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Feature #15251

Updated by chopraanmol1 (Anmol Chopra) about 1 year ago

I'm not sure if current behavior is expected one or a bug. So fell free to change tracker type.

Currently Hash ASET aset checks if non-tainted string exists in fstring table or not, if it doesn't then ruby duplicates string and freeze it. This works well for string_literal because they are already registered in fstring table, table during compilation, but it doesn't work for non-string literal.

Patch

https://github.com/ruby/ruby/pull/1993

O/P of attached file on trunk:
~~~
string_literal => 1
string times 1 => 1
string times 3 string times 3 string times 3 => 100
interpolated_string => 100
string add => 100
string append => 100
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
fstring
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
string_literal => 1
string times 1 => 1
string times 3 string times 3 string times 3 => 1
interpolated_string => 1
string add => 1
string append => 1
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
fstring + GC
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
string_literal => 1
string times 1 => 1
string times 3 string times 3 string times 3 => 100
interpolated_string => 100
string add => 100
string append => 100
~~~

after patch
~~~
string_literal => 1
string times 1 => 1
string times 3 string times 3 string times 3 => 1
interpolated_string => 1
string add => 1
string append => 1
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
fstring
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
string_literal => 1
string times 1 => 1
string times 3 string times 3 string times 3 => 1
interpolated_string => 1
string add => 1
string append => 1
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
fstring + GC
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
string_literal => 1
string times 1 => 1
string times 3 string times 3 string times 3 => 1
interpolated_string => 1
string add => 1
string append => 1
~~~

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