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c3b407f430
(ritem_longest_rhs): Use it. * src/gram.h (rule_t): `number' is a new member. * src/reader.c (packgram): Set it. * src/reduce.c (reduce_grammar_tables): Move the useless rules at the end of `rules', and count them out of `nrules'. (reduce_output, dump_grammar): Adjust. * src/print.c (print_grammar): It is no longer needed to check for the usefulness of a rule, as useless rules are beyond `nrules + 1'. * tests/reduce.at (Reduced Automaton): New test.
290 lines
5.3 KiB
Plaintext
290 lines
5.3 KiB
Plaintext
# Exercising Bison Grammar Reduction. -*- Autotest -*-
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# Copyright 2001 Free Software Foundation, Inc.
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2, or (at your option)
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# any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
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# 02111-1307, USA.
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AT_BANNER([[Grammar Reduction.]])
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## ------------------- ##
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## Useless Terminals. ##
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## ------------------- ##
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AT_SETUP([Useless Terminals])
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AT_DATA([[input.y]],
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[[%verbose
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%output="input.c"
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%token useless1
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%token useless2
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%token useless3
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%token useless4
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%token useless5
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%token useless6
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%token useless7
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%token useless8
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%token useless9
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%token useful
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%%
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exp: useful;
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]])
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AT_CHECK([[bison input.y]])
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AT_CHECK([[sed -n '/^Grammar/q;/^$/!p' input.output]], 0,
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[[Terminals which are not used:
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useless1
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useless2
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useless3
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useless4
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useless5
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useless6
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useless7
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useless8
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useless9
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]])
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AT_CLEANUP
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## ---------------------- ##
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## Useless Nonterminals. ##
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## ---------------------- ##
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AT_SETUP([Useless Nonterminals])
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AT_DATA([[input.y]],
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[[%verbose
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%output="input.c"
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%nterm useless1
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%nterm useless2
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%nterm useless3
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%nterm useless4
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%nterm useless5
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%nterm useless6
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%nterm useless7
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%nterm useless8
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%nterm useless9
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%token useful
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%%
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exp: useful;
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]])
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AT_CHECK([[bison input.y]], 0, [],
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[[input.y contains 9 useless nonterminals
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]])
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AT_CHECK([[sed -n '/^Grammar/q;/^$/!p' input.output]], 0,
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[[Useless nonterminals:
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useless1
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useless2
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useless3
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useless4
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useless5
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useless6
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useless7
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useless8
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useless9
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]])
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AT_CLEANUP
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## --------------- ##
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## Useless Rules. ##
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## --------------- ##
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AT_SETUP([Useless Rules])
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AT_DATA([[input.y]],
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[[%verbose
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%output="input.c"
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%token useful
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%%
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exp: useful;
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useless1: '1';
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useless2: '2';
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useless3: '3';
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useless4: '4';
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useless5: '5';
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useless6: '6';
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useless7: '7';
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useless8: '8';
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useless9: '9';
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]])
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AT_CHECK([[bison input.y]], 0, [],
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[[input.y contains 9 useless nonterminals and 9 useless rules
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]])
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AT_CHECK([[sed -n '/^Grammar/q;/^$/!p' input.output]], 0,
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[[Useless nonterminals:
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useless1
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useless2
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useless3
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useless4
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useless5
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useless6
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useless7
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useless8
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useless9
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Terminals which are not used:
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'1'
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'2'
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'3'
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'4'
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'5'
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'6'
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'7'
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'8'
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'9'
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Useless rules:
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#2 useless1: '1';
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#3 useless2: '2';
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#4 useless3: '3';
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#5 useless4: '4';
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#6 useless5: '5';
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#7 useless6: '6';
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#8 useless7: '7';
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#9 useless8: '8';
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#10 useless9: '9';
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]])
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AT_CLEANUP
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## ------------------- ##
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## Reduced Automaton. ##
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## ------------------- ##
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# Check that the automaton is that as the for the grammar reduced by
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# hand.
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AT_SETUP([Reduced Automaton])
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# The non reduced grammar.
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# ------------------------
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AT_DATA([[not-reduced.y]],
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[[/* A useless token. */
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%token useless_token
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/* A useful one. */
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%token useful
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%verbose
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%output="not-reduced.c"
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%%
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exp: useful { /* A useful action. */ }
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| non_productive { /* A non productive action. */ }
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;
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not_reachable: useful { /* A not reachable action. */ }
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;
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non_productive: non_productive useless_token
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{ /* Another non productive action. */ }
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;
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]])
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AT_CHECK([[bison not-reduced.y]], 0, [],
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[[not-reduced.y contains 2 useless nonterminals and 3 useless rules
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]])
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AT_CHECK([[sed -n '/^Grammar/q;/^$/!p' not-reduced.output]], 0,
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[[Useless nonterminals:
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not_reachable
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non_productive
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Terminals which are not used:
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useless_token
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Useless rules:
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#2 exp: non_productive;
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#3 not_reachable: useful;
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#4 non_productive: non_productive useless_token;
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]])
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# The reduced grammar.
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# --------------------
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AT_DATA([[reduced.y]],
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[[/* A useless token. */
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%token useless_token
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/* A useful one. */
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%token useful
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%verbose
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%output="reduced.c"
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%%
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exp: useful { /* A useful action. */ }
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// | non_productive { /* A non productive action. */ } */
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;
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//not_reachable: useful { /* A not reachable action. */ }
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// ;
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//non_productive: non_productive useless_token
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// { /* Another non productive action. */ }
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// ;
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]])
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AT_CHECK([[bison reduced.y]])
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# Comparing the parsers.
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cp reduced.c expout
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AT_CHECK([sed 's/not-reduced/reduced/g' not-reduced.c], 0, [expout])
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AT_CLEANUP
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## ------------------- ##
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## Underivable Rules. ##
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## ------------------- ##
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AT_SETUP([Underivable Rules])
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AT_DATA([[input.y]],
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[[%verbose
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%output="input.c"
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%token useful
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%%
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exp: useful | underivable;
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underivable: indirection;
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indirection: underivable;
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]])
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AT_CHECK([[bison input.y]], 0, [],
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[[input.y contains 2 useless nonterminals and 3 useless rules
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]])
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AT_CHECK([[sed -n '/^Grammar/q;/^$/!p' input.output]], 0,
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[[Useless nonterminals:
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underivable
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indirection
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Useless rules:
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#2 exp: underivable;
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#3 underivable: indirection;
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#4 indirection: underivable;
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]])
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AT_CLEANUP
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