tables: scope reduction

[bison.git] / NEWS

diff --git a/NEWS b/NEWS
index a1bb0f91c8a1f9aee932ca01ef0ca434f370d4e7..d4f8a750283be5563c5c20bca956793ff18ccfdc 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -6,10 +6,13 @@ GNU Bison NEWS
 
 *** Obsolete features
 
 
 *** Obsolete features
 

-  Support for YYFAIL is removed (deprecated in Bison 2.4.2).
-  Support for yystype and yyltype (instead of YYSTYPE and YYLTYPE)
-  is removed (deprecated in Bison 1.875).
-  Support for YYPARSE_PARAM is removed (deprecated in Bison 1.875).
+  Support for YYFAIL is removed (deprecated in Bison 2.4.2): use YYERROR.
+
+  Support for yystype and yyltype is removed (deprecated in Bison 1.875):
+  use YYSTYPE and YYLTYPE.
+
+  Support for YYLEX_PARAM and YYPARSE_PARAM is removed (deprecated in Bison
+  1.875): use %lex-param, %parse-param, or %param.

 
 ** Warnings
 
 
 ** Warnings
 


@@ -240,39 +243,70 @@ GNU Bison NEWS
   It used to be an error only if used in non GLR mode, _and_ if there are
   reduce/reduce conflicts.
 
   It used to be an error only if used in non GLR mode, _and_ if there are
   reduce/reduce conflicts.
 

-* Noteworthy changes in release ?.? (????-??-??) [?]
+* Noteworthy changes in release 2.7 (2012-12-12) [stable]

 
 

-** New value for %define variable: api.pure full
+** Bug fixes

 
 

-  The %define variable api.pure requests a pure (reentrant) parser. However,
-  for historical reasons, using it in a location-tracking Yacc parser resulted
-  in an yyerror function that did not take a location as a parameter. With this
-  new value, the user may request a better pure parser, where yyerror does take
-  a location as a parameter (in location-tracking parsers).
+  Warnings about uninitialized yylloc in yyparse have been fixed.

 
 

-  The use of "%define api.pure true" is deprecated in favor of this new
-  "%define api.pure full".
+  Restored C90 compliance (yet no report was ever made).

 
 

-** Changes in the format of error messages
+** Diagnostics are improved
+
+*** Changes in the format of error messages

 
   This used to be the format of many error reports:
 
 
   This used to be the format of many error reports:
 

-    foo.y:5.10-24: result type clash on merge function 'merge': <t3> != <t2>
-    foo.y:4.13-27: previous declaration
+    input.y:2.7-12: %type redeclaration for exp
+    input.y:1.7-12: previous declaration

 
   It is now:
 
 
   It is now:
 

-    foo.y:5.10-25: result type clash on merge function 'merge': <t3> != <t2>
-    foo.y:4.13-27:     previous declaration
+    input.y:2.7-12: error: %type redeclaration for exp
+    input.y:1.7-12:     previous declaration

 
 

-** Exception safety (lalr1.cc)
+*** New format for error reports: carets

 
 

-  The parse function now catches exceptions, uses the %destructors to
-  release memory (the lookahead symbol and the symbols pushed on the stack)
-  before re-throwing the exception.
+  Caret errors have been added to Bison:

 
 

-  This feature is somewhat experimental.  User feedback would be
-  appreciated.
+    input.y:2.7-12: error: %type redeclaration for exp
+     %type <sval> exp
+           ^^^^^^
+    input.y:1.7-12:     previous declaration
+     %type <ival> exp
+           ^^^^^^
+
+  or
+
+    input.y:3.20-23: error: ambiguous reference: '$exp'
+     exp: exp '+' exp { $exp = $1 + $3; };
+                        ^^^^
+    input.y:3.1-3:       refers to: $exp at $$
+     exp: exp '+' exp { $exp = $1 + $3; };
+     ^^^
+    input.y:3.6-8:       refers to: $exp at $1
+     exp: exp '+' exp { $exp = $1 + $3; };
+          ^^^
+    input.y:3.14-16:     refers to: $exp at $3
+     exp: exp '+' exp { $exp = $1 + $3; };
+                  ^^^
+
+  The default behaviour for now is still not to display these unless
+  explictly asked with -fcaret (or -fall). However, in a later release, it
+  will be made the default behavior (but may still be deactivated with
+  -fno-caret).
+
+** New value for %define variable: api.pure full
+
+  The %define variable api.pure requests a pure (reentrant) parser. However,
+  for historical reasons, using it in a location-tracking Yacc parser
+  resulted in a yyerror function that did not take a location as a
+  parameter. With this new value, the user may request a better pure parser,
+  where yyerror does take a location as a parameter (in location-tracking
+  parsers).
+
+  The use of "%define api.pure true" is deprecated in favor of this new
+  "%define api.pure full".

 
 ** New %define variable: api.location.type (glr.cc, lalr1.cc, lalr1.java)
 
 
 ** New %define variable: api.location.type (glr.cc, lalr1.cc, lalr1.java)
 


@@ -293,6 +327,15 @@ GNU Bison NEWS
   position_type are deprecated in favor of api.location.type and
   api.position.type.
 
   position_type are deprecated in favor of api.location.type and
   api.position.type.
 

+** Exception safety (lalr1.cc)
+
+  The parse function now catches exceptions, uses the %destructors to
+  release memory (the lookahead symbol and the symbols pushed on the stack)
+  before re-throwing the exception.
+
+  This feature is somewhat experimental.  User feedback would be
+  appreciated.
+

 ** Graph improvements in DOT and XSLT
 
   The graphical presentation of the states is more readable: their shape is
 ** Graph improvements in DOT and XSLT
 
   The graphical presentation of the states is more readable: their shape is


@@ -305,19 +348,21 @@ GNU Bison NEWS
   These changes are present in both --graph output and xml2dot.xsl XSLT
   processing, with minor (documented) differences.
 
   These changes are present in both --graph output and xml2dot.xsl XSLT
   processing, with minor (documented) differences.
 

-  Two nodes were added to the documentation: Xml and Graphviz.
-
-* Noteworthy changes in release ?.? (????-??-??) [?]
-
-** Bug fixes
+** %language is no longer an experimental feature.

 
 

-  Warnings about uninitialized yylloc in yyparse have been fixed.
+  The introduction of this feature, in 2.4, was four years ago. The
+  --language option and the %language directive are no longer experimental.

 
 ** Documentation
 
   The sections about shift/reduce and reduce/reduce conflicts resolution
   have been fixed and extended.
 
 
 ** Documentation
 
   The sections about shift/reduce and reduce/reduce conflicts resolution
   have been fixed and extended.
 

+  Although introduced more than four years ago, XML and Graphviz reports
+  were not properly documented.
+
+  The translation of mid-rule actions is now described.
+

 * Noteworthy changes in release 2.6.5 (2012-11-07) [stable]
 
   We consider compiler warnings about Bison generated parsers to be bugs.
 * Noteworthy changes in release 2.6.5 (2012-11-07) [stable]
 
   We consider compiler warnings about Bison generated parsers to be bugs.


@@ -703,6 +748,7 @@ GNU Bison NEWS
 
   These features are experimental in this version.  More user feedback
   will help to stabilize them.
 
   These features are experimental in this version.  More user feedback
   will help to stabilize them.

+  Contributed by Alex Rozenman.

 
 ** IELR(1) and canonical LR(1):
 
 
 ** IELR(1) and canonical LR(1):
 


@@ -1219,6 +1265,7 @@ GNU Bison NEWS
 
   The current Java interface is experimental and may evolve.  More user
   feedback will help to stabilize it.
 
   The current Java interface is experimental and may evolve.  More user
   feedback will help to stabilize it.

+  Contributed by Paolo Bonzini.

 
 ** %language
 
 
 ** %language
 


@@ -1232,6 +1279,7 @@ GNU Bison NEWS
   Bison can now generate an XML report of the LALR(1) automaton using the new
   "--xml" option.  The current XML schema is experimental and may evolve.  More
   user feedback will help to stabilize it.
   Bison can now generate an XML report of the LALR(1) automaton using the new
   "--xml" option.  The current XML schema is experimental and may evolve.  More
   user feedback will help to stabilize it.

+  Contributed by Wojciech Polak.

 
 ** The grammar file may now specify the name of the parser header file using
   %defines.  For example:
 
 ** The grammar file may now specify the name of the parser header file using
   %defines.  For example: