Feature #8953: `str =~ /pattern/` does not call =~ method if (1) str is a String, (2) /pattern/ is a Regexp literal

• Status: Closed
• Assignee: matz (Yukihiro Matsumoto)
• Target version: -

[gfx (Goro FUJI)]

The expression a =~ b does not call the =~ method in some cases.
I think it is a bug that results from optimizations.

See the following code for details:

Code that does not work as expected (shows nothing):

$ ruby -e 's = "foo"; class << s; def =~ (rhs); raise "a"; end; end; s =~ /foo/' # does nothing

Code that works as expected (raises errors):

$ ruby -e 's = "foo"; class << s; def =~ (rhs); raise "a"; end; end; s.=~ /foo/' # call =~ as a method
$ ruby -e 's = "foo"; class << s; def =~ (rhs); raise "a"; end; end; s =~ -> { /foo/ }.call' # RHS is not a Regexp literal but a Regexp object
$ ruby -e 's = Objec.new; class << s; def =~ (rhs); raise "a"; end; end; s =~ /foo/' # LHS is not a String

[sorah (Sorah Fukumori)]

hm...

ruby -e'class Regexp; def =~(o); true; end; end; p /a/ =~ "b"' #=> nil

• Status changed from Open to Closed
• % Done changed from 0 to 100

This issue was solved with changeset r43050.
Goro, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

---

• insns.def (opt_regexpmatch1): check Regexp#=~ is not defined before
  calling rb_reg_match()

• test/ruby/test_regexp.rb: add test

• vm.c (ruby_vm_redefined_flag): change type to short[]

• vm.c (vm_redefinition_check_flag): return REGEXP_REDEFINED_OP_FLAG if
  klass == rb_cRegexp

• vm.c (vm_init_redefined_flag): setup BOP flag for Regexp#=~

• vm_insnhelper.h: add REGEXP_REDEFINED_OP_FLAG

[ruby-core:57385] [Bug #8953]

[sorah (Sorah Fukumori)]

• Status changed from Closed to Open
• % Done changed from 100 to 50

The problem still exists for opt_regexpmatch1, right?

[sorah (Sorah Fukumori)]

The problem still exists for opt_regexpmatch1, right?

s/opt_regexpmatch1/opt_regexpmatch2/

Ah you are right. Thanks for pointing that out sorah.

[sorah (Sorah Fukumori)]

• Status changed from Open to Assigned
• Assignee set to sorah (Sorah Fukumori)

Testing my patch on my machine for regexpmatch2

[sorah (Sorah Fukumori)]

• Status changed from Assigned to Closed
• % Done changed from 50 to 100

This issue was solved with changeset r43052.
Goro, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

---

• insns.def (opt_regexpmatch2): Check String#=~ hasn't overridden
  before calling rb_reg_match().

• test/ruby/test_string.rb: Test for above.

• vm.c (vm_init_redefined_flag): Add BOP flag for String#=~

[ruby-core:57385] [Bug #8953]

[sorah (Sorah Fukumori)]

• Backport changed from 1.9.3: UNKNOWN, 2.0.0: UNKNOWN to 1.9.3: UNKNOWN, 2.0.0: REQUIRED

Please backport r43050, 43052

[nagachika (Tomoyuki Chikanaga)]

• Tracker changed from Bug to Backport
• Project changed from Ruby master to Backport200
• Status changed from Closed to Assigned
• Assignee changed from sorah (Sorah Fukumori) to nagachika (Tomoyuki Chikanaga)

[ko1 (Koichi Sasada)]

I checked previous behavior.

versions/install-tags_v1_6_5_/bin/ruby
versions/install-tags_v1_6_6_/bin/ruby
versions/install-tags_v1_6_7_/bin/ruby
versions/install-tags_v1_6_8_/bin/ruby
versions/install-tags_v1_8_5_/bin/ruby
versions/install-tags_v1_8_5_113_/bin/ruby
versions/install-tags_v1_8_5_114_/bin/ruby
versions/install-tags_v1_8_5_115_/bin/ruby
versions/install-tags_v1_8_5_11_/bin/ruby
versions/install-tags_v1_8_5_12_/bin/ruby
versions/install-tags_v1_8_5_231_/bin/ruby
versions/install-tags_v1_8_5_2_/bin/ruby
versions/install-tags_v1_8_5_35_/bin/ruby
versions/install-tags_v1_8_5_52_/bin/ruby
versions/install-tags_v1_8_5_preview1_/bin/ruby
versions/install-tags_v1_8_5_preview2_/bin/ruby
versions/install-tags_v1_8_5_preview3_/bin/ruby
versions/install-tags_v1_8_5_preview4_/bin/ruby
versions/install-tags_v1_8_5_preview5_/bin/ruby
versions/install-tags_v1_8_6_/bin/ruby
versions/install-tags_v1_8_6_110_/bin/ruby
versions/install-tags_v1_8_6_111_/bin/ruby
versions/install-tags_v1_8_6_114_/bin/ruby
versions/install-tags_v1_8_6_230_/bin/ruby
versions/install-tags_v1_8_6_286_/bin/ruby
versions/install-tags_v1_8_6_287_/bin/ruby
versions/install-tags_v1_8_6_368_/bin/ruby
versions/install-tags_v1_8_6_369_/bin/ruby
versions/install-tags_v1_8_6_36_/bin/ruby
versions/install-tags_v1_8_6_383_/bin/ruby
versions/install-tags_v1_8_6_388_/bin/ruby
versions/install-tags_v1_8_6_398_/bin/ruby
versions/install-tags_v1_8_6_399_/bin/ruby
versions/install-tags_v1_8_6_420_/bin/ruby
versions/install-tags_v1_8_6_preview1_/bin/ruby
versions/install-tags_v1_8_6_preview2_/bin/ruby
versions/install-tags_v1_8_6_preview3_/bin/ruby
versions/install-tags_v1_8_7_/bin/ruby
versions/install-tags_v1_8_7_160_/bin/ruby
versions/install-tags_v1_8_7_173_/bin/ruby
versions/install-tags_v1_8_7_174_/bin/ruby
versions/install-tags_v1_8_7_17_/bin/ruby
versions/install-tags_v1_8_7_22_/bin/ruby
versions/install-tags_v1_8_7_248_/bin/ruby
versions/install-tags_v1_8_7_249_/bin/ruby
versions/install-tags_v1_8_7_299_/bin/ruby
versions/install-tags_v1_8_7_301_/bin/ruby
versions/install-tags_v1_8_7_302_/bin/ruby
versions/install-tags_v1_8_7_330_/bin/ruby
versions/install-tags_v1_8_7_334_/bin/ruby
versions/install-tags_v1_8_7_352_/bin/ruby
versions/install-tags_v1_8_7_357_/bin/ruby
versions/install-tags_v1_8_7_358_/bin/ruby
versions/install-tags_v1_8_7_369_/bin/ruby
versions/install-tags_v1_8_7_370_/bin/ruby
versions/install-tags_v1_8_7_371_/bin/ruby
versions/install-tags_v1_8_7_373_/bin/ruby
versions/install-tags_v1_8_7_374_/bin/ruby
versions/install-tags_v1_8_7_71_/bin/ruby
versions/install-tags_v1_8_7_72_/bin/ruby
versions/install-tags_v1_8_7_preview1_/bin/ruby
versions/install-tags_v1_8_7_preview2_/bin/ruby
versions/install-tags_v1_8_7_preview3_/bin/ruby
versions/install-tags_v1_8_7_preview4_/bin/ruby
versions/install-tags_v1_9_0_0_/bin/ruby
versions/install-tags_v1_9_0_1_/bin/ruby
versions/install-tags_v1_9_0_2_/bin/ruby
versions/install-tags_v1_9_0_3_/bin/ruby
versions/install-tags_v1_9_0_4_/bin/ruby
versions/install-tags_v1_9_0_5_/bin/ruby
versions/install-tags_v1_9_1_0_/bin/ruby
versions/install-tags_v1_9_1_126_/bin/ruby
versions/install-tags_v1_9_1_127_/bin/ruby
versions/install-tags_v1_9_1_128_/bin/ruby
versions/install-tags_v1_9_1_129_/bin/ruby
versions/install-tags_v1_9_1_243_/bin/ruby
versions/install-tags_v1_9_1_376_/bin/ruby
versions/install-tags_v1_9_1_378_/bin/ruby
versions/install-tags_v1_9_1_429_/bin/ruby
versions/install-tags_v1_9_1_430_/bin/ruby
versions/install-tags_v1_9_1_431_/bin/ruby
versions/install-tags_v1_9_1_preview1_/bin/ruby
versions/install-tags_v1_9_1_preview2_/bin/ruby
versions/install-tags_v1_9_1_rc1_/bin/ruby
versions/install-tags_v1_9_1_rc2_/bin/ruby
versions/install-tags_v1_9_2_0_/bin/ruby
versions/install-tags_v1_9_2_136_/bin/ruby
versions/install-tags_v1_9_2_180_/bin/ruby
versions/install-tags_v1_9_2_290_/bin/ruby
versions/install-tags_v1_9_2_318_/bin/ruby
versions/install-tags_v1_9_2_320_/bin/ruby
versions/install-tags_v1_9_2_preview1_/bin/ruby
versions/install-tags_v1_9_2_preview2_/bin/ruby
versions/install-tags_v1_9_2_preview3_/bin/ruby
versions/install-tags_v1_9_2_rc1_/bin/ruby
versions/install-tags_v1_9_2_rc2_/bin/ruby
versions/install-tags_v1_9_3_0_/bin/ruby
versions/install-tags_v1_9_3_125_/bin/ruby
versions/install-tags_v1_9_3_194_/bin/ruby
versions/install-tags_v1_9_3_195_/bin/ruby
versions/install-tags_v1_9_3_286_/bin/ruby
versions/install-tags_v1_9_3_327_/bin/ruby
versions/install-tags_v1_9_3_360_/bin/ruby
versions/install-tags_v1_9_3_362_/bin/ruby
versions/install-tags_v1_9_3_374_/bin/ruby
versions/install-tags_v1_9_3_385_/bin/ruby
versions/install-tags_v1_9_3_392_/bin/ruby
versions/install-tags_v1_9_3_429_/bin/ruby
versions/install-tags_v1_9_3_448_/bin/ruby
versions/install-tags_v1_9_3_preview1_/bin/ruby
versions/install-tags_v1_9_3_rc1_/bin/ruby
versions/install-tags_v2_0_0_0_/bin/ruby
versions/install-tags_v2_0_0_195_/bin/ruby
versions/install-tags_v2_0_0_247_/bin/ruby
versions/install-tags_v2_0_0_preview1_/bin/ruby
versions/install-tags_v2_0_0_preview2_/bin/ruby
versions/install-tags_v2_0_0_rc1_/bin/ruby
versions/install-tags_v2_0_0_rc2_/bin/ruby

And all of versions ignore the redefinition.
I implemented 1.9 VM as this behaviour because I think it is spec.

Could you ask matz?

[ko1 (Koichi Sasada)]

(2013/09/27 1:13), ko1 (Koichi Sasada) wrote:

And all of versions ignore the redefinition.
I implemented 1.9 VM as this behaviour because I think it is spec.

Could you ask matz?

I have no objection about that.
However, please be more careful to change the behavior.
(this phrase is also for me, of course)

--
// SASADA Koichi at atdot dot net

[akr (Akira Tanaka)]

2013/9/27 ko1 (Koichi Sasada) [e-mail]:

Issue #8953 has been updated by ko1 (Koichi Sasada).

And all of versions ignore the redefinition.
I implemented 1.9 VM as this behaviour because I think it is spec.

I also think so.
The spec is one of the reason Ruby can assign named capture to local variable.

% ruby -e '/def(?.*)/ =~ "abcdefghi"; p var'
"ghi"

Tanaka Akira

[nagachika (Tomoyuki Chikanaga)]

• Tracker changed from Backport to Feature
• Project changed from Backport200 to Ruby master
• Assignee changed from nagachika (Tomoyuki Chikanaga) to Anonymous

[ko1 (Koichi Sasada)]

• Category set to core
• Target version set to 2.1.0
• Assignee changed from Anonymous to matz (Yukihiro Matsumoto)

Could you check it?

[hsbt (Hiroshi SHIBATA)]

• Target version changed from 2.1.0 to 2.2.0

[naruse (Yui NARUSE)]

• Target version deleted (2.2.0)

[jeremyevans0 (Jeremy Evans)]

• Status changed from Assigned to Closed

This was fixed in Ruby 2.2:

$ ruby22 -ve 's = "foo"; class << s; def =~ (rhs); raise "a"; end; end; s =~ /foo/'
ruby 2.2.10p489 (2018-03-28 revision 63023) [x86_64-openbsd]
-e:1:in `=~': a (RuntimeError)
        from -e:1:in `<main>'