Original bug ID: 63
Reporter: administrator
Status: closed
Resolution: fixed
Priority: normal
Severity: feature
Category: ~DO NOT USE (was: OCaml general)

Bug description

Full_Name: David McClain
Version: 2.99
OS: Win/NT 4.0 (pl 3)
Submission from: dialup001ip074.tus.azstarnet.com (169.197.12.74)

Misspelled nonterminals are not caught by CAMLYACC nor by subsequent
compilation.
It appears that the new YACC converts non-terminal names into "modern"-style
backquoted polymorphic variant labels. A misspelled label makes its way through
all stages of compilation without complaint, but of course, the end result does
not work as expected. This can be a very difficult bug to track down!

E.g.,

param_tail:
AMPEROPT option_pattern_list
{ $2 }
| AMPEROPT option_patternm_list COMMA AMPERKEY key_pattern
{ $5 @ $2 }
| AMPERKEY key_pattern
{ $2 }
;

The second clause has a hard to notice misspelling: the correct nonterminal name
is
"option_pattern_list", but the misspelling is "option_patternM_list"
(misspelling
capitalized so you can see it more easily). When compiled the parser fails with

syntax errors galore where it was intended to handle the clause without
complaint.

I beleive this behavior is new to version 2.99, but I have not tried
misspellings on
any of the older versions recently...