.concat(names - sorted)
end
locals << names
when ClassNode, ModuleNode, ProgramNode, SingletonClassNode
locals << node.locals
when ForNode
locals << []
when PostExecutionNode
locals.push([], [])
end
stack.concat(node.child_nodes.compact)
end
locals
end
def self.newlines(source)
YARP.parse(source).source.offsets
end
def self.parse_serialize_file(filepath)
parse_serialize_file_metadata(filepath, [filepath.bytesize, filepath.b, 0].pack("LA*L"))
end
end
# Marking this as private so that consumers don't see it. It makes it a little
# annoying for testing since you have to const_get it to access the methods,
# but at least this way it's clear it's not meant for consumers.
private_constant :Debug
end
require_relative "yarp/lex_compat"
require_relative "yarp/node"
require_relative "yarp/ripper_compat"
require_relative "yarp/serialize"
require_relative "yarp/pack"
if RUBY_ENGINE == "ruby" and !ENV["YARP_FFI_BACKEND"]
require "yarp/yarp"
else
require "yarp/ffi"
end
|