api.prefix.

[bison.git] / NEWS

diff --git a/NEWS b/NEWS
index 10829f5438df93d6bbe0e3d67079d92c276ffc8c..371b9333c68ef641aa52ae971b65cb5993348aa9 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -13,14 +13,16 @@ GNU Bison NEWS
   generated for C supprt ISO C90, and are tested with ISO C99 and ISO C11
   compilers.
 
-*** Deprecated features
+*** Features deprecated since Bison 1.875
 
-  The definitions of yystype and yyltype will be removed, as announced since
-  Bison 1.875.  Use YYSTYPE and YYLTYPE only.
+  The definitions of yystype and yyltype will be removed; use YYSTYPE and
+  YYLTYPE.
 
-  YYPARSE_PARAM and YYLEX_PARAM, which were deprecated in favor of
-  %parse-param and %lex-param (introduced in Bison 1.875), will no longer be
-  supported.
+  YYPARSE_PARAM and YYLEX_PARAM, deprecated in favor of %parse-param and
+  %lex-param, will no longer be supported.
+
+  Support for the preprocessor symbol YYERROR_VERBOSE will be removed, use
+  %error-verbose.
 
 *** The generated header will be included (yacc.c)
 
@@ -30,9 +32,9 @@ GNU Bison NEWS
   because existing versions of ylwrap (e.g., Automake 1.12.1) do not support
   it.
 
-** Headers (yacc.c, glr.c, glr.cc)
+** Headers
 
-*** Guards
+*** Guards (yacc.c, glr.c, glr.cc)
 
   The generated headers are now guarded, as is already the case for C++
   parsers (lalr1.cc).  For intance, with --defines=foo.h:
@@ -42,7 +44,7 @@ GNU Bison NEWS
     ...
     #endif /* !YY_FOO_H  */
 
-*** New declarations
+*** New declarations (yacc.c, glr.c)
 
   The generated header now declares yydebug and yyparse.  Both honor
   --name-prefix=bar_, and yield
@@ -57,6 +59,71 @@ GNU Bison NEWS
   in order to facilitate the inclusion of several parser headers inside a
   single compilation unit.
 
+*** Exported symbols in C++
+
+  The symbols YYTOKEN_TABLE and YYERROR_VERBOSE, which were defined in the
+  header, are removed, as they prevent the possibility of including several
+  generated headers from a single compilation unit.
+
+*** YYLSP_NEEDED
+
+  For the same reasons, the undocumented and unused macro YYLSP_NEEDED is no
+  longer defined.
+
+** New %define variable: api.prefix
+
+  Now that the generated headers are more complete and properly protected
+  against multiple inclusions, constant names, such as YYSTYPE are a
+  problem.  While yyparse and others are properly renamed by %name-prefix,
+  YYSTYPE, YYDEBUG and others have never been affected by it.  Because it
+  would introduce backward compatibility issues in projects not expecting
+  YYSTYPE to be renamed, instead of changing the behavior of %name-prefix,
+  it is deprecated in favor of a new %define variable: api.prefix.
+
+  The following examples compares both:
+
+    %name-prefix "bar_"               | %define api.prefix "bar_"
+    %token <ival> FOO                   %token <ival> FOO
+    %union { int ival; }                %union { int ival; }
+    %%                                  %%
+    exp: 'a';                           exp: 'a';
+
+  bison generates:
+
+    #ifndef BAR_FOO_H                   #ifndef BAR_FOO_H
+    # define BAR_FOO_H                  # define BAR_FOO_H
+
+    /* Enabling traces.  */             /* Enabling traces.  */
+    # ifndef YYDEBUG                    # ifndef YYDEBUG
+    #  define YYDEBUG 0                 #  define YYDEBUG 0
+    # endif                             # endif
+    # if YYDEBUG                        # if YYDEBUG
+    extern int bar_debug;               extern int bar_debug;
+    # endif                             # endif
+
+    /* Tokens.  */                      /* Tokens.  */
+    # ifndef YYTOKENTYPE              | # ifndef BAR_TOKENTYPE
+    #  define YYTOKENTYPE             | #  define BAR_TOKENTYPE
+       enum yytokentype {             |    enum bar_tokentype {
+         FOO = 258                           FOO = 258
+       };                                  };
+    # endif                             # endif
+
+    #if ! defined YYSTYPE \           | #if ! defined BAR_STYPE \
+     && ! defined YYSTYPE_IS_DECLARED |  && ! defined BAR_STYPE_IS_DECLARED
+    typedef union YYSTYPE             | typedef union BAR_STYPE
+    {                                   {
+     int ival;                           int ival;
+    } YYSTYPE;                        | } BAR_STYPE;
+    # define YYSTYPE_IS_DECLARED 1    | # define BAR_STYPE_IS_DECLARED 1
+    #endif                              #endif
+
+    extern YYSTYPE bar_lval;          | extern BAR_STYPE bar_lval;
+
+    int bar_parse (void);               int bar_parse (void);
+
+    #endif /* !BAR_FOO_H  */            #endif /* !BAR_FOO_H  */
+
 * Noteworthy changes in release 2.5.1 (2012-06-05) [stable]
 
 ** Future changes: