[ruby-core:119204] [Ruby master Bug#20726] Issue with hash without braces when assigned to constant with ractor literals

15 Sep 2024

      Issue #20726 has been updated by osyo (manga osyo).

This problem was not reproduced with `--parser=prism`, but with `--parser=parse.y`.

```ruby
# shareable_constant_value: literal
# test.rb
puts RUBY_DESCRIPTION

A = [a: 1]
p A
```

```shell
$ ruby --parser=prism test.rb
ruby 3.4.0dev (2024-09-15T01:06:11Z master 532af89e3b) +PRISM [x86_64-linux]
test.rb:5:in 'ensure_shareable': cannot assign unshareable object to A (Ractor::IsolationError)
        from test.rb:5:in '<main>'
$ ruby --parser=parse.y test.rb
-- raw disasm--------
   trace: 1
   0000 putself                                                          (   3)
   0001 opt_getconstant_path [:RUBY_DESCRIPTION]                         (   3)
   0003 opt_send_without_block <calldata:puts, 1>                        (   3)
   0005 pop                                                              (   3)
   trace: 1
   0006 newarray             1                                           (   5)
   0008 putspecialobject     3                                           (   5)
*  0010 setconstant          :A                                          (   5)
   trace: 1
   0012 putself                                                          (   6)
   0013 opt_getconstant_path [:A]                                        (   6)
   0015 opt_send_without_block <calldata:p, 1>                           (   6)
   0017 leave                                                            (   6)
---------------------
test.rb:5: argument stack underflow (-1)
test.rb: compile error (SyntaxError)
```

----------------------------------------
Bug #20726: Issue with hash without braces when assigned to constant with ractor literals
https://bugs.ruby-lang.org/issues/20726#change-109786

* Author: luke-gru (Luke Gruber)
* Status: Open
* ruby -v: 3.4.0dev
* Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN
----------------------------------------
```ruby
# shareable_constant_value: literal
a = 'hi'
A = ['hello' => a]
p A
```

gives:

```
./ruby -I../ruby/lib -I. -I.ext/x86_64-linux -I.ext/common -r./x86_64-linux-fake ../ruby/test.rb

-- raw disasm--------

   trace: 1

   0000 putchilledstring     "hi"                                     (   3)

   0002 setlocal_WC_0        3                                           (   3)

   trace: 1

   0004 newarray             1                                           (   4)

   0006 putspecialobject     3                                           (   4)

*  0008 setconstant          :A                                          (   4)

   trace: 1

   0010 putself                                                          (   5)

   0011 opt_getconstant_path [:A]                                        (   5)

   0013 opt_send_without_block <calldata:p, 1>                           (   5)

   0015 leave                                                            (   5)

---------------------

../ruby/test.rb:4: argument stack underflow (-1)

../ruby/test.rb: compile error (SyntaxError)
```

This is due to a line in `compile.c`, function `compile_shareable_literal_constant`:

```c
if (!RNODE_HASH(node)->nd_brace) { }
```

I'm not sure why this condition is there so I'm not confident in making a fix. Also, my git-fu isn't the best so I can't track down the right commit where it was added.

Expected:

It works just the same as when pragma `shareable_constant_value: literal` is not given. Which is to say, `[{'hello' => 'hi'}]` is is the value of `A`.

-- 
https://bugs.ruby-lang.org/