X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/9503b0a4a8928afa0fdab88672f6127ee7e87963..2b45240d6c1b9177533aa5d83ac1c879198111c5:/NEWS

diff --git a/NEWS b/NEWS
index 7e5bda2d..fd1cadd4 100644
--- a/NEWS
+++ b/NEWS
@@ -13,18 +13,58 @@ GNU Bison NEWS
 
 ** Warnings
 
+*** Enhancements of the -Werror option
+
+  The -Werror=CATEGORY option is now recognized, and will treat specified
+  warnings as errors. The warnings need not have been explictly activated
+  using the -W option, this is similar to what gcc 4.7 does.
+
+  For example, given the following command line, Bison will treat both
+  warnings related to POSIX Yacc incompatiblities and S/R conflicts as
+  errors (and only those):
+
+    $ bison -Werror=yacc,error=conflicts-sr input.y
+
+  If no categories are specified, -Werror will make all active warnings into
+  errors. For example, the following line does the same the previous example:
+
+    $ bison -Werror -Wnone -Wyacc -Wconflicts-sr input.y
+
+  (By default -Wconflicts-sr,conflicts-rr,deprecated,other is enabled.)
+
+  Note that the categories in this -Werror option may not be prefixed with
+  "no-". However, -Wno-error[=CATEGORY] is valid.
+
+  Note that -y enables -Werror=yacc. Therefore it is now possible to require
+  Yacc-like behavior (e.g., always generate y.tab.c), but to report
+  incompatibilities as warnings: "-y -Wno-error=yacc".
+
+*** The display of warnings is now richer
+
+  The option that controls a given warning is now displayed:
+
+    foo.y:4.6: warning: type clash on default action: <foo> != <bar> [-Wother]
+
+  In the case of warnings treated as errors, the prefix is changed from
+  "warning: " to "error: ", and the suffix is displayed, in a manner similar
+  to gcc, as [-Werror=CATEGORY].
+
+  For instance, where the previous version of Bison would report (and exit
+  with failure):
+
+    bison: warnings being treated as errors
+    input.y:1.1: warning: stray ',' treated as white space
+
+  it now reports:
+
+    input.y:1.1: error: stray ',' treated as white space [-Werror=other]
+
 *** Deprecated constructs
 
   The new 'deprecated' warning category flags obsolete constructs whose
   support will be discontinued.  It is enabled by default.  These warnings
   used to be reported as 'other' warnings.
 
-*** Warning categories are now displayed
-
-  For instance:
-
-  foo.y:4.6: warning: type clash on default action: <foo> != <bar> [-Wother]
-
 *** Useless semantic types
 
   Bison now warns about useless (uninhabited) semantic types.  Since
@@ -210,7 +250,9 @@ GNU Bison NEWS
   Incorrect definitions of YY_, issued by yacc.c when no parser header is
   generated, are removed.
 
-** Changes in the format of errors and exceptions output
+  All the generated headers are self-contained.
+
+** Changes in the format of error messages
 
   This used to be the format of many error reports:
 
@@ -222,6 +264,17 @@ 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.
+
 * Noteworthy changes in release 2.6.2 (2012-08-03) [stable]
 
 ** Bug fixes
@@ -2080,7 +2133,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
  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 Wother nterm arg init
- LocalWords:  TOK
+ LocalWords:  TOK calc yyo fval
 
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