tests: remove quote magic from the bison test wrapper.

[bison.git] / NEWS

diff --git a/NEWS b/NEWS
index 99814004ff6b96128ad26592920e240da479cc2a..293e2dfda6a20e13191d58702d220fa313f77bcb 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -24,6 +24,15 @@ Bison News
   Also, it is possible to add code to the parser's constructors using
   "%code init" and "%define init_throws".
 
   Also, it is possible to add code to the parser's constructors using
   "%code init" and "%define init_throws".
 

+** C++ skeleton improvements
+
+  The C++ parser features a syntax_error exception, which can be
+  thrown from the scanner or from user rules to raise syntax errors.
+  This facilitates reporting errors caught in sub-functions (e.g.,
+  rejecting too large integral literals from a conversion function
+  used by the scanner, or rejecting invalid combinations from a
+  factory invoked by the user actions).
+

 ** Variable api.tokens.prefix
 
   The variable api.tokens.prefix changes the way tokens are identified in
 ** Variable api.tokens.prefix
 
   The variable api.tokens.prefix changes the way tokens are identified in


@@ -60,7 +69,23 @@ Bison News
   allow the programmer to prune possible parses based on the values of
   runtime expressions.
 
   allow the programmer to prune possible parses based on the values of
   runtime expressions.
 

-* Changes in version 2.5 (????-??-??):
+* Changes in version 2.5.1 (????-??-??):
+
+** Some portability problems in the test suite have been fixed.
+
+** Minor improvements have been made to the manual.
+
+** YYBACKUP works as expected.
+
+* Changes in version 2.5 (2011-05-14):
+
+** Grammar symbol names can now contain non-initial dashes:
+
+  Consistently with directives (such as %error-verbose) and with
+  %define variables (e.g. push-pull), grammar symbol names may contain
+  dashes in any position except the beginning.  This is a GNU
+  extension over POSIX Yacc.  Thus, use of this extension is reported
+  by -Wyacc and rejected in Yacc mode (--yacc).

 
 ** Named references:
 
 
 ** Named references:
 


@@ -72,12 +97,12 @@ Bison News
   When no ambiguity is possible, original symbol names may be used
   as named references:
 
   When no ambiguity is possible, original symbol names may be used
   as named references:
 

-    if_stmt : 'if' cond_expr 'then' then_stmt ';'
+    if_stmt : "if" cond_expr "then" then_stmt ';'

     { $if_stmt = mk_if_stmt($cond_expr, $then_stmt); }
 
   In the more common case, explicit names may be declared:
 
     { $if_stmt = mk_if_stmt($cond_expr, $then_stmt); }
 
   In the more common case, explicit names may be declared:
 

-    stmt[res] : 'if' expr[cond] 'then' stmt[then] 'else' stmt[else] ';'
+    stmt[res] : "if" expr[cond] "then" stmt[then] "else" stmt[else] ';'

     { $res = mk_if_stmt($cond, $then, $else); }
 
   Location information is also accessible using @name syntax.  When
     { $res = mk_if_stmt($cond, $then, $else); }
 
   Location information is also accessible using @name syntax.  When


@@ -91,7 +116,7 @@ Bison News
 
   IELR(1) is a minimal LR(1) parser table generation algorithm.  That
   is, given any context-free grammar, IELR(1) generates parser tables
 
   IELR(1) is a minimal LR(1) parser table generation algorithm.  That
   is, given any context-free grammar, IELR(1) generates parser tables

-  with the full language recognition power of canonical LR(1) but with
+  with the full language-recognition power of canonical LR(1) but with

   nearly the same number of parser states as LALR(1).  This reduction
   in parser states is often an order of magnitude.  More importantly,
   because canonical LR(1)'s extra parser states may contain duplicate
   nearly the same number of parser states as LALR(1).  This reduction
   in parser states is often an order of magnitude.  More importantly,
   because canonical LR(1)'s extra parser states may contain duplicate


@@ -108,27 +133,27 @@ Bison News
     %define lr.type ielr
     %define lr.type canonical-lr
 
     %define lr.type ielr
     %define lr.type canonical-lr
 

-  The default reduction optimization in the parser tables can also be
-  adjusted using `%define lr.default-reductions'.  See the documentation
-  for `%define lr.type' and `%define lr.default-reductions' in the
-  section `Bison Declaration Summary' in the Bison manual for the
-  details.
+  The default-reduction optimization in the parser tables can also be
+  adjusted using `%define lr.default-reductions'.  For details on both
+  of these features, see the new section `Tuning LR' in the Bison
+  manual.

 
   These features are experimental.  More user feedback will help to
   stabilize them.
 
 
   These features are experimental.  More user feedback will help to
   stabilize them.
 

-** LAC (lookahead correction) for syntax error handling:
+** LAC (Lookahead Correction) for syntax error handling:

 
   Canonical LR, IELR, and LALR can suffer from a couple of problems
   upon encountering a syntax error.  First, the parser might perform
   additional parser stack reductions before discovering the syntax
 
   Canonical LR, IELR, and LALR can suffer from a couple of problems
   upon encountering a syntax error.  First, the parser might perform
   additional parser stack reductions before discovering the syntax

-  error.  Such reductions perform user semantic actions that are
+  error.  Such reductions can perform user semantic actions that are

   unexpected because they are based on an invalid token, and they
   cause error recovery to begin in a different syntactic context than
   the one in which the invalid token was encountered.  Second, when
   unexpected because they are based on an invalid token, and they
   cause error recovery to begin in a different syntactic context than
   the one in which the invalid token was encountered.  Second, when

-  verbose error messages are enabled (with %error-verbose or `#define
-  YYERROR_VERBOSE'), the expected token list in the syntax error
-  message can both contain invalid tokens and omit valid tokens.
+  verbose error messages are enabled (with %error-verbose or the
+  obsolete `#define YYERROR_VERBOSE'), the expected token list in the
+  syntax error message can both contain invalid tokens and omit valid
+  tokens.

 
   The culprits for the above problems are %nonassoc, default
   reductions in inconsistent states, and parser state merging.  Thus,
 
   The culprits for the above problems are %nonassoc, default
   reductions in inconsistent states, and parser state merging.  Thus,


@@ -136,11 +161,11 @@ Bison News
   %nonassoc is used or if default reductions are enabled for
   inconsistent states.
 
   %nonassoc is used or if default reductions are enabled for
   inconsistent states.
 

-  LAC is a new mechanism within the parsing algorithm that completely
-  solves these problems for canonical LR, IELR, and LALR without
-  sacrificing %nonassoc, default reductions, or state mering.  When
-  LAC is in use, canonical LR and IELR behave exactly the same for
-  both syntactically acceptable and syntactically unacceptable input.
+  LAC is a new mechanism within the parsing algorithm that solves
+  these problems for canonical LR, IELR, and LALR without sacrificing
+  %nonassoc, default reductions, or state merging.  When LAC is in
+  use, canonical LR and IELR behave almost exactly the same for both
+  syntactically acceptable and syntactically unacceptable input.

   While LALR still does not support the full language-recognition
   power of canonical LR and IELR, LAC at least enables LALR's syntax
   error handling to correctly reflect LALR's language-recognition
   While LALR still does not support the full language-recognition
   power of canonical LR and IELR, LAC at least enables LALR's syntax
   error handling to correctly reflect LALR's language-recognition


@@ -151,20 +176,14 @@ Bison News
 
     %define parse.lac full
 
 
     %define parse.lac full
 

-  See the documentation for `%define parse.lac' in the section `Bison
-  Declaration Summary' in the Bison manual for additional details.
+  See the new section `LAC' in the Bison manual for additional
+  details including a few caveats.

 
   LAC is an experimental feature.  More user feedback will help to
   stabilize it.
 
 
   LAC is an experimental feature.  More user feedback will help to
   stabilize it.
 

-** Unrecognized %code qualifiers are now errors not warnings.
-

 ** %define improvements:
 
 ** %define improvements:
 

-*** Unrecognized variables are now errors not warnings.
-
-*** Multiple invocations for any variable is now an error not a warning.
-

 *** Can now be invoked via the command line:
 
   Each of these command-line options
 *** Can now be invoked via the command line:
 
   Each of these command-line options


@@ -182,7 +201,7 @@ Bison News
   except that the manner in which Bison processes multiple definitions
   for the same NAME differs.  Most importantly, -F and --force-define
   quietly override %define, but -D and --define do not.  For further
   except that the manner in which Bison processes multiple definitions
   for the same NAME differs.  Most importantly, -F and --force-define
   quietly override %define, but -D and --define do not.  For further

-  details, see the section "Bison Options" in the Bison manual.
+  details, see the section `Bison Options' in the Bison manual.

 
 *** Variables renamed:
 
 
 *** Variables renamed:
 


@@ -199,7 +218,7 @@ Bison News
   The old names are now deprecated but will be maintained indefinitely
   for backward compatibility.
 
   The old names are now deprecated but will be maintained indefinitely
   for backward compatibility.
 

-*** Values no longer need to be quoted in grammar file:
+*** Values no longer need to be quoted in the grammar file:

 
   If a %define value is an identifier, it no longer needs to be placed
   within quotations marks.  For example,
 
   If a %define value is an identifier, it no longer needs to be placed
   within quotations marks.  For example,


@@ -210,13 +229,73 @@ Bison News
 
     %define api.push-pull push
 
 
     %define api.push-pull push
 

-** Grammar symbol names can now contain dashes:
+*** Unrecognized variables are now errors not warnings.
+
+*** Multiple invocations for any variable is now an error not a warning.
+
+** Unrecognized %code qualifiers are now errors not warnings.
+
+** Character literals not of length one:
+
+  Previously, Bison quietly converted all character literals to length
+  one.  For example, without warning, Bison interpreted the operators in
+  the following grammar to be the same token:
+
+    exp: exp '++'
+       | exp '+' exp
+       ;
+
+  Bison now warns when a character literal is not of length one.  In
+  some future release, Bison will start reporting an error instead.
+
+** Destructor calls fixed for lookaheads altered in semantic actions:
+
+  Previously for deterministic parsers in C, if a user semantic action
+  altered yychar, the parser in some cases used the old yychar value to
+  determine which destructor to call for the lookahead upon a syntax
+  error or upon parser return.  This bug has been fixed.
+
+** C++ parsers use YYRHSLOC:
+
+  Similarly to the C parsers, the C++ parsers now define the YYRHSLOC
+  macro and use it in the default YYLLOC_DEFAULT.  You are encouraged
+  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)

 
 

-  Consistently with directives (such as %error-verbose) and variables
-  (e.g. push-pull), grammar symbol names may include dashes in any
-  position, similarly to periods and underscores.  This is GNU
-  extension over POSIX Yacc whose use is reported by -Wyacc, and
-  rejected in Yacc mode (--yacc).
+  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)
+
+** YYLLOC_DEFAULT in C++:
+
+  The default implementation of YYLLOC_DEFAULT used to be issued in
+  the header file.  It is now output in the implementation file, after
+  the user %code sections so that its #ifndef guard does not try to
+  override the user's YYLLOC_DEFAULT if provided.

 
 ** YYFAIL now produces warnings and Java parsers no longer implement it:
 
 
 ** YYFAIL now produces warnings and Java parsers no longer implement it:
 


@@ -250,33 +329,20 @@ Bison News
   about a missing semicolon where it did not before.  Future releases of
   Bison will cease to append semicolons entirely.
 
   about a missing semicolon where it did not before.  Future releases of
   Bison will cease to append semicolons entirely.
 

-** Character literals not of length one:
-
-  Previously, Bison quietly converted all character literals to length
-  one.  For example, without warning, Bison interpreted the operators in
-  the following grammar to be the same token:
-
-    exp: exp '++'
-       | exp '+' exp
-       ;
-
-  Bison now warns when a character literal is not of length one.  In
-  some future release, Bison will start reporting an error instead.
-

 ** Verbose syntax error message fixes:
 
 ** Verbose syntax error message fixes:
 

-  When %error-verbose or `#define YYERROR_VERBOSE' is specified,
-  syntax error messages produced by the generated parser include the
-  unexpected token as well as a list of expected tokens.  The effect
-  of %nonassoc on these verbose messages has been corrected in two
-  ways, but a complete fix requires LAC, described above:
+  When %error-verbose or the obsolete `#define YYERROR_VERBOSE' is
+  specified, syntax error messages produced by the generated parser
+  include the unexpected token as well as a list of expected tokens.
+  The effect of %nonassoc on these verbose messages has been corrected
+  in two ways, but a more complete fix requires LAC, described above:

 
 *** When %nonassoc is used, there can exist parser states that accept no
     tokens, and so the parser does not always require a lookahead token
     in order to detect a syntax error.  Because no unexpected token or
     expected tokens can then be reported, the verbose syntax error
     message described above is suppressed, and the parser instead
 
 *** When %nonassoc is used, there can exist parser states that accept no
     tokens, and so the parser does not always require a lookahead token
     in order to detect a syntax error.  Because no unexpected token or
     expected tokens can then be reported, the verbose syntax error
     message described above is suppressed, and the parser instead

-    reports the simpler message, "syntax error".  Previously, this
+    reports the simpler message, `syntax error'.  Previously, this

     suppression was sometimes erroneously triggered by %nonassoc when a
     lookahead was actually required.  Now verbose messages are
     suppressed only when all previous lookaheads have already been
     suppression was sometimes erroneously triggered by %nonassoc when a
     lookahead was actually required.  Now verbose messages are
     suppressed only when all previous lookaheads have already been


@@ -301,54 +367,67 @@ Bison News
     canonical LR.  However, LAC is still experimental and is disabled
     by default.
 
     canonical LR.  However, LAC is still experimental and is disabled
     by default.
 

-** Destructor calls fixed for lookaheads altered in semantic actions:
+** Java skeleton fixes:

 
 

-  Previously for deterministic parsers in C, if a user semantic action
-  altered yychar, the parser in some cases used the old yychar value to
-  determine which destructor to call for the lookahead upon a syntax
-  error or upon parser return.  This bug has been fixed.
+*** A location handling bug has been fixed.

 
 

-** C++ parsers use YYRHSLOC:
+*** The top element of each of the value stack and location stack is now
+    cleared when popped so that it can be garbage collected.

 
 

-  Similarly to the C parsers, the C++ parsers now define the YYRHSLOC
-  macro and use it in the default YYLLOC_DEFAULT.  You are encouraged
-  to use it.  If, for instance, your location structure has "first"
-  and "last" members, instead of
+*** Parser traces now print the top element of the stack.

 
 

-      # 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)
+** -W/--warnings fixes:

 
 

-  use:
+*** Bison now properly recognizes the `no-' versions of categories:

 
 

-      # 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)
+  For example, given the following command line, Bison now enables all
+  warnings except warnings for incompatibilities with POSIX Yacc:

 
 

-** YYLLOC_DEFAULT in C++:
+    bison -Wall,no-yacc gram.y

 
 

-  The default implementation of YYLLOC_DEFAULT used to be issued in
-  the header file.  It is now output in the implementation file, after
-  the user %code sections so that its #ifndef guard does not try to
-  override the user's YYLLOC_DEFAULT if provided.
+*** Bison now treats S/R and R/R conflicts like other warnings:
+
+  Previously, conflict reports were independent of Bison's normal
+  warning system.  Now, Bison recognizes the warning categories
+  `conflicts-sr' and `conflicts-rr'.  This change has important
+  consequences for the -W and --warnings command-line options.  For
+  example:
+
+    bison -Wno-conflicts-sr gram.y  # S/R conflicts not reported
+    bison -Wno-conflicts-rr gram.y  # R/R conflicts not reported
+    bison -Wnone            gram.y  # no conflicts are reported
+    bison -Werror           gram.y  # any conflict is an error
+
+  However, as before, if the %expect or %expect-rr directive is
+  specified, an unexpected number of conflicts is an error, and an
+  expected number of conflicts is not reported, so -W and --warning
+  then have no effect on the conflict report.
+
+*** The `none' category no longer disables a preceding `error':
+
+  For example, for the following command line, Bison now reports
+  errors instead of warnings for incompatibilities with POSIX Yacc:
+
+    bison -Werror,none,yacc gram.y
+
+*** The `none' category now disables all Bison warnings:
+
+  Previously, the `none' category disabled only Bison warnings for
+  which there existed a specific -W/--warning category.  However,
+  given the following command line, Bison is now guaranteed to
+  suppress all warnings:
+
+    bison -Wnone gram.y
+
+** Precedence directives can now assign token number 0:
+
+  Since Bison 2.3b, which restored the ability of precedence
+  directives to assign token numbers, doing so for token number 0 has
+  produced an assertion failure.  For example:
+
+    %left END 0
+
+  This bug has been fixed.

 
 * Changes in version 2.4.3 (2010-08-05):
 
 
 * Changes in version 2.4.3 (2010-08-05):
 


@@ -828,26 +907,26 @@ 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.


@@ -1091,16 +1170,16 @@ 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.


@@ -1511,9 +1590,7 @@ End:
 
 -----
 
 
 -----
 

-Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
-2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation,
-Inc.
+Copyright (C) 1995-2012 Free Software Foundation, Inc.

 
 This file is part of Bison, the GNU Parser Generator.
 
 
 This file is part of Bison, the GNU Parser Generator.