c++: fix position operator signatures

[bison.git] / NEWS

diff --git a/NEWS b/NEWS
index ae8b297ced4fdeb52b2a6fe5e83ac6e22c042d80..37b8e2c02dbdae7675d7149740ee23492973f22b 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -2,45 +2,255 @@ GNU Bison NEWS
 
 * Noteworthy changes in release ?.? (????-??-??) [?]
 
 
 * Noteworthy changes in release ?.? (????-??-??) [?]
 

-** Future changes:
+  We consider compiler warnings about Bison generated parsers to be bugs.
+  Rather than working around them in your own project, please consider
+  reporting them to us.
+
+** Bug fixes
+
+  Warnings about uninitialized yylval and/or yylloc for push parsers with a
+  pure interface have been fixed for GCC 4.0 up to 4.8, and Clang 2.9 to
+  3.2.
+
+  Other issues in the test suite have been addressed.
+
+  Nul characters are correctly displayed in error messages.
+
+* Noteworthy changes in release 2.6.4 (2012-10-23) [stable]
+
+  Bison 2.6.3's --version was incorrect.  This release fixes this issue.
+
+* Noteworthy changes in release 2.6.3 (2012-10-22) [stable]
+
+** Bug fixes
+
+  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.
+
+  Stray Info files shipped by accident are removed.
+
+  Incorrect definitions of YY_, issued by yacc.c when no parser header is
+  generated, are removed.
+
+  All the generated headers are self-contained.
+
+** 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.
+
+** 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:

 
 

-  The next major release will drop support for generating parsers in K&R C,
-  and remove the definition of yystype (removal announced since Bison
-  1.875).
+    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.
+
+* Noteworthy changes in release 2.6.2 (2012-08-03) [stable]
+
+** Bug fixes
+
+  Buffer overruns, complaints from Flex, and portability issues in the test
+  suite have been fixed.
+
+** Spaces in %lex- and %parse-param (lalr1.cc, glr.cc)
+
+  Trailing end-of-lines in %parse-param or %lex-param would result in
+  invalid C++.  This is fixed.
+
+** Spurious spaces and end-of-lines
+
+  The generated files no longer end (nor start) with empty lines.
+
+* Noteworthy changes in release 2.6.1 (2012-07-30) [stable]
+
+ Bison no longer executes user-specified M4 code when processing a grammar.
+
+** Future Changes
+
+  In addition to the removal of the features announced in Bison 2.6, the
+  next major release will remove the "Temporary hack for adding a semicolon
+  to the user action", as announced in the release 2.5.  Instead of:
+
+    exp: exp "+" exp { $$ = $1 + $3 };
+
+  write:
+
+    exp: exp "+" exp { $$ = $1 + $3; };
+
+** Bug fixes

 
 

-** The generated header is included (yacc.c)
+*** Type names are now properly escaped.
+
+*** glr.cc: set_debug_level and debug_level work as expected.
+
+*** Stray @ or $ in actions
+
+  While Bison used to warn about stray $ or @ in action rules, it did not
+  for other actions such as printers, destructors, or initial actions.  It
+  now does.
+
+** Type names in actions
+
+  For consistency with rule actions, it is now possible to qualify $$ by a
+  type-name in destructors, printers, and initial actions.  For instance:
+
+    %printer { fprintf (yyo, "(%d, %f)", $<ival>$, $<fval>$); } <*> <>;
+
+  will display two values for each typed and untyped symbol (provided
+  that YYSTYPE has both "ival" and "fval" fields).
+
+* Noteworthy changes in release 2.6 (2012-07-19) [stable]
+
+** Future Changes
+
+  The next major release of Bison will drop support for the following
+  deprecated features.  Please report disagreements to bug-bison@gnu.org.
+
+*** K&R C parsers
+
+  Support for generating parsers in K&R C will be removed.  Parsers
+  generated for C support ISO C90, and are tested with ISO C99 and ISO C11
+  compilers.
+
+*** Features deprecated since Bison 1.875
+
+  The definitions of yystype and yyltype will be removed; use YYSTYPE and
+  YYLTYPE.
+
+  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)

 
   Instead of duplicating the content of the generated header (definition of
 
   Instead of duplicating the content of the generated header (definition of

-  YYSTYPE, yyltype etc.), the generated parser now includes it, as was
-  already the case for GLR or C++ parsers.
+  YYSTYPE, yyparse declaration etc.), the generated parser will include it,
+  as is already the case for GLR or C++ parsers.  This change is deferred
+  because existing versions of ylwrap (e.g., Automake 1.12.1) do not support
+  it.

 
 

-** Headers (yacc.c, glr.c, glr.cc)
+** Generated Parser Headers

 
 

-*** Guards
+*** Guards (yacc.c, glr.c, glr.cc)

 
   The generated headers are now guarded, as is already the case for C++
 
   The generated headers are now guarded, as is already the case for C++

-  parsers (lalr1.cc).  For intance, with --defines=foo.h:
+  parsers (lalr1.cc).  For instance, with --defines=foo.h:

 
 

-  #ifndef YY_FOO_H
-  # define YY_FOO_H
-  ...
-  #endif /* !YY_FOO_H  */
+    #ifndef YY_FOO_H
+    # define YY_FOO_H
+    ...
+    #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
 
 
   The generated header now declares yydebug and yyparse.  Both honor
   --name-prefix=bar_, and yield
 

-  int bar_parse (void);
+    int bar_parse (void);

 
   rather than
 
 
   rather than
 

-  #define yyparse bar_parse
-  int yyparse (void);
+    #define yyparse bar_parse
+    int yyparse (void);

 
   in order to facilitate the inclusion of several parser headers inside a
   single compilation unit.
 
 
   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 BAR_DEBUG
+                                      > #  if defined YYDEBUG
+                                      > #   if YYDEBUG
+                                      > #    define BAR_DEBUG 1
+                                      > #   else
+                                      > #    define BAR_DEBUG 0
+                                      > #   endif
+                                      > #  else
+    #  define YYDEBUG 0               | #   define BAR_DEBUG 0
+                                      > #  endif
+    # endif                           | # endif
+
+    # if YYDEBUG                      | # if BAR_DEBUG
+    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:
 * Noteworthy changes in release 2.5.1 (2012-06-05) [stable]
 
 ** Future changes:


@@ -78,10 +288,10 @@ GNU Bison NEWS
   The header files such as "parser.hh", "location.hh", etc. used a constant
   name for preprocessor guards, for instance:
 
   The header files such as "parser.hh", "location.hh", etc. used a constant
   name for preprocessor guards, for instance:
 

-  #ifndef BISON_LOCATION_HH
-  # define BISON_LOCATION_HH
-  ...
-  #endif // !BISON_LOCATION_HH
+    #ifndef BISON_LOCATION_HH
+    # define BISON_LOCATION_HH
+    ...
+    #endif // !BISON_LOCATION_HH

 
   The inclusion guard is now computed from "PREFIX/FILE-NAME", where lower
   case characters are converted to upper case, and series of
 
   The inclusion guard is now computed from "PREFIX/FILE-NAME", where lower
   case characters are converted to upper case, and series of


@@ -89,10 +299,10 @@ GNU Bison NEWS
 
   With "bison -o lang++/parser.cc", "location.hh" would now include:
 
 
   With "bison -o lang++/parser.cc", "location.hh" would now include:
 

-  #ifndef YY_LANG_LOCATION_HH
-  # define YY_LANG_LOCATION_HH
-  ...
-  #endif // !YY_LANG_LOCATION_HH
+    #ifndef YY_LANG_LOCATION_HH
+    # define YY_LANG_LOCATION_HH
+    ...
+    #endif // !YY_LANG_LOCATION_HH

 
 *** C++ locations:
 
 
 *** C++ locations:
 


@@ -323,33 +533,33 @@ GNU Bison NEWS
   to use it.  If, for instance, your location structure has "first"
   and "last" members, instead of
 
   to use it.  If, for instance, your location structure has "first"
   and "last" members, instead of
 

-      # define YYLLOC_DEFAULT(Current, Rhs, N)                             \
-        do                                                                 \
-          if (N)                                                           \
-            {                                                              \
-              (Current).first = (Rhs)[1].location.first;                   \
-              (Current).last  = (Rhs)[N].location.last;                    \
-            }                                                              \
-          else                                                             \
-            {                                                              \
-              (Current).first = (Current).last = (Rhs)[0].location.last;   \
-            }                                                              \
-        while (false)
+    # define YYLLOC_DEFAULT(Current, Rhs, N)                             \
+      do                                                                 \
+        if (N)                                                           \
+          {                                                              \
+            (Current).first = (Rhs)[1].location.first;                   \
+            (Current).last  = (Rhs)[N].location.last;                    \
+          }                                                              \
+        else                                                             \
+          {                                                              \
+            (Current).first = (Current).last = (Rhs)[0].location.last;   \
+          }                                                              \
+      while (false)

 
   use:
 
 
   use:
 

-      # define YYLLOC_DEFAULT(Current, Rhs, N)                             \
-        do                                                                 \
-          if (N)                                                           \
-            {                                                              \
-              (Current).first = YYRHSLOC (Rhs, 1).first;                   \
-              (Current).last  = YYRHSLOC (Rhs, N).last;                    \
-            }                                                              \
-          else                                                             \
-            {                                                              \
-              (Current).first = (Current).last = YYRHSLOC (Rhs, 0).last;   \
-            }                                                              \
-        while (false)
+    # define YYLLOC_DEFAULT(Current, Rhs, N)                             \
+      do                                                                 \
+        if (N)                                                           \
+          {                                                              \
+            (Current).first = YYRHSLOC (Rhs, 1).first;                   \
+            (Current).last  = YYRHSLOC (Rhs, N).last;                    \
+          }                                                              \
+        else                                                             \
+          {                                                              \
+            (Current).first = (Current).last = YYRHSLOC (Rhs, 0).last;   \
+          }                                                              \
+      while (false)

 
 ** YYLLOC_DEFAULT in C++:
 
 
 ** YYLLOC_DEFAULT in C++:
 


@@ -968,26 +1178,26 @@ GNU Bison NEWS
   if the symbols have destructors.  For instance:
 
      exp: exp "?" exp ":" exp { $1 ? $1 : $3; }
   if the symbols have destructors.  For instance:
 
      exp: exp "?" exp ":" exp { $1 ? $1 : $3; }

-       | exp "+" exp
-       ;
+        | exp "+" exp
+        ;

 
   will trigger a warning about $$ and $5 in the first rule, and $3 in
   the second ($1 is copied to $$ by the default rule).  This example
   most likely contains three errors, and could be rewritten as:
 
      exp: exp "?" exp ":" exp
 
   will trigger a warning about $$ and $5 in the first rule, and $3 in
   the second ($1 is copied to $$ by the default rule).  This example
   most likely contains three errors, and could be rewritten as:
 
      exp: exp "?" exp ":" exp

-           { $$ = $1 ? $3 : $5; free ($1 ? $5 : $3); free ($1); }
-       | exp "+" exp
-           { $$ = $1 ? $1 : $3; if ($1) free ($3); }
-       ;
+            { $$ = $1 ? $3 : $5; free ($1 ? $5 : $3); free ($1); }
+        | exp "+" exp
+            { $$ = $1 ? $1 : $3; if ($1) free ($3); }
+        ;

 
   However, if the original actions were really intended, memory leaks
   and all, the warnings can be suppressed by letting Bison believe the
   values are used, e.g.:
 
      exp: exp "?" exp ":" exp { $1 ? $1 : $3; (void) ($$, $5); }
 
   However, if the original actions were really intended, memory leaks
   and all, the warnings can be suppressed by letting Bison believe the
   values are used, e.g.:
 
      exp: exp "?" exp ":" exp { $1 ? $1 : $3; (void) ($$, $5); }

-       | exp "+" exp         { $$ = $1; (void) $3; }
-       ;
+        | exp "+" exp         { $$ = $1; (void) $3; }
+        ;

 
   If there are mid-rule actions, the warning is issued if no action
   uses it.  The following triggers no warning: $1 and $3 are used.
 
   If there are mid-rule actions, the warning is issued if no action
   uses it.  The following triggers no warning: $1 and $3 are used.


@@ -1202,6 +1412,33 @@ GNU Bison NEWS
   - "parsing stack overflow..." -> "parser stack overflow"
     GLR parsers now report "parser stack overflow" as per the Bison manual.
 
   - "parsing stack overflow..." -> "parser stack overflow"
     GLR parsers now report "parser stack overflow" as per the Bison manual.
 

+** %parse-param and %lex-param
+  The macros YYPARSE_PARAM and YYLEX_PARAM provide a means to pass
+  additional context to yyparse and yylex.  They suffer from several
+  shortcomings:
+
+  - a single argument only can be added,
+  - their types are weak (void *),
+  - this context is not passed to ancillary functions such as yyerror,
+  - only yacc.c parsers support them.
+
+  The new %parse-param/%lex-param directives provide a more precise control.
+  For instance:
+
+    %parse-param {int *nastiness}
+    %lex-param   {int *nastiness}
+    %parse-param {int *randomness}
+
+  results in the following signatures:
+
+    int yylex   (int *nastiness);
+    int yyparse (int *nastiness, int *randomness);
+
+  or, if both %pure-parser and %locations are used:
+
+    int yylex   (YYSTYPE *lvalp, YYLTYPE *llocp, int *nastiness);
+    int yyparse (int *nastiness, int *randomness);
+

 ** Bison now warns if it detects conflicting outputs to the same file,
   e.g., it generates a warning for "bison -d -o foo.h foo.y" since
   that command outputs both code and header to foo.h.
 ** Bison now warns if it detects conflicting outputs to the same file,
   e.g., it generates a warning for "bison -d -o foo.h foo.y" since
   that command outputs both code and header to foo.h.


@@ -1231,16 +1468,16 @@ GNU Bison NEWS
   In agreement with POSIX and with other Yaccs, leaving a default
   action is valid when $$ is untyped, and $1 typed:
 
   In agreement with POSIX and with other Yaccs, leaving a default
   action is valid when $$ is untyped, and $1 typed:
 

-       untyped: ... typed;
+        untyped: ... typed;

 
   but the converse remains an error:
 
 
   but the converse remains an error:
 

-       typed: ... untyped;
+        typed: ... untyped;

 
 ** Values of mid-rule actions
   The following code:
 
 
 ** Values of mid-rule actions
   The following code:
 

-       foo: { ... } { $$ = $1; } ...
+        foo: { ... } { $$ = $1; } ...

 
   was incorrectly rejected: $1 is defined in the second mid-rule
   action, and is equal to the $$ of the first mid-rule action.
 
   was incorrectly rejected: $1 is defined in the second mid-rule
   action, and is equal to the $$ of the first mid-rule action.


@@ -1322,9 +1559,9 @@ GNU Bison NEWS
 ** Incorrect "Token not used"
   On a grammar such as
 
 ** Incorrect "Token not used"
   On a grammar such as
 

-           %token useless useful
-           %%
-           exp: '0' %prec useful;
+    %token useless useful
+    %%
+    exp: '0' %prec useful;

 
   where a token was used to set the precedence of the last rule,
   bison reported both "useful" and "useless" as useless tokens.
 
   where a token was used to set the precedence of the last rule,
   bison reported both "useful" and "useless" as useless tokens.


@@ -1343,9 +1580,9 @@ GNU Bison NEWS
   the user symbol is used in the reports, the graphs, and the verbose
   error messages instead of "$end", which remains being the default.
   For instance
   the user symbol is used in the reports, the graphs, and the verbose
   error messages instead of "$end", which remains being the default.
   For instance

-     %token MYEOF 0
+    %token MYEOF 0

   or
   or

-     %token MYEOF 0 "end of file"
+    %token MYEOF 0 "end of file"

 
 ** Semantic parser
   This old option, which has been broken for ages, is removed.
 
 ** Semantic parser
   This old option, which has been broken for ages, is removed.


@@ -1381,9 +1618,9 @@ GNU Bison NEWS
   Previous versions don't complain when there is a type clash on
   the default action if the rule has a mid-rule action, such as in:
 
   Previous versions don't complain when there is a type clash on
   the default action if the rule has a mid-rule action, such as in:
 

-      %type <foo> bar
-      %%
-      bar: '0' {} '0';
+    %type <foo> bar
+    %%
+    bar: '0' {} '0';

 
   This is fixed.
 
 
   This is fixed.
 


@@ -1680,9 +1917,11 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
  LocalWords:  struct yystype DJGPP lex param Haible NUM alloca YYSTACK NUL goto
  LocalWords:  YYMAXDEPTH Unescaped UCNs YYLTYPE's yyltype typedefs inline Yaccs
  LocalWords:  Heriyanto Reenable dprec Hilfinger Eggert MYEOF Folle Menezes EOF
  LocalWords:  struct yystype DJGPP lex param Haible NUM alloca YYSTACK NUL goto
  LocalWords:  YYMAXDEPTH Unescaped UCNs YYLTYPE's yyltype typedefs inline Yaccs
  LocalWords:  Heriyanto Reenable dprec Hilfinger Eggert MYEOF Folle Menezes EOF

- LocalWords:  Lackovic define's itemset Groff Gettext malloc NEWS'ed YYDEBUG
+ LocalWords:  Lackovic define's itemset Groff Gettext malloc NEWS'ed YYDEBUG YY

  LocalWords:  namespaces strerror const autoconfiguration Dconst Autoconf's FDL
  LocalWords:  namespaces strerror const autoconfiguration Dconst Autoconf's FDL

- LocalWords:  Automake TMPDIR LESSEQ
+ 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 calc yyo fval

 
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