Bug #20748: Issue with defined? given method call with block in prism compiler

• Status: Closed
• Assignee: kddnewton (Kevin Newton)
• Target version: -
• ruby -v: 3.4.0dev
• Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN

[luke-gru (Luke Gruber)]

test.rb

puts defined?(undefined_method(){})

./ruby --parser=parse.y -I../ruby/lib -I. -I.ext/x86_64-linux -I.ext/common -r./x86_64-linux-fake ../ruby/test.rb
expression

./ruby --parser=prism -I../ruby/lib -I. -I.ext/x86_64-linux -I.ext/common -r./x86_64-linux-fake ../ruby/test.rb
# empty line

[kddnewton (Kevin Newton)]

• Assignee set to kddnewton (Kevin Newton)

I have opened a PR for this to match the behavior exactly, but I will say I think Prism's behavior is actually correct here. Right now compile.c results in:

puts defined?(undefined_method(){}) # => "expression"
puts defined?(undefined_method(&b)) # => ""

whereas Prism results in:

puts defined?(undefined_method(){}) # => ""
puts defined?(undefined_method(&b)) # => ""

I have updated the code to match compile.c, but I think it's incorrect that we are falling back to "expression" because it has an explicit block versus an implicit one.

[luke-gru (Luke Gruber)]

I agree it's weird but it could cause an incompatibility I guess, defined?() is a weird one for sure.

[kddnewton (Kevin Newton)]

• Status changed from Open to Closed

Applied in changeset commit:git|1e52dde82af10f2a2ec648b34dce30bec4154245.

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[PRISM] Match defined behavior for explicit block

Fixes [Bug #20748]