# frozen_string_literal: false
#
# irb/ruby-lex.rb - ruby lexcal analyzer
# by Keiju ISHITSUKA(keiju@ruby-lang.org)
#
require "ripper"
require "jruby" if RUBY_ENGINE == "jruby"
require_relative "nesting_parser"
module IRB
# :stopdoc:
class RubyLex
ASSIGNMENT_NODE_TYPES = [
# Local, instance, global, class, constant, instance, and index assignment:
# "foo = bar",
# "@foo = bar",
# "$foo = bar",
# "@@foo = bar",
# "::Foo = bar",
# "a::Foo = bar",
# "Foo = bar"
# "foo.bar = 1"
# "foo[1] = bar"
:assign,
# Operation assignment:
# "foo += bar"
# "foo -= bar"
# "foo ||= bar"
# "foo &&= bar"
:opassign,
# Multiple assignment:
# "foo, bar = 1, 2
:massign,
]
class TerminateLineInput < StandardError
def initialize
super("Terminate Line Input")
end
end
def self.compile_with_errors_suppressed(code, line_no: 1)
begin
result = yield code, line_no
rescue ArgumentError
# Ruby can issue an error for the code if there is an
# incomplete magic comment for encoding in it. Force an
# expression with a new line before the code in this
# case to prevent magic comment handling. To make sure
# line numbers in the lexed code remain the same,
# decrease the line number by one.
code = ";\n#{code}"
line_no -= 1
result = yield code, line_no
end
result
end
ERROR_TOKENS = [
:on_parse_error,
:compile_error,
:on_assign_error,
:on_alias_error,
:on_class_name_error,
:on_param_error
]
def self.generate_local_variables_assign_code(local_variables)
"#{local_variables.join('=')}=nil;" unless local_variables.empty?
end
# Some part of the code is not included in Ripper's token.
# Example: DATA part, token after heredoc_beg when heredoc has unclosed embexpr.
# With interpolated tokens, tokens.map(&:tok).join will be equal to code.
def self.interpolate_ripper_ignored_tokens(code, tokens)
line_positions = [0]
code.lines.each do |line|
line_positions << line_positions.last + line.bytesize
end
prev_byte_pos = 0
interpolated = []
prev_line = 1
tokens.each do |t|
line, col = t.pos
byte_pos = line_positions[line - 1] + col
if prev_byte_pos < byte_pos
tok = code.byteslice(prev_byte_pos...byte_pos)
pos = [prev_line, prev_byte_pos - line_positions[prev_line - 1]]
interpolated << Ripper::Lexer::Elem.new(pos, :on_ignored_by_ripper, tok, 0)
prev_line += tok.count("\n")
end
interpolated << t
prev_byte_pos = byte_pos + t.tok.bytesize
prev_line += t.tok.count("\n")
end
if prev_byte_pos < code.bytesize
tok = code.byteslice(prev_byte_pos..)
pos = [prev_line, prev_byte_pos - line_positions[prev_line - 1]]
interpolated << Ripper::Lexer::Elem.new(pos, :on_ignored_by_ripper, tok, 0)
end
interpolated
end
def self.ripper_lex_without_warning(code, local_variables: [])
verbose, $VERBOSE = $VERBOSE, nil
lvars_code = generate_local_variables_assign_code(local_variables)
original_code = code
if lvars_code
code = "#{lvars_code}\n#{code}"
line_no = 0
else
line_no = 1
end
compile_with_errors_suppressed(code, line_no: line_no) do |inner_code, line_no|
lexer = Ripper::Lexer.new(inner_code, '-', line_no)
tokens = []
lexer.scan.each do |t|
next if t.pos.first == 0
prev_tk = tokens.last
position_overlapped = prev_tk && t.pos[0] == prev_tk.pos[0] && t.pos[1] < prev_tk.pos[1] + prev_tk.tok.bytesize
if position_overlapped
tokens[-1] = t if ERROR_TOKENS.include?(prev_tk.event) && !ERROR_TOKENS.include?(t.event)
else
tokens << t
end
end
interpolate_ripper_ignored_tokens(original_code, tokens)
end
ensure
$VERBOSE = verbose
end
def check_code_state(code, local_variables:)
tokens = self.class.ripper_lex_without_warning(code, local_variables: local_variables)
opens = NestingParser.open_tokens(tokens)
[tokens, opens, code_terminated?(code, tokens, opens, local_variables: local_variables)]
end
def code_terminated?(code, tokens, opens, local_variables:)
case check_code_syntax(code, local_variables: local_variables)
when :unrecoverable_error
true
when :recoverable_error
false
when :other_error
opens.empty? && !should_continue?(tokens)
when :valid
!should_continue?(tokens)
end
end
def assignment_expression?(code, local_variables:)
# Try to parse the code and check if the last of possibly multiple
# expressions is an assignment type.
# If the expression is invalid, Ripper.sexp should return nil which will
# result in false being returned. Any valid expression should return an
# s-expression where the second element of the top level array is an
# array of parsed expressions. The first element of each expression is the
# expression's type.
verbose, $VERBOSE = $VERBOSE, nil
code = "#{RubyLex.generate_local_variables_assign_code(local_variables) || 'nil;'}\n#{code}"
# Get the last node_type of the line. drop(1) is to ignore the local_variables_assign_code part.
node_type = Ripper.sexp(code)&.dig(1)&.drop(1)&.dig(-1, 0)
ASSIGNMENT_NODE_TYPES.include?(node_type)
ensure
$VERBOSE = verbose
end
def should_continue?(tokens)
# Look at the last token and check if IRB need to continue reading next line.
# Example code that should continue: `a\` `a +` `a.`
# Trailing spaces, newline, comments are skipped
return true if tokens.last&.event == :on_sp && tokens.last.tok == "\\\n"
tokens.reverse_each do |token|
case token.event
when :on_sp, :on_nl, :on_ignored_nl, :on_comment, :on_embdoc_beg, :on_embdoc, :on_embdoc_end
# Skip
when :on_regexp_end, :on_heredoc_end, :on_semicolon
# State is EXPR_BEG but should not continue
return false
else
# Endless range should not continue
return false if token.event == :on_op && token.tok.match?(/\A\.\.\.?\z/)
# EXPR_DOT and most of the EXPR_BEG should continue
return token.state.anybits?(Ripper::EXPR_BEG | Ripper::EXPR_DOT)
end
end
false
end
def check_code_syntax(code, local_variables:)
lvars_code = RubyLex.generate_local_variables_assign_code(local_variables)
code = "#{lvars_code}\n#{code}"
begin # check if parser error are available
verbose, $VERBOSE = $VERBOSE, nil
case RUBY_ENGINE
when 'ruby'
self.class.compile_with_errors_suppressed(code) do |inner_code, line_no|
RubyVM::InstructionSequence.compile(inner_code, nil, nil, line_no)
end
when 'jruby'
JRuby.compile_ir(code)
else
catch(:valid) do
eval("BEGIN { throw :valid, true }\n#{code}")
false
end
end
rescue EncodingError
# This is for a hash with invalid encoding symbol, {"\xAE": 1}
:unrecoverable_error
rescue SyntaxError => e
case e.message
when /unterminated (?:string|regexp) meets end of file/
# "unterminated regexp meets end of file"
#
# example:
# /
#
# "unterminated string meets end of file"
#
# example:
# '
return :recoverable_error
when /syntax error, unexpected end-of-input/
# "syntax error, unexpected end-of-input, expecting keyword_end"
#
# example:
# if true
# hoge
# if false
# fuga
# end
return :recoverable_error
when /syntax error, unexpected keyword_end/
# "syntax error, unexpected keyword_end"
#
# example:
# if (
# end
#
# example:
# end
return :unrecoverable_error
when /syntax error, unexpected '\.'/
# "syntax error, unexpected '.'"
#
# example:
# .
return :unrecoverable_error
when /unexpected tREGEXP_BEG/
# "syntax error, unexpected tREGEXP_BEG, expecting keyword_do or '{' or '('"
#
# example:
# method / f /
return :unrecoverable_error
else
return :other_error
end
ensure
$VERBOSE = verbose
end
:valid
end
def calc_indent_level(opens)
indent_level = 0
opens.each_with_index do |t, index|
case t.event
when :on_heredoc_beg
if opens[index + 1]&.event != :on_heredoc_beg
if t.tok.match?(/^<<[~-]/)
indent_level += 1
else
indent_level = 0
end
end
when :on_tstring_beg, :on_regexp_beg, :on_symbeg, :on_backtick
# No indent: "", //, :"", ``
# Indent: %(), %r(), %i(), %x()
indent_level += 1 if t.tok.start_with? '%'
when :on_embdoc_beg
indent_level = 0
else
indent_level += 1
end
end
indent_level
end
FREE_INDENT_TOKENS = %i[on_tstring_beg on_backtick on_regexp_beg on_symbeg]
def free_indent_token?(token)
FREE_INDENT_TOKENS.include?(token&.event)
end
# Calculates the difference of pasted code's indent and indent calculated from tokens
def indent_difference(lines, line_results, line_index)
loop do
_tokens, prev_opens, _next_opens, min_depth = line_results[line_index]
open_token = prev_opens.last
if !open_token || (open_token.event != :on_heredoc_beg && !free_indent_token?(open_token))
# If the leading whitespace is an indent, return the difference
indent_level = calc_indent_level(prev_opens.take(min_depth))
calculated_indent = 2 * indent_level
actual_indent = lines[line_index][/^ */].size
return actual_indent - calculated_indent
elsif open_token.event == :on_heredoc_beg && open_token.tok.match?(/^<<[^-~]/)
return 0
end
# If the leading whitespace is not an indent but part of a multiline token
# Calculate base_indent of the multiline token's beginning line
line_index = open_token.pos[0] - 1
end
end
def process_indent_level(tokens, lines, line_index, is_newline)
line_results = NestingParser.parse_by_line(tokens)
result = line_results[line_index]
if result
_tokens, prev_opens, next_opens, min_depth = result
else
# When last line is empty
prev_opens = next_opens = line_results.last[2]
min_depth = next_opens.size
end
# To correctly indent line like `end.map do`, we use shortest open tokens on each line for indent calculation.
# Shortest open tokens can be calculated by `opens.take(min_depth)`
indent = 2 * calc_indent_level(prev_opens.take(min_depth))
preserve_indent = lines[line_index - (is_newline ? 1 : 0)][/^ */].size
prev_open_token = prev_opens.last
next_open_token = next_opens.last
# Calculates base indent for pasted code on the line where prev_open_token is located
# irb(main):001:1* if a # base_indent is 2, indent calculated from tokens is 0
# irb(main):002:1* if b # base_indent is 6, indent calculated from tokens is 2
# irb(main):003:0> c # base_indent is 6, indent calculated from tokens is 4
if prev_open_token
base_indent = [0, indent_difference(lines, line_results, prev_open_token.pos[0] - 1)].max
else
base_indent = 0
end
if free_indent_token?(prev_open_token)
if is_newline && prev_open_token.pos[0] == line_index
# First newline inside free-indent token
base_indent + indent
else
# Accept any number of indent inside free-indent token
preserve_indent
end
elsif prev_open_token&.event == :on_embdoc_beg || next_open_token&.event == :on_embdoc_beg
if prev_open_token&.event == next_open_token&.event
# Accept any number of indent inside embdoc content
preserve_indent
else
# =begin or =end
0
end
elsif prev_open_token&.event == :on_heredoc_beg
tok = prev_open_token.tok
if prev_opens.size <= next_opens.size
if is_newline && lines[line_index].empty? && line_results[line_index - 1][1].last != next_open_token
# First line in heredoc
tok.match?(/^<<[-~]/) ? base_indent + indent : indent
elsif tok.match?(/^<<~/)
# Accept extra indent spaces inside `<<~` heredoc
[base_indent + indent, preserve_indent].max
else
# Accept any number of indent inside other heredoc
preserve_indent
end
else
# Heredoc close
prev_line_indent_level = calc_indent_level(prev_opens)
tok.match?(/^<<[~-]/) ? base_indent + 2 * (prev_line_indent_level - 1) : 0
end
else
base_indent + indent
end
end
LTYPE_TOKENS = %i[
on_heredoc_beg on_tstring_beg
on_regexp_beg on_symbeg on_backtick
on_symbols_beg on_qsymbols_beg
on_words_beg on_qwords_beg
]
def ltype_from_open_tokens(opens)
start_token = opens.reverse_each.find do |tok|
LTYPE_TOKENS.include?(tok.event)
end
return nil unless start_token
case start_token&.event
when :on_tstring_beg
case start_token&.tok
when ?" then ?"
when /^%.$/ then ?"
when /^%Q.$/ then ?"
when ?' then ?'
when /^%q.$/ then ?'
end
when :on_regexp_beg then ?/
when :on_symbeg then ?:
when :on_backtick then ?`
when :on_qwords_beg then ?]
when :on_words_beg then ?]
when :on_qsymbols_beg then ?]
when :on_symbols_beg then ?]
when :on_heredoc_beg
start_token&.tok =~ /<<[-~]?(['"`])\w+\1/
$1 || ?"
else
nil
end
end
def check_termination_in_prev_line(code, local_variables:)
tokens = self.class.ripper_lex_without_warning(code, local_variables: local_variables)
past_first_newline = false
index = tokens.rindex do |t|
# traverse first token before last line
if past_first_newline
if t.tok.include?("\n")
true
end
elsif t.tok.include?("\n")
past_first_newline = true
false
else
false
end
end
if index
first_token = nil
last_line_tokens = tokens[(index + 1)..(tokens.size - 1)]
last_line_tokens.each do |t|
unless [:on_sp, :on_ignored_sp, :on_comment].include?(t.event)
first_token = t
break
end
end
if first_token && first_token.state != Ripper::EXPR_DOT
tokens_without_last_line = tokens[0..index]
code_without_last_line = tokens_without_last_line.map(&:tok).join
opens_without_last_line = NestingParser.open_tokens(tokens_without_last_line)
if code_terminated?(code_without_last_line, tokens_without_last_line, opens_without_last_line, local_variables: local_variables)
return last_line_tokens.map(&:tok).join
end
end
end
false
end
end
# :startdoc:
end
RubyLex = IRB::RubyLex
Object.deprecate_constant(:RubyLex)