Merge remote-tracking branch 'origin/maint'

[bison.git] / data / glr.c

diff --git a/data/glr.c b/data/glr.c
index 699d7304819b61bd1a3b3fd0dd7f00cee865cfcd..2aa12b50d686716d14b1b4636b1bfe053ad2cc99 100644 (file)
--- a/data/glr.c
+++ b/data/glr.c
@@ -123,7 +123,15 @@ m4_define([b4_locuser_args],
 # --------------------
 # Expansion of $<TYPE>$.
 m4_define([b4_lhs_value],
 # --------------------
 # Expansion of $<TYPE>$.
 m4_define([b4_lhs_value],

-[((*yyvalp)[]m4_ifval([$1], [.$1]))])
+[b4_symbol_value([(*yyvalp)], [$1])])
+
+
+# b4_rhs_data(RULE-LENGTH, NUM)
+# -----------------------------
+# Expand to the semantic stack place that contains value and location
+# of symbol number NUM in a rule of length RULE-LENGTH.
+m4_define([b4_rhs_data],
+[((yyGLRStackItem const *)yyvsp)@{YYFILL (b4_subtract([$2], [$1]))@}.yystate])

 
 
 # b4_rhs_value(RULE-LENGTH, NUM, [TYPE])
 
 
 # b4_rhs_value(RULE-LENGTH, NUM, [TYPE])


@@ -131,7 +139,7 @@ m4_define([b4_lhs_value],
 # Expansion of $<TYPE>NUM, where the current rule has RULE-LENGTH
 # symbols on RHS.
 m4_define([b4_rhs_value],
 # Expansion of $<TYPE>NUM, where the current rule has RULE-LENGTH
 # symbols on RHS.
 m4_define([b4_rhs_value],

-[(((yyGLRStackItem const *)yyvsp)@{YYFILL (($2) - ($1))@}.yystate.yysemantics.yysval[]m4_ifval([$3], [.$3]))])
+[b4_symbol_value([b4_rhs_data([$1], [$2]).yysemantics.yysval], [$3])])

 
 
 
 
 
 


@@ -151,7 +159,7 @@ m4_define([b4_lhs_location],
 # Expansion of @NUM, where the current rule has RULE-LENGTH symbols
 # on RHS.
 m4_define([b4_rhs_location],
 # Expansion of @NUM, where the current rule has RULE-LENGTH symbols
 # on RHS.
 m4_define([b4_rhs_location],

-[(((yyGLRStackItem const *)yyvsp)@{YYFILL (($2) - ($1))@}.yystate.yyloc)])
+[(b4_rhs_data([$1], [$2]).yyloc)])

 
 
 ## -------------- ##
 
 
 ## -------------- ##


@@ -205,14 +213,14 @@ b4_percent_code_get([[top]])[
 ]b4_null_define[
 
 ]b4_defines_if([[#include "@basename(]b4_spec_defines_file[@)"]],
 ]b4_null_define[
 
 ]b4_defines_if([[#include "@basename(]b4_spec_defines_file[@)"]],

-               [b4_shared_declarations])[
+              [b4_shared_declarations])[

 
 /* Enabling verbose error messages.  */
 #ifdef YYERROR_VERBOSE
 # undef YYERROR_VERBOSE
 # define YYERROR_VERBOSE 1
 #else
 
 /* Enabling verbose error messages.  */
 #ifdef YYERROR_VERBOSE
 # undef YYERROR_VERBOSE
 # define YYERROR_VERBOSE 1
 #else

-# define YYERROR_VERBOSE ]b4_error_verbose_flag[
+# define YYERROR_VERBOSE ]b4_error_verbose_if([1], [0])[

 #endif
 
 /* Default (constant) value used for initialization for null
 #endif
 
 /* Default (constant) value used for initialization for null


@@ -342,19 +350,6 @@ static const ]b4_int_type_for([b4_translate])[ yytranslate[] =
 };
 
 #if YYDEBUG
 };
 
 #if YYDEBUG

-/* YYPRHS[YYN] -- Index of the first RHS symbol of rule number YYN in
-   YYRHS.  */
-static const ]b4_int_type_for([b4_prhs])[ yyprhs[] =
-{
-  ]b4_prhs[
-};
-
-/* YYRHS -- A `-1'-separated list of the rules' RHS.  */
-static const ]b4_int_type_for([b4_rhs])[ yyrhs[] =
-{
-  ]b4_rhs[
-};
-

 /* YYRLINE[YYN] -- source line where rule number YYN was defined.  */
 static const ]b4_int_type_for([b4_rline])[ yyrline[] =
 {
 /* YYRLINE[YYN] -- source line where rule number YYN was defined.  */
 static const ]b4_int_type_for([b4_rline])[ yyrline[] =
 {


@@ -371,17 +366,10 @@ static const char *const yytname[] =
 };
 #endif
 
 };
 #endif
 

-/* YYR1[YYN] -- Symbol number of symbol that rule YYN derives.  */
-static const ]b4_int_type_for([b4_r1])[ yyr1[] =
-{
-  ]b4_r1[
-};
+#define YYPACT_NINF ]b4_pact_ninf[
+#define YYTABLE_NINF ]b4_table_ninf[

 
 

-/* YYR2[YYN] -- Number of symbols composing right hand side of rule YYN.  */
-static const ]b4_int_type_for([b4_r2])[ yyr2[] =
-{
-  ]b4_r2[
-};
+]b4_parser_tables_define[

 
 /* YYDPREC[RULE-NUM] -- Dynamic precedence of rule #RULE-NUM (0 if none).  */
 static const ]b4_int_type_for([b4_dprec])[ yydprec[] =
 
 /* YYDPREC[RULE-NUM] -- Dynamic precedence of rule #RULE-NUM (0 if none).  */
 static const ]b4_int_type_for([b4_dprec])[ yydprec[] =


@@ -395,41 +383,11 @@ static const ]b4_int_type_for([b4_merger])[ yymerger[] =
   ]b4_merger[
 };
 
   ]b4_merger[
 };
 

-/* YYDEFACT[S] -- default reduction number in state S.  Performed when
-   YYTABLE doesn't specify something else to do.  Zero means the default
-   is an error.  */
-static const ]b4_int_type_for([b4_defact])[ yydefact[] =
+/* YYIMMEDIATE[RULE-NUM] -- True iff rule #RULE-NUM is not to be deferred, as
+   in the case of predicates.  */
+static const yybool yyimmediate[] =

 {
 {

-  ]b4_defact[
-};
-
-/* YYPDEFGOTO[NTERM-NUM].  */
-static const ]b4_int_type_for([b4_defgoto])[ yydefgoto[] =
-{
-  ]b4_defgoto[
-};
-
-/* YYPACT[STATE-NUM] -- Index in YYTABLE of the portion describing
-   STATE-NUM.  */
-#define YYPACT_NINF ]b4_pact_ninf[
-static const ]b4_int_type_for([b4_pact])[ yypact[] =
-{
-  ]b4_pact[
-};
-
-/* YYPGOTO[NTERM-NUM].  */
-static const ]b4_int_type_for([b4_pgoto])[ yypgoto[] =
-{
-  ]b4_pgoto[
-};
-
-/* YYTABLE[YYPACT[STATE-NUM]].  What to do in state STATE-NUM.  If
-   positive, shift that token.  If negative, reduce the rule which
-   number is the opposite.  If YYTABLE_NINF, syntax error.  */
-#define YYTABLE_NINF ]b4_table_ninf[
-static const ]b4_int_type_for([b4_table])[ yytable[] =
-{
-  ]b4_table[
+  ]b4_immediate[

 };
 
 /* YYCONFLP[YYPACT[STATE-NUM]] -- Pointer into YYCONFL of start of
 };
 
 /* YYCONFLP[YYPACT[STATE-NUM]] -- Pointer into YYCONFL of start of


@@ -450,19 +408,6 @@ dnl We probably ought to introduce a type for confl.
 {
   ]b4_conflicting_rules[
 };
 {
   ]b4_conflicting_rules[
 };

-
-static const ]b4_int_type_for([b4_check])[ yycheck[] =
-{
-  ]b4_check[
-};
-
-/* YYSTOS[STATE-NUM] -- The (internal number of the) accessing
-   symbol of state STATE-NUM.  */
-static const ]b4_int_type_for([b4_stos])[ yystos[] =
-{
-  ]b4_stos[
-};
-

 \f
 /* Error token number */
 #define YYTERROR 1
 \f
 /* Error token number */
 #define YYTERROR 1


@@ -541,9 +486,12 @@ static const int YYEMPTY = -2;
 
 typedef enum { yyok, yyaccept, yyabort, yyerr } YYRESULTTAG;
 
 
 typedef enum { yyok, yyaccept, yyabort, yyerr } YYRESULTTAG;
 

-#define YYCHK(YYE)                                                           \
-   do { YYRESULTTAG yyflag = YYE; if (yyflag != yyok) return yyflag; }       \
-   while (YYID (0))
+#define YYCHK(YYE)                              \
+  do {                                          \
+    YYRESULTTAG yychk_flag = YYE;               \
+    if (yychk_flag != yyok)                     \
+      return yychk_flag;                        \
+  } while (YYID (0))

 
 #if YYDEBUG
 
 
 #if YYDEBUG
 


@@ -552,22 +500,22 @@ typedef enum { yyok, yyaccept, yyabort, yyerr } YYRESULTTAG;
 # endif
 
 # define YYDPRINTF(Args)                        \
 # endif
 
 # define YYDPRINTF(Args)                        \

-do {                                            \
-  if (yydebug)                                  \
-    YYFPRINTF Args;                             \
-} while (YYID (0))
+  do {                                          \
+    if (yydebug)                                \
+      YYFPRINTF Args;                           \
+  } while (YYID (0))

 
 ]b4_yy_symbol_print_generate([b4_c_ansi_function_def])[
 
 
 ]b4_yy_symbol_print_generate([b4_c_ansi_function_def])[
 

-# define YY_SYMBOL_PRINT(Title, Type, Value, Location)          \
-do {                                                            \
-  if (yydebug)                                                  \
-    {                                                           \
-      YYFPRINTF (stderr, "%s ", Title);                         \
-      yy_symbol_print (stderr, Type, Value]b4_locuser_args([Location])[);        \
-      YYFPRINTF (stderr, "\n");                                 \
-    }                                                           \
-} while (YYID (0))
+# define YY_SYMBOL_PRINT(Title, Type, Value, Location)                  \
+  do {                                                                  \
+    if (yydebug)                                                        \
+      {                                                                 \
+        YYFPRINTF (stderr, "%s ", Title);                               \
+        yy_symbol_print (stderr, Type, Value]b4_locuser_args([Location])[);        \
+        YYFPRINTF (stderr, "\n");                                       \
+      }                                                                 \
+  } while (YYID (0))

 
 /* Nonzero means print parse trace.  It is left uninitialized so that
    multiple parsers can coexist.  */
 
 /* Nonzero means print parse trace.  It is left uninitialized so that
    multiple parsers can coexist.  */


@@ -604,13 +552,7 @@ int yydebug;
 #define YYHEADROOM 2
 
 #ifndef YYSTACKEXPANDABLE
 #define YYHEADROOM 2
 
 #ifndef YYSTACKEXPANDABLE

-# if (! defined __cplusplus \
-      || (]b4_locations_if([[defined YYLTYPE_IS_TRIVIAL && YYLTYPE_IS_TRIVIAL \
-          && ]])[defined YYSTYPE_IS_TRIVIAL && YYSTYPE_IS_TRIVIAL))

 #  define YYSTACKEXPANDABLE 1
 #  define YYSTACKEXPANDABLE 1

-# else
-#  define YYSTACKEXPANDABLE 0
-# endif

 #endif
 
 #if YYSTACKEXPANDABLE
 #endif
 
 #if YYSTACKEXPANDABLE


@@ -707,7 +649,7 @@ typedef int yyStateNum;
 typedef int yyRuleNum;
 
 /** Grammar symbol */
 typedef int yyRuleNum;
 
 /** Grammar symbol */

-typedef short int yySymbol;
+typedef int yySymbol;

 
 /** Item references, as in LALR(1) machine */
 typedef short int yyItemNum;
 
 /** Item references, as in LALR(1) machine */
 typedef short int yyItemNum;


@@ -728,7 +670,7 @@ struct yyGLRState {
   yyStateNum yylrState;
   /** Preceding state in this stack */
   yyGLRState* yypred;
   yyStateNum yylrState;
   /** Preceding state in this stack */
   yyGLRState* yypred;

-  /** Source position of the first token produced by my symbol */
+  /** Source position of the last token produced by my symbol */

   size_t yyposn;
   union {
     /** First in a chain of alternative reductions producing the
   size_t yyposn;
   union {
     /** First in a chain of alternative reductions producing the


@@ -840,9 +782,16 @@ yyfillin (yyGLRStackItem *yyvsp, int yylow0, int yylow1)
   yyGLRState *s = yyvsp[yylow0].yystate.yypred;
   for (i = yylow0-1; i >= yylow1; i -= 1)
     {
   yyGLRState *s = yyvsp[yylow0].yystate.yypred;
   for (i = yylow0-1; i >= yylow1; i -= 1)
     {

-      YYASSERT (s->yyresolved);
-      yyvsp[i].yystate.yyresolved = yytrue;
-      yyvsp[i].yystate.yysemantics.yysval = s->yysemantics.yysval;]b4_locations_if([[
+#if YYDEBUG
+      yyvsp[i].yystate.yylrState = s->yylrState;
+#endif
+      yyvsp[i].yystate.yyresolved = s->yyresolved;
+      if (s->yyresolved)
+        yyvsp[i].yystate.yysemantics.yysval = s->yysemantics.yysval;
+      else
+        /* The effect of using yysval or yyloc (in an immediate rule) is
+         * undefined.  */
+        yyvsp[i].yystate.yysemantics.yyfirstVal = YY_NULL;]b4_locations_if([[

       yyvsp[i].yystate.yyloc = s->yyloc;]])[
       s = yyvsp[i].yystate.yypred = s->yypred;
     }
       yyvsp[i].yystate.yyloc = s->yyloc;]])[
       s = yyvsp[i].yystate.yypred = s->yypred;
     }


@@ -877,7 +826,7 @@ yyuserAction (yyRuleNum yyn, int yyrhslen, yyGLRStackItem* yyvsp,
   yybool yynormal __attribute__ ((__unused__)) =
     (yystackp->yysplitPoint == YY_NULL);
   int yylow;
   yybool yynormal __attribute__ ((__unused__)) =
     (yystackp->yysplitPoint == YY_NULL);
   int yylow;

-]b4_parse_param_use[]dnl
+]b4_parse_param_use([yyvalp], [yylocp])dnl

 [# undef yyerrok
 # define yyerrok (yystackp->yyerrState = 0)
 # undef YYACCEPT
 [# undef yyerrok
 # define yyerrok (yystackp->yyerrState = 0)
 # undef YYACCEPT


@@ -980,7 +929,7 @@ yydestroyGLRState (char const *yymsg, yyGLRState *yys]b4_user_formals[)
     }
 }
 
     }
 }
 

-/** Left-hand-side symbol for rule #RULE.  */
+/** Left-hand-side symbol for rule #YYRULE.  */

 static inline yySymbol
 yylhsNonterm (yyRuleNum yyrule)
 {
 static inline yySymbol
 yylhsNonterm (yyRuleNum yyrule)
 {


@@ -990,7 +939,7 @@ yylhsNonterm (yyRuleNum yyrule)
 #define yypact_value_is_default(yystate) \
   ]b4_table_value_equals([[pact]], [[yystate]], [b4_pact_ninf])[
 
 #define yypact_value_is_default(yystate) \
   ]b4_table_value_equals([[pact]], [[yystate]], [b4_pact_ninf])[
 

-/** True iff LR state STATE has only a default reduction (regardless
+/** True iff LR state YYSTATE has only a default reduction (regardless

  *  of token).  */
 static inline yybool
 yyisDefaultedState (yyStateNum yystate)
  *  of token).  */
 static inline yybool
 yyisDefaultedState (yyStateNum yystate)


@@ -998,7 +947,7 @@ yyisDefaultedState (yyStateNum yystate)
   return yypact_value_is_default (yypact[yystate]);
 }
 
   return yypact_value_is_default (yypact[yystate]);
 }
 

-/** The default reduction for STATE, assuming it has one.  */
+/** The default reduction for YYSTATE, assuming it has one.  */

 static inline yyRuleNum
 yydefaultAction (yyStateNum yystate)
 {
 static inline yyRuleNum
 yydefaultAction (yyStateNum yystate)
 {


@@ -1013,8 +962,8 @@ yydefaultAction (yyStateNum yystate)
  *    R < 0:  Reduce on rule -R.
  *    R = 0:  Error.
  *    R > 0:  Shift to state R.
  *    R < 0:  Reduce on rule -R.
  *    R = 0:  Error.
  *    R > 0:  Shift to state R.

- *  Set *CONFLICTS to a pointer into yyconfl to 0-terminated list of
- *  conflicting reductions.
+ *  Set *YYCONFLICTS to a pointer into yyconfl to a 0-terminated list
+ *  of conflicting reductions.

  */
 static inline void
 yygetLRActions (yyStateNum yystate, int yytoken,
  */
 static inline void
 yygetLRActions (yyStateNum yystate, int yytoken,


@@ -1042,8 +991,7 @@ yygetLRActions (yyStateNum yystate, int yytoken,
 static inline yyStateNum
 yyLRgotoState (yyStateNum yystate, yySymbol yylhs)
 {
 static inline yyStateNum
 yyLRgotoState (yyStateNum yystate, yySymbol yylhs)
 {

-  int yyr;
-  yyr = yypgoto[yylhs - YYNTOKENS] + yystate;
+  int yyr = yypgoto[yylhs - YYNTOKENS] + yystate;

   if (0 <= yyr && yyr <= YYLAST && yycheck[yyr] == yystate)
     return yytable[yyr];
   else
   if (0 <= yyr && yyr <= YYLAST && yycheck[yyr] == yystate)
     return yytable[yyr];
   else


@@ -1064,9 +1012,10 @@ yyisErrorAction (int yyaction)
 
                                 /* GLRStates */
 
 
                                 /* GLRStates */
 

-/** Return a fresh GLRStackItem.  Callers should call
- * YY_RESERVE_GLRSTACK afterwards to make sure there is sufficient
- * headroom.  */
+/** Return a fresh GLRStackItem in YYSTACKP.  The item is an LR state
+ *  if YYISSTATE, and otherwise a semantic option.  Callers should call
+ *  YY_RESERVE_GLRSTACK afterwards to make sure there is sufficient
+ *  headroom.  */

 
 static inline yyGLRStackItem*
 yynewGLRStackItem (yyGLRStack* yystackp, yybool yyisState)
 
 static inline yyGLRStackItem*
 yynewGLRStackItem (yyGLRStack* yystackp, yybool yyisState)


@@ -1079,16 +1028,16 @@ yynewGLRStackItem (yyGLRStack* yystackp, yybool yyisState)
 }
 
 /** Add a new semantic action that will execute the action for rule
 }
 
 /** Add a new semantic action that will execute the action for rule

- *  RULENUM on the semantic values in RHS to the list of
- *  alternative actions for STATE.  Assumes that RHS comes from
- *  stack #K of *STACKP. */
+ *  YYRULE on the semantic values in YYRHS to the list of
+ *  alternative actions for YYSTATE.  Assumes that YYRHS comes from
+ *  stack #YYK of *YYSTACKP. */

 static void
 yyaddDeferredAction (yyGLRStack* yystackp, size_t yyk, yyGLRState* yystate,
 static void
 yyaddDeferredAction (yyGLRStack* yystackp, size_t yyk, yyGLRState* yystate,

-                     yyGLRState* rhs, yyRuleNum yyrule)
+                     yyGLRState* yyrhs, yyRuleNum yyrule)

 {
   yySemanticOption* yynewOption =
     &yynewGLRStackItem (yystackp, yyfalse)->yyoption;
 {
   yySemanticOption* yynewOption =
     &yynewGLRStackItem (yystackp, yyfalse)->yyoption;

-  yynewOption->yystate = rhs;
+  yynewOption->yystate = yyrhs;

   yynewOption->yyrule = yyrule;
   if (yystackp->yytops.yylookaheadNeeds[yyk])
     {
   yynewOption->yyrule = yyrule;
   if (yystackp->yytops.yylookaheadNeeds[yyk])
     {


@@ -1106,7 +1055,7 @@ yyaddDeferredAction (yyGLRStack* yystackp, size_t yyk, yyGLRState* yystate,
 
                                 /* GLRStacks */
 
 
                                 /* GLRStacks */
 

-/** Initialize SET to a singleton set containing an empty stack.  */
+/** Initialize YYSET to a singleton set containing an empty stack.  */

 static yybool
 yyinitStateSet (yyGLRStateSet* yyset)
 {
 static yybool
 yyinitStateSet (yyGLRStateSet* yyset)
 {


@@ -1132,8 +1081,8 @@ static void yyfreeStateSet (yyGLRStateSet* yyset)
   YYFREE (yyset->yylookaheadNeeds);
 }
 
   YYFREE (yyset->yylookaheadNeeds);
 }
 

-/** Initialize STACK to a single empty stack, with total maximum
- *  capacity for all stacks of SIZE.  */
+/** Initialize *YYSTACKP to a single empty stack, with total maximum
+ *  capacity for all stacks of YYSIZE.  */

 static yybool
 yyinitGLRStack (yyGLRStack* yystackp, size_t yysize)
 {
 static yybool
 yyinitGLRStack (yyGLRStack* yystackp, size_t yysize)
 {


@@ -1155,7 +1104,7 @@ yyinitGLRStack (yyGLRStack* yystackp, size_t yysize)
 # define YYRELOC(YYFROMITEMS,YYTOITEMS,YYX,YYTYPE) \
   &((YYTOITEMS) - ((YYFROMITEMS) - (yyGLRStackItem*) (YYX)))->YYTYPE
 
 # define YYRELOC(YYFROMITEMS,YYTOITEMS,YYX,YYTYPE) \
   &((YYTOITEMS) - ((YYFROMITEMS) - (yyGLRStackItem*) (YYX)))->YYTYPE
 

-/** If STACK is expandable, extend it.  WARNING: Pointers into the
+/** If *YYSTACKP is expandable, extend it.  WARNING: Pointers into the

     stack from outside should be considered invalid after this call.
     We always expand when there are 1 or fewer items left AFTER an
     allocation, so that we can avoid having external pointers exist
     stack from outside should be considered invalid after this call.
     We always expand when there are 1 or fewer items left AFTER an
     allocation, so that we can avoid having external pointers exist


@@ -1225,9 +1174,9 @@ yyfreeGLRStack (yyGLRStack* yystackp)
   yyfreeStateSet (&yystackp->yytops);
 }
 
   yyfreeStateSet (&yystackp->yytops);
 }
 

-/** Assuming that S is a GLRState somewhere on STACK, update the
- *  splitpoint of STACK, if needed, so that it is at least as deep as
- *  S.  */
+/** Assuming that YYS is a GLRState somewhere on *YYSTACKP, update the
+ *  splitpoint of *YYSTACKP, if needed, so that it is at least as deep as
+ *  YYS.  */

 static inline void
 yyupdateSplit (yyGLRStack* yystackp, yyGLRState* yys)
 {
 static inline void
 yyupdateSplit (yyGLRStack* yystackp, yyGLRState* yys)
 {


@@ -1235,7 +1184,7 @@ yyupdateSplit (yyGLRStack* yystackp, yyGLRState* yys)
     yystackp->yysplitPoint = yys;
 }
 
     yystackp->yysplitPoint = yys;
 }
 

-/** Invalidate stack #K in STACK.  */
+/** Invalidate stack #YYK in *YYSTACKP.  */

 static inline void
 yymarkStackDeleted (yyGLRStack* yystackp, size_t yyk)
 {
 static inline void
 yymarkStackDeleted (yyGLRStack* yystackp, size_t yyk)
 {


@@ -1244,8 +1193,8 @@ yymarkStackDeleted (yyGLRStack* yystackp, size_t yyk)
   yystackp->yytops.yystates[yyk] = YY_NULL;
 }
 
   yystackp->yytops.yystates[yyk] = YY_NULL;
 }
 

-/** Undelete the last stack that was marked as deleted.  Can only be
-    done once after a deletion, and only when all other stacks have
+/** Undelete the last stack in *YYSTACKP that was marked as deleted.  Can
+    only be done once after a deletion, and only when all other stacks have

     been deleted.  */
 static void
 yyundeleteLastStack (yyGLRStack* yystackp)
     been deleted.  */
 static void
 yyundeleteLastStack (yyGLRStack* yystackp)


@@ -1294,8 +1243,9 @@ yyremoveDeletes (yyGLRStack* yystackp)
     }
 }
 
     }
 }
 

-/** Shift to a new state on stack #K of STACK, corresponding to LR state
- * LRSTATE, at input position POSN, with (resolved) semantic value SVAL.  */
+/** Shift to a new state on stack #YYK of *YYSTACKP, corresponding to LR
+ * state YYLRSTATE, at input position YYPOSN, with (resolved) semantic
+ * value *YYVALP and source location *YYLOCP.  */

 static inline void
 yyglrShift (yyGLRStack* yystackp, size_t yyk, yyStateNum yylrState,
             size_t yyposn,
 static inline void
 yyglrShift (yyGLRStack* yystackp, size_t yyk, yyStateNum yylrState,
             size_t yyposn,


@@ -1314,12 +1264,12 @@ yyglrShift (yyGLRStack* yystackp, size_t yyk, yyStateNum yylrState,
   YY_RESERVE_GLRSTACK (yystackp);
 }
 
   YY_RESERVE_GLRSTACK (yystackp);
 }
 

-/** Shift stack #K of YYSTACK, to a new state corresponding to LR
+/** Shift stack #YYK of *YYSTACKP, to a new state corresponding to LR

  *  state YYLRSTATE, at input position YYPOSN, with the (unresolved)
  *  semantic value of YYRHS under the action for YYRULE.  */
 static inline void
 yyglrShiftDefer (yyGLRStack* yystackp, size_t yyk, yyStateNum yylrState,
  *  state YYLRSTATE, at input position YYPOSN, with the (unresolved)
  *  semantic value of YYRHS under the action for YYRULE.  */
 static inline void
 yyglrShiftDefer (yyGLRStack* yystackp, size_t yyk, yyStateNum yylrState,

-                 size_t yyposn, yyGLRState* rhs, yyRuleNum yyrule)
+                 size_t yyposn, yyGLRState* yyrhs, yyRuleNum yyrule)

 {
   yyGLRState* yynewState = &yynewGLRStackItem (yystackp, yytrue)->yystate;
 
 {
   yyGLRState* yynewState = &yynewGLRStackItem (yystackp, yytrue)->yystate;
 


@@ -1331,14 +1281,55 @@ yyglrShiftDefer (yyGLRStack* yystackp, size_t yyk, yyStateNum yylrState,
   yystackp->yytops.yystates[yyk] = yynewState;
 
   /* Invokes YY_RESERVE_GLRSTACK.  */
   yystackp->yytops.yystates[yyk] = yynewState;
 
   /* Invokes YY_RESERVE_GLRSTACK.  */

-  yyaddDeferredAction (yystackp, yyk, yynewState, rhs, yyrule);
+  yyaddDeferredAction (yystackp, yyk, yynewState, yyrhs, yyrule);

 }
 
 }
 

-/** Pop the symbols consumed by reduction #RULE from the top of stack
- *  #K of STACK, and perform the appropriate semantic action on their
+#if !YYDEBUG
+# define YY_REDUCE_PRINT(Args)
+#else
+# define YY_REDUCE_PRINT(Args)          \
+do {                                    \
+  if (yydebug)                          \
+    yy_reduce_print Args;               \
+} while (YYID (0))
+
+/*----------------------------------------------------------------------.
+| Report that stack #YYK of *YYSTACKP is going to be reduced by YYRULE. |
+`----------------------------------------------------------------------*/
+
+/*ARGSUSED*/ static inline void
+yy_reduce_print (int yynormal, yyGLRStackItem* yyvsp, size_t yyk,
+                 yyRuleNum yyrule]b4_user_formals[)
+{
+  int yynrhs = yyrhsLength (yyrule);]b4_locations_if([
+  int yylow = 1;])[
+  int yyi;
+  YYFPRINTF (stderr, "Reducing stack %lu by rule %d (line %lu):\n",
+             (unsigned long int) yyk, yyrule - 1,
+             (unsigned long int) yyrline[yyrule]);
+  if (! yynormal)
+    yyfillin (yyvsp, 1, -yynrhs);
+  /* The symbols being reduced.  */
+  for (yyi = 0; yyi < yynrhs; yyi++)
+    {
+      YYFPRINTF (stderr, "   $%d = ", yyi + 1);
+      yy_symbol_print (stderr,
+                       yystos[yyvsp[yyi - yynrhs + 1].yystate.yylrState],
+                       &yyvsp[yyi - yynrhs + 1].yystate.yysemantics.yysval
+                       ]b4_locations_if([, &]b4_rhs_location(yynrhs, yyi + 1))[]dnl
+                       b4_user_args[);
+      if (!yyvsp[yyi - yynrhs + 1].yystate.yyresolved)
+        YYFPRINTF (stderr, " (unresolved)");
+      YYFPRINTF (stderr, "\n");
+    }
+}
+#endif
+
+/** Pop the symbols consumed by reduction #YYRULE from the top of stack
+ *  #YYK of *YYSTACKP, and perform the appropriate semantic action on their

  *  semantic values.  Assumes that all ambiguities in semantic values
  *  semantic values.  Assumes that all ambiguities in semantic values

- *  have been previously resolved.  Set *VALP to the resulting value,
- *  and *LOCP to the computed location (if any).  Return value is as
+ *  have been previously resolved.  Set *YYVALP to the resulting value,
+ *  and *YYLOCP to the computed location (if any).  Return value is as

  *  for userAction.  */
 static inline YYRESULTTAG
 yydoAction (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
  *  for userAction.  */
 static inline YYRESULTTAG
 yydoAction (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,


@@ -1349,20 +1340,17 @@ yydoAction (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
   if (yystackp->yysplitPoint == YY_NULL)
     {
       /* Standard special case: single stack.  */
   if (yystackp->yysplitPoint == YY_NULL)
     {
       /* Standard special case: single stack.  */

-      yyGLRStackItem* rhs = (yyGLRStackItem*) yystackp->yytops.yystates[yyk];
+      yyGLRStackItem* yyrhs = (yyGLRStackItem*) yystackp->yytops.yystates[yyk];

       YYASSERT (yyk == 0);
       yystackp->yynextFree -= yynrhs;
       yystackp->yyspaceLeft += yynrhs;
       yystackp->yytops.yystates[0] = & yystackp->yynextFree[-1].yystate;
       YYASSERT (yyk == 0);
       yystackp->yynextFree -= yynrhs;
       yystackp->yyspaceLeft += yynrhs;
       yystackp->yytops.yystates[0] = & yystackp->yynextFree[-1].yystate;

-      return yyuserAction (yyrule, yynrhs, rhs, yystackp,
+      YY_REDUCE_PRINT ((1, yyrhs, yyk, yyrule]b4_user_args[));
+      return yyuserAction (yyrule, yynrhs, yyrhs, yystackp,

                            yyvalp]b4_locuser_args[);
     }
   else
     {
                            yyvalp]b4_locuser_args[);
     }
   else
     {

-      /* At present, doAction is never called in nondeterministic
-       * mode, so this branch is never taken.  It is here in
-       * anticipation of a future feature that will allow immediate
-       * evaluation of selected actions in nondeterministic mode.  */

       int yyi;
       yyGLRState* yys;
       yyGLRStackItem yyrhsVals[YYMAXRHS + YYMAXLEFT + 1];
       int yyi;
       yyGLRState* yys;
       yyGLRStackItem yyrhsVals[YYMAXRHS + YYMAXLEFT + 1];


@@ -1378,62 +1366,21 @@ yydoAction (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
         }
       yyupdateSplit (yystackp, yys);
       yystackp->yytops.yystates[yyk] = yys;
         }
       yyupdateSplit (yystackp, yys);
       yystackp->yytops.yystates[yyk] = yys;

+      YY_REDUCE_PRINT ((0, yyrhsVals + YYMAXRHS + YYMAXLEFT - 1, yyk, yyrule]b4_user_args[));

       return yyuserAction (yyrule, yynrhs, yyrhsVals + YYMAXRHS + YYMAXLEFT - 1,
                            yystackp, yyvalp]b4_locuser_args[);
     }
 }
 
       return yyuserAction (yyrule, yynrhs, yyrhsVals + YYMAXRHS + YYMAXLEFT - 1,
                            yystackp, yyvalp]b4_locuser_args[);
     }
 }
 

-#if !YYDEBUG
-# define YY_REDUCE_PRINT(Args)
-#else
-# define YY_REDUCE_PRINT(Args)          \
-do {                                    \
-  if (yydebug)                          \
-    yy_reduce_print Args;               \
-} while (YYID (0))
-
-/*----------------------------------------------------------.
-| Report that the RULE is going to be reduced on stack #K.  |
-`----------------------------------------------------------*/
-
-/*ARGSUSED*/ static inline void
-yy_reduce_print (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
-                 YYSTYPE* yyvalp]b4_locuser_formals[)
-{
-  int yynrhs = yyrhsLength (yyrule);
-  yybool yynormal __attribute__ ((__unused__)) =
-    (yystackp->yysplitPoint == YY_NULL);
-  yyGLRStackItem* yyvsp = (yyGLRStackItem*) yystackp->yytops.yystates[yyk];
-  int yylow = 1;
-  int yyi;
-  YYUSE (yyvalp);]b4_locations_if([
-  YYUSE (yylocp);])[
-]b4_parse_param_use[]dnl
-[  YYFPRINTF (stderr, "Reducing stack %lu by rule %d (line %lu):\n",
-             (unsigned long int) yyk, yyrule - 1,
-             (unsigned long int) yyrline[yyrule]);
-  /* The symbols being reduced.  */
-  for (yyi = 0; yyi < yynrhs; yyi++)
-    {
-      YYFPRINTF (stderr, "   $%d = ", yyi + 1);
-      yy_symbol_print (stderr, yyrhs[yyprhs[yyrule] + yyi],
-                       &]b4_rhs_value(yynrhs, yyi + 1)[
-                       ]b4_locations_if([, &]b4_rhs_location(yynrhs, yyi + 1))[]dnl
-                       b4_user_args[);
-      YYFPRINTF (stderr, "\n");
-    }
-}
-#endif
-
-/** Pop items off stack #K of STACK according to grammar rule RULE,
+/** Pop items off stack #YYK of *YYSTACKP according to grammar rule YYRULE,

  *  and push back on the resulting nonterminal symbol.  Perform the
  *  and push back on the resulting nonterminal symbol.  Perform the

- *  semantic action associated with RULE and store its value with the
- *  newly pushed state, if FORCEEVAL or if STACK is currently
+ *  semantic action associated with YYRULE and store its value with the
+ *  newly pushed state, if YYFORCEEVAL or if *YYSTACKP is currently

  *  unambiguous.  Otherwise, store the deferred semantic action with
  *  the new state.  If the new state would have an identical input
  *  position, LR state, and predecessor to an existing state on the stack,
  *  unambiguous.  Otherwise, store the deferred semantic action with
  *  the new state.  If the new state would have an identical input
  *  position, LR state, and predecessor to an existing state on the stack,

- *  it is identified with that existing state, eliminating stack #K from
- *  the STACK.  In this case, the (necessarily deferred) semantic value is
+ *  it is identified with that existing state, eliminating stack #YYK from
+ *  *YYSTACKP.  In this case, the semantic value is

  *  added to the options for the existing state's semantic value.
  */
 static inline YYRESULTTAG
  *  added to the options for the existing state's semantic value.
  */
 static inline YYRESULTTAG


@@ -1444,11 +1391,18 @@ yyglrReduce (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
 
   if (yyforceEval || yystackp->yysplitPoint == YY_NULL)
     {
 
   if (yyforceEval || yystackp->yysplitPoint == YY_NULL)
     {

+      YYRESULTTAG yyflag;

       YYSTYPE yysval;]b4_locations_if([
       YYLTYPE yyloc;])[
 
       YYSTYPE yysval;]b4_locations_if([
       YYLTYPE yyloc;])[
 

-      YY_REDUCE_PRINT ((yystackp, yyk, yyrule, &yysval]b4_locuser_args([&yyloc])[));
-      YYCHK (yydoAction (yystackp, yyk, yyrule, &yysval]b4_locuser_args([&yyloc])[));
+      yyflag = yydoAction (yystackp, yyk, yyrule, &yysval]b4_locuser_args([&yyloc])[);
+      if (yyflag == yyerr && yystackp->yysplitPoint != YY_NULL)
+        {
+          YYDPRINTF ((stderr, "Parse on stack %lu rejected by rule #%d.\n",
+                     (unsigned long int) yyk, yyrule - 1));
+        }
+      if (yyflag != yyok)
+        return yyflag;

       YY_SYMBOL_PRINT ("-> $$ =", yyr1[yyrule], &yysval, &yyloc);
       yyglrShift (yystackp, yyk,
                   yyLRgotoState (yystackp->yytops.yystates[yyk]->yylrState,
       YY_SYMBOL_PRINT ("-> $$ =", yyr1[yyrule], &yysval, &yyloc);
       yyglrShift (yystackp, yyk,
                   yyLRgotoState (yystackp->yytops.yystates[yyk]->yylrState,


@@ -1471,7 +1425,8 @@ yyglrReduce (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
       yyupdateSplit (yystackp, yys);
       yynewLRState = yyLRgotoState (yys->yylrState, yylhsNonterm (yyrule));
       YYDPRINTF ((stderr,
       yyupdateSplit (yystackp, yys);
       yynewLRState = yyLRgotoState (yys->yylrState, yylhsNonterm (yyrule));
       YYDPRINTF ((stderr,

-                  "Reduced stack %lu by rule #%d; action deferred.  Now in state %d.\n",
+                  "Reduced stack %lu by rule #%d; action deferred.  "
+                  "Now in state %d.\n",

                   (unsigned long int) yyk, yyrule - 1, yynewLRState));
       for (yyi = 0; yyi < yystackp->yytops.yysize; yyi += 1)
         if (yyi != yyk && yystackp->yytops.yystates[yyi] != YY_NULL)
                   (unsigned long int) yyk, yyrule - 1, yynewLRState));
       for (yyi = 0; yyi < yystackp->yytops.yysize; yyi += 1)
         if (yyi != yyk && yystackp->yytops.yystates[yyi] != YY_NULL)


@@ -1542,7 +1497,7 @@ yysplitStack (yyGLRStack* yystackp, size_t yyk)
   return yystackp->yytops.yysize-1;
 }
 
   return yystackp->yytops.yysize-1;
 }
 

-/** True iff Y0 and Y1 represent identical options at the top level.
+/** True iff YYY0 and YYY1 represent identical options at the top level.

  *  That is, they represent the same rule applied to RHS symbols
  *  that produce the same terminal symbols.  */
 static yybool
  *  That is, they represent the same rule applied to RHS symbols
  *  that produce the same terminal symbols.  */
 static yybool


@@ -1564,8 +1519,8 @@ yyidenticalOptions (yySemanticOption* yyy0, yySemanticOption* yyy1)
     return yyfalse;
 }
 
     return yyfalse;
 }
 

-/** Assuming identicalOptions (Y0,Y1), destructively merge the
- *  alternative semantic values for the RHS-symbols of Y1 and Y0.  */
+/** Assuming identicalOptions (YYY0,YYY1), destructively merge the
+ *  alternative semantic values for the RHS-symbols of YYY1 and YYY0.  */

 static void
 yymergeOptionSets (yySemanticOption* yyy0, yySemanticOption* yyy1)
 {
 static void
 yymergeOptionSets (yySemanticOption* yyy0, yySemanticOption* yyy1)
 {


@@ -1644,11 +1599,11 @@ static YYRESULTTAG yyresolveValue (yyGLRState* yys,
                                    yyGLRStack* yystackp]b4_user_formals[);
 
 
                                    yyGLRStack* yystackp]b4_user_formals[);
 
 

-/** Resolve the previous N states starting at and including state S.  If result
- *  != yyok, some states may have been left unresolved possibly with empty
- *  semantic option chains.  Regardless of whether result = yyok, each state
- *  has been left with consistent data so that yydestroyGLRState can be invoked
- *  if necessary.  */
+/** Resolve the previous YYN states starting at and including state YYS
+ *  on *YYSTACKP. If result != yyok, some states may have been left
+ *  unresolved possibly with empty semantic option chains.  Regardless
+ *  of whether result = yyok, each state has been left with consistent
+ *  data so that yydestroyGLRState can be invoked if necessary.  */

 static YYRESULTTAG
 yyresolveStates (yyGLRState* yys, int yyn,
                  yyGLRStack* yystackp]b4_user_formals[)
 static YYRESULTTAG
 yyresolveStates (yyGLRState* yys, int yyn,
                  yyGLRStack* yystackp]b4_user_formals[)


@@ -1663,9 +1618,10 @@ yyresolveStates (yyGLRState* yys, int yyn,
   return yyok;
 }
 
   return yyok;
 }
 

-/** Resolve the states for the RHS of OPT, perform its user action, and return
- *  the semantic value and location.  Regardless of whether result = yyok, all
- *  RHS states have been destroyed (assuming the user action destroys all RHS
+/** Resolve the states for the RHS of YYOPT on *YYSTACKP, perform its
+ *  user action, and return the semantic value and location in *YYVALP
+ *  and *YYLOCP.  Regardless of whether result = yyok, all RHS states
+ *  have been destroyed (assuming the user action destroys all RHS

  *  semantic values if invoked).  */
 static YYRESULTTAG
 yyresolveAction (yySemanticOption* yyopt, yyGLRStack* yystackp,
  *  semantic values if invoked).  */
 static YYRESULTTAG
 yyresolveAction (yySemanticOption* yyopt, yyGLRStack* yystackp,


@@ -1739,11 +1695,11 @@ yyreportTree (yySemanticOption* yyx, int yyindent)
         {
           if (yystates[yyi-1]->yyposn+1 > yystates[yyi]->yyposn)
             YYFPRINTF (stderr, "%*s%s <empty>\n", yyindent+2, "",
         {
           if (yystates[yyi-1]->yyposn+1 > yystates[yyi]->yyposn)
             YYFPRINTF (stderr, "%*s%s <empty>\n", yyindent+2, "",

-                       yytokenName (yyrhs[yyprhs[yyx->yyrule]+yyi-1]));
+                       yytokenName (yystos[yystates[yyi]->yylrState]));

           else
             YYFPRINTF (stderr, "%*s%s <tokens %lu .. %lu>\n", yyindent+2, "",
           else
             YYFPRINTF (stderr, "%*s%s <tokens %lu .. %lu>\n", yyindent+2, "",

-                       yytokenName (yyrhs[yyprhs[yyx->yyrule]+yyi-1]),
-                       (unsigned long int) (yystates[yyi - 1]->yyposn + 1),
+                       yytokenName (yystos[yystates[yyi]->yylrState]),
+                       (unsigned long int) (yystates[yyi-1]->yyposn + 1),

                        (unsigned long int) yystates[yyi]->yyposn);
         }
       else
                        (unsigned long int) yystates[yyi]->yyposn);
         }
       else


@@ -1772,9 +1728,9 @@ yyreportAmbiguity (yySemanticOption* yyx0,
   return yyabort;
 }]b4_locations_if([[
 
   return yyabort;
 }]b4_locations_if([[
 

-/** Starting at and including state S1, resolve the location for each of the
- *  previous N1 states that is unresolved.  The first semantic option of a state
- *  is always chosen.  */
+/** Resolve the locations for each of the YYN1 states in *YYSTACKP,
+ *  ending at YYS1.  Has no effect on previously resolved states.
+ *  The first semantic option of a state is always chosen.  */

 static void
 yyresolveLocations (yyGLRState* yys1, int yyn1,
                     yyGLRStack *yystackp]b4_user_formals[)
 static void
 yyresolveLocations (yyGLRState* yys1, int yyn1,
                     yyGLRStack *yystackp]b4_user_formals[)


@@ -1828,11 +1784,12 @@ yyresolveLocations (yyGLRState* yys1, int yyn1,
     }
 }]])[
 
     }
 }]])[
 

-/** Resolve the ambiguity represented in state S, perform the indicated
- *  actions, and set the semantic value of S.  If result != yyok, the chain of
- *  semantic options in S has been cleared instead or it has been left
- *  unmodified except that redundant options may have been removed.  Regardless
- *  of whether result = yyok, S has been left with consistent data so that
+/** Resolve the ambiguity represented in state YYS in *YYSTACKP,
+ *  perform the indicated actions, and set the semantic value of YYS.
+ *  If result != yyok, the chain of semantic options in YYS has been
+ *  cleared instead or it has been left unmodified except that
+ *  redundant options may have been removed.  Regardless of whether
+ *  result = yyok, YYS has been left with consistent data so that

  *  yydestroyGLRState can be invoked if necessary.  */
 static YYRESULTTAG
 yyresolveValue (yyGLRState* yys, yyGLRStack* yystackp]b4_user_formals[)
  *  yydestroyGLRState can be invoked if necessary.  */
 static YYRESULTTAG
 yyresolveValue (yyGLRState* yys, yyGLRStack* yystackp]b4_user_formals[)


@@ -1970,10 +1927,6 @@ static YYRESULTTAG
 yyprocessOneStack (yyGLRStack* yystackp, size_t yyk,
                    size_t yyposn]b4_pure_formals[)
 {
 yyprocessOneStack (yyGLRStack* yystackp, size_t yyk,
                    size_t yyposn]b4_pure_formals[)
 {

-  int yyaction;
-  const short int* yyconflicts;
-  yyRuleNum yyrule;
-

   while (yystackp->yytops.yystates[yyk] != YY_NULL)
     {
       yyStateNum yystate = yystackp->yytops.yystates[yyk]->yylrState;
   while (yystackp->yytops.yystates[yyk] != YY_NULL)
     {
       yyStateNum yystate = yystackp->yytops.yystates[yyk]->yylrState;


@@ -1984,7 +1937,8 @@ yyprocessOneStack (yyGLRStack* yystackp, size_t yyk,
 
       if (yyisDefaultedState (yystate))
         {
 
       if (yyisDefaultedState (yystate))
         {

-          yyrule = yydefaultAction (yystate);
+          YYRESULTTAG yyflag;
+          yyRuleNum yyrule = yydefaultAction (yystate);

           if (yyrule == 0)
             {
               YYDPRINTF ((stderr, "Stack %lu dies.\n",
           if (yyrule == 0)
             {
               YYDPRINTF ((stderr, "Stack %lu dies.\n",


@@ -1992,11 +1946,25 @@ yyprocessOneStack (yyGLRStack* yystackp, size_t yyk,
               yymarkStackDeleted (yystackp, yyk);
               return yyok;
             }
               yymarkStackDeleted (yystackp, yyk);
               return yyok;
             }

-          YYCHK (yyglrReduce (yystackp, yyk, yyrule, yyfalse]b4_user_args[));
+          yyflag = yyglrReduce (yystackp, yyk, yyrule, yyimmediate[yyrule]]b4_user_args[);
+          if (yyflag == yyerr)
+            {
+              YYDPRINTF ((stderr,
+                          "Stack %lu dies "
+                          "(predicate failure or explicit user error).\n",
+                          (unsigned long int) yyk));
+              yymarkStackDeleted (yystackp, yyk);
+              return yyok;
+            }
+          if (yyflag != yyok)
+            return yyflag;

         }
       else
         {
           yySymbol yytoken;
         }
       else
         {
           yySymbol yytoken;

+          int yyaction;
+          const short int* yyconflicts;
+

           yystackp->yytops.yylookaheadNeeds[yyk] = yytrue;
           if (yychar == YYEMPTY)
             {
           yystackp->yytops.yylookaheadNeeds[yyk] = yytrue;
           if (yychar == YYEMPTY)
             {


@@ -2019,14 +1987,25 @@ yyprocessOneStack (yyGLRStack* yystackp, size_t yyk,
 
           while (*yyconflicts != 0)
             {
 
           while (*yyconflicts != 0)
             {

+              YYRESULTTAG yyflag;

               size_t yynewStack = yysplitStack (yystackp, yyk);
               YYDPRINTF ((stderr, "Splitting off stack %lu from %lu.\n",
                           (unsigned long int) yynewStack,
                           (unsigned long int) yyk));
               size_t yynewStack = yysplitStack (yystackp, yyk);
               YYDPRINTF ((stderr, "Splitting off stack %lu from %lu.\n",
                           (unsigned long int) yynewStack,
                           (unsigned long int) yyk));

-              YYCHK (yyglrReduce (yystackp, yynewStack,
-                                  *yyconflicts, yyfalse]b4_user_args[));
-              YYCHK (yyprocessOneStack (yystackp, yynewStack,
-                                        yyposn]b4_pure_args[));
+              yyflag = yyglrReduce (yystackp, yynewStack,
+                                    *yyconflicts,
+                                    yyimmediate[*yyconflicts]]b4_user_args[);
+              if (yyflag == yyok)
+                YYCHK (yyprocessOneStack (yystackp, yynewStack,
+                                          yyposn]b4_pure_args[));
+              else if (yyflag == yyerr)
+                {
+                  YYDPRINTF ((stderr, "Stack %lu dies.\n",
+                              (unsigned long int) yynewStack));
+                  yymarkStackDeleted (yystackp, yynewStack);
+                }
+              else
+                return yyflag;

               yyconflicts += 1;
             }
 
               yyconflicts += 1;
             }
 


@@ -2040,8 +2019,21 @@ yyprocessOneStack (yyGLRStack* yystackp, size_t yyk,
               break;
             }
           else
               break;
             }
           else

-            YYCHK (yyglrReduce (yystackp, yyk, -yyaction,
-                                yyfalse]b4_user_args[));
+            {
+              YYRESULTTAG yyflag = yyglrReduce (yystackp, yyk, -yyaction,
+                                                yyimmediate[-yyaction]]b4_user_args[);
+              if (yyflag == yyerr)
+                {
+                  YYDPRINTF ((stderr,
+                              "Stack %lu dies "
+                              "(predicate failure or explicit user error).\n",
+                              (unsigned long int) yyk));
+                  yymarkStackDeleted (yystackp, yyk);
+                  break;
+                }
+              else if (yyflag != yyok)
+                return yyflag;
+            }

         }
     }
   return yyok;
         }
     }
   return yyok;


@@ -2294,7 +2286,6 @@ yyrecoverSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
     }                                                                        \
   } while (YYID (0))
 
     }                                                                        \
   } while (YYID (0))
 

-

 /*----------.
 | yyparse.  |
 `----------*/
 /*----------.
 | yyparse.  |
 `----------*/


@@ -2616,9 +2607,7 @@ yypdumpstack (yyGLRStack* yystackp)
   YYFPRINTF (stderr, "\n");
 }
 #endif
   YYFPRINTF (stderr, "\n");
 }
 #endif

-]
-
-b4_epilogue
+]b4_epilogue[]dnl

 dnl
 dnl glr.cc produces its own header.
 dnl
 dnl
 dnl glr.cc produces its own header.
 dnl