# Exercising Bison Grammar Reduction.                      -*- Autotest -*-
# Copyright 2001 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 2, 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, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
# 02111-1307, USA.

AT_BANNER([[Grammar Reduction.]])


## ------------------- ##
## Useless Terminals.  ##
## ------------------- ##

AT_SETUP([Useless Terminals])

AT_DATA([[input.y]],
[[%verbose
%output="input.c"

%token useless1
%token useless2
%token useless3
%token useless4
%token useless5
%token useless6
%token useless7
%token useless8
%token useless9

%token useful
%%
exp: useful;
]])

AT_CHECK([[bison input.y]])

AT_CHECK([[sed -n '/^Grammar/q;/^$/!p' input.output]], 0,
[[Terminals which are not used:
   useless1
   useless2
   useless3
   useless4
   useless5
   useless6
   useless7
   useless8
   useless9
]])

AT_CLEANUP



## ---------------------- ##
## Useless Nonterminals.  ##
## ---------------------- ##

AT_SETUP([Useless Nonterminals])

AT_DATA([[input.y]],
[[%verbose
%output="input.c"

%nterm useless1
%nterm useless2
%nterm useless3
%nterm useless4
%nterm useless5
%nterm useless6
%nterm useless7
%nterm useless8
%nterm useless9

%token useful
%%
exp: useful;
]])

AT_CHECK([[bison input.y]], 0, [],
[[input.y contains 9 useless nonterminals
]])

AT_CHECK([[sed -n '/^Grammar/q;/^$/!p' input.output]], 0,
[[Useless nonterminals:
   useless1
   useless2
   useless3
   useless4
   useless5
   useless6
   useless7
   useless8
   useless9
]])

AT_CLEANUP



## --------------- ##
## Useless Rules.  ##
## --------------- ##

AT_SETUP([Useless Rules])

AT_DATA([[input.y]],
[[%verbose
%output="input.c"
%token useful
%%
exp: useful;
useless1: '1';
useless2: '2';
useless3: '3';
useless4: '4';
useless5: '5';
useless6: '6';
useless7: '7';
useless8: '8';
useless9: '9';
]])

AT_CHECK([[bison input.y]], 0, [],
[[input.y contains 9 useless nonterminals and 9 useless rules
]])

AT_CHECK([[sed -n '/^Grammar/q;/^$/!p' input.output]], 0,
[[Useless nonterminals:
   useless1
   useless2
   useless3
   useless4
   useless5
   useless6
   useless7
   useless8
   useless9
Terminals which are not used:
   '1'
   '2'
   '3'
   '4'
   '5'
   '6'
   '7'
   '8'
   '9'
Useless rules:
#2     useless1: '1';
#3     useless2: '2';
#4     useless3: '3';
#5     useless4: '4';
#6     useless5: '5';
#7     useless6: '6';
#8     useless7: '7';
#9     useless8: '8';
#10    useless9: '9';
]])

AT_CLEANUP



## ------------------- ##
## Reduced Automaton.  ##
## ------------------- ##

# Check that the automaton is that as the for the grammar reduced by
# hand.

AT_SETUP([Reduced Automaton])

# The non reduced grammar.
# ------------------------
AT_DATA([[not-reduced.y]],
[[/* A useless token. */
%token useless_token
/* A useful one. */
%token useful
%verbose
%output="not-reduced.c"

%%

exp: useful            { /* A useful action. */ }
   | non_productive    { /* A non productive action. */ }
   ;

not_reachable: useful  { /* A not reachable action. */ }
             ;

non_productive: non_productive useless_token
                       { /* Another non productive action. */ }
              ;
]])

AT_CHECK([[bison not-reduced.y]], 0, [],
[[not-reduced.y contains 2 useless nonterminals and 3 useless rules
]])

AT_CHECK([[sed -n '/^Grammar/q;/^$/!p' not-reduced.output]], 0,
[[Useless nonterminals:
   not_reachable
   non_productive
Terminals which are not used:
   useless_token
Useless rules:
#2     exp: non_productive;
#3     not_reachable: useful;
#4     non_productive: non_productive useless_token;
]])

# The reduced grammar.
# --------------------
AT_DATA([[reduced.y]],
[[/* A useless token. */
%token useless_token
/* A useful one. */
%token useful
%verbose
%output="reduced.c"

%%

exp: useful            { /* A useful action. */ }
//   | non_productive    { /* A non productive action. */ } */
   ;

//not_reachable: useful  { /* A not reachable action. */ }
//             ;

//non_productive: non_productive useless_token
//                       { /* Another non productive action. */ }
//              ;
]])

AT_CHECK([[bison reduced.y]])

# Comparing the parsers.
cp reduced.c expout
AT_CHECK([sed 's/not-reduced/reduced/g' not-reduced.c], 0, [expout])

AT_CLEANUP



## ------------------- ##
## Underivable Rules.  ##
## ------------------- ##

AT_SETUP([Underivable Rules])

AT_DATA([[input.y]],
[[%verbose
%output="input.c"
%token useful
%%
exp: useful | underivable;
underivable: indirection;
indirection: underivable;
]])

AT_CHECK([[bison input.y]], 0, [],
[[input.y contains 2 useless nonterminals and 3 useless rules
]])

AT_CHECK([[sed -n '/^Grammar/q;/^$/!p' input.output]], 0,
[[Useless nonterminals:
   underivable
   indirection
Useless rules:
#2     exp: underivable;
#3     underivable: indirection;
#4     indirection: underivable;
]])

AT_CLEANUP