wrong parse-error line/column numbers at ocaml-menhir backend

[JoAllg]

the Test*.ml created by the ocaml-menhir backend does not report parse errors with correct line/column numbers. The error is always
Parse error at 0.-1-0.-1

This can for example be checked with this erroneus grammar test.cf :

`token Nat digit+ ;
token Int '-'? digit+ ;

entrypoints Prog ;
Code. Prog ::= Instr ";" [Instr] ;

separator Instr ";" ;
_.      Instr ::= Instr ";" ;
IPUSH.  Instr  ::= "PUSH" CType Data ;
IADD.   Instr  ::= "DROP" ;

DInt.   Data         ::= Int ;
CInt.   CType        ::= "int" ;

and testfile test_contract.tz:

DROP;
ADD;
DROP;
PUSH int -5;
PUSH int 1;

and execution with

bnfc --ocaml-menhir -m -o test test.cf && make -C test
`./ocaml_backend/TestMichelson test_contract.tz

[andreasabel]

I can confirm that this is a problem in --ocaml-menhir but not in --ocaml.

[andreasabel]

@JoAllg: Thanks for the bug report! I pushed a fix, could you please check that it works for you?

[JoAllg]

@andreasabel thanks for the quick fix! It does work! Though both column numbers are offset by one char, should be +1 char to the right

[andreasabel]

@JoAllg: It seems that the column is computed wrongly in:

bnfc/source/src/BNFC/Backend/OCaml/CFtoOCamlTest.hs

Lines 76 to 77 in fb4606b

	[ "start_pos.pos_lnum (start_pos.pos_cnum - start_pos.pos_bol)"
	, "end_pos.pos_lnum (end_pos.pos_cnum - end_pos.pos_bol);" ]

Looking at e.g.
https://github.com/let-def/ocamllex/blob/e5c8421f8fe56017e9b4e58c3496356631843802/lexer.mll#L54
it seems like a +1 is missing here.
I'll push a fix. Thanks for the alert!

[andreasabel]

@JoAllg: I pushed a fix for the column, so that it is now counted from 1 (and not from 0). Welcome to test again!

[JoAllg]

@andreasabel works like a charm now :-)