Bug #21132: Changed postposition `rescue` and `if` behavior since Ruby 3.4

• Status: Closed
• Assignee: prism
• Target version: -
• Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN

[watson1978 (Shizuo Fujita)]

When I use postposition rescue and if at same line, the behavior is changed since Ruby 3.4.

Reproduction

def foo
  return "hogehoge" rescue nil if false
  return "fugafuga"
end

foo

Result with Ruby 3.3

irb(main):001> RUBY_VERSION
=> "3.3.6"
irb(main):002* def foo
irb(main):003*   return "hogehoge" rescue nil if false
irb(main):004*   return "fugafuga"
irb(main):005> end
=> :foo
irb(main):006> foo
=> "fugafuga"

YARV bytecode

ruby 3.3.6 (2024-11-05 revision 75015d4c1f) [x86_64-linux]
== disasm: #<ISeq:<compiled>@<compiled>:1 (1,0)-(6,3)>
0000 definemethod                           :foo, foo                 (   1)[Li]
0003 putself                                                          (   6)[Li]
0004 opt_send_without_block                 <calldata!mid:foo, argc:0, FCALL|VCALL|ARGS_SIMPLE>
0006 leave

== disasm: #<ISeq:foo@<compiled>:1 (1,0)-(4,3)>
0000 putstring                              "fugafuga"                (   3)[LiCa]
0002 leave                                                            (   4)[Re]

Result with Ruby 3.4

irb(main):001> RUBY_VERSION
=> "3.4.1"
irb(main):002* def foo
irb(main):003*   return "hogehoge" rescue nil if false
irb(main):004*   return "fugafuga"
irb(main):005> end
=> :foo
irb(main):006> foo
=> "hogehoge"

YARV bytecode

ruby 3.4.1 (2024-12-25 revision 48d4efcb85) +PRISM [x86_64-linux]
== disasm: #<ISeq:<compiled>@<compiled>:1 (1,0)-(1,54)>
0000 putself                                                          (   1)[Li]
0001 opt_getconstant_path                   <ic:0 RubyVM::InstructionSequence>
0003 opt_getconstant_path                   <ic:1 DATA>
0005 opt_send_without_block                 <calldata!mid:new, argc:1, ARGS_SIMPLE>
0007 opt_send_without_block                 <calldata!mid:disassemble, argc:0, ARGS_SIMPLE>
0009 opt_send_without_block                 <calldata!mid:puts, argc:1, FCALL|ARGS_SIMPLE>

[watson1978 (Shizuo Fujita)]

• Description updated (diff)

[watson1978 (Shizuo Fujita)]

• Subject changed from Changed postposition `resque` and `if` behavior since Ruby 3.4 to Changed postposition `rescue` and `if` behavior since Ruby 3.4

[watson1978 (Shizuo Fujita)]

When I switched parser to parse.y, it has same result with Ruby 3.3.

[~/tmp]$ ruby -v --parser=parse.y t.rb
ruby 3.4.1 (2024-12-25 revision 48d4efcb85) [x86_64-linux]
"fugafuga"
[~/tmp]$ ruby -v --parser=prism t.rb
ruby 3.4.1 (2024-12-25 revision 48d4efcb85) +PRISM [x86_64-linux]
"hogehoge"

[nobu (Nobuyoshi Nakada)]

• Related to Bug #21097: `x = a rescue b in c` and `def f = a rescue b in c` parsed differently between parse.y and prism added

[nobu (Nobuyoshi Nakada)]

• Assignee set to prism

[hsbt (Hiroshi SHIBATA)]

• Is duplicate of Bug #21048: [Prism] rescue in modifier form with condition behaves differently added

[watson1978 (Shizuo Fujita)]

My problem will be solved by https://github.com/ruby/ruby/commit/c2908613368b2ae404d094a15df61d830fc46dc9
Thanks

[watson1978 (Shizuo Fujita)]

• Status changed from Open to Closed