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%expect-rr: fix the computation of the overall number of conflicts

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On a grammar such as

   exp: "num" | "num" | "num"

we currently report only one RR conflict, instead of two.

This bug is present since the origins of Bison

    commit 08089d5d35
    Author: David MacKenzie <djm@djmnet.org>
    Date:   Tue Apr 20 05:42:52 1993 +0000

       Initial revision

and was preserved in

    commit 676385e29c
    Author: Paul Hilfinger <Hilfinger@CS.Berkeley.EDU>
    Date:   Fri Jun 28 02:26:44 2002 +0000

       Initial check-in introducing experimental GLR parsing.  See entry in
       ChangeLog dated 2002-06-27 from Paul Hilfinger for details.

See
https://lists.gnu.org/archive/html/bison-patches/2018-11/msg00011.html

* src/conflicts.h, src/conflicts.c (count_state_rr_conflicts)
(count_rr_conflicts): Use only the correct count of conflicts.
* tests/glr-regression.at: Fix expectations.
This commit is contained in:
Akim Demaille
2018-11-08 21:46:16 +01:00
parent 260ae5481c
commit ad0b4661d1
4 changed files with 33 additions and 23 deletions
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14
NEWS
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@@ -26,6 +26,20 @@ GNU Bison NEWS
The use of the %error-verbose directive is deprecated in favor of "%define
parse.error verbose" since Bison 3.0, but no warning was issued.
** Bug fixes
*** Incorrect number of reduce-reduce conflicts
On a grammar such as
exp: "num" | "num" | "num"
bison used report a single RR conflict, instead of two. This is now
fixed. This was the oldest (known) bug in Bison: it was there when Bison
was entered in the RCS version control system, in December 1987.
Some grammar files might have to adjust their %expect-rr.
* Noteworthy changes in release 3.2.2 (2018-11-21) [stable]
** Bug fixes