version 2.7

* NEWS: Record release date.

.prev-version

@@ -1 +1 @@
-2.6.5
+2.6.90

NEWS

@@ -1,20 +1,39 @@
 GNU Bison NEWS
 
-* Noteworthy changes in release 2.6.90 (2012-12-07) [beta]
+* Noteworthy changes in release 2.7 (2012-12-12) [stable]
 
 ** Bug fixes
 
   Warnings about uninitialized yylloc in yyparse have been fixed.
 
-** %language is no longer an experimental feature.
+  Restored C90 compliance (yet no report was ever made).
 
-  The introduction of this feature, in 2.4, was four years ago. The --language
-  option and the %language directive are no longer experimental.
+** Diagnostics are improved
 
-** New format for error reports: carets
+*** Changes in the format of error messages
 
-  Caret errors have been added to Bison, for example (taken from the
-  documentation):
+  This used to be the format of many error reports:
+
+    input.y:2.7-12: %type redeclaration for exp
+    input.y:1.7-12: previous declaration
+
+  It is now:
+
+    input.y:2.7-12: error: %type redeclaration for exp
+    input.y:1.7-12:     previous declaration
+
+*** New format for error reports: carets
+
+  Caret errors have been added to Bison:
+
+    input.y:2.7-12: error: %type redeclaration for exp
+     %type <sval> exp
+           ^^^^^^
+    input.y:1.7-12:     previous declaration
+     %type <ival> exp
+           ^^^^^^
+
+  or
 
     input.y:3.20-23: error: ambiguous reference: '$exp'
      exp: exp '+' exp { $exp = $1 + $3; };
@@ -29,42 +48,23 @@ GNU Bison NEWS
      exp: exp '+' exp { $exp = $1 + $3; };
                   ^^^
 
-  The default behaviour for now is still not to display these unless explictly
-  asked with -fall of -fcaret. However, in a later release, it will be made the
-  default behavior (but may still be deactivated with -fno-caret).
+  The default behaviour for now is still not to display these unless
+  explictly asked with -fcaret (or -fall). However, in a later release, it
+  will be made the default behavior (but may still be deactivated with
+  -fno-caret).
 
 ** New value for %define variable: api.pure full
 
   The %define variable api.pure requests a pure (reentrant) parser. However,
-  for historical reasons, using it in a location-tracking Yacc parser resulted
-  in a yyerror function that did not take a location as a parameter. With this
-  new value, the user may request a better pure parser, where yyerror does take
-  a location as a parameter (in location-tracking parsers).
+  for historical reasons, using it in a location-tracking Yacc parser
+  resulted in a yyerror function that did not take a location as a
+  parameter. With this new value, the user may request a better pure parser,
+  where yyerror does take a location as a parameter (in location-tracking
+  parsers).
 
   The use of "%define api.pure true" is deprecated in favor of this new
   "%define api.pure full".
 
-** Changes in the format of error messages
-
-  This used to be the format of many error reports:
-
-    foo.y:5.10-24: result type clash on merge function 'merge': <t3> != <t2>
-    foo.y:4.13-27: previous declaration
-
-  It is now:
-
-    foo.y:5.10-25: result type clash on merge function 'merge': <t3> != <t2>
-    foo.y:4.13-27:     previous declaration
-
-** 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.
-
 ** 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
@@ -84,6 +84,15 @@ GNU Bison NEWS
   position_type are deprecated in favor of api.location.type and
   api.position.type.
 
+** 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.
+
 ** Graph improvements in DOT and XSLT
 
   The graphical presentation of the states is more readable: their shape is
@@ -96,13 +105,21 @@ GNU Bison NEWS
   These changes are present in both --graph output and xml2dot.xsl XSLT
   processing, with minor (documented) differences.
 
-  Two nodes were added to the documentation: Xml and Graphviz.
+** %language is no longer an experimental feature.
+
+  The introduction of this feature, in 2.4, was four years ago. The
+  --language option and the %language directive are no longer experimental.
 
 ** Documentation
 
   The sections about shift/reduce and reduce/reduce conflicts resolution
   have been fixed and extended.
 
+  Although introduced more than four years ago, XML and Graphviz reports
+  were not properly documented.
+
+  The translation of mid-rule actions is now described.
+
 * Noteworthy changes in release 2.6.5 (2012-11-07) [stable]
 
   We consider compiler warnings about Bison generated parsers to be bugs.

configure.ac

@@ -135,8 +135,9 @@ if test "$enable_gcc_warnings" = yes; then
 fi
 
 BISON_TEST_FOR_WORKING_C_COMPILER
-BISON_TEST_FOR_WORKING_CXX_COMPILER
 BISON_C_COMPILER_POSIXLY_CORRECT
+BISON_TEST_FOR_WORKING_CXX_COMPILER
+BISON_CXX_COMPILER_POSIXLY_CORRECT
 
 AC_ARG_ENABLE([yacc],
   [AC_HELP_STRING([--disable-yacc],

data/glr.c

@@ -287,7 +287,7 @@ b4_percent_code_get[]dnl
 # include <setjmp.h>
 # define YYJMP_BUF jmp_buf
 # define YYSETJMP(Env) setjmp (Env)
-// Pacify clang.
+/* Pacify clang.  */
 # define YYLONGJMP(Env, Val) (longjmp (Env, Val), YYASSERT (0))
 #endif
 
@@ -2013,10 +2013,10 @@ yyreportSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
 #if ! YYERROR_VERBOSE
   yyerror (]b4_lyyerror_args[YY_("syntax error"));
 #else
+  {
   yySymbol yytoken = yychar == YYEMPTY ? YYEMPTY : YYTRANSLATE (yychar);
   size_t yysize0 = yytnamerr (YY_NULL, yytokenName (yytoken));
   size_t yysize = yysize0;
-  size_t yysize1;
   yybool yysize_overflow = yyfalse;
   char* yymsg = YY_NULL;
   enum { YYERROR_VERBOSE_ARGS_MAXIMUM = 5 };
@@ -2076,9 +2076,11 @@ yyreportSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
                     break;
                   }
                 yyarg[yycount++] = yytokenName (yyx);
-                yysize1 = yysize + yytnamerr (YY_NULL, yytokenName (yyx));
-                yysize_overflow |= yysize1 < yysize;
-                yysize = yysize1;
+                {
+                  size_t yysz = yysize + yytnamerr (YY_NULL, yytokenName (yyx));
+                  yysize_overflow |= yysz < yysize;
+                  yysize = yysz;
+                }
               }
         }
     }
@@ -2098,9 +2100,11 @@ yyreportSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
 #undef YYCASE_
     }
 
-  yysize1 = yysize + strlen (yyformat);
-  yysize_overflow |= yysize1 < yysize;
-  yysize = yysize1;
+  {
+    size_t yysz = yysize + strlen (yyformat);
+    yysize_overflow |= yysz < yysize;
+    yysize = yysz;
+  }
 
   if (!yysize_overflow)
     yymsg = (char *) YYMALLOC (yysize);
@@ -2130,6 +2134,7 @@ yyreportSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
       yyerror (]b4_lyyerror_args[YY_("syntax error"));
       yyMemoryExhausted (yystackp);
     }
+  }
 #endif /* YYERROR_VERBOSE */
   yynerrs += 1;
 }

data/yacc.c

@@ -1247,7 +1247,6 @@ yysyntax_error (YYSIZE_T *yymsg_alloc, char **yymsg,
 {
   YYSIZE_T yysize0 = yytnamerr (YY_NULL, yytname[yytoken]);
   YYSIZE_T yysize = yysize0;
-  YYSIZE_T yysize1;
   enum { YYERROR_VERBOSE_ARGS_MAXIMUM = 5 };
   /* Internationalized format string. */
   const char *yyformat = YY_NULL;
@@ -1328,11 +1327,13 @@ yysyntax_error (YYSIZE_T *yymsg_alloc, char **yymsg,
                     break;
                   }
                 yyarg[yycount++] = yytname[yyx];
-                yysize1 = yysize + yytnamerr (YY_NULL, yytname[yyx]);
-                if (! (yysize <= yysize1
-                       && yysize1 <= YYSTACK_ALLOC_MAXIMUM))
-                  return 2;
-                yysize = yysize1;
+                {
+                  YYSIZE_T yysize1 = yysize + yytnamerr (YY_NULL, yytname[yyx]);
+                  if (! (yysize <= yysize1
+                         && yysize1 <= YYSTACK_ALLOC_MAXIMUM))
+                    return 2;
+                  yysize = yysize1;
+                }
               }
         }]b4_lac_if([[
 # if ]b4_api_PREFIX[DEBUG
@@ -1356,10 +1357,12 @@ yysyntax_error (YYSIZE_T *yymsg_alloc, char **yymsg,
 # undef YYCASE_
     }
 
-  yysize1 = yysize + yystrlen (yyformat);
-  if (! (yysize <= yysize1 && yysize1 <= YYSTACK_ALLOC_MAXIMUM))
-    return 2;
-  yysize = yysize1;
+  {
+    YYSIZE_T yysize1 = yysize + yystrlen (yyformat);
+    if (! (yysize <= yysize1 && yysize1 <= YYSTACK_ALLOC_MAXIMUM))
+      return 2;
+    yysize = yysize1;
+  }
 
   if (*yymsg_alloc < yysize)
     {

doc/Makefile.am

@@ -96,13 +96,14 @@ PREPATH = $(top_builddir)/src
 
 nodist_man_MANS = yacc.1
 
-## ----------------------------- ##
-## Graphviz examples generation. ##
-## ----------------------------- ##
+## ------------------------------ ##
+## Graphviz examples generation.  ##
+## ------------------------------ ##
 
 CLEANDIRS += figs
-FIGS_DOT = figs/example-reduce.dot figs/example-shift.dot
+FIGS_DOT = figs/example.dot figs/example-reduce.dot figs/example-shift.dot
 EXTRA_DIST +=								\
+  figs/example.y							\
   $(FIGS_DOT)								\
   $(FIGS_DOT:.dot=.eps) $(FIGS_DOT:.dot=.pdf) $(FIGS_DOT:.dot=.png)
 SUFFIXES += .dot .eps .pdf .png

doc/bison.texi

@@ -208,6 +208,12 @@ Defining Language Semantics
                       This says when, why and how to use the exceptional
                         action in the middle of a rule.
 
+Actions in Mid-Rule
+
+* Using Mid-Rule Actions::       Putting an action in the middle of a rule.
+* Mid-Rule Action Translation::  How mid-rule actions are actually processed.
+* Mid-Rule Conflicts::           Mid-rule actions can cause conflicts.
+
 Tracking Locations
 
 * Location Type::               Specifying a data type for locations.
@@ -2722,6 +2728,9 @@ The Bison grammar file conventionally has a name ending in @samp{.y}.
 
 @node Grammar Outline
 @section Outline of a Bison Grammar
+@cindex comment
+@findex // @dots{}
+@findex /* @dots{} */
 
 A Bison grammar file has four main sections, shown here with the
 appropriate delimiters:
@@ -2741,8 +2750,8 @@ appropriate delimiters:
 @end example
 
 Comments enclosed in @samp{/* @dots{} */} may appear in any of the sections.
-As a GNU extension, @samp{//} introduces a comment that
-continues until end of line.
+As a GNU extension, @samp{//} introduces a comment that continues until end
+of line.
 
 @menu
 * Prologue::              Syntax and usage of the prologue.
@@ -3736,6 +3745,15 @@ Occasionally it is useful to put an action in the middle of a rule.
 These actions are written just like usual end-of-rule actions, but they
 are executed before the parser even recognizes the following components.
 
+@menu
+* Using Mid-Rule Actions::       Putting an action in the middle of a rule.
+* Mid-Rule Action Translation::  How mid-rule actions are actually processed.
+* Mid-Rule Conflicts::           Mid-rule actions can cause conflicts.
+@end menu
+
+@node Using Mid-Rule Actions
+@subsubsection Using Mid-Rule Actions
+
 A mid-rule action may refer to the components preceding it using
 @code{$@var{n}}, but it may not refer to subsequent components because
 it is run before they are parsed.
@@ -3768,10 +3786,16 @@ remove it afterward.  Here is how it is done:
 @example
 @group
 stmt:
-  LET '(' var ')'
-    @{ $<context>$ = push_context (); declare_variable ($3); @}
+  "let" '(' var ')'
+    @{
+      $<context>$ = push_context ();
+      declare_variable ($3);
+    @}
   stmt
-    @{ $$ = $6; pop_context ($<context>5); @}
+    @{
+      $$ = $6;
+      pop_context ($<context>5);
+    @}
 @end group
 @end example
 
@@ -3782,8 +3806,27 @@ list of accessible variables) as its semantic value, using alternative
 @code{context} in the data-type union.  Then it calls
 @code{declare_variable} to add the new variable to that list.  Once the
 first action is finished, the embedded statement @code{stmt} can be
-parsed.  Note that the mid-rule action is component number 5, so the
-@samp{stmt} is component number 6.
+parsed.
+
+Note that the mid-rule action is component number 5, so the @samp{stmt} is
+component number 6.  Named references can be used to improve the readability
+and maintainability (@pxref{Named References}):
+
+@example
+@group
+stmt:
+  "let" '(' var ')'
+    @{
+      $<context>let = push_context ();
+      declare_variable ($3);
+    @}[let]
+  stmt
+    @{
+      $$ = $6;
+      pop_context ($<context>let);
+    @}
+@end group
+@end example
 
 After the embedded statement is parsed, its semantic value becomes the
 value of the entire @code{let}-statement.  Then the semantic value from the
@@ -3817,13 +3860,13 @@ stmt:
   let stmt
     @{
       $$ = $2;
-      pop_context ($1);
+      pop_context ($let);
     @};
 
 let:
-  LET '(' var ')'
+  "let" '(' var ')'
     @{
-      $$ = push_context ();
+      $let = push_context ();
       declare_variable ($3);
     @};
 
@@ -3835,6 +3878,76 @@ Note that the action is now at the end of its rule.
 Any mid-rule action can be converted to an end-of-rule action in this way, and
 this is what Bison actually does to implement mid-rule actions.
 
+@node Mid-Rule Action Translation
+@subsubsection Mid-Rule Action Translation
+@vindex $@@@var{n}
+@vindex @@@var{n}
+
+As hinted earlier, mid-rule actions are actually transformed into regular
+rules and actions.  The various reports generated by Bison (textual,
+graphical, etc., see @ref{Understanding, , Understanding Your Parser})
+reveal this translation, best explained by means of an example.  The
+following rule:
+
+@example
+exp: @{ a(); @} "b" @{ c(); @} @{ d(); @} "e" @{ f(); @};
+@end example
+
+@noindent
+is translated into:
+
+@example
+$@@1: /* empty */ @{ a(); @};
+$@@2: /* empty */ @{ c(); @};
+$@@3: /* empty */ @{ d(); @};
+exp: $@@1 "b" $@@2 $@@3 "e" @{ f(); @};
+@end example
+
+@noindent
+with new nonterminal symbols @code{$@@@var{n}}, where @var{n} is a number.
+
+A mid-rule action is expected to generate a value if it uses @code{$$}, or
+the (final) action uses @code{$@var{n}} where @var{n} denote the mid-rule
+action.  In that case its nonterminal is rather named @code{@@@var{n}}:
+
+@example
+exp: @{ a(); @} "b" @{ $$ = c(); @} @{ d(); @} "e" @{ f = $1; @};
+@end example
+
+@noindent
+is translated into
+
+@example
+@@1: /* empty */ @{ a(); @};
+@@2: /* empty */ @{ $$ = c(); @};
+$@@3: /* empty */ @{ d(); @};
+exp: @@1 "b" @@2 $@@3 "e" @{ f = $1; @}
+@end example
+
+There are probably two errors in the above example: the first mid-rule
+action does not generate a value (it does not use @code{$$} although the
+final action uses it), and the value of the second one is not used (the
+final action does not use @code{$3}).  Bison reports these errors when the
+@code{midrule-value} warnings are enabled (@pxref{Invocation, ,Invoking
+Bison}):
+
+@example
+$ bison -fcaret -Wmidrule-value mid.y
+@group
+mid.y:2.6-13: warning: unset value: $$
+ exp: @{ a(); @} "b" @{ $$ = c(); @} @{ d(); @} "e" @{ f = $1; @};
+      ^^^^^^^^
+@end group
+@group
+mid.y:2.19-31: warning: unused value: $3
+ exp: @{ a(); @} "b" @{ $$ = c(); @} @{ d(); @} "e" @{ f = $1; @};
+                   ^^^^^^^^^^^^^
+@end group
+@end example
+
+
+@node Mid-Rule Conflicts
+@subsubsection Conflicts due to Mid-Rule Actions
 Taking action before a rule is completely recognized often leads to
 conflicts since the parser must commit to a parse in order to execute the
 action.  For example, the following two rules, without mid-rule actions,
@@ -3932,6 +4045,7 @@ compound:
 Now Bison can execute the action in the rule for @code{subroutine} without
 deciding which rule for @code{compound} it will eventually use.
 
+
 @node Tracking Locations
 @section Tracking Locations
 @cindex location
@@ -5389,8 +5503,8 @@ I.e., if @samp{%locations %define api.pure} is passed then the prototypes for
 @code{yyerror} are:
 
 @example
-void yyerror (char const *msg);                 /* Yacc parsers.  */
-void yyerror (YYLTYPE *locp, char const *msg);  /* GLR parsers.  */
+void yyerror (char const *msg);                 // Yacc parsers.
+void yyerror (YYLTYPE *locp, char const *msg);  // GLR parsers.
 @end example
 
 But if @samp{%locations %define api.pure %parse-param @{int *nastiness@}} is
@@ -6386,7 +6500,6 @@ Actions}).
 @end deffn
 
 @deffn {Value} @@$
-@findex @@$
 Acts like a structure variable containing information on the textual
 location of the grouping made by the current rule.  @xref{Tracking
 Locations}.
@@ -6445,7 +6558,7 @@ GNU Automake.
 @item
 @cindex bison-i18n.m4
 Into the directory containing the GNU Autoconf macros used
-by the package---often called @file{m4}---copy the
+by the package ---often called @file{m4}--- copy the
 @file{bison-i18n.m4} file installed by Bison under
 @samp{share/aclocal/bison-i18n.m4} in Bison's installation directory.
 For example:
@@ -8191,8 +8304,26 @@ clear the flag.
 
 Developing a parser can be a challenge, especially if you don't understand
 the algorithm (@pxref{Algorithm, ,The Bison Parser Algorithm}).  This
-chapter explains how to generate and read the detailed description of the
-automaton, and how to enable and understand the parser run-time traces.
+chapter explains how understand and debug a parser.
+
+The first sections focus on the static part of the parser: its structure.
+They explain how to generate and read the detailed description of the
+automaton.  There are several formats available:
+@itemize @minus
+@item
+as text, see @ref{Understanding, , Understanding Your Parser};
+
+@item
+as a graph, see @ref{Graphviz,, Visualizing Your Parser};
+
+@item
+or as a markup report that can be turned, for instance, into HTML, see
+@ref{Xml,, Visualizing your parser in multiple formats}.
+@end itemize
+
+The last section focuses on the dynamic part of the parser: how to enable
+and understand the parser run-time traces (@pxref{Tracing, ,Tracing Your
+Parser}).
 
 @menu
 * Understanding::     Understanding the structure of your parser.
@@ -8207,8 +8338,7 @@ automaton, and how to enable and understand the parser run-time traces.
 As documented elsewhere (@pxref{Algorithm, ,The Bison Parser Algorithm})
 Bison parsers are @dfn{shift/reduce automata}.  In some cases (much more
 frequent than one would hope), looking at this automaton is required to
-tune or simply fix a parser.  Bison provides two different
-representation of it, either textually or graphically (as a DOT file).
+tune or simply fix a parser.
 
 The textual file is generated when the options @option{--report} or
 @option{--verbose} are specified, see @ref{Invocation, , Invoking
@@ -8222,9 +8352,12 @@ The following grammar file, @file{calc.y}, will be used in the sequel:
 
 @example
 %token NUM STR
+@group
 %left '+' '-'
 %left '*'
+@end group
 %%
+@group
 exp:
   exp '+' exp
 | exp '-' exp
@@ -8232,6 +8365,7 @@ exp:
 | exp '/' exp
 | NUM
 ;
+@end group
 useless: STR;
 %%
 @end example
@@ -8241,8 +8375,8 @@ useless: STR;
 @example
 calc.y: warning: 1 nonterminal useless in grammar
 calc.y: warning: 1 rule useless in grammar
-calc.y:11.1-7: warning: nonterminal useless in grammar: useless
-calc.y:11.10-12: warning: rule useless in grammar: useless: STR
+calc.y:12.1-7: warning: nonterminal useless in grammar: useless
+calc.y:12.10-12: warning: rule useless in grammar: useless: STR
 calc.y: conflicts: 7 shift/reduce
 @end example
 
@@ -8336,7 +8470,7 @@ item is a production rule together with a point (@samp{.}) marking
 the location of the input cursor.
 
 @example
-state 0
+State 0
 
     0 $accept: . exp $end
 
@@ -8366,7 +8500,7 @@ you want to see more detail you can invoke @command{bison} with
 @option{--report=itemset} to list the derived items as well:
 
 @example
-state 0
+State 0
 
     0 $accept: . exp $end
     1 exp: . exp '+' exp
@@ -8384,7 +8518,7 @@ state 0
 In the state 1@dots{}
 
 @example
-state 1
+State 1
 
     5 exp: NUM .
 
@@ -8394,11 +8528,11 @@ state 1
 @noindent
 the rule 5, @samp{exp: NUM;}, is completed.  Whatever the lookahead token
 (@samp{$default}), the parser will reduce it.  If it was coming from
-state 0, then, after this reduction it will return to state 0, and will
+State 0, then, after this reduction it will return to state 0, and will
 jump to state 2 (@samp{exp: go to state 2}).
 
 @example
-state 2
+State 2
 
     0 $accept: exp . $end
     1 exp: exp . '+' exp
@@ -8426,7 +8560,7 @@ The state 3 is named the @dfn{final state}, or the @dfn{accepting
 state}:
 
 @example
-state 3
+State 3
 
     0 $accept: exp $end .
 
@@ -8441,7 +8575,7 @@ The interpretation of states 4 to 7 is straightforward, and is left to
 the reader.
 
 @example
-state 4
+State 4
 
     1 exp: exp '+' . exp
 
@@ -8450,7 +8584,7 @@ state 4
     exp  go to state 8
 
 
-state 5
+State 5
 
     2 exp: exp '-' . exp
 
@@ -8459,7 +8593,7 @@ state 5
     exp  go to state 9
 
 
-state 6
+State 6
 
     3 exp: exp '*' . exp
 
@@ -8468,7 +8602,7 @@ state 6
     exp  go to state 10
 
 
-state 7
+State 7
 
     4 exp: exp '/' . exp
 
@@ -8481,7 +8615,7 @@ As was announced in beginning of the report, @samp{State 8 conflicts:
 1 shift/reduce}:
 
 @example
-state 8
+State 8
 
     1 exp: exp . '+' exp
     1    | exp '+' exp .
@@ -8524,7 +8658,7 @@ with some set of possible lookahead tokens.  When run with
 @option{--report=lookahead}, Bison specifies these lookahead tokens:
 
 @example
-state 8
+State 8
 
     1 exp: exp . '+' exp
     1    | exp '+' exp .  [$end, '+', '-', '/']
@@ -8556,7 +8690,7 @@ The remaining states are similar:
 
 @example
 @group
-state 9
+State 9
 
     1 exp: exp . '+' exp
     2    | exp . '-' exp
@@ -8572,7 +8706,7 @@ state 9
 @end group
 
 @group
-state 10
+State 10
 
     1 exp: exp . '+' exp
     2    | exp . '-' exp
@@ -8587,7 +8721,7 @@ state 10
 @end group
 
 @group
-state 11
+State 11
 
     1 exp: exp . '+' exp
     2    | exp . '-' exp
@@ -8610,12 +8744,11 @@ state 11
 
 @noindent
 Observe that state 11 contains conflicts not only due to the lack of
-precedence of @samp{/} with respect to @samp{+}, @samp{-}, and
-@samp{*}, but also because the
-associativity of @samp{/} is not specified.
+precedence of @samp{/} with respect to @samp{+}, @samp{-}, and @samp{*}, but
+also because the associativity of @samp{/} is not specified.
 
-Note that Bison may also produce an HTML version of this output, via an XML
-file and XSLT processing (@pxref{Xml}).
+Bison may also produce an HTML version of this output, via an XML file and
+XSLT processing (@pxref{Xml,,Visualizing your parser in multiple formats}).
 
 @c ================================================= Graphical Representation
 
@@ -8635,7 +8768,10 @@ This file is generated when the @option{--graph} option is specified
 (@pxref{Invocation, , Invoking Bison}).  Its name is made by removing
 @samp{.tab.c} or @samp{.c} from the parser implementation file name, and
 adding @samp{.dot} instead.  If the grammar file is @file{foo.y}, the
-Graphviz output file is called @file{foo.dot}.
+Graphviz output file is called @file{foo.dot}.  A DOT file may also be
+produced via an XML file and XSLT processing (@pxref{Xml,,Visualizing your
+parser in multiple formats}).
+
 
 The following grammar file, @file{rr.y}, will be used in the sequel:
 
@@ -8648,10 +8784,20 @@ b: "0";
 @end group
 @end example
 
-The graphical output is very similar to the textual one, and as such it is
-easier understood by making direct comparisons between them. See
-@ref{Debugging, , Debugging Your Parser} for a detailled analysis of the
-textual report.
+The graphical output
+@ifnotinfo
+(see @ref{fig:graph})
+@end ifnotinfo
+is very similar to the textual one, and as such it is easier understood by
+making direct comparisons between them.  @xref{Debugging, , Debugging Your
+Parser}, for a detailled analysis of the textual report.
+
+@ifnotinfo
+@float Figure,fig:graph
+@image{figs/example, 430pt}
+@caption{A graphical rendering of the parser.}
+@end float
+@end ifnotinfo
 
 @subheading Graphical Representation of States
 
@@ -8676,7 +8822,7 @@ shift. The following describes a reduction in the @file{rr.output} file:
 
 @example
 @group
-state 3
+State 3
 
     1 exp: a . ";"
 
@@ -8697,7 +8843,7 @@ action for the given state, there is no such label.
 
 This is how reductions are represented in the verbose file @file{rr.output}:
 @example
-state 1
+State 1
 
     3 a: "0" .  [";"]
     4 b: "0" .  ["."]
@@ -8716,17 +8862,14 @@ reduction, see @ref{Shift/Reduce, , Shift/Reduce Conflicts}.  Discarded actions
 are distinguished by a red filling color on these nodes, just like how they are
 reported between square brackets in the verbose file.
 
-The reduction corresponding to the rule number 0 is the acceptation state. It
-is shown as a blue diamond, labelled "Acc".
+The reduction corresponding to the rule number 0 is the acceptation
+state. It is shown as a blue diamond, labelled ``Acc''.
 
 @subheading Graphical representation of go tos
 
 The @samp{go to} jump transitions are represented as dotted lines bearing
 the name of the rule being jumped to.
 
-Note that a DOT file may also be produced via an XML file and XSLT
-processing (@pxref{Xml}).
-
 @c ================================================= XML
 
 @node Xml
@@ -8734,8 +8877,10 @@ processing (@pxref{Xml}).
 @cindex xml
 
 Bison supports two major report formats: textual output
-(@pxref{Understanding}) when invoked with option @option{--verbose}, and DOT
-(@pxref{Graphviz}) when invoked with option @option{--graph}. However,
+(@pxref{Understanding, ,Understanding Your Parser}) when invoked
+with option @option{--verbose}, and DOT
+(@pxref{Graphviz,, Visualizing Your Parser}) when invoked with
+option @option{--graph}. However,
 another alternative is to output an XML file that may then be, with
 @command{xsltproc}, rendered as either a raw text format equivalent to the
 verbose file, or as an HTML version of the same file, with clickable
@@ -8743,7 +8888,7 @@ transitions, or even as a DOT. The @file{.output} and DOT files obtained via
 XSLT have no difference whatsoever with those obtained by invoking
 @command{bison} with options @option{--verbose} or @option{--graph}.
 
-The textual file is generated when the options @option{-x} or
+The XML file is generated when the options @option{-x} or
 @option{--xml[=FILE]} are specified, see @ref{Invocation,,Invoking Bison}.
 If not specified, its name is made by removing @samp{.tab.c} or @samp{.c}
 from the parser implementation file name, and adding @samp{.xml} instead.
@@ -8757,19 +8902,19 @@ files to apply to the XML file. Their names are non-ambiguous:
 @item xml2dot.xsl
 Used to output a copy of the DOT visualization of the automaton.
 @item xml2text.xsl
-Used to output a copy of the .output file.
+Used to output a copy of the @samp{.output} file.
 @item xml2xhtml.xsl
-Used to output an xhtml enhancement of the .output file.
+Used to output an xhtml enhancement of the @samp{.output} file.
 @end table
 
-Sample usage (requires @code{xsltproc}):
+Sample usage (requires @command{xsltproc}):
 @example
-$ bison -x input.y
+$ bison -x gr.y
 @group
 $ bison --print-datadir
 /usr/local/share/bison
 @end group
-$ xsltproc /usr/local/share/bison/xslt/xml2xhtml.xsl input.xml > input.html
+$ xsltproc /usr/local/share/bison/xslt/xml2xhtml.xsl gr.xml >gr.html
 @end example
 
 @c ================================================= Tracing
@@ -8960,7 +9105,7 @@ Entering state 24
 
 @noindent
 The previous reduction demonstrates the @code{%printer} directive for
-@code{<val>}: both the token @code{NUM} and the resulting non-terminal
+@code{<val>}: both the token @code{NUM} and the resulting nonterminal
 @code{exp} have @samp{1} as value.
 
 @example
@@ -9250,7 +9395,7 @@ Show caret errors, in a manner similar to GCC's
 @option{-fdiagnostics-show-caret}, or Clang's @option{-fcaret-diagnotics}. The
 location provided with the message is used to quote the corresponding line of
 the source file, underlining the important part of it with carets (^). Here is
-an example, using the following file @file{input.y}:
+an example, using the following file @file{in.y}:
 
 @example
 %type <ival> exp
@@ -9262,27 +9407,27 @@ When invoked with @option{-fcaret}, Bison will report:
 
 @example
 @group
-input.y:3.20-23: error: ambiguous reference: '$exp'
+in.y:3.20-23: error: ambiguous reference: '$exp'
  exp: exp '+' exp @{ $exp = $1 + $2; @};
                     ^^^^
 @end group
 @group
-input.y:3.1-3:       refers to: $exp at $$
+in.y:3.1-3:       refers to: $exp at $$
  exp: exp '+' exp @{ $exp = $1 + $2; @};
  ^^^
 @end group
 @group
-input.y:3.6-8:       refers to: $exp at $1
+in.y:3.6-8:       refers to: $exp at $1
  exp: exp '+' exp @{ $exp = $1 + $2; @};
       ^^^
 @end group
 @group
-input.y:3.14-16:     refers to: $exp at $3
+in.y:3.14-16:     refers to: $exp at $3
  exp: exp '+' exp @{ $exp = $1 + $2; @};
               ^^^
 @end group
 @group
-input.y:3.32-33: error: $2 of 'exp' has no declared type
+in.y:3.32-33: error: $2 of 'exp' has no declared type
  exp: exp '+' exp @{ $exp = $1 + $2; @};
                                 ^^
 @end group
@@ -10295,19 +10440,30 @@ It is convenient to use a typedef to shorten
 %@{
   typedef yy::calcxx_parser::token token;
 %@}
-           /* Convert ints to the actual type of tokens.  */
-[-+*/]     return yy::calcxx_parser::token_type (yytext[0]);
-":="       return token::ASSIGN;
-@{int@}      @{
-  errno = 0;
-  long n = strtol (yytext, NULL, 10);
-  if (! (INT_MIN <= n && n <= INT_MAX && errno != ERANGE))
-    driver.error (*yylloc, "integer is out of range");
-  yylval->ival = n;
-  return token::NUMBER;
-@}
-@{id@}       yylval->sval = new std::string (yytext); return token::IDENTIFIER;
-.          driver.error (*yylloc, "invalid character");
+         /* Convert ints to the actual type of tokens.  */
+[-+*/]   return yy::calcxx_parser::token_type (yytext[0]);
+
+":="     return token::ASSIGN;
+
+@group
+@{int@}    @{
+           errno = 0;
+           long n = strtol (yytext, NULL, 10);
+           if (! (INT_MIN <= n && n <= INT_MAX && errno != ERANGE))
+             driver.error (*yylloc, "integer is out of range");
+           yylval->ival = n;
+           return token::NUMBER;
+         @}
+@end group
+
+@group
+@{id@}     @{
+           yylval->sval = new std::string (yytext);
+           return token::IDENTIFIER;
+         @}
+@end group
+
+.        driver.error (*yylloc, "invalid character");
 %%
 @end example
 
@@ -11353,18 +11509,23 @@ In an action, the location of the left-hand side of the rule.
 @end deffn
 
 @deffn {Variable} @@@var{n}
+@deffnx {Symbol} @@@var{n}
 In an action, the location of the @var{n}-th symbol of the right-hand side
 of the rule.  @xref{Tracking Locations}.
+
+In a grammar, the Bison-generated nonterminal symbol for a mid-rule action
+with a semantical value.  @xref{Mid-Rule Action Translation}.
 @end deffn
 
 @deffn {Variable} @@@var{name}
-In an action, the location of a symbol addressed by name.  @xref{Tracking
-Locations}.
+@deffnx {Variable} @@[@var{name}]
+In an action, the location of a symbol addressed by @var{name}.
+@xref{Tracking Locations}.
 @end deffn
 
-@deffn {Variable} @@[@var{name}]
-In an action, the location of a symbol addressed by name.  @xref{Tracking
-Locations}.
+@deffn {Symbol} $@@@var{n}
+In a grammar, the Bison-generated nonterminal symbol for a mid-rule action
+with no semantical value.  @xref{Mid-Rule Action Translation}.
 @end deffn
 
 @deffn {Variable} $$
@@ -11378,12 +11539,8 @@ right-hand side of the rule.  @xref{Actions}.
 @end deffn
 
 @deffn {Variable} $@var{name}
-In an action, the semantic value of a symbol addressed by name.
-@xref{Actions}.
-@end deffn
-
-@deffn {Variable} $[@var{name}]
-In an action, the semantic value of a symbol addressed by name.
+@deffnx {Variable} $[@var{name}]
+In an action, the semantic value of a symbol addressed by @var{name}.
 @xref{Actions}.
 @end deffn
 
@@ -11401,8 +11558,9 @@ the grammar file.  @xref{Grammar Outline, ,Outline of a Bison
 Grammar}.
 @end deffn
 
-@deffn {Construct} /*@dots{}*/
-Comment delimiters, as in C.
+@deffn {Construct} /* @dots{} */
+@deffnx {Construct} // @dots{}
+Comments, as in C/C++.
 @end deffn
 
 @deffn {Delimiter} :
@@ -11885,7 +12043,7 @@ Data type of semantic values; @code{int} by default.
 @item Accepting state
 A state whose only action is the accept action.
 The accepting state is thus a consistent state.
-@xref{Understanding,,}.
+@xref{Understanding, ,Understanding Your Parser}.
 
 @item Backus-Naur Form (BNF; also called ``Backus Normal Form'')
 Formal method of specifying context-free grammars originally proposed

doc/figs/example.dot

@@ -0,0 +1,35 @@
+// Generated by GNU Bison 2.6.90.
+// Report bugs to <[email protected]>.
+// Home page: <http://www.gnu.org/software/bison/>.
+
+digraph "/tmp/fo.y"
+{
+  node [fontname = courier, shape = box, colorscheme = paired6]
+  edge [fontname = courier]
+
+  0 [label="State 0\n\l  0 $accept: . exp $end\l  1 exp: . a \";\"\l  2    | . b \".\"\l  3 a: . \"0\"\l  4 b: . \"0\"\l"]
+  0 -> 1 [style=solid label="\"0\""]
+  0 -> 2 [style=dashed label="exp"]
+  0 -> 3 [style=dashed label="a"]
+  0 -> 4 [style=dashed label="b"]
+  1 [label="State 1\n\l  3 a: \"0\" .  [\";\"]\l  4 b: \"0\" .  [\".\"]\l"]
+  1 -> "1R3" [style=solid]
+ "1R3" [label="R3", fillcolor=3, shape=diamond, style=filled]
+  1 -> "1R4" [label="[\".\"]", style=solid]
+ "1R4" [label="R4", fillcolor=3, shape=diamond, style=filled]
+  2 [label="State 2\n\l  0 $accept: exp . $end\l"]
+  2 -> 5 [style=solid label="$end"]
+  3 [label="State 3\n\l  1 exp: a . \";\"\l"]
+  3 -> 6 [style=solid label="\";\""]
+  4 [label="State 4\n\l  2 exp: b . \".\"\l"]
+  4 -> 7 [style=solid label="\".\""]
+  5 [label="State 5\n\l  0 $accept: exp $end .\l"]
+  5 -> "5R0" [style=solid]
+ "5R0" [label="Acc", fillcolor=1, shape=diamond, style=filled]
+  6 [label="State 6\n\l  1 exp: a \";\" .\l"]
+  6 -> "6R1" [style=solid]
+ "6R1" [label="R1", fillcolor=3, shape=diamond, style=filled]
+  7 [label="State 7\n\l  2 exp: b \".\" .\l"]
+  7 -> "7R2" [style=solid]
+ "7R2" [label="R2", fillcolor=3, shape=diamond, style=filled]
+}

doc/figs/example.y

@@ -0,0 +1,4 @@
+%%
+exp: a ";" | b ".";
+a: "0";
+b: "0";

m4/c-working.m4

@@ -24,6 +24,7 @@ AC_DEFUN([BISON_TEST_FOR_WORKING_C_COMPILER], [
 	 int test_array[CHAR_BIT];]])],
     [],
     [AC_MSG_FAILURE([cannot compile a simple C program])])
+   AC_SUBST([BISON_C_WORKS], [:])
 ])
 
 # BISON_CHECK_WITH_POSIXLY_CORRECT(CODE)
@@ -47,25 +48,32 @@ case $gl_had_POSIXLY_CORRECT in
 esac
 ])
 
-# BISON_C_COMPILER_POSIXLY_CORRECT
-# --------------------------------
-# Whether the compiler supports -g in POSIXLY_CORRECT mode.  clang-2.9
-# on OS X does not, because "clang-mp-2.9 -o test -g test.c" launches
-# "/usr/bin/dsymutil test -o test.dSYM" which fails with "error:
-# unable to open executable '-o'".
+# BISON_LANG_COMPILER_POSIXLY_CORRECT
+# -----------------------------------
+# Whether the compiler for the current language supports -g in
+# POSIXLY_CORRECT mode.  clang-2.9 on OS X does not, because
+# "clang-mp-2.9 -o test -g test.c" launches "/usr/bin/dsymutil test -o
+# test.dSYM" which fails with "error: unable to open executable '-o'".
 #
-# Sets C_COMPILER_POSIXLY_CORRECT to true/false.
-AC_DEFUN([BISON_C_COMPILER_POSIXLY_CORRECT],
-[AC_CACHE_CHECK([whether $CC supports POSIXLY_CORRECT=1],
-                [bison_cv_cc_supports_posixly_correct],
+# Sets <LANG>_COMPILER_POSIXLY_CORRECT to true/false.
+AC_DEFUN([BISON_LANG_COMPILER_POSIXLY_CORRECT],
+[AC_CACHE_CHECK([whether $_AC_CC supports POSIXLY_CORRECT=1],
+                [bison_cv_[]_AC_LANG_ABBREV[]_supports_posixly_correct],
 [BISON_CHECK_WITH_POSIXLY_CORRECT(
-[AC_LANG_PUSH([C])
-AC_LINK_IFELSE([AC_LANG_PROGRAM],
-                [bison_cv_cc_supports_posixly_correct=yes],
-                [bison_cv_cc_supports_posixly_correct=no])
-AC_LANG_POP([C])])])
-case $bison_cv_cc_supports_posixly_correct in
-  yes) AC_SUBST([C_COMPILER_POSIXLY_CORRECT], [true]) ;;
-  no)  AC_SUBST([C_COMPILER_POSIXLY_CORRECT], [false]);;
+[AC_LINK_IFELSE([AC_LANG_PROGRAM],
+                [bison_cv_[]_AC_LANG_ABBREV[]_supports_posixly_correct=yes],
+                [bison_cv_[]_AC_LANG_ABBREV[]_supports_posixly_correct=no])])])
+case $bison_cv_[]_AC_LANG_ABBREV[]_supports_posixly_correct in
+  yes) AC_SUBST(_AC_LANG_PREFIX[_COMPILER_POSIXLY_CORRECT], [true]) ;;
+  no)  AC_SUBST(_AC_LANG_PREFIX[_COMPILER_POSIXLY_CORRECT], [false]);;
 esac
 ])
+
+# BISON_C_COMPILER_POSIXLY_CORRECT
+# --------------------------------
+# Whether the C compiler supports -g in POSIXLY_CORRECT mode.
+AC_DEFUN([BISON_C_COMPILER_POSIXLY_CORRECT],
+[AC_LANG_PUSH([C])
+BISON_LANG_COMPILER_POSIXLY_CORRECT
+AC_LANG_POP([C])
+])

m4/cxx.m4

@@ -58,3 +58,12 @@ AC_DEFUN([BISON_TEST_FOR_WORKING_CXX_COMPILER],
  AC_SUBST([BISON_CXX_WORKS])
  AM_CONDITIONAL(BISON_CXX_WORKS, test $bison_cv_cxx_works = yes)
 ])
+
+# BISON_CXX_COMPILER_POSIXLY_CORRECT
+# ----------------------------------
+# Whether the C++ compiler supports -g in POSIXLY_CORRECT mode.
+AC_DEFUN([BISON_CXX_COMPILER_POSIXLY_CORRECT],
+[AC_LANG_PUSH([C++])
+BISON_LANG_COMPILER_POSIXLY_CORRECT
+AC_LANG_POP([C++])
+])

src/graphviz.h

@@ -24,38 +24,48 @@
 
 #include "state.h"
 
-/// Begin a Dot graph.
-/// \param fout   output stream.
+/** Begin a Dot graph.
+ *
+ * \param fout   output stream.
+ */
 void start_graph (FILE *fout);
 
-/// Output a Dot node.
-/// \param id     identifier of the node
-/// \param label  human readable label of the node (no Dot escaping needed).
-/// \param fout   output stream.
+/** Output a Dot node.
+ *
+ * \param id     identifier of the node
+ * \param label  human readable label of the node (no Dot escaping needed).
+ * \param fout   output stream.
+ */
 void output_node (int id, char const *label, FILE *fout);
 
-/// Output a Dot edge.
-/// \param source       id of the source node
-/// \param destination  id of the target node
-/// \param label        human readable label of the edge
-///                     (no Dot escaping needed).  Can be 0.
-/// \param style        Dot style of the edge (e.g., "dotted" or "solid").
-/// \param fout         output stream.
+/** Output a Dot edge.
+ * \param source       id of the source node
+ * \param destination  id of the target node
+ * \param label        human readable label of the edge
+ *                     (no Dot escaping needed).  Can be 0.
+ * \param style        Dot style of the edge (e.g., "dotted" or "solid").
+ * \param fout         output stream.
+ */
 void output_edge (int source, int destination, char const *label,
                   char const *style, FILE *fout);
 
-/// Output a reduction.
-/// \param s            current state
-/// \param reds         the set of reductions
-/// \param fout         output stream.
+/** Output a reduction.
+ * \param s            current state
+ * \param reds         the set of reductions
+ * \param fout         output stream.
+ */
 void output_red (state const *s, reductions const *reds, FILE *fout);
 
-/// End a Dot graph.
-/// \param fout  output stream.
+/** End a Dot graph.
+ *
+ * \param fout  output stream.
+ */
 void finish_graph (FILE *fout);
 
-/// Escape a lookahead token.
-/// \param name         the token.
+/** Escape a lookahead token.
+ *
+ * \param name         the token.
+ */
 char const *escape (char const *name);
 
 #endif /* ! GRAPHVIZ_H_ */

src/ielr.c

@@ -758,8 +758,8 @@ ielr_compute_state (bitsetv follow_kernel_items, bitsetv always_follows,
                     if (!bitset_empty_p (lookaheads[i]))
                       break;
                   }
-                // bitset_equal_p uses the size of the first argument, so
-                // lookaheads[i] must be the second argument.
+                /* bitset_equal_p uses the size of the first argument,
+                   so lookaheads[i] must be the second argument.  */
                 else if (!bitset_equal_p ((*this_isocorep)->lookaheads[i],
                                           lookaheads[i]))
                   break;
@@ -1187,8 +1187,8 @@ ielr (void)
   free (to_state);
   if (lr_type == LR_TYPE__CANONICAL_LR)
     {
-      // Reduction lookaheads are computed in ielr_split_states above but are
-      // timed as part of phase 4.
+      /* Reduction lookaheads are computed in ielr_split_states above
+         but are timed as part of phase 4. */
       set_goto_map ();
     }
   else

src/reader.c

@@ -325,9 +325,9 @@ grammar_rule_check (const symbol_list *r)
             void (*warn_at_ptr)(location, char const*, ...) =
               midrule_warning ? midrule_value_at : warn_at;
             if (n)
-              warn_at_ptr (r->location, _("unused value: $%d"), n);
+              warn_at_ptr (l->location, _("unused value: $%d"), n);
             else
-              warn_at_ptr (r->location, _("unset value: $$"));
+              warn_at_ptr (l->location, _("unset value: $$"));
           }
       }
   }

src/scan-gram.l

@@ -883,7 +883,7 @@ unexpected_end (boundary start, char const *msgid, char const *token_end)
   loc.start = start;
   loc.end = scanner_cursor;
   token_end = quote (token_end);
-  // Instead of '\'', display "'".
+  /* Instead of '\'', display "'".  */
   if (!strcmp (token_end, "'\\''"))
     token_end = "\"'\"";
   complain_at (loc, _(msgid), token_end);

src/system.h

@@ -51,7 +51,7 @@
 typedef size_t uintptr_t;
 # endif
 
-// Version mismatch.
+/* Version mismatch. */
 # define EX_MISMATCH 63
 
 /*---------.

tests/actions.at

@@ -90,7 +90,7 @@ AT_DATA_GRAMMAR([[input.y]],
 %code
 {
 # include <stdio.h>
-# include <stdlib.h> // getenv
+# include <stdlib.h> /* getenv */
 ]AT_YYERROR_DECLARE[
 ]AT_YYLEX_DECLARE[
 }
@@ -195,7 +195,7 @@ AT_DATA_GRAMMAR([[input.y]],
 %code
 {
 # include <stdio.h>
-# include <stdlib.h> // getenv
+# include <stdlib.h> /* getenv */
 ]AT_YYERROR_DECLARE[
 ]AT_YYLEX_DECLARE[
 }
@@ -223,6 +223,7 @@ main (void)
 
   TEST(7, 2, 0, 2);
   TEST(8, 0, 8, 0);
+  return 0;
 }
 ]])
 
@@ -1301,16 +1302,16 @@ AT_BISON_OPTION_POPDEFS
 
 AT_BISON_CHECK([-o input.c input.y], 0,,
 [[input.y:33.3-23: warning: unset value: $$
-input.y:30.3-35.37: warning: unused value: $3
+input.y:32.3-23: warning: unused value: $3
 ]])
 
 AT_BISON_CHECK([-fcaret -o input.c input.y], 0,,
 [[input.y:33.3-23: warning: unset value: $$
    {           @$ = 4; } // Only used.
    ^^^^^^^^^^^^^^^^^^^^^
-input.y:30.3-35.37: warning: unused value: $3
-   {           @$ = 1; } // Not set or used.
-   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+input.y:32.3-23: warning: unused value: $3
+   { USE ($$); @$ = 3; } // Only set.
+   ^^^^^^^^^^^^^^^^^^^^^
 ]])
 
 AT_COMPILE([input])

tests/atlocal.in

@@ -19,6 +19,15 @@
 # We need `config.h'.
 CPPFLAGS="-I$abs_top_builddir/lib @CPPFLAGS@"
 
+# Don't just check if $POSIXLY_CORRECT is set, as Bash, when launched
+# as /bin/sh, sets the shell variable POSIXLY_CORRECT to y, but not
+# the environment variable.
+if env | grep '^POSIXLY_CORRECT=' >/dev/null; then
+  POSIXLY_CORRECT_IS_EXPORTED=true
+else
+  POSIXLY_CORRECT_IS_EXPORTED=false
+fi
+
 ## ------------------- ##
 ## C/C++ Compilation.  ##
 ## ------------------- ##
@@ -38,15 +47,28 @@ NO_WERROR_CXXFLAGS='@CXXFLAGS@ @WARN_CXXFLAGS@ @WARN_CXXFLAGS_TEST@'
   CFLAGS="$NO_WERROR_CFLAGS   @WERROR_CFLAGS@"
 CXXFLAGS="$NO_WERROR_CXXFLAGS @WERROR_CXXFLAGS@"
 
-# If 'exit 77'; skip all C++ tests; otherwise ':'.
+# If 'exit 77'; skip all C/C++ tests; otherwise ':'.
+BISON_C_WORKS='@BISON_C_WORKS@'
 BISON_CXX_WORKS='@BISON_CXX_WORKS@'
 
+# Whether the compiler supports POSIXLY_CORRECT defined.
+: ${C_COMPILER_POSIXLY_CORRECT='@C_COMPILER_POSIXLY_CORRECT@'}
+: ${CXX_COMPILER_POSIXLY_CORRECT='@CXX_COMPILER_POSIXLY_CORRECT@'}
+
+if $POSIXLY_CORRECT_IS_EXPORTED; then
+  $C_COMPILER_POSIXLY_CORRECT ||
+    BISON_C_WORKS="as_fn_error 77 POSIXLY_CORRECT"
+  $CXX_COMPILER_POSIXLY_CORRECT ||
+    BISON_CXX_WORKS="as_fn_error 77 POSIXLY_CORRECT"
+fi
+
 # Handle --compile-c-with-cxx here, once CXX and CXXFLAGS are known.
 if "$at_arg_compile_c_with_cxx"; then
   CC_IS_CXX=1
   CC=$CXX
   NO_WERROR_CFLAGS=$NO_WERROR_CXXFLAGS
   CFLAGS=$CXXFLAGS
+  BISON_C_WORKS=$BISON_CXX_WORKS
 else
   CC_IS_CXX=0
 fi
@@ -79,13 +101,3 @@ LIBS="$abs_top_builddir/lib/libbison.a @LIBS@ @INTLLIBS@"
 : ${XSLTPROC='@XSLTPROC@'}
 
 : ${PERL='@PERL@'}
-
-# Don't just check if $POSIXLY_CORRECT is set, as Bash, when launched
-# as /bin/sh, sets the shell variable POSIXLY_CORRECT to y, but not
-# the environment variable.
-: ${C_COMPILER_POSIXLY_CORRECT='@C_COMPILER_POSIXLY_CORRECT@'}
-if env | grep '^POSIXLY_CORRECT=' >/dev/null; then
-  POSIXLY_CORRECT_IS_EXPORTED=true
-else
-  POSIXLY_CORRECT_IS_EXPORTED=false
-fi

tests/glr-regression.at

@@ -18,9 +18,9 @@
 
 AT_BANNER([[GLR Regression Tests]])
 
-## --------------------------- ##
-## Badly Collapsed GLR States. ##
-## --------------------------- ##
+## ---------------------------- ##
+## Badly Collapsed GLR States.  ##
+## ---------------------------- ##
 
 AT_SETUP([Badly Collapsed GLR States])
 
@@ -67,7 +67,7 @@ static YYSTYPE exprMerge (YYSTYPE x0, YYSTYPE x1)
   return 0;
 }
 
-const char *input = NULL;
+const char *input = YY_NULL;
 
 int
 main (int argc, const char* argv[])
@@ -105,9 +105,9 @@ E -> E 'P' E
 
 AT_CLEANUP
 
-## ------------------------------------------------------------ ##
-## Improper handling of embedded actions and $-N in GLR parsers ##
-## ------------------------------------------------------------ ##
+## -------------------------------------------------------------- ##
+## Improper handling of embedded actions and $-N in GLR parsers.  ##
+## -------------------------------------------------------------- ##
 
 AT_SETUP([Improper handling of embedded actions and dollar(-N) in GLR parsers])
 
@@ -195,10 +195,11 @@ yylex (void)
 int
 main (int argc, char **argv)
 {
+  int res;
   input = stdin;
   if (argc == 2 && !(input = fopen (argv[1], "r")))
     return 3;
-  int res = yyparse ();
+  res = yyparse ();
   if (argc == 2 && fclose (input))
     return 4;
   return res;
@@ -236,9 +237,9 @@ AT_PARSER_CHECK([[./glr-regr2a input3.txt]], 0,
 
 AT_CLEANUP
 
-## ------------------------------------------------------------ ##
-## Improper merging of GLR delayed action sets                  ##
-## ------------------------------------------------------------ ##
+## --------------------------------------------- ##
+## Improper merging of GLR delayed action sets.  ##
+## --------------------------------------------- ##
 
 AT_SETUP([Improper merging of GLR delayed action sets])
 
@@ -327,10 +328,11 @@ int yylex (void)
 int
 main(int argc, char* argv[])
 {
+  int res;
   input = stdin;
   if (argc == 2 && !(input = fopen (argv[1], "r")))
     return 3;
-  int res = yyparse ();
+  res = yyparse ();
   if (argc == 2 && fclose (input))
     return 4;
   return res;
@@ -354,10 +356,10 @@ AT_PARSER_CHECK([[./glr-regr3 input.txt]],
 AT_CLEANUP
 
 
-## ------------------------------------------------------------------------- ##
-## Duplicate representation of merged trees.  See			     ##
-## <http://lists.gnu.org/archive/html/help-bison/2005-07/msg00013.html>.     ##
-## ------------------------------------------------------------------------- ##
+## ---------------------------------------------------------------------- ##
+## Duplicate representation of merged trees.  See                         ##
+## <http://lists.gnu.org/archive/html/help-bison/2005-07/msg00013.html>.  ##
+## ---------------------------------------------------------------------- ##
 
 AT_SETUP([Duplicate representation of merged trees])
 
@@ -445,10 +447,10 @@ AT_PARSER_CHECK([[./glr-regr4]], 0,
 AT_CLEANUP
 
 
-## -------------------------------------------------------------------------- ##
-## User destructor for unresolved GLR semantic value.  See		      ##
-## <http://lists.gnu.org/archive/html/bison-patches/2005-08/msg00016.html>.   ##
-## -------------------------------------------------------------------------- ##
+## ------------------------------------------------------------------------- ##
+## User destructor for unresolved GLR semantic value.  See                   ##
+## <http://lists.gnu.org/archive/html/bison-patches/2005-08/msg00016.html>.  ##
+## ------------------------------------------------------------------------- ##
 
 AT_SETUP([User destructor for unresolved GLR semantic value])
 
@@ -505,10 +507,10 @@ AT_PARSER_CHECK([[./glr-regr5]], 0, [],
 AT_CLEANUP
 
 
-## -------------------------------------------------------------------------- ##
-## User destructor after an error during a split parse.  See		      ##
-## <http://lists.gnu.org/archive/html/bison-patches/2005-08/msg00029.html>.   ##
-## -------------------------------------------------------------------------- ##
+## ------------------------------------------------------------------------- ##
+## User destructor after an error during a split parse.  See                 ##
+## <http://lists.gnu.org/archive/html/bison-patches/2005-08/msg00029.html>.  ##
+## ------------------------------------------------------------------------- ##
 
 AT_SETUP([User destructor after an error during a split parse])
 
@@ -560,7 +562,7 @@ AT_CLEANUP
 
 
 ## ------------------------------------------------------------------------- ##
-## Duplicated user destructor for lookahead.  See			     ##
+## Duplicated user destructor for lookahead.  See                            ##
 ## <http://lists.gnu.org/archive/html/bison-patches/2005-08/msg00035.html>.  ##
 ## ------------------------------------------------------------------------- ##
 
@@ -743,7 +745,7 @@ AT_CLEANUP
 
 
 ## ------------------------------------------------------------------------- ##
-## No users destructors if stack 0 deleted.  See			     ##
+## No users destructors if stack 0 deleted.  See                             ##
 ## <http://lists.gnu.org/archive/html/bison-patches/2005-09/msg00109.html>.  ##
 ## ------------------------------------------------------------------------- ##
 
@@ -820,9 +822,9 @@ AT_PARSER_CHECK([[./glr-regr9]], 0, [],
 AT_CLEANUP
 
 
-## ------------------------------------------------------------------------- ##
-## Corrupted semantic options if user action cuts parse.	             ##
-## ------------------------------------------------------------------------- ##
+## ------------------------------------------------------ ##
+## Corrupted semantic options if user action cuts parse.  ##
+## ------------------------------------------------------ ##
 
 AT_SETUP([Corrupted semantic options if user action cuts parse])
 
@@ -874,9 +876,9 @@ AT_PARSER_CHECK([[./glr-regr10]], 0, [], [])
 AT_CLEANUP
 
 
-## ------------------------------------------------------------------------- ##
-## Undesirable destructors if user action cuts parse.			     ##
-## ------------------------------------------------------------------------- ##
+## --------------------------------------------------- ##
+## Undesirable destructors if user action cuts parse.  ##
+## --------------------------------------------------- ##
 
 AT_SETUP([Undesirable destructors if user action cuts parse])
 
@@ -932,9 +934,9 @@ AT_PARSER_CHECK([[./glr-regr11]], 0, [], [])
 AT_CLEANUP
 
 
-## ------------------------------------------------------------------------- ##
-## Leaked semantic values if user action cuts parse.			     ##
-## ------------------------------------------------------------------------- ##
+## -------------------------------------------------- ##
+## Leaked semantic values if user action cuts parse.  ##
+## -------------------------------------------------- ##
 
 AT_SETUP([Leaked semantic values if user action cuts parse])
 
@@ -1179,9 +1181,9 @@ start <- defstate_init defstate_shift 'b':
 AT_CLEANUP
 
 
-## ------------------------------------------------------------------------- ##
-## Incorrect lookahead during nondeterministic GLR.			     ##
-## ------------------------------------------------------------------------- ##
+## ------------------------------------------------- ##
+## Incorrect lookahead during nondeterministic GLR.  ##
+## ------------------------------------------------- ##
 
 AT_SETUP([Incorrect lookahead during nondeterministic GLR])
 
@@ -1396,9 +1398,9 @@ start <- merge 'c' stack_explosion:
 AT_CLEANUP
 
 
-## ------------------------------------------------------------------------- ##
-## Leaked semantic values when reporting ambiguity.			     ##
-## ------------------------------------------------------------------------- ##
+## ------------------------------------------------- ##
+## Leaked semantic values when reporting ambiguity.  ##
+## ------------------------------------------------- ##
 
 AT_SETUP([Leaked semantic values when reporting ambiguity])
 
@@ -1478,9 +1480,9 @@ AT_PARSER_CHECK([[./glr-regr15]], 0, [],
 AT_CLEANUP
 
 
-## ------------------------------------------------------------------------- ##
-## Leaked lookahead after nondeterministic parse syntax error.		     ##
-## ------------------------------------------------------------------------- ##
+## ------------------------------------------------------------ ##
+## Leaked lookahead after nondeterministic parse syntax error.  ##
+## ------------------------------------------------------------ ##
 
 AT_SETUP([Leaked lookahead after nondeterministic parse syntax error])
 
@@ -1538,9 +1540,9 @@ AT_PARSER_CHECK([[./glr-regr16]], 0, [],
 AT_CLEANUP
 
 
-## ------------------------------------------------------------------------- ##
-## Uninitialized location when reporting ambiguity.			     ##
-## ------------------------------------------------------------------------- ##
+## ------------------------------------------------- ##
+## Uninitialized location when reporting ambiguity.  ##
+## ------------------------------------------------- ##
 
 AT_SETUP([Uninitialized location when reporting ambiguity])
 
@@ -1616,9 +1618,9 @@ AT_PARSER_CHECK([[./glr-regr17]], 0, [],
 AT_CLEANUP
 
 
-## -------------------------------------------------------------##
-## Missed %merge type warnings when LHS type is declared later. ##
-## -------------------------------------------------------------##
+## ------------------------------------------------------------- ##
+## Missed %merge type warnings when LHS type is declared later.  ##
+## ------------------------------------------------------------- ##
 
 AT_SETUP([Missed %merge type warnings when LHS type is declared later])
 

tests/input.at

@@ -174,42 +174,109 @@ l: INT | INT { $<integer>$ = $<integer>1; } INT { $<integer>$ = $<integer>2 + $<
 _AT_UNUSED_VALUES_DECLARATIONS])
 )
 
-AT_BISON_CHECK(m4_ifval($2, [ --warnings=midrule-values ])[ input.y], [0], [],
-[[input.y:11.10-32: warning: unset value: $]$[
-input.y:11.10-32: warning: unused value: $]1[
-input.y:11.10-32: warning: unused value: $]3[
-input.y:11.10-32: warning: unused value: $]5[
+AT_BISON_CHECK(m4_ifval($2, [--warnings=midrule-values ])[-fcaret input.y],
+               [0], [],
+[[input.y:11.10-32: warning: unset value: $][$
+ a: INT | INT { } INT { } INT { };
+          ^^^^^^^^^^^^^^^^^^^^^^^
+input.y:11.10-12: warning: unused value: $][1
+ a: INT | INT { } INT { } INT { };
+          ^^^
+input.y:11.18-20: warning: unused value: $][3
+ a: INT | INT { } INT { } INT { };
+                  ^^^
+input.y:11.26-28: warning: unused value: $][5
+ a: INT | INT { } INT { } INT { };
+                          ^^^
 input.y:12.9: warning: empty rule for typed nonterminal, and no action
-]]m4_ifval($2, [[[input.y:13.14-20: warning: unset value: $$
-input.y:13.26-41: warning: unset value: $$
-]]])[[input.y:13.10-62: warning: unset value: $]$[
-input.y:13.10-62: warning: unused value: $]3[
-input.y:13.10-62: warning: unused value: $]5[
-]]m4_ifval($2, [[[input.y:14.14-16: warning: unset value: $$
-]]])[[input.y:14.10-49: warning: unset value: $]$[
-input.y:14.10-49: warning: unused value: $]3[
-input.y:14.10-49: warning: unused value: $]5[
-input.y:15.10-37: warning: unset value: $]$[
-input.y:15.10-37: warning: unused value: $]3[
-input.y:15.10-37: warning: unused value: $]5[
-input.y:17.10-58: warning: unset value: $]$[
-input.y:17.10-58: warning: unused value: $]1[
-]]m4_ifval($2, [[[input.y:17.10-58: warning: unused value: $]2[
-]]])[[input.y:17.10-58: warning: unused value: $]3[
-]]m4_ifval($2, [[[input.y:17.10-58: warning: unused value: $]4[
-]]])[[input.y:17.10-58: warning: unused value: $]5[
-input.y:18.10-72: warning: unset value: $]$[
-input.y:18.10-72: warning: unused value: $]1[
-input.y:18.10-72: warning: unused value: $]3[
-]]m4_ifval($2, [[[input.y:18.10-72: warning: unused value: $]4[
-]]])[[input.y:18.10-72: warning: unused value: $]5[
-]]m4_ifval($2, [[[input.y:20.10-55: warning: unused value: $]3[
-]]])[[input.y:21.10-68: warning: unset value: $]$[
-input.y:21.10-68: warning: unused value: $]1[
-input.y:21.10-68: warning: unused value: $]2[
-]]m4_ifval($2, [[[input.y:21.10-68: warning: unused value: $]4[
-]]]))])
-
+ b: INT | /* empty */;
+         ^
+]]m4_ifval($2, [[[input.y:13.14-20: warning: unset value: $][$
+ c: INT | INT { $][1; } INT { $<integer>2; } INT { $<integer>4; };
+              ^^^^^^^
+input.y:13.26-41: warning: unset value: $][$
+ c: INT | INT { $][1; } INT { $<integer>2; } INT { $<integer>4; };
+                          ^^^^^^^^^^^^^^^^
+]]])[[input.y:13.10-62: warning: unset value: $][$
+ c: INT | INT { $][1; } INT { $<integer>2; } INT { $<integer>4; };
+          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+input.y:13.22-24: warning: unused value: $][3
+ c: INT | INT { $][1; } INT { $<integer>2; } INT { $<integer>4; };
+                      ^^^
+input.y:13.43-45: warning: unused value: $][5
+ c: INT | INT { $][1; } INT { $<integer>2; } INT { $<integer>4; };
+                                           ^^^
+]]m4_ifval($2, [[[input.y:14.14-16: warning: unset value: $][$
+ d: INT | INT { } INT { $][1; } INT { $<integer>2; };
+              ^^^
+]]])[[input.y:14.10-49: warning: unset value: $][$
+ d: INT | INT { } INT { $][1; } INT { $<integer>2; };
+          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+input.y:14.18-20: warning: unused value: $][3
+ d: INT | INT { } INT { $][1; } INT { $<integer>2; };
+                  ^^^
+input.y:14.30-32: warning: unused value: $][5
+ d: INT | INT { } INT { $][1; } INT { $<integer>2; };
+                              ^^^
+input.y:15.10-37: warning: unset value: $][$
+ e: INT | INT { } INT {  } INT { $][1; };
+          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+input.y:15.18-20: warning: unused value: $][3
+ e: INT | INT { } INT {  } INT { $][1; };
+                  ^^^
+input.y:15.27-29: warning: unused value: $][5
+ e: INT | INT { } INT {  } INT { $][1; };
+                           ^^^
+input.y:17.10-58: warning: unset value: $][$
+ g: INT | INT { $<integer>$; } INT { $<integer>$; } INT { };
+          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+input.y:17.10-12: warning: unused value: $][1
+ g: INT | INT { $<integer>$; } INT { $<integer>$; } INT { };
+          ^^^
+]]m4_ifval($2, [[[input.y:17.14-29: warning: unused value: $][2
+ g: INT | INT { $<integer>$; } INT { $<integer>$; } INT { };
+              ^^^^^^^^^^^^^^^^
+]]])[[input.y:17.31-33: warning: unused value: $][3
+ g: INT | INT { $<integer>$; } INT { $<integer>$; } INT { };
+                               ^^^
+]]m4_ifval($2, [[[input.y:17.35-50: warning: unused value: $][4
+ g: INT | INT { $<integer>$; } INT { $<integer>$; } INT { };
+                                   ^^^^^^^^^^^^^^^^
+]]])[[input.y:17.52-54: warning: unused value: $][5
+ g: INT | INT { $<integer>$; } INT { $<integer>$; } INT { };
+                                                    ^^^
+input.y:18.10-72: warning: unset value: $][$
+ h: INT | INT { $<integer>$; } INT { $<integer>$ = $<integer>2; } INT { };
+          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+input.y:18.10-12: warning: unused value: $][1
+ h: INT | INT { $<integer>$; } INT { $<integer>$ = $<integer>2; } INT { };
+          ^^^
+input.y:18.31-33: warning: unused value: $][3
+ h: INT | INT { $<integer>$; } INT { $<integer>$ = $<integer>2; } INT { };
+                               ^^^
+]]m4_ifval($2, [[[input.y:18.35-64: warning: unused value: $][4
+ h: INT | INT { $<integer>$; } INT { $<integer>$ = $<integer>2; } INT { };
+                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+]]])[[input.y:18.66-68: warning: unused value: $][5
+ h: INT | INT { $<integer>$; } INT { $<integer>$ = $<integer>2; } INT { };
+                                                                  ^^^
+]]m4_ifval($2, [[[input.y:20.18-37: warning: unused value: $][3
+ j: INT | INT INT { $<integer>$ = 1; } { $][$ = $][1 + $][2; };
+                  ^^^^^^^^^^^^^^^^^^^^
+]]])[[input.y:21.10-68: warning: unset value: $][$
+ k: INT | INT INT { $<integer>$; } { $<integer>$ = $<integer>3; } { };
+          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+input.y:21.10-12: warning: unused value: $][1
+ k: INT | INT INT { $<integer>$; } { $<integer>$ = $<integer>3; } { };
+          ^^^
+input.y:21.14-16: warning: unused value: $][2
+ k: INT | INT INT { $<integer>$; } { $<integer>$ = $<integer>3; } { };
+              ^^^
+]]m4_ifval($2, [[[input.y:21.35-64: warning: unused value: $][4
+ k: INT | INT INT { $<integer>$; } { $<integer>$ = $<integer>3; } { };
+                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+]]]))
+])
 
 ## --------------- ##
 ## Unused values.  ##
@@ -353,7 +420,7 @@ tagged: { } ;
 
 AT_BISON_CHECK([input.y], [0], [],
 [[input.y:6.8-45: warning: unset value: $$
-input.y:6.8-45: warning: unused value: $2
+input.y:6.12-14: warning: unused value: $2
 input.y:7.6-8: warning: unset value: $$
 ]])
 
@@ -369,7 +436,7 @@ tagged: { } ;
 ]])
 
 AT_BISON_CHECK([input.y], [0], [],
-[[input.y:6.8-45: warning: unused value: $4
+[[input.y:6.23-28: warning: unused value: $4
 input.y:8.9-11: warning: unset value: $$
 ]])
 
@@ -394,7 +461,7 @@ end: { }  ;
 
 AT_BISON_CHECK([input.y], [0], [],
 [[input.y:6.8-22: warning: unset value: $$
-input.y:6.8-22: warning: unused value: $2
+input.y:6.12-14: warning: unused value: $2
 input.y:7.6-8: warning: unset value: $$
 ]])
 

tests/local.at

@@ -600,9 +600,7 @@ m4_define([AT_QUELL_VALGRIND],
 # otherwise pass "-c"; this is a hack.  The default SOURCES is OUTPUT
 # with trailing .o removed, and ".c" appended.
 m4_define([AT_COMPILE],
-[AT_CHECK([case $POSIXLY_CORRECT_IS_EXPORTED:$C_COMPILER_POSIXLY_CORRECT in
-  true:false) echo 'cannot compile properly with POSIXLY_CORRECT' && exit 77;;
-esac])
+[AT_CHECK([$BISON_C_WORKS], 0, ignore, ignore)
 AT_CHECK(m4_join([ ],
                   [$CC $CFLAGS $CPPFLAGS],
                   [m4_bmatch([$1], [[.]], [-c], [$LDFLAGS])],

tests/synclines.at

@@ -54,7 +54,7 @@ m4_define([AT_SYNCLINES_COMPILE],
 #    #error "1"
 #     ^
 #
-# And possibly distcc adds its bits.
+# Possibly distcc adds its bits.
 #
 #   distcc[33187] ERROR: compile (null) on localhost failed
 #   syncline.c:1:2: error: #error "1"
@@ -71,11 +71,18 @@ m4_define([AT_SYNCLINES_COMPILE],
 #    #error "1"
 #     ^
 #    1 error generated.
+#
+# When c++ is used to compiler C, we might have more messages (Clang 3.2):
+#
+#    clang: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated
+
 AT_CHECK([[$PERL -p -0777 - stderr <<\EOF
   # 1. Remove useless lines.
 
   # distcc clutter.
   s/^distcc\[\d+\] .*\n//gm;
+  # c vs. c++.
+  s/^clang: warning: treating 'c' input as 'c\+\+'.*\n//gm;
   # Function context.
   s/^[^:]*: In function '[^']+':\n//gm;
   # Caret error.
@@ -120,7 +127,7 @@ AT_BISON_OPTION_PUSHDEFS
 
 AT_DATA([syncline.c],
 [[#error "1"
-int i; // avoids -pedantic warning about an empty translation unit
+int i; /* avoids -pedantic warning about an empty translation unit. */
 ]])
 
 AT_SYNCLINES_COMPILE([syncline.c])