Re: bison-2.4.2 released [stable]

[Joel E. Denny]

On Tue, 30 Mar 2010, Joel E. Denny wrote:

> On Mon, 29 Mar 2010, Richard Stallman wrote:
> 
> >       POSIX specifies that an error be reported for any identifier that does
> >       not appear on the LHS of a grammar rule and that is not defined by
> >       %token, %left, %right, or %nonassoc.  Bison 2.3b and later lost this
> >       error report for the case when an identifier appears only after a
> >       %prec directive.  It is now restored.  However, for backward
> >       compatibility with recent Bison releases, it is only a warning for
> >       now.  In Bison 2.5 and later, it will return to being an error.
> > 
> > Why not keep it as a warning only?
> 
> Fine with me.  Any opinions from anyone else?

I pushed the first patch below to master and branch-2.5.  I pushed the 
second patch to branch-2.4.3, branch-2.5, and master.

>From 02354690ee02dfa05564137aafc6721eb54d21ab Mon Sep 17 00:00:00 2001
From: Joel E. Denny <address@hidden>
Date: Fri, 30 Apr 2010 14:41:07 -0400
Subject: [PATCH] Revert 2009-12-30 change for undefined %prec token complaints.

That is, keep them as warnings because that should be sufficient
to satisfy POSIX without creating backward compatibility issues.
Suggested by Richard Stallman at
<http://lists.gnu.org/archive/html/bison-patches/2010-03/msg00033.html>.
* NEWS (2.5): Remove mention of complaint.
* src/reader.c (grammar_rule_check): Convert warning back to
complaint.
* tests/input.at (%prec's token must be defined): Update.
---
 ChangeLog      |   12 ++++++++++++
 NEWS           |    6 ------
 src/reader.c   |    4 ++--
 tests/input.at |    4 ++--
 4 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index f16e056..c129357 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2010-04-30  Joel E. Denny  <address@hidden>
+
+       Revert 2009-12-30 change for undefined %prec token complaints.
+       That is, keep them as warnings because that should be sufficient
+       to satisfy POSIX without creating backward compatibility issues.
+       Suggested by Richard Stallman at
+       <http://lists.gnu.org/archive/html/bison-patches/2010-03/msg00033.html>.
+       * NEWS (2.5): Remove mention of complaint.
+       * src/reader.c (grammar_rule_check): Convert warning back to
+       complaint.
+       * tests/input.at (%prec's token must be defined): Update.
+
 2010-04-25  Joel E. Denny  <address@hidden>
 
        build: don't require src/bison during bootstrap.
diff --git a/NEWS b/NEWS
index 4c4409b..acdd5be 100644
--- a/NEWS
+++ b/NEWS
@@ -180,12 +180,6 @@ Bison News
   discussion of how to suppress C preprocessor warnings about YYFAIL
   being unused, see the Bison 2.4.2 NEWS entry.
 
-** `%prec IDENTIFIER' requires IDENTIFIER to be defined separately.
-
-  As promised in Bison 2.4.2's NEWS entry, it is now an error if a token
-  that appears after a %prec directive is not defined by %token, %left,
-  %right, or %nonassoc.  This is required by POSIX.
-
 ** Temporary hack for adding a semicolon to the user action.
 
   Previously, Bison appended a semicolon to every user action for
diff --git a/src/reader.c b/src/reader.c
index 03c5bae..f1be24b 100644
--- a/src/reader.c
+++ b/src/reader.c
@@ -327,8 +327,8 @@ grammar_rule_check (const symbol_list *r)
   if (r->ruleprec
       && r->ruleprec->tag[0] != '\'' && r->ruleprec->tag[0] != '"'
       && !r->ruleprec->declared && !r->ruleprec->prec)
-    complain_at (r->location, _("token for %%prec is not defined: %s"),
-                 r->ruleprec->tag);
+    warn_at (r->location, _("token for %%prec is not defined: %s"),
+             r->ruleprec->tag);
 }
 
 
diff --git a/tests/input.at b/tests/input.at
index 71fc356..64a1809 100644
--- a/tests/input.at
+++ b/tests/input.at
@@ -806,8 +806,8 @@ AT_DATA([[input.y]],
 start: %prec PREC ;
 ]])
 
-AT_BISON_CHECK([[input.y]], [[1]], [],
-[[input.y:2.8-17: token for %prec is not defined: PREC
+AT_BISON_CHECK([[input.y]], [[0]], [],
+[[input.y:2.8-17: warning: token for %prec is not defined: PREC
 ]])
 
 AT_CLEANUP
-- 
1.5.4.3

>From ff1f7871df81d5183eafeff380104da7a4a94749 Mon Sep 17 00:00:00 2001
From: Joel E. Denny <address@hidden>
Date: Fri, 30 Apr 2010 15:29:23 -0400
Subject: [PATCH] Document that undefined %prec identifier warnings will remain.

* NEWS (2.4.3): Here.
(2.4.2): Here.
---
 ChangeLog |    6 ++++++
 NEWS      |    7 +++++++
 2 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 18b0946..a1dbfbf 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2010-04-30  Joel E. Denny  <address@hidden>
+
+       Document that undefined %prec identifier warnings will remain.
+       * NEWS (2.4.3): Here.
+       (2.4.2): Here.
+
 2010-04-25  Joel E. Denny  <address@hidden>
 
        build: don't require src/bison during bootstrap.
diff --git a/NEWS b/NEWS
index ceee3d9..66622ac 100644
--- a/NEWS
+++ b/NEWS
@@ -11,6 +11,11 @@ Bison News
 ** Failures in the test suite for some versions of Sun Studio C++ have
    been fixed.
 
+** Contrary to Bison 2.4.2's NEWS entry, it has been decided that
+   warnings about undefined %prec identifiers will not be converted to
+   errors in Bison 2.5.  They will remain warnings, which should be
+   sufficient for POSIX while avoiding backward compatibility issues.
+
 * Changes in version 2.4.2 (2010-03-20):
 
 ** Some portability problems that resulted in failures and livelocks
@@ -28,6 +33,8 @@ Bison News
   %prec directive.  It is now restored.  However, for backward
   compatibility with recent Bison releases, it is only a warning for
   now.  In Bison 2.5 and later, it will return to being an error.
+  [Between the 2.4.2 and 2.4.3 releases, it was decided that this
+  warning will not be converted to an error in Bison 2.5.]
 
 ** Detection of GNU M4 1.4.6 or newer during configure is improved.
 
-- 
1.5.4.3