mirror of
https://git.savannah.gnu.org/git/bison.git
synced 2026-03-12 05:43:03 +00:00
1ccb4be02b
In Bison we refer to "shift/reduce" conflicts, not "shift-reduce" (in
Bison 3.6.3 186 occurrences vs 15). Enforce consistency on this.
Instead of "spending" a second line for each conflict to report the
lookaheads, put that on the same line as the type of conflict. Also,
prefer "token" to "symbol". Maybe we should even prefer "lookahead".
While at it, enable internationalization, with plurals where
appropriate.
As a consequence, instead of
Shift-Reduce Conflict:
6: 3 b: . %empty
6: 6 d: c . A
On Symbol: A
display
Shift/reduce conflict on token A:
6: 3 b: . %empty
6: 6 d: c . A
* NEWS, doc/bison.texi, src/conflicts.c: Spell it "shift/reduce", not
"shift-reduce".
* src/counterexample.c (counterexample_report_shift_reduce)
(counterexample_report_reduce_reduce): Reformat and internationalize
output.
* tests/counterexample.at: Adjust expectations.
587 lines
14 KiB
Plaintext
587 lines
14 KiB
Plaintext
# Exercising Bison on counterexamples. -*- Autotest -*-
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# Copyright (C) 2020 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 3 of the License, or
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# (at your option) any later version.
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#
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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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#
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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, see <http://www.gnu.org/licenses/>.
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AT_BANNER([[Counterexamples.]])
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m4_define([AT_BISON_CHECK_CEX],
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[AT_DATA([experr], [$4])
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sed -e ['s/time limit exceeded: [0-9][.0-9]*/time limit exceeded: XXX/g'] \
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experr >expout
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AT_BISON_CHECK([-Wcounterexample $1], [$2], [$3], [stderr])
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AT_CHECK([[sed -e 's/time limit exceeded: [0-9][.0-9]*/time limit exceeded: XXX/g' stderr]],
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[], [expout])
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])
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## --------------------- ##
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## Simple Unifying S/R. ##
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## --------------------- ##
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AT_SETUP([Unifying S/R])
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AT_KEYWORDS([cex])
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AT_DATA([[input.y]],
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[[%token A B C
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%%
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s: a x | y c;
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a: A;
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c: C;
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x: B | B C;
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y: A | A B;
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]])
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AT_BISON_CHECK_CEX([input.y], [], [],
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[[Shift/reduce conflict on token B:
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1: 3 a: A .
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1: 8 y: A . B
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Example A • B C
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First derivation s ::=[ a ::=[ A • ] x ::=[ B C ] ]
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Second derivation s ::=[ y ::=[ A • B ] c ::=[ C ] ]
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input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
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input.y:4.4: warning: rule useless in parser due to conflicts [-Wother]
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]])
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AT_CLEANUP
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## ------------------- ##
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## Deep Unifying S/R. ##
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## ------------------- ##
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AT_SETUP([Deep Unifying S/R])
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AT_KEYWORDS([cex])
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AT_DATA([[input.y]],
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[[%token A B C
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%%
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s: ac | a bc;
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ac: A ac C | b;
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b: B | B b;
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a: A | A a;
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bc: B bc C | B C;
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]])
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AT_BISON_CHECK_CEX([input.y], [], [],
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[[Shift/reduce conflict on token B:
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1: 7 a: A .
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1: 5 b: . B
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Example A • B C
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First derivation s ::=[ a ::=[ A • ] bc ::=[ B C ] ]
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Second derivation s ::=[ ac ::=[ A ac ::=[ b ::=[ • B ] ] C ] ]
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input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
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input.y:6.4: warning: rule useless in parser due to conflicts [-Wother]
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]])
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AT_CLEANUP
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## ------------------------------------ ##
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## S/R Conflict with Nullable Symbols. ##
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## ------------------------------------ ##
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AT_SETUP([S/R Conflict with Nullable Symbols])
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AT_KEYWORDS([cex])
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AT_DATA([[input.y]],
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[[%token A B X Y
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%%
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s: ax by | A xby;
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ax: A x;
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x: %empty | X x;
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by: B y;
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y: %empty | Y y;
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xby: B | X xby Y;
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]])
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AT_BISON_CHECK_CEX([input.y], [], [],
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[[Shift/reduce conflict on token B:
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1: 4 x: . %empty
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1: 9 xby: . B
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Example A • B y
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First derivation s ::=[ ax ::=[ A x ::=[ • ] ] by ::=[ B y ] ]
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Second derivation s ::=[ A xby ::=[ • B ] ]
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Shift/reduce conflict on token B:
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5: 4 x: . %empty
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5: 9 xby: . B
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First Example A X • B y $end
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First derivation $accept ::=[ s ::=[ ax ::=[ A x ::=[ X x ::=[ • ] ] ] by ::=[ B y ] ] $end ]
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Second Example A X • B Y $end
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Second derivation $accept ::=[ s ::=[ A xby ::=[ X xby ::=[ • B ] Y ] ] $end ]
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input.y: warning: 2 shift/reduce conflicts [-Wconflicts-sr]
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input.y:5.4-9: warning: rule useless in parser due to conflicts [-Wother]
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]])
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AT_CLEANUP
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## ---------------------------- ##
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## Non-unifying Ambiguous S/R. ##
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## ---------------------------- ##
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AT_SETUP([Non-unifying Ambiguous S/R])
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AT_KEYWORDS([cex])
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AT_DATA([[input.y]],
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[[%token A B C D E
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%%
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g: s | x;
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s: A x E | A x D E;
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x: b cd | bc;
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b: B;
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cd: C D;
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bc: B C;
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]])
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AT_BISON_CHECK_CEX([input.y], [], [],
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[[Shift/reduce conflict on token C:
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2: 7 b: B .
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2: 9 bc: B . C
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First Example B • C D $end
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First derivation $accept ::=[ g ::=[ x ::=[ b ::=[ B • ] cd ::=[ C D ] ] ] $end ]
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Second Example B • C $end
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Second derivation $accept ::=[ g ::=[ x ::=[ bc ::=[ B • C ] ] ] $end ]
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input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
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input.y:6.4: warning: rule useless in parser due to conflicts [-Wother]
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]])
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AT_CLEANUP
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## ------------------------------ ##
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## Non-unifying Unambiguous S/R. ##
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## ------------------------------ ##
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AT_SETUP([Non-unifying Unambiguous S/R])
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AT_KEYWORDS([cex])
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AT_DATA([[input.y]],
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[[%token A B
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%%
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s: t | s t;
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t: x | y;
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x: A;
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y: A A B;
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]])
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AT_BISON_CHECK_CEX([input.y], [], [],
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[[Shift/reduce conflict on token A:
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1: 5 x: A .
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1: 6 y: A . A B
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First Example A • A $end
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First derivation $accept ::=[ s ::=[ s ::=[ t ::=[ x ::=[ A • ] ] ] t ::=[ x ::=[ A ] ] ] $end ]
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Second Example A • A B $end
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Second derivation $accept ::=[ s ::=[ t ::=[ y ::=[ A • A B ] ] ] $end ]
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input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
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]])
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AT_CLEANUP
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## ----------------------- ##
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## S/R after first token. ##
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## ----------------------- ##
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AT_SETUP([S/R after first token])
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AT_KEYWORDS([cex])
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AT_DATA([[input.y]],
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[[%token A B X Y
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%%
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a: r t | s;
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r: b;
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b: B;
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t: A xx | A x xy;
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s: b A xx y;
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x: X;
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xx: X X;
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xy: X Y;
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y: Y;
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]])
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AT_BISON_CHECK_CEX([input.y], [], [],
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[[Shift/reduce conflict on token A:
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4: 3 r: b .
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4: 7 s: b . A xx y
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Example b • A X X Y
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First derivation a ::=[ r ::=[ b • ] t ::=[ A x ::=[ X ] xy ::=[ X Y ] ] ]
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Second derivation a ::=[ s ::=[ b • xx ::=[ A X X ] y ::=[ Y ] ] ]
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Shift/reduce conflict on token X:
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10: 8 x: X .
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10: 9 xx: X . X
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First Example X • X xy
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First derivation a ::=[ x ::=[ X • ] t ::=[ X xy ] ]
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Second Example A X • X
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Second derivation a ::=[ t ::=[ A xx ::=[ X • X ] ] ]
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input.y: warning: 2 shift/reduce conflicts [-Wconflicts-sr]
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input.y:4.4: warning: rule useless in parser due to conflicts [-Wother]
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input.y:8.4: warning: rule useless in parser due to conflicts [-Wother]
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]])
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AT_CLEANUP
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## ----------------------------- ##
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## Unifying R/R counterexample. ##
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## ----------------------------- ##
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AT_SETUP([Unifying R/R counterexample])
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AT_KEYWORDS([cex])
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AT_DATA([[input.y]],
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[[%token A
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%%
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a : A b ;
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b : A | b;
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]])
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AT_BISON_CHECK_CEX([input.y], [], [],
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[[Reduce/reduce conflict on token $end:
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4: 1 a: A b .
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4: 3 b: b .
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Example A b •
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First derivation a ::=[ A b • ]
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Second derivation a ::=[ A b ::=[ b • ] ]
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input.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
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input.y:4.9: warning: rule useless in parser due to conflicts [-Wother]
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]])
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AT_CLEANUP
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## ------------------------------- ##
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## Non-unifying R/R lr1 conflict. ##
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## ------------------------------- ##
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AT_SETUP([Non-unifying R/R lr1 conflict])
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AT_KEYWORDS([cex])
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AT_DATA([[input.y]],
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[[%token A B C D
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%%
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s: a A | B a C | b C | B b A;
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a: D;
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b: D;
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]])
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AT_BISON_CHECK_CEX([input.y], [], [],
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[[Reduce/reduce conflict on tokens A, C:
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2: 5 a: D .
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2: 6 b: D .
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First Example D • A $end
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First derivation $accept ::=[ s ::=[ a ::=[ D • ] A ] $end ]
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Second Example B D • A $end
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Second derivation $accept ::=[ s ::=[ B b ::=[ D • ] A ] $end ]
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input.y: warning: 2 reduce/reduce conflicts [-Wconflicts-rr]
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input.y:5.4: warning: rule useless in parser due to conflicts [-Wother]
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]])
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AT_CLEANUP
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## ------------------------------- ##
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## Non-unifying R/R lr2 conflict. ##
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## ------------------------------- ##
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AT_SETUP([Non-unifying R/R lr2 conflict])
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AT_KEYWORDS([cex])
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AT_DATA([[input.y]],
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[[%token H J K X
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%%
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s: a J;
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a: H i;
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i: X | i J K;
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]])
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AT_BISON_CHECK_CEX([input.y], [], [],
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[[Shift/reduce conflict on token J:
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5: 2 a: H i .
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5: 4 i: i . J K
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time limit exceeded: XXX
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First Example H i • J $end
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First derivation $accept ::=[ s ::=[ a ::=[ H i • ] J ] $end ]
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Second Example H i • J K $end
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Second derivation $accept ::=[ a ::=[ H i ::=[ i • J K ] ] $end ]
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input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
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input.y:4.4-6: warning: rule useless in parser due to conflicts [-Wother]
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]])
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AT_CLEANUP
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## -------------------- ##
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## Cex Search Prepend. ##
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## -------------------- ##
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# Tests prepend steps in uniying counterexample
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# graph search
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AT_SETUP([Cex Search Prepend])
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AT_KEYWORDS([cex])
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AT_DATA([[input.y]],
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[[%token N A B C D
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%%
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s: n | n C;
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n: N n D | N n C | N a B | N b;
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a: A;
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b: A B C | A B D;
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]])
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AT_BISON_CHECK_CEX([input.y], [], [],
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[[Shift/reduce conflict on token B:
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4: 7 a: A .
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4: 8 b: A . B C
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Example N A • B C
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First derivation s ::=[ n ::=[ N a ::=[ A • ] B ] C ]
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Second derivation s ::=[ n ::=[ N b ::=[ A • B C ] ] ]
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input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
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input.y:5.4: warning: rule useless in parser due to conflicts [-Wother]
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]])
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AT_CLEANUP
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## ------------------- ##
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## R/R cex with prec. ##
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## ------------------- ##
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# Tests that counterexamples containing rules using
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# precedence/associativity directives work.
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AT_SETUP([R/R cex with prec])
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AT_KEYWORDS([cex])
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AT_DATA([[input.y]],
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[[%left b
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%right c
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%%
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S: B C | C B;
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A : B | C | %empty;
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B : A b A;
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C : A c A;
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]])
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AT_BISON_CHECK_CEX([input.y], [], [],
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[[Reduce/reduce conflict on tokens b, c:
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3: 3 A: B .
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3: 5 A: . %empty
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Example B • b A A c A
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First derivation S ::=[ B ::=[ A ::=[ B • ] b A ] C ::=[ A c A ] ]
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Second derivation S ::=[ B C ::=[ A ::=[ B ::=[ A ::=[ • ] b A ] ] c A ] ]
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Reduce/reduce conflict on tokens b, c:
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4: 4 A: C .
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4: 5 A: . %empty
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Example C • c A A b A
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First derivation S ::=[ C ::=[ A ::=[ C • ] c A ] B ::=[ A b A ] ]
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Second derivation S ::=[ C B ::=[ A ::=[ C ::=[ A ::=[ • ] c A ] ] b A ] ]
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input.y: warning: 4 reduce/reduce conflicts [-Wconflicts-rr]
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]])
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AT_CLEANUP
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## ------------------- ##
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## Null nonterminals. ##
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## ------------------- ##
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AT_SETUP([Null nonterminals])
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AT_KEYWORDS([cex])
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AT_DATA([[input.y]],
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[[%token A
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%%
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a : b d | c d ;
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b : ;
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c : ;
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d : a | c A | d;
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]])
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AT_BISON_CHECK_CEX([input.y], [], [],
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[[Reduce/reduce conflict on token A:
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0: 3 b: . %empty
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0: 4 c: . %empty
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First Example • c A A $end
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First derivation $accept ::=[ a ::=[ b ::=[ • ] d ::=[ c A A ] ] $end ]
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Second Example • c A A $end
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Second derivation $accept ::=[ a ::=[ c ::=[ • ] d ::=[ c A A ] ] $end ]
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Reduce/reduce conflict on token A:
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2: 3 b: . %empty
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2: 4 c: . %empty
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time limit exceeded: XXX
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First Example b • c A A $end
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First derivation $accept ::=[ a ::=[ b d ::=[ a ::=[ b ::=[ • ] d ::=[ c A A ] ] ] ] $end ]
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Second Example b • A $end
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Second derivation $accept ::=[ a ::=[ b d ::=[ c ::=[ • ] A ] ] $end ]
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Reduce/reduce conflict on token A:
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3: 3 b: . %empty
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3: 4 c: . %empty
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time limit exceeded: XXX
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First Example c • c A A $end
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First derivation $accept ::=[ a ::=[ c d ::=[ a ::=[ b ::=[ • ] d ::=[ c A A ] ] ] ] $end ]
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Second Example c • A $end
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Second derivation $accept ::=[ a ::=[ c d ::=[ c ::=[ • ] A ] ] $end ]
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Shift/reduce conflict on token A:
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6: 3 b: . %empty
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6: 6 d: c . A
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time limit exceeded: XXX
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First Example b c • c A A $end
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First derivation $accept ::=[ a ::=[ b d ::=[ a ::=[ c d ::=[ a ::=[ b ::=[ • ] d ::=[ c A A ] ] ] ] ] ] $end ]
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Second Example b c • A
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Second derivation a ::=[ b d ::=[ c • A ] ]
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Reduce/reduce conflict on token A:
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6: 3 b: . %empty
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6: 4 c: . %empty
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First Example b c • c A A $end
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First derivation $accept ::=[ a ::=[ b d ::=[ a ::=[ c d ::=[ a ::=[ b ::=[ • ] d ::=[ c A A ] ] ] ] ] ] $end ]
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Second Example b c • A $end
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Second derivation $accept ::=[ a ::=[ b d ::=[ a ::=[ c d ::=[ c ::=[ • ] A ] ] ] ] $end ]
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Shift/reduce conflict on token A:
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6: 4 c: . %empty
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6: 6 d: c . A
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First Example b c • A $end
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First derivation $accept ::=[ a ::=[ b d ::=[ a ::=[ c d ::=[ c ::=[ • ] A ] ] ] ] $end ]
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Second Example b c • A
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Second derivation a ::=[ b d ::=[ c • A ] ]
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Reduce/reduce conflict on token $end:
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7: 1 a: b d .
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7: 7 d: d .
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Example b d •
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First derivation a ::=[ b d • ]
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Second derivation a ::=[ b d ::=[ d • ] ]
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Reduce/reduce conflict on token $end:
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8: 2 a: c d .
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8: 7 d: d .
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Example c d •
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First derivation a ::=[ c d • ]
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Second derivation a ::=[ c d ::=[ d • ] ]
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input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
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input.y: warning: 6 reduce/reduce conflicts [-Wconflicts-rr]
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input.y:5.4: warning: rule useless in parser due to conflicts [-Wother]
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input.y:6.15: warning: rule useless in parser due to conflicts [-Wother]
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]])
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AT_CLEANUP
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## --------------------------- ##
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## Non-unifying Prefix Share. ##
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## --------------------------- ##
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AT_SETUP([Non-unifying Prefix Share])
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AT_KEYWORDS([cex])
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# Tests for a counterexample which should start its derivation
|
|
# at a shared symbol rather than the start symbol.
|
|
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|
AT_DATA([[input.y]],
|
|
[[%token H J
|
|
%%
|
|
s: a | a J;
|
|
a: H i J J
|
|
i: %empty | i J;
|
|
]])
|
|
|
|
AT_BISON_CHECK_CEX([input.y], [], [],
|
|
[[Shift/reduce conflict on token J:
|
|
7: 5 i: i J .
|
|
7: 3 a: H i J . J
|
|
Example H i J • J J
|
|
First derivation s ::=[ a ::=[ H i ::=[ i J • ] J J ] ]
|
|
Second derivation s ::=[ a ::=[ H i J • J ] J ]
|
|
|
|
input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
|
|
input.y:5.13-15: warning: rule useless in parser due to conflicts [-Wother]
|
|
]])
|
|
|
|
AT_CLEANUP
|
|
|
|
## -------------------- ##
|
|
## Deep Null Unifying. ##
|
|
## ---------------------##
|
|
|
|
# Tests that nested nullable nonterminals
|
|
# are derived correctly.
|
|
|
|
AT_SETUP([Deep Null Unifying])
|
|
AT_KEYWORDS([cex])
|
|
|
|
AT_DATA([[input.y]],
|
|
[[%token a d
|
|
%%
|
|
S: a A D | a A A D;
|
|
A: B;
|
|
B: C
|
|
C: %empty
|
|
D: d;
|
|
]])
|
|
|
|
AT_BISON_CHECK_CEX([input.y], [], [],
|
|
[[Shift/reduce conflict on token d:
|
|
3: 5 C: . %empty
|
|
3: 6 D: . d
|
|
Example a A • d
|
|
First derivation S ::=[ a A A ::=[ B ::=[ C ::=[ • ] ] ] D ::=[ d ] ]
|
|
Second derivation S ::=[ a A D ::=[ • d ] ]
|
|
|
|
input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
|
|
]])
|
|
|
|
AT_CLEANUP
|
|
|
|
## ------------------------ ##
|
|
## Deep Null Non-unifying. ##
|
|
## -------------------------##
|
|
|
|
# Tests that expand_to_conflict works with nullable sybols
|
|
|
|
AT_SETUP([Deep Null Non-unifying])
|
|
AT_KEYWORDS([cex])
|
|
|
|
AT_DATA([[input.y]],
|
|
[[%token a d e
|
|
%%
|
|
S: a A D | a A A D e;
|
|
A: B;
|
|
B: C
|
|
C: %empty
|
|
D: d;
|
|
]])
|
|
|
|
AT_BISON_CHECK_CEX([input.y], [], [],
|
|
[[Shift/reduce conflict on token d:
|
|
3: 5 C: . %empty
|
|
3: 6 D: . d
|
|
First Example a A • d e $end
|
|
First derivation $accept ::=[ S ::=[ a A A ::=[ B ::=[ C ::=[ • ] ] ] D ::=[ d ] e ] $end ]
|
|
Second Example a A • d $end
|
|
Second derivation $accept ::=[ S ::=[ a A D ::=[ • d ] ] $end ]
|
|
|
|
input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
|
|
]])
|
|
|
|
AT_CLEANUP
|