%expect-rr is for GLR only

[bison.git] / tests / conflicts.at

diff --git a/tests/conflicts.at b/tests/conflicts.at
index 655a666c0c0a5e0d0383417f62d2699b911d441b..169509f2756fa172963218a9022b47576211498c 100644 (file)
--- a/tests/conflicts.at
+++ b/tests/conflicts.at
@@ -1,7 +1,6 @@
 # Exercising Bison on conflicts.                         -*- Autotest -*-
 
 # Exercising Bison on conflicts.                         -*- Autotest -*-
 

-# Copyright (C) 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010 Free
-# Software Foundation, Inc.
+# Copyright (C) 2002-2005, 2007-2012 Free Software Foundation, Inc.

 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by


@@ -38,7 +37,7 @@ e: 'e' | /* Nothing. */;
 ]])
 
 AT_BISON_CHECK([-o input.c input.y], 0, [],
 ]])
 
 AT_BISON_CHECK([-o input.c input.y], 0, [],

-[[input.y:4.9: warning: rule useless in parser due to conflicts: e: /* empty */
+[[input.y:4.9: warning: rule useless in parser due to conflicts: e: /* empty */ [-Wother]

 ]])
 
 AT_CLEANUP
 ]])
 
 AT_CLEANUP


@@ -50,20 +49,17 @@ AT_CLEANUP
 
 AT_SETUP([%nonassoc and eof])
 
 
 AT_SETUP([%nonassoc and eof])
 

+AT_BISON_OPTION_PUSHDEFS

 AT_DATA_GRAMMAR([input.y],
 [[
 %{
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 AT_DATA_GRAMMAR([input.y],
 [[
 %{
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

+#include <assert.h>

 
 #define YYERROR_VERBOSE 1
 
 #define YYERROR_VERBOSE 1

-static void
-yyerror (const char *msg)
-{
-  fprintf (stderr, "%s\n", msg);
-}
-
+]AT_YYERROR_DEFINE[

 /* The current argument. */
 static const char *input;
 
 /* The current argument. */
 static const char *input;
 


@@ -71,8 +67,7 @@ static int
 yylex (void)
 {
   static size_t toknum;
 yylex (void)
 {
   static size_t toknum;

-  if (! (toknum <= strlen (input)))
-    abort ();
+  assert (toknum <= strlen (input));

   return input[toknum++];
 }
 
   return input[toknum++];
 }
 


@@ -93,47 +88,54 @@ main (int argc, const char *argv[])
   return yyparse ();
 }
 ]])
   return yyparse ();
 }
 ]])

+AT_BISON_OPTION_POPDEFS

 
 

-# Specify the output files to avoid problems on different file systems.
-AT_BISON_CHECK([-o input.c input.y])
+m4_pushdef([AT_NONASSOC_AND_EOF_CHECK],
+[AT_BISON_CHECK([$1[ -o input.c input.y]])

 AT_COMPILE([input])
 
 AT_COMPILE([input])
 

+m4_pushdef([AT_EXPECTING], [m4_if($2, [correct], [[, expecting $end]])])
+

 AT_PARSER_CHECK([./input '0<0'])
 AT_PARSER_CHECK([./input '0<0<0'], [1], [],
 AT_PARSER_CHECK([./input '0<0'])
 AT_PARSER_CHECK([./input '0<0<0'], [1], [],

-         [syntax error, unexpected '<'
+         [syntax error, unexpected '<'AT_EXPECTING

 ])
 
 AT_PARSER_CHECK([./input '0>0'])
 AT_PARSER_CHECK([./input '0>0>0'], [1], [],
 ])
 
 AT_PARSER_CHECK([./input '0>0'])
 AT_PARSER_CHECK([./input '0>0>0'], [1], [],

-         [syntax error, unexpected '>'
+         [syntax error, unexpected '>'AT_EXPECTING

 ])
 
 AT_PARSER_CHECK([./input '0<0>0'], [1], [],
 ])
 
 AT_PARSER_CHECK([./input '0<0>0'], [1], [],

-         [syntax error, unexpected '>'
+         [syntax error, unexpected '>'AT_EXPECTING

 ])
 
 ])
 

-# We must disable default reductions in inconsistent states in order to
-# have an explicit list of all expected tokens.  (However, unless we use
-# canonical LR, lookahead sets are merged for different left contexts,
-# so it is still possible to have extra incorrect tokens in the expected
-# list.  That just doesn't happen to be a problem for this test case.)
+m4_popdef([AT_EXPECTING])])

 
 

-AT_BISON_CHECK([-Dlr.default-reductions=consistent -o input.c input.y])
-AT_COMPILE([input])
+# Expected token list is missing.
+AT_NONASSOC_AND_EOF_CHECK([], [[incorrect]])

 
 

-AT_PARSER_CHECK([./input '0<0'])
-AT_PARSER_CHECK([./input '0<0<0'], [1], [],
-         [syntax error, unexpected '<', expecting $end
-])
-
-AT_PARSER_CHECK([./input '0>0'])
-AT_PARSER_CHECK([./input '0>0>0'], [1], [],
-         [syntax error, unexpected '>', expecting $end
-])
-
-AT_PARSER_CHECK([./input '0<0>0'], [1], [],
-         [syntax error, unexpected '>', expecting $end
-])
+# We must disable default reductions in inconsistent states in order to
+# have an explicit list of all expected tokens.
+AT_NONASSOC_AND_EOF_CHECK([[-Dlr.default-reductions=consistent]],
+                          [[correct]])
+
+# lr.default-reductions=consistent happens to work for this test case.
+# However, for other grammars, lookahead sets can be merged for
+# different left contexts, so it is still possible to have an incorrect
+# expected list.  Canonical LR is almost a general solution (that is, it
+# can fail only when %nonassoc is used), so make sure it gives the same
+# result as above.
+AT_NONASSOC_AND_EOF_CHECK([[-Dlr.type=canonical-lr]], [[correct]])
+
+# parse.lac=full is a completely general solution that does not require
+# any of the above sacrifices.  Of course, it does not extend the
+# language-recognition power of LALR to (IE)LR, but it does ensure that
+# the reported list of expected tokens matches what the given parser
+# would have accepted in place of the unexpected token.
+AT_NONASSOC_AND_EOF_CHECK([[-Dparse.lac=full]], [[correct]])
+
+m4_popdef([AT_NONASSOC_AND_EOF_CHECK])

 
 AT_CLEANUP
 
 
 AT_CLEANUP
 


@@ -164,7 +166,7 @@ AT_SKEL_JAVA_IF([AT_DATA], [AT_DATA_GRAMMAR])([input.y],
   #include <string>]], [[
   #include <assert.h>
   #include <stdio.h>
   #include <string>]], [[
   #include <assert.h>
   #include <stdio.h>

-  void yyerror (char const *msg);]])[
+  ]AT_YYERROR_DECLARE])[

   ]AT_YYLEX_PROTOTYPE[;
   #define USE(Var)
 }
   ]AT_YYLEX_PROTOTYPE[;
   #define USE(Var)
 }


@@ -205,31 +207,11 @@ public Object getLVal ()
   *lvalp = 1;
   return *input++;
 }]])[
   *lvalp = 1;
   return *input++;
 }]])[

-
-/*----------.
-| yyerror.  |
-`----------*/]AT_SKEL_JAVA_IF([[
-
-public void yyerror (String msg)
-{
-  System.err.println (msg);
-}
-
+]AT_YYERROR_DEFINE[
+]AT_SKEL_JAVA_IF([[

 };
 
 };
 

-%%]], [AT_SKEL_CC_IF([[
-
-void
-yy::parser::error (std::string const &msg)
-{
-  std::cerr << msg << std::endl;
-}]], [[
-
-void
-yyerror (char const *msg)
-{
-  fprintf (stderr, "%s\n", msg);
-}]])])[
+%%]])[

 
 /*-------.
 | main.  |
 
 /*-------.
 | main.  |


@@ -342,6 +324,18 @@ AT_CONSISTENT_ERRORS_CHECK([[%define lr.type canonical-lr]],
                            [AT_PREVIOUS_STATE_INPUT],
                            [[$end]], [[ab]])
 
                            [AT_PREVIOUS_STATE_INPUT],
                            [[$end]], [[ab]])
 

+# Only LAC gets it right.
+AT_CONSISTENT_ERRORS_CHECK([[%define lr.type canonical-lr
+                             %define parse.lac full]],
+                           [AT_PREVIOUS_STATE_GRAMMAR],
+                           [AT_PREVIOUS_STATE_INPUT],
+                           [[$end]], [[b]])
+AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr
+                             %define parse.lac full]],
+                           [AT_PREVIOUS_STATE_GRAMMAR],
+                           [AT_PREVIOUS_STATE_INPUT],
+                           [[$end]], [[b]])
+

 m4_popdef([AT_PREVIOUS_STATE_GRAMMAR])
 m4_popdef([AT_PREVIOUS_STATE_INPUT])
 
 m4_popdef([AT_PREVIOUS_STATE_GRAMMAR])
 m4_popdef([AT_PREVIOUS_STATE_INPUT])
 


@@ -417,6 +411,16 @@ AT_CONSISTENT_ERRORS_CHECK([[%define lr.type canonical-lr]],
                            [AT_USER_ACTION_INPUT],
                            [[$end]], [[a]])
 
                            [AT_USER_ACTION_INPUT],
                            [[$end]], [[a]])
 

+AT_CONSISTENT_ERRORS_CHECK([[%define parse.lac full]],
+                           [AT_USER_ACTION_GRAMMAR],
+                           [AT_USER_ACTION_INPUT],
+                           [['b']], [[none]])
+AT_CONSISTENT_ERRORS_CHECK([[%define parse.lac full
+                             %define lr.default-reductions accepting]],
+                           [AT_USER_ACTION_GRAMMAR],
+                           [AT_USER_ACTION_INPUT],
+                           [[$end]], [[none]])
+

 m4_popdef([AT_USER_ACTION_GRAMMAR])
 m4_popdef([AT_USER_ACTION_INPUT])
 
 m4_popdef([AT_USER_ACTION_GRAMMAR])
 m4_popdef([AT_USER_ACTION_INPUT])
 


@@ -426,6 +430,103 @@ AT_CLEANUP
 
 
 
 
 
 

+## ------------------------------------------------------- ##
+## LAC: %nonassoc requires splitting canonical LR states.  ##
+## ------------------------------------------------------- ##
+
+# This test case demonstrates that, when %nonassoc is used, canonical
+# LR(1) parser table construction followed by conflict resolution
+# without further state splitting is not always sufficient to produce a
+# parser that can detect all syntax errors as soon as possible on one
+# token of lookahead.  However, LAC solves the problem completely even
+# with minimal LR parser tables.
+
+AT_SETUP([[LAC: %nonassoc requires splitting canonical LR states]])
+AT_BISON_OPTION_PUSHDEFS
+AT_DATA_GRAMMAR([[input.y]],
+[[%code {
+  #include <stdio.h>
+  ]AT_YYERROR_DECLARE[
+  ]AT_YYLEX_DECLARE[
+}
+
+%error-verbose
+%nonassoc 'a'
+
+%%
+
+start:
+  'a' problem 'a' // First context.
+| 'b' problem 'b' // Second context.
+| 'c' reduce-nonassoc // Just makes reduce-nonassoc useful.
+;
+
+problem:
+  look reduce-nonassoc
+| look 'a'
+| look 'b'
+;
+
+// For the state reached after shifting the 'a' in these productions,
+// lookahead sets are the same in both the first and second contexts.
+// Thus, canonical LR reuses the same state for both contexts.  However,
+// the lookahead 'a' for the reduction "look: 'a'" later becomes an
+// error action only in the first context.  In order to immediately
+// detect the syntax error on 'a' here for only the first context, this
+// canonical LR state would have to be split into two states, and the
+// 'a' lookahead would have to be removed from only one of the states.
+look:
+  'a' // Reduction lookahead set is always ['a', 'b'].
+| 'a' 'b'
+| 'a' 'c' // 'c' is forgotten as an expected token.
+;
+
+reduce-nonassoc: %prec 'a';
+
+%%
+]AT_YYERROR_DEFINE[
+]AT_YYLEX_DEFINE(["aaa"])[
+
+int
+main (void)
+{
+  return yyparse ();
+}
+]])
+AT_BISON_OPTION_POPDEFS
+
+# Show canonical LR's failure.
+AT_BISON_CHECK([[-Dlr.type=canonical-lr -o input.c input.y]],
+               [[0]], [[]],
+[[input.y: conflicts: 2 shift/reduce
+]])
+AT_COMPILE([[input]])
+AT_PARSER_CHECK([[./input]], [[1]], [[]],
+[[syntax error, unexpected 'a', expecting 'b'
+]])
+
+# It's corrected by LAC.
+AT_BISON_CHECK([[-Dlr.type=canonical-lr -Dparse.lac=full \
+                 -o input.c input.y]], [[0]], [[]],
+[[input.y: conflicts: 2 shift/reduce
+]])
+AT_COMPILE([[input]])
+AT_PARSER_CHECK([[./input]], [[1]], [[]],
+[[syntax error, unexpected 'a', expecting 'b' or 'c'
+]])
+
+# IELR is sufficient when LAC is used.
+AT_BISON_CHECK([[-Dlr.type=ielr -Dparse.lac=full -o input.c input.y]],
+               [[0]], [[]],
+[[input.y: conflicts: 2 shift/reduce
+]])
+AT_COMPILE([[input]])
+AT_PARSER_CHECK([[./input]], [[1]], [[]],
+[[syntax error, unexpected 'a', expecting 'b' or 'c'
+]])
+
+AT_CLEANUP
+

 ## ------------------------- ##
 ## Unresolved SR Conflicts.  ##
 ## ------------------------- ##
 ## ------------------------- ##
 ## Unresolved SR Conflicts.  ##
 ## ------------------------- ##


@@ -684,7 +785,7 @@ cond:
 
 AT_BISON_CHECK([-o input.c input.y], 0, [],
 [[input.y: conflicts: 1 shift/reduce
 
 AT_BISON_CHECK([-o input.c input.y], 0, [],
 [[input.y: conflicts: 1 shift/reduce

-input.y:12.3-18: warning: rule useless in parser due to conflicts: cond: cond "then" cond
+input.y:12.3-18: warning: rule useless in parser due to conflicts: cond: cond "then" cond [-Wother]

 ]])
 
 AT_CLEANUP
 ]])
 
 AT_CLEANUP


@@ -728,7 +829,7 @@ id : '0';
 
 AT_BISON_CHECK([-o input.c --report=all input.y], 0, [],
 [[input.y: conflicts: 1 reduce/reduce
 
 AT_BISON_CHECK([-o input.c --report=all input.y], 0, [],
 [[input.y: conflicts: 1 reduce/reduce

-input.y:4.6-8: warning: rule useless in parser due to conflicts: id: '0'
+input.y:4.6-8: warning: rule useless in parser due to conflicts: id: '0' [-Wother]

 ]])
 
 # Check the contents of the report.
 ]])
 
 # Check the contents of the report.


@@ -1048,13 +1149,13 @@ reported_conflicts:
 
 AT_BISON_CHECK([[--report=all input.y]], 0, [],
 [[input.y: conflicts: 1 shift/reduce, 1 reduce/reduce
 
 AT_BISON_CHECK([[--report=all input.y]], 0, [],
 [[input.y: conflicts: 1 shift/reduce, 1 reduce/reduce

-input.y:12.5-20: warning: rule useless in parser due to conflicts: resolved_conflict: 'a' unreachable1
-input.y:20.5-20: warning: rule useless in parser due to conflicts: unreachable1: 'a' unreachable2
-input.y:21.4: warning: rule useless in parser due to conflicts: unreachable1: /* empty */
-input.y:25.13: warning: rule useless in parser due to conflicts: unreachable2: /* empty */
-input.y:25.16: warning: rule useless in parser due to conflicts: unreachable2: /* empty */
-input.y:31.5-7: warning: rule useless in parser due to conflicts: reported_conflicts: 'a'
-input.y:32.4: warning: rule useless in parser due to conflicts: reported_conflicts: /* empty */
+input.y:12.5-20: warning: rule useless in parser due to conflicts: resolved_conflict: 'a' unreachable1 [-Wother]
+input.y:20.5-20: warning: rule useless in parser due to conflicts: unreachable1: 'a' unreachable2 [-Wother]
+input.y:21.4: warning: rule useless in parser due to conflicts: unreachable1: /* empty */ [-Wother]
+input.y:25.13: warning: rule useless in parser due to conflicts: unreachable2: /* empty */ [-Wother]
+input.y:25.16: warning: rule useless in parser due to conflicts: unreachable2: /* empty */ [-Wother]
+input.y:31.5-7: warning: rule useless in parser due to conflicts: reported_conflicts: 'a' [-Wother]
+input.y:32.4: warning: rule useless in parser due to conflicts: reported_conflicts: /* empty */ [-Wother]

 ]])
 
 AT_CHECK([[cat input.output]], 0,
 ]])
 
 AT_CHECK([[cat input.output]], 0,


@@ -1200,10 +1301,10 @@ AT_CHECK([[cat input.y >> input-keep.y]])
 
 AT_BISON_CHECK([[input-keep.y]], 0, [],
 [[input-keep.y: conflicts: 2 shift/reduce, 2 reduce/reduce
 
 AT_BISON_CHECK([[input-keep.y]], 0, [],
 [[input-keep.y: conflicts: 2 shift/reduce, 2 reduce/reduce

-input-keep.y:22.4: warning: rule useless in parser due to conflicts: unreachable1: /* empty */
-input-keep.y:26.16: warning: rule useless in parser due to conflicts: unreachable2: /* empty */
-input-keep.y:32.5-7: warning: rule useless in parser due to conflicts: reported_conflicts: 'a'
-input-keep.y:33.4: warning: rule useless in parser due to conflicts: reported_conflicts: /* empty */
+input-keep.y:22.4: warning: rule useless in parser due to conflicts: unreachable1: /* empty */ [-Wother]
+input-keep.y:26.16: warning: rule useless in parser due to conflicts: unreachable2: /* empty */ [-Wother]
+input-keep.y:32.5-7: warning: rule useless in parser due to conflicts: reported_conflicts: 'a' [-Wother]
+input-keep.y:33.4: warning: rule useless in parser due to conflicts: reported_conflicts: /* empty */ [-Wother]

 ]])
 
 AT_CLEANUP
 ]])
 
 AT_CLEANUP


@@ -1356,3 +1457,135 @@ AT_CHECK([[cat input.output | sed -n '/^state 0$/,/^state 1$/p']], 0,
 state 1
 ]])
 AT_CLEANUP
 state 1
 ]])
 AT_CLEANUP

+
+
+## -------------------- ##
+## %expect-rr non GLR.  ##
+## -------------------- ##
+
+AT_SETUP([[%expect-rr non GLR]])
+
+AT_DATA([[1.y]],
+[[%expect-rr 0
+%%
+exp: 'a'
+]])
+
+AT_BISON_CHECK([[1.y]], [[0]], [],
+[[1.y: warning: %expect-rr applies only to GLR parsers [-Wother]
+]])
+
+AT_DATA([[2.y]],
+[[%expect-rr 1
+%%
+exp: 'a' | 'a';
+]])
+
+AT_BISON_CHECK([[2.y]], [[0]], [],
+[[2.y: warning: %expect-rr applies only to GLR parsers [-Wother]
+2.y: conflicts: 1 reduce/reduce
+2.y:3.12-14: warning: rule useless in parser due to conflicts: exp: 'a' [-Wother]
+]])
+
+AT_CLEANUP
+
+
+## ---------------------------------- ##
+## -W versus %expect and %expect-rr.  ##
+## ---------------------------------- ##
+
+AT_SETUP([[-W versus %expect and %expect-rr]])
+
+AT_DATA([[sr-rr.y]],
+[[%glr-parser
+%%
+start: 'a' | A 'a' | B 'a' ;
+A: ;
+B: ;
+]])
+AT_DATA([[sr.y]],
+[[%glr-parser
+%%
+start: 'a' | A 'a' ;
+A: ;
+]])
+AT_DATA([[rr.y]],
+[[%glr-parser
+%%
+start: A | B ;
+A: ;
+B: ;
+]])
+
+AT_BISON_CHECK([[sr-rr.y]], [[0]], [[]],
+[[sr-rr.y: conflicts: 1 shift/reduce, 1 reduce/reduce
+]])
+AT_BISON_CHECK([[-Wno-conflicts-sr sr-rr.y]], [[0]], [[]],
+[[sr-rr.y: conflicts: 1 reduce/reduce
+]])
+AT_BISON_CHECK([[-Wno-conflicts-rr sr-rr.y]], [[0]], [[]],
+[[sr-rr.y: conflicts: 1 shift/reduce
+]])
+
+[for gram in sr-rr sr rr; do
+  for sr_exp_i in '' 0 1 2; do
+    for rr_exp_i in '' 0 1 2; do
+      test -z "$sr_exp_i" && test -z "$rr_exp_i" && continue
+
+      # Build grammar file.
+      sr_exp=0
+      rr_exp=0
+      file=$gram
+      directives=
+      if test -n "$sr_exp_i"; then
+        sr_exp=$sr_exp_i
+        file=$file-expect-$sr_exp
+        directives="%expect $sr_exp"
+      fi
+      if test -n "$rr_exp_i"; then
+        rr_exp=$rr_exp_i
+        file=$file-expect-rr-$rr_exp
+        directives="$directives %expect-rr $rr_exp"
+      fi
+      file=$file.y
+      echo "$directives" > $file
+      cat $gram.y >> $file
+
+      # Count actual conflicts.
+      conflicts=
+      sr_count=0
+      rr_count=0
+      if test $gram = sr || test $gram = sr-rr; then
+        conflicts="1 shift/reduce"
+        sr_count=1
+      fi
+      if test $gram = rr || test $gram = sr-rr; then
+        if test -n "$conflicts"; then
+          conflicts="$conflicts, "
+        fi
+        conflicts="${conflicts}1 reduce/reduce"
+        rr_count=1
+      fi
+
+      # Run tests.
+      if test $sr_count -eq $sr_exp && test $rr_count -eq $rr_exp; then
+        ]AT_BISON_CHECK([[-Wnone $file]])[
+        ]AT_BISON_CHECK([[-Werror $file]])[
+      else
+        echo "$file: conflicts: $conflicts" > experr
+        if test $sr_count -ne $sr_exp; then
+          if test $sr_exp -ne 1; then s=s; else s= ; fi
+          echo "$file: expected $sr_exp shift/reduce conflict$s" >> experr
+        fi
+        if test $rr_count -ne $rr_exp; then
+          if test $rr_exp -ne 1; then s=s; else s= ; fi
+          echo "$file: expected $rr_exp reduce/reduce conflict$s" >> experr
+        fi
+        ]AT_BISON_CHECK([[-Wnone $file]], [[1]], [[]], [[experr]])[
+        ]AT_BISON_CHECK([[-Werror $file]], [[1]], [[]], [[experr]])[
+      fi
+    done
+  done
+done]
+
+AT_CLEANUP