Bug #15188
closedIncorrect warning "assigned but unused variable" when using ripper with $VERBOSE = true
Description
The following code:
require 'ripper'
class Parser < Ripper
def warn(fmt, *args)
puts "#{filename}:#{lineno} - #{fmt % args}"
end
end
if __FILE__ == $0 then
$VERBOSE = true
s = 'foo = 42; p foo'
parser = Parser.new(s)
parser.parse
end
produces this warning:
(ripper):1 - assigned but unused variable - foo
but clearly foo is not unused.
Files
Updated by nagachika (Tomoyuki Chikanaga) about 6 years ago
- Backport changed from 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN to 2.3: DONTNEED, 2.4: DONTNEED, 2.5: REQUIRED
Updated by jeremyevans0 (Jeremy Evans) about 5 years ago
Ripper doesn't track usage of local variables as far as I can see. In parse.y
, LVAR_USED
is used to mark local variables as being used. In normal compilation mode, this is set by mark_lvar_used
, called by value_expr_check
, called by value_expr_gen
(aliased to value_expr
). In ripper mode, #define value_expr(node) ((void)(node))
. It seems best to just not attempt to print unused variable warnings in ripper, which the attached patch does.
Updated by jeremyevans (Jeremy Evans) almost 5 years ago
- Status changed from Open to Closed
Applied in changeset git|447d583536274a2489efc8792653ad35d6f7128a.
Silence incorrect assigned but unused variable warnings in ripper
To only emit the warnings in correct cases would require tracking
local variable usage in ripper, which ripper currently does not do.
Fixes [Bug #15188]