ruby/bootstraptest
John Hawthorn 733500e9d0
Lazily create singletons on instance_{exec,eval} (#5146)
* Lazily create singletons on instance_{exec,eval}

Previously when instance_exec or instance_eval was called on an object,
that object would be given a singleton class so that method
definitions inside the block would be added to the object rather than
its class.

This commit aims to improve performance by delaying the creation of the
singleton class unless/until one is needed for method definition. Most
of the time instance_eval is used without any method definition.

This was implemented by adding a flag to the cref indicating that it
represents a singleton of the object rather than a class itself. In this
case CREF_CLASS returns the object's existing class, but in cases that
we are defining a method (either via definemethod or
VM_SPECIAL_OBJECT_CBASE which is used for undef and alias).

This also happens to fix what I believe is a bug. Previously
instance_eval behaved differently with regards to constant access for
true/false/nil than for all other objects. I don't think this was
intentional.

    String::Foo = "foo"
    "".instance_eval("Foo")   # => "foo"
    Integer::Foo = "foo"
    123.instance_eval("Foo")  # => "foo"
    TrueClass::Foo = "foo"
    true.instance_eval("Foo") # NameError: uninitialized constant Foo

This also slightly changes the error message when trying to define a method
through instance_eval on an object which can't have a singleton class.

Before:

    $ ruby -e '123.instance_eval { def foo; end }'
    -e:1:in `block in <main>': no class/module to add method (TypeError)

After:

    $ ./ruby -e '123.instance_eval { def foo; end }'
    -e:1:in `block in <main>': can't define singleton (TypeError)

IMO this error is a small improvement on the original and better matches
the (both old and new) message when definging a method using `def self.`

    $ ruby -e '123.instance_eval{ def self.foo; end }'
    -e:1:in `block in <main>': can't define singleton (TypeError)

Co-authored-by: Matthew Draper <matthew@trebex.net>

* Remove "under" argument from yield_under

* Move CREF_SINGLETON_SET into vm_cref_new

* Simplify vm_get_const_base

* Fix leaf VM_SPECIAL_OBJECT_CONST_BASE

Co-authored-by: Matthew Draper <matthew@trebex.net>
2021-12-02 15:53:39 -08:00
..
pending.rb Moved already resolved test 2020-04-27 10:39:07 +09:00
runner.rb Rename RubyVM::MJIT to RubyVM::JIT 2021-01-13 22:46:51 -08:00
test_attr.rb
test_autoload.rb
test_block.rb
test_class.rb
test_env.rb fallback env encoding to ASCII-8BIT 2018-09-26 17:24:00 +00:00
test_eval.rb Lazily create singletons on instance_{exec,eval} (#5146) 2021-12-02 15:53:39 -08:00
test_exception.rb error.c: bypass Exception.new 2018-02-20 10:08:27 +00:00
test_fiber.rb Replace copy coroutine with pthread implementation. 2021-07-01 11:23:03 +12:00
test_finalizer.rb
test_flip.rb
test_flow.rb Make proc/Proc.new without block an error instead of warning 2020-06-10 17:49:54 -07:00
test_fork.rb bootstraptest/test_fork.rb: Stop too restrict NPROC test temporarily 2018-01-09 08:05:40 +00:00
test_gc.rb
test_insns.rb Add one more test example for swap instruction 2021-11-09 16:56:44 +09:00
test_io.rb bootstraptest update test_io.rb [Bug #15060] [Fix GH-1495] 2018-09-04 05:28:38 +00:00
test_jump.rb Make yield in singleton class definitions in methods a SyntaxError 2020-02-11 12:44:23 -08:00
test_literal.rb st.c (rb_hash_bulk_insert_into_st_table): avoid out-of-bounds write 2019-01-15 14:19:19 +00:00
test_literal_suffix.rb parse.y: more token names 2019-01-21 10:24:56 +00:00
test_load.rb
test_marshal.rb
test_massign.rb
test_method.rb relax error message format 2015-10-24 06:42:22 +00:00
test_objectspace.rb Use a monotonically increasing number for object_id 2019-11-07 09:31:07 -08:00
test_proc.rb Make proc/Proc.new without block an error instead of warning 2020-06-10 17:49:54 -07:00
test_ractor.rb rb_id_serial_to_id: return unregistered ID as an internal ID 2021-11-07 12:40:27 +09:00
test_string.rb
test_struct.rb
test_syntax.rb Turn class variable warnings into exceptions 2020-04-10 00:29:05 -07:00
test_thread.rb should check pending interrupts correctly. 2020-04-09 12:51:51 +09:00
test_yjit.rb YJIT: Fail gracefully while OOM for new entry points 2021-12-01 12:25:28 -05:00
test_yjit_30k_ifelse.rb * append newline at EOF. [ci skip] 2021-10-21 08:12:53 +09:00
test_yjit_30k_methods.rb * append newline at EOF. [ci skip] 2021-10-21 08:12:53 +09:00