graphs: documentation

[bison.git] / NEWS

diff --git a/NEWS b/NEWS
index e8b2d952cd17da0a9bbe970d514a7bd98affab51..d1b66564f40c037512b62df9098d34bf118e00c0 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -4,7 +4,7 @@ GNU Bison NEWS
 
 ** Bug fixes
 
-  Bugs in the test suite have been fixed.
+  Bugs and portability issues in the test suite have been fixed.
 
   Some errors in translations have been addressed, and --help now directs
   users to the appropriate place to report them.
@@ -14,6 +14,8 @@ GNU Bison NEWS
   Incorrect definitions of YY_, issued by yacc.c when no parser header is
   generated, are removed.
 
+  All the generated headers are self-contained.
+
 ** Changes in the format of error messages
 
   This used to be the format of many error reports:
@@ -26,6 +28,71 @@ GNU Bison NEWS
     foo.y:5.10-25: result type clash on merge function 'merge': <t3> != <t2>
     foo.y:4.13-27:     previous declaration
 
+** Header guards (yacc.c, glr.c, glr.cc)
+
+  In order to avoid collisions, the header guards are now
+  YY_<PREFIX>_<FILE>_INCLUDED, instead of merely <PREFIX>_<FILE>.
+  For instance the header generated from
+
+    %define api.prefix "calc"
+    %defines "lib/parse.h"
+
+  will use YY_CALC_LIB_PARSE_H_INCLUDED as guard.
+
+** 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.
+
+** Fix compiler warnings in the generated parser (yacc.c, glr.c)
+
+  The compilation of pure parsers (%define api.pure) can trigger GCC
+  warnings such as:
+
+    input.c: In function 'yyparse':
+    input.c:1503:12: warning: 'yylval' may be used uninitialized in this
+                              function [-Wmaybe-uninitialized]
+       *++yyvsp = yylval;
+                ^
+
+  This is now fixed; pragmas to avoid these warnings are no longer needed.
+
+  Warnings from clang ("equality comparison with extraneous parentheses" and
+  "function declared 'noreturn' should not return") have also been
+  addressed.
+
+** New %define variable: api.location.type (glr.cc, lalr1.cc, lalr1.java)
+
+  The %define variable api.location.type defines the name of the type to use
+  for locations.  When defined, Bison no longer generates the position.hh
+  and location.hh files, nor does the parser will include them: the user is
+  then responsible to define her type.
+
+  This can be used in programs with several parsers to factor their location
+  and position files: let one of them generate them, and the others just use
+  them.
+
+  This feature was actually introduced, but not documented, in Bison 2.5,
+  under the name "location_type" (which is maintained for backward
+  compatibility).
+
+  For consistency, lalr1.java's %define variables location_type and
+  position_type are deprecated in favor of api.location.type and
+  api.position.type.
+
+** Graphviz improvements
+
+  The graphical presentation of the states is more readable: their shape is
+  now rectangular, the state number is clearly displayed, and the items are
+  numbered and left-justified.
+
+  The reductions are now explicitly represented as transitions to other
+  diamond shaped nodes.
+
 * Noteworthy changes in release 2.6.2 (2012-08-03) [stable]
 
 ** Bug fixes
@@ -1883,7 +1950,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
  LocalWords:  namespaces strerror const autoconfiguration Dconst Autoconf's FDL
  LocalWords:  Automake TMPDIR LESSEQ ylwrap endif yydebug YYTOKEN YYLSP ival hh
  LocalWords:  extern YYTOKENTYPE TOKENTYPE yytokentype tokentype STYPE lval pdf
- LocalWords:  lang yyoutput dvi html ps POSIX lvalp llocp
+ LocalWords:  lang yyoutput dvi html ps POSIX lvalp llocp calc yyo fval Wmaybe
+ LocalWords:  yyvsp pragmas noreturn java's
 
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