# Exercising Bison on counterexamples.                         -*- Autotest -*-

# Copyright (C) 2020 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
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

AT_BANNER([[Counterexamples.]])

## --------------------- ##
## Simple Unifying S/R.  ##
## --------------------- ##

AT_SETUP([Unifying S/R])

AT_DATA([[input.y]],
[[%token A B C
%%
s: a x | y c;
a: A;
c: C;
x: B | B C;
y: A | A B;
]])

AT_BISON_CHECK([-Wcounterexample input.y], 0, [],
[[
]])

AT_CLEANUP

## ------------------- ##
## Deep Unifying S/R.  ##
## ------------------- ##

AT_SETUP([Deep Unifying S/R])

AT_DATA([[input.y]],
[[%token A B C
%%
s: ac | a bc;
ac: A ac C | b;
b: B | B b;
a: A | A a;
bc: B bc C | B C;
]])

AT_BISON_CHECK([-Wcounterexample input.y], 0, [],
[[
]])

AT_CLEANUP

## ------------------------------------ ##
## S/R Conflict with Nullable Symbols.  ##
## ------------------------------------ ##

AT_SETUP([S/R Conflict with Nullable Symbols])

AT_DATA([[input.y]],
[[%token A B X Y
%%
s: ax by | A xby;
ax: A x;
x: %empty | X x;
by: B y;
y: %empty | Y y;
xby: B | X xby Y;
]])

AT_BISON_CHECK([-Wcounterexample input.y], 0, [],
[[
]])

AT_CLEANUP

## ---------------------------- ##
## Non-unifying Ambiguous S/R.  ##
## ---------------------------- ##

AT_SETUP([Non-unifying Ambiguous S/R])

AT_DATA([[input.y]],
[[%token A B C D E
%%
g: s | x;
s: A x E | A x D E;
x: b cd | bc;
b: B;
cd: C D;
bc: B C;
]])

AT_BISON_CHECK([-Wcounterexample input.y], 0, [],
[[
]])

AT_CLEANUP

## ------------------------------ ##
## Non-unifying Unambiguous S/R.  ##
## ------------------------------ ##

AT_SETUP([Non-unifying Unambiguous S/R])

AT_DATA([[input.y]],
[[%token A B
%%
s: t | s t;
t: x | y;
x: A;
y: A A B;
]])

AT_BISON_CHECK([-Wcounterexample input.y], 0, [],
[[
]])

AT_CLEANUP

## ----------------------- ##
## S/R after first token.  ##
## ----------------------- ##

AT_SETUP([S/R after first token])

AT_DATA([[input.y]],
[[%token A B X Y
%%
a: r t | s;
r: b;
b: B;
t: A xx | A x xy;
s: b A xx y;
x: X;
xx: X X;
xy: X Y;
y: Y;
]])

AT_BISON_CHECK([-Wcounterexample input.y], 0, [],
[[
]])

AT_CLEANUP

## ----------------------------- ##
## Unifying R/R counterexample.  ##
## ----------------------------- ##

AT_SETUP([Unifying R/R counterexample])

AT_DATA([[input.y]],
[[%token A
%%
a : A b ;
b : A | b;
]])

AT_BISON_CHECK([-Wcounterexample input.y], 0, [],
[[
]])

AT_CLEANUP

## ------------------------------- ##
## Non-unifying R/R lr1 conflict.  ##
## ------------------------------- ##

AT_SETUP([Non-unifying R/R lr1 conflict])

AT_DATA([[input.y]],
[[%token A B C D
%%
s: a A | B a C | b C | B b A;
a: D;
b: D;
]])

AT_BISON_CHECK([-Wcounterexample input.y], 0, [],
[[
]])

AT_CLEANUP

## ------------------------------- ##
## Non-unifying R/R lr2 conflict.  ##
## ------------------------------- ##

AT_SETUP([Non-unifying R/R lr2 conflict])

AT_DATA([[input.y]],
[[%token H J K X
%%
s: a J;
a: H i;
i: X | i J K;
]])

AT_BISON_CHECK([-Wcounterexample input.y], 0, [],
[[
]])

AT_CLEANUP

## -------------------- ##
## Cex Search Prepend.  ##
## -------------------- ##

# Tests prepend steps in uniying counterexample
# graph search

AT_SETUP([Cex Search Prepend])

AT_DATA([[input.y]],
[[%token N A B C D
%%
s: n | n C;
n: N n D | N n C | N a B | N b;
a: A;
b: A B C | A B D;
]])

AT_BISON_CHECK([-Wcounterexample input.y], 0, [],
[[
]])

AT_CLEANUP

## ------------------- ##
## R/R cex with prec.  ##
## ------------------- ##

# Tests that counterexamples containing rules using
# precedence/associativity directives work.

AT_SETUP([R/R cex with prec])

AT_DATA([[input.y]],
[[%left b
%right c
%%
S: B C | C B;
A : B  | C  | %empty;
B : A b A;
C : A c A;
]])

AT_BISON_CHECK([-Wcounterexample input.y], 0, [],
[[
]])

AT_CLEANUP

## ------------------- ##
## Null nonterminals.  ##
## ------------------- ##

AT_SETUP([Null nonterminals])

AT_DATA([[input.y]],
[[%token A
%%
a : b d | c d ;
b : ;
c : ;
d : a | c A | d;
]])

AT_BISON_CHECK([-Wcounterexample input.y], 0, [],
[[
]])

AT_CLEANUP

## --------------------------- ##
## Non-unifying Prefix Share.  ##
## --------------------------- ##

AT_SETUP([Non-unifying Prefix Share])

# Tests for a counterexample which should start its derivation
# at a shared symbol rather than the start symbol.

AT_DATA([[input.y]],
[[%token H J
%%
s: a | a J;
a: H i J J
i: %empty | i J;
]])

AT_BISON_CHECK([-Wcounterexample input.y], 0, [],
[[
]])

AT_CLEANUP

## -------------------- ##
## Deep Null Unifying.  ##
## ---------------------##

# Tests that nested nullable nonterminals
# are derived correctly.

AT_SETUP([Deep Null Unifying])

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([-Wcounterexample input.y], 0, [],
[[
]])

AT_CLEANUP

## ------------------------ ##
## Deep Null Non-unifying.  ##
## -------------------------##

# Tests that expand_to_conflict works with nullable sybols

AT_SETUP([Deep Null Non-unifying])

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([-Wcounterexample input.y], 0, [],
[[
]])

AT_CLEANUP