Future/bison
1
0
Fork 0
mirror of https://git.savannah.gnu.org/git/bison.git synced 2026-03-09 20:33:03 +00:00
Code Issues Packages Projects Releases Wiki Activity

cex: prefer → to ::=

Browse Source 
It does not make a lot of sense to use ::= in our counterexamples,
that's not something that belongs to the Bison "vocabulary".  Using
the colon makes sense, but it's too discreet.  Let's use the arrow,
which we already use in some reports (HTML and Dot).

* src/gram.h (print_dot_fallback): Generalize into...
(print_fallback): this.
(print_arrow): New.
* src/derivation.c: Use it.

* NEWS, tests/conflicts.at, tests/counterexample.at,
* tests/diagnostics.at, tests/report.at: Adjust.
* doc/bison.texi: Ditto.
Unfortunately the literal `→` is output as `↦`.  So we need to use
@arrow.
This commit is contained in:
Akim Demaille
2020-07-11 18:25:49 +02:00
parent a2ad33dca6
commit ee86ea8839
8 changed files with 147 additions and 125 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
NEWS
View File

@@ -45,8 +45,8 @@ GNU Bison NEWS
conflict. For example:
Example exp '+' exp • '/' exp
First derivation exp ::=[ exp ::=[ exp '+' exp • ] '/' exp ]
Second derivation exp ::=[ exp '+' exp ::=[ exp • '/' exp ] ]
First derivation exp → [ exp → [ exp '+' exp • ] '/' exp ]
Second derivation exp → [ exp '+' exp → [ exp • '/' exp ] ]
When Bison is installed with text styling enabled, the example is actually
shown twice, with colors highlighting the ambiguity.
@@ -57,9 +57,9 @@ GNU Bison NEWS
generates two examples that are the same up until the dot:
First example expr • ID $end
First derivation $accept ::=[ s ::=[ a ::=[ expr • ] ID ] $end ]
First derivation $accept → [ s → [ a → [ expr • ] ID ] $end ]
Second example expr • ID ',' ID $end
Second derivation $accept ::=[ s ::=[ a ::=[ expr ::=[ expr • ID ',' ] ] ID ] $end ]
Second derivation $accept → [ s → [ a → [ expr → [ expr • ID ',' ] ] ID ] $end ]
In these cases, the parser usually doesn't have enough lookahead to
differentiate the two given examples.

28
doc/bison.texi
View File

@@ -9937,9 +9937,9 @@ output is actually in color)}:
Shift/reduce conflict on token "else":
@group
Example @yellow{"if" expr "then"} @blue{"if" expr "then" stmt} @red{•} @yellow{"else" stmt}
First derivation @yellow{if_stmt ::=[ "if" expr "then"} @green{stmt ::=[} @blue{if_stmt ::=[ "if" expr "then" stmt} @red{•} @blue{]} @green{]} @yellow{"else" stmt ]}
First derivation @yellow{if_stmt @arrow [ "if" expr "then"} @green{stmt @arrow [} @blue{if_stmt @arrow [ "if" expr "then" stmt} @red{•} @blue{]} @green{]} @yellow{"else" stmt ]}
Example @yellow{"if" expr "then"} @blue{"if" expr "then" stmt} @red{•} @blue{"else" stmt}
Second derivation @yellow{if_stmt ::=[ "if" expr "then"} @green{stmt ::=[} @blue{if_stmt ::=[ "if" expr "then" stmt} @red{•} @blue{"else" stmt ]} @green{]} @yellow{]}
Second derivation @yellow{if_stmt @arrow [ "if" expr "then"} @green{stmt @arrow [} @blue{if_stmt @arrow [ "if" expr "then" stmt} @red{•} @blue{"else" stmt ]} @green{]} @yellow{]}
@end group
@end example
@end ifhtml
@@ -9950,11 +9950,11 @@ Shift/reduce conflict on token "else":
Example
@yellow{"if" expr "then"} @blue{"if" expr "then" stmt} @red{•} @yellow{"else" stmt}
First derivation
@yellow{if_stmt ::=[ "if" expr "then"} @green{stmt ::=[} @blue{if_stmt ::=[ "if" expr "then" stmt} @red{•} @blue{]} @green{]} @yellow{"else" stmt ]}
@yellow{if_stmt @arrow [ "if" expr "then"} @green{stmt @arrow [} @blue{if_stmt @arrow [ "if" expr "then" stmt} @red{•} @blue{]} @green{]} @yellow{"else" stmt ]}
Example
@yellow{"if" expr "then"} @blue{"if" expr "then" stmt} @red{•} @blue{"else" stmt}
Second derivation
@yellow{if_stmt ::=[ "if" expr "then"} @green{stmt ::=[} @blue{if_stmt ::=[ "if" expr "then" stmt} @red{•} @blue{"else" stmt ]} @green{]} @yellow{]}
@yellow{if_stmt @arrow [ "if" expr "then"} @green{stmt @arrow [} @blue{if_stmt @arrow [ "if" expr "then" stmt} @red{•} @blue{"else" stmt ]} @green{]} @yellow{]}
@end group
@end smallexample
@end ifnothtml
@@ -9988,21 +9988,21 @@ sequence.y: @dwarning{warning}: 1 shift/reduce conflict [@dwarning{-Wconflicts-s
sequence.y: @dwarning{warning}: 2 reduce/reduce conflicts [@dwarning{-Wconflicts-rr}]
Shift/reduce conflict on token "word":
Example @red{•} @yellow{"word"}
First derivation @yellow{sequence ::=[} @green{sequence ::=[} @red{•} @green{]} @yellow{"word" ]}
First derivation @yellow{sequence @arrow [} @green{sequence @arrow [} @red{•} @green{]} @yellow{"word" ]}
Example @red{•} @green{"word"}
Second derivation @yellow{sequence ::=[} @green{maybeword ::=[} @red{•} @green{"word" ]} @yellow{]}
Second derivation @yellow{sequence @arrow [} @green{maybeword @arrow [} @red{•} @green{"word" ]} @yellow{]}
Reduce/reduce conflict on tokens $end, "word":
Example @red{•}
First derivation @yellow{sequence ::=[} @red{•} @yellow{]}
First derivation @yellow{sequence @arrow [} @red{•} @yellow{]}
Example @red{•}
Second derivation @yellow{sequence ::=[} @green{maybeword ::=[} @red{•} @green{]} @yellow{]}
Second derivation @yellow{sequence @arrow [} @green{maybeword @arrow [} @red{•} @green{]} @yellow{]}
Shift/reduce conflict on token "word":
Example @red{•} @yellow{"word"}
First derivation @yellow{sequence ::=[} @green{sequence ::=[} @blue{maybeword ::=[} @red{•} @blue{]} @green{]} @yellow{"word" ]}
First derivation @yellow{sequence @arrow [} @green{sequence @arrow [} @blue{maybeword @arrow [} @red{•} @blue{]} @green{]} @yellow{"word" ]}
Example @red{•} @green{"word"}
Second derivation @yellow{sequence ::=[} @green{maybeword ::=[} @red{•} @green{"word" ]} @yellow{]}
Second derivation @yellow{sequence @arrow [} @green{maybeword @arrow [} @red{•} @green{"word" ]} @yellow{]}
sequence.y:8.3-45: @dwarning{warning}: rule useless in parser due to conflicts [@dwarning{-Wother}]
8 | @dwarning{%empty @{ printf ("empty maybeword\n"); @}}
@@ -10034,9 +10034,9 @@ expr: %empty | expr ID ','
@smallexample
Shift/reduce conflict on token ID:
First example @blue{expr} @red{•} @green{ID} @yellow{$end}
First derivation @yellow{$accept ::=[} @green{s ::=[} @blue{a ::=[ expr} @red{•} @blue{]} @green{ID ]} @yellow{$end ]}
First derivation @yellow{$accept @arrow [} @green{s @arrow [} @blue{a @arrow [ expr} @red{•} @blue{]} @green{ID ]} @yellow{$end ]}
Second example @purple{expr} @red{•} @purple{ID ','} @green{ID} @yellow{$end}
Second derivation @yellow{$accept ::=[} @green{s ::=[} @blue{a ::=[} @purple{expr ::=[ expr} @red{•} @purple{ID ',' ]} @blue{]} @green{ID ]} @yellow{$end ]}
Second derivation @yellow{$accept @arrow [} @green{s @arrow [} @blue{a @arrow [} @purple{expr @arrow [ expr} @red{•} @purple{ID ',' ]} @blue{]} @green{ID ]} @yellow{$end ]}
@end smallexample
This conflict is caused by the parser not having enough information to know
@@ -10433,9 +10433,9 @@ Shift/reduce conflict on token '/':
1 exp: exp '+' exp •
4 exp: exp • '/' exp
Example @green{exp '+' exp} @red{•} @yellow{'/' exp}
First derivation @yellow{exp ::=[} @green{exp ::=[ exp '+' exp} @red{•} @green{]} @yellow{'/' exp ]}
First derivation @yellow{exp @arrow [} @green{exp @arrow [ exp '+' exp} @red{•} @green{]} @yellow{'/' exp ]}
Example @yellow{exp '+'} @green{exp} @red{•} @green{'/' exp}
Second derivation @yellow{exp ::=[ exp '+'} @green{exp ::=[ exp} @red{•} @green{'/' exp ]} @yellow{]}
Second derivation @yellow{exp @arrow [ exp '+'} @green{exp @arrow [ exp} @red{•} @green{'/' exp ]} @yellow{]}
@end example
This shows two separate derivations in the grammar for the same @code{exp}:

4
src/derivation.c
View File

@@ -145,7 +145,9 @@ derivation_print_impl (const derivation *deriv, FILE *f,
{
fputs (prefix, f);
begin_use_class ("cex-step", f);
fprintf (f, "%s ::=[ ", sym->tag);
fprintf (f, "%s ", sym->tag);
print_arrow (f);
fprintf (f, " [ ");
end_use_class ("cex-step", f);
prefix = "";
}

30
src/gram.h
View File

@@ -217,23 +217,41 @@ typedef struct
extern rule *rules;
extern rule_number nrules;
/* Fallback in case we can't print "•". */
/* Fallback in case we can't print "•" or "→". */
static inline long
print_dot_fallback (unsigned int code _GL_UNUSED,
const char *msg _GL_UNUSED,
void *callback_arg)
print_fallback (unsigned int code _GL_UNUSED,
const char *msg _GL_UNUSED,
void *callback_arg)
{
FILE *out = (FILE *) callback_arg;
putc ('.', out);
switch (code)
{
case 0x2022:
putc ('.', out);
break;
case 0x2192:
fputs ("->", out);
break;
default:
abort ();
}
return -1;
}
/* Print "→", the symbol used to separate the lhs of a rule from its
rhs. */
static inline void
print_arrow (FILE *out)
{
unicode_to_mb (0x2192, fwrite_success_callback, print_fallback, out);
}
/* Print "•", the symbol used to represent a point in an item (aka, a
dotted rule). */
static inline void
print_dot (FILE *out)
{
unicode_to_mb (0x2022, fwrite_success_callback, print_dot_fallback, out);
unicode_to_mb (0x2022, fwrite_success_callback, print_fallback, out);
}
/* Get the rule associated to this item. ITEM points inside RITEM. */

24
tests/conflicts.at
View File

@@ -865,8 +865,8 @@ State 5
1 exp: exp OP exp .
1 exp: exp . OP exp
Example exp OP exp . OP exp
First derivation exp ::=[ exp ::=[ exp OP exp . ] OP exp ]
Second derivation exp ::=[ exp OP exp ::=[ exp . OP exp ] ]
First derivation exp -> [ exp -> [ exp OP exp . ] OP exp ]
Second derivation exp -> [ exp OP exp -> [ exp . OP exp ] ]
]])
@@ -1207,8 +1207,8 @@ State 1
3 num: '0' .
4 id: '0' .
Example '0' .
First derivation exp ::=[ num ::=[ '0' . ] ]
Second derivation exp ::=[ id ::=[ '0' . ] ]
First derivation exp -> [ num -> [ '0' . ] ]
Second derivation exp -> [ id -> [ '0' . ] ]
@@ -1754,17 +1754,17 @@ State 4
10 reported_conflicts: . %empty
8 reported_conflicts: . 'a'
First example resolved_conflict . 'a'
First derivation start ::=[ resolved_conflict reported_conflicts ::=[ . ] 'a' ]
First derivation start -> [ resolved_conflict reported_conflicts -> [ . ] 'a' ]
Second example resolved_conflict . 'a' 'a'
Second derivation start ::=[ resolved_conflict reported_conflicts ::=[ . 'a' ] 'a' ]
Second derivation start -> [ resolved_conflict reported_conflicts -> [ . 'a' ] 'a' ]
Shift/reduce conflict on token 'a':
10 reported_conflicts: . %empty
9 reported_conflicts: . 'a'
First example resolved_conflict . 'a'
First derivation start ::=[ resolved_conflict reported_conflicts ::=[ . ] 'a' ]
First derivation start -> [ resolved_conflict reported_conflicts -> [ . ] 'a' ]
Second example resolved_conflict . 'a' 'a'
Second derivation start ::=[ resolved_conflict reported_conflicts ::=[ . 'a' ] 'a' ]
Second derivation start -> [ resolved_conflict reported_conflicts -> [ . 'a' ] 'a' ]
@@ -1781,8 +1781,8 @@ State 5
8 reported_conflicts: 'a' .
9 reported_conflicts: 'a' .
Example 'a' .
First derivation reported_conflicts ::=[ 'a' . ]
Second derivation reported_conflicts ::=[ 'a' . ]
First derivation reported_conflicts -> [ 'a' . ]
Second derivation reported_conflicts -> [ 'a' . ]
@@ -1965,8 +1965,8 @@ AT_CHECK([[cat input.output | sed -n '/^State 0$/,/^State 1$/p']], 0,
12 empty_c2: . %empty
13 empty_c3: . %empty
Example . 'c'
First derivation start ::=[ empty_c2 ::=[ . ] 'c' ]
Second derivation start ::=[ empty_c3 ::=[ . ] 'c' ]
First derivation start -> [ empty_c2 -> [ . ] 'c' ]
Second derivation start -> [ empty_c3 -> [ . ] 'c' ]

108
tests/counterexample.at
View File

@@ -47,8 +47,8 @@ AT_BISON_CHECK_CEX([input.y], [], [],
[[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
Shift/reduce conflict on token B:
Example A . B C
First derivation s ::=[ a ::=[ A . ] x ::=[ B C ] ]
Second derivation s ::=[ y ::=[ A . B ] c ::=[ C ] ]
First derivation s -> [ a -> [ A . ] x -> [ B C ] ]
Second derivation s -> [ y -> [ A . B ] c -> [ C ] ]
input.y:4.4: warning: rule useless in parser due to conflicts [-Wother]
]])
@@ -76,13 +76,13 @@ AT_BISON_CHECK_CEX([input.y], [], [],
[[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
Shift/reduce conflict on token B:
Example A . B C
First derivation s ::=[ a ::=[ A . ] bc ::=[ B C ] ]
Second derivation s ::=[ ac ::=[ A ac ::=[ b ::=[ . B ] ] C ] ]
First derivation s -> [ a -> [ A . ] bc -> [ B C ] ]
Second derivation s -> [ ac -> [ A ac -> [ b -> [ . B ] ] C ] ]
Shift/reduce conflict on token B:
Example A A . B B C C
First derivation s ::=[ a ::=[ A a ::=[ A . ] ] bc ::=[ B bc ::=[ B C ] C ] ]
Second derivation s ::=[ ac ::=[ A ac ::=[ A ac ::=[ b ::=[ . b ::=[ B B ] ] ] C ] C ] ]
First derivation s -> [ a -> [ A a -> [ A . ] ] bc -> [ B bc -> [ B C ] C ] ]
Second derivation s -> [ ac -> [ A ac -> [ A ac -> [ b -> [ . b -> [ B B ] ] ] C ] C ] ]
input.y:6.4: warning: rule useless in parser due to conflicts [-Wother]
]])
@@ -111,14 +111,14 @@ AT_BISON_CHECK_CEX([input.y], [], [],
[[input.y: warning: 2 shift/reduce conflicts [-Wconflicts-sr]
Shift/reduce conflict on token B:
Example A . B
First derivation s ::=[ ax ::=[ A x ::=[ . ] ] by ::=[ B y ::=[ ] ] ]
Second derivation s ::=[ A xby ::=[ . B ] ]
First derivation s -> [ ax -> [ A x -> [ . ] ] by -> [ B y -> [ ] ] ]
Second derivation s -> [ A xby -> [ . B ] ]
Shift/reduce conflict on token B:
First example A X . B y $end
First derivation $accept ::=[ s ::=[ ax ::=[ A x ::=[ X x ::=[ . ] ] ] by ::=[ B y ] ] $end ]
First derivation $accept -> [ s -> [ ax -> [ A x -> [ X x -> [ . ] ] ] by -> [ B y ] ] $end ]
Second example A X . B Y $end
Second derivation $accept ::=[ s ::=[ A xby ::=[ X xby ::=[ . B ] Y ] ] $end ]
Second derivation $accept -> [ s -> [ A xby -> [ X xby -> [ . B ] Y ] ] $end ]
input.y:5.4-9: warning: rule useless in parser due to conflicts [-Wother]
]])
@@ -147,9 +147,9 @@ AT_BISON_CHECK_CEX([input.y], [], [],
[[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
Shift/reduce conflict on token C:
First example B . C D $end
First derivation $accept ::=[ g ::=[ x ::=[ b ::=[ B . ] cd ::=[ C D ] ] ] $end ]
First derivation $accept -> [ g -> [ x -> [ b -> [ B . ] cd -> [ C D ] ] ] $end ]
Second example B . C $end
Second derivation $accept ::=[ g ::=[ x ::=[ bc ::=[ B . C ] ] ] $end ]
Second derivation $accept -> [ g -> [ x -> [ bc -> [ B . C ] ] ] $end ]
input.y:6.4: warning: rule useless in parser due to conflicts [-Wother]
]])
@@ -176,9 +176,9 @@ AT_BISON_CHECK_CEX([input.y], [], [],
[[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
Shift/reduce conflict on token A:
First example A . A $end
First derivation $accept ::=[ s ::=[ s ::=[ t ::=[ x ::=[ A . ] ] ] t ::=[ x ::=[ A ] ] ] $end ]
First derivation $accept -> [ s -> [ s -> [ t -> [ x -> [ A . ] ] ] t -> [ x -> [ A ] ] ] $end ]
Second example A . A B $end
Second derivation $accept ::=[ s ::=[ t ::=[ y ::=[ A . A B ] ] ] $end ]
Second derivation $accept -> [ s -> [ t -> [ y -> [ A . A B ] ] ] $end ]
]])
@@ -209,14 +209,14 @@ AT_BISON_CHECK_CEX([input.y], [], [],
[[input.y: warning: 2 shift/reduce conflicts [-Wconflicts-sr]
Shift/reduce conflict on token A:
Example b . A X X Y
First derivation a ::=[ r ::=[ b . ] t ::=[ A x ::=[ X ] xy ::=[ X Y ] ] ]
Second derivation a ::=[ s ::=[ b . xx ::=[ A X X ] y ::=[ Y ] ] ]
First derivation a -> [ r -> [ b . ] t -> [ A x -> [ X ] xy -> [ X Y ] ] ]
Second derivation a -> [ s -> [ b . xx -> [ A X X ] y -> [ Y ] ] ]
Shift/reduce conflict on token X:
First example X . X xy
First derivation a ::=[ x ::=[ X . ] t ::=[ X xy ] ]
First derivation a -> [ x -> [ X . ] t -> [ X xy ] ]
Second example A X . X
Second derivation a ::=[ t ::=[ A xx ::=[ X . X ] ] ]
Second derivation a -> [ t -> [ A xx -> [ X . X ] ] ]
input.y:4.4: warning: rule useless in parser due to conflicts [-Wother]
input.y:8.4: warning: rule useless in parser due to conflicts [-Wother]
@@ -242,8 +242,8 @@ AT_BISON_CHECK_CEX([input.y], [], [],
[[input.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
Reduce/reduce conflict on token $end:
Example A b .
First derivation a ::=[ A b . ]
Second derivation a ::=[ A b ::=[ b . ] ]
First derivation a -> [ A b . ]
Second derivation a -> [ A b -> [ b . ] ]
input.y:4.9: warning: rule useless in parser due to conflicts [-Wother]
]])
@@ -269,9 +269,9 @@ AT_BISON_CHECK_CEX([input.y], [], [],
[[input.y: warning: 2 reduce/reduce conflicts [-Wconflicts-rr]
Reduce/reduce conflict on tokens A, C:
First example D . A $end
First derivation $accept ::=[ s ::=[ a ::=[ D . ] A ] $end ]
First derivation $accept -> [ s -> [ a -> [ D . ] A ] $end ]
Second example B D . A $end
Second derivation $accept ::=[ s ::=[ B b ::=[ D . ] A ] $end ]
Second derivation $accept -> [ s -> [ B b -> [ D . ] A ] $end ]
input.y:5.4: warning: rule useless in parser due to conflicts [-Wother]
]])
@@ -298,9 +298,9 @@ AT_BISON_CHECK_CEX([input.y], [], [],
Shift/reduce conflict on token J:
time limit exceeded: XXX
First example H i . J $end
First derivation $accept ::=[ s ::=[ a ::=[ H i . ] J ] $end ]
First derivation $accept -> [ s -> [ a -> [ H i . ] J ] $end ]
Second example H i . J K $end
Second derivation $accept ::=[ a ::=[ H i ::=[ i . J K ] ] $end ]
Second derivation $accept -> [ a -> [ H i -> [ i . J K ] ] $end ]
input.y:4.4-6: warning: rule useless in parser due to conflicts [-Wother]
]])
@@ -330,13 +330,13 @@ AT_BISON_CHECK_CEX([input.y], [], [],
[[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
Shift/reduce conflict on token B:
Example N A . B C
First derivation s ::=[ n ::=[ N a ::=[ A . ] B ] C ]
Second derivation s ::=[ n ::=[ N b ::=[ A . B C ] ] ]
First derivation s -> [ n -> [ N a -> [ A . ] B ] C ]
Second derivation s -> [ n -> [ N b -> [ A . B C ] ] ]
Shift/reduce conflict on token B:
Example N N A . B D C
First derivation s ::=[ n ::=[ N n ::=[ N a ::=[ A . ] B ] D ] C ]
Second derivation s ::=[ n ::=[ N n ::=[ N b ::=[ A . B D ] ] C ] ]
First derivation s -> [ n -> [ N n -> [ N a -> [ A . ] B ] D ] C ]
Second derivation s -> [ n -> [ N n -> [ N b -> [ A . B D ] ] C ] ]
input.y:5.4: warning: rule useless in parser due to conflicts [-Wother]
]])
@@ -367,13 +367,13 @@ AT_BISON_CHECK_CEX([input.y], [], [],
[[input.y: warning: 4 reduce/reduce conflicts [-Wconflicts-rr]
Reduce/reduce conflict on tokens b, c:
Example B . b c
First derivation S ::=[ B ::=[ A ::=[ B . ] b A ::=[ ] ] C ::=[ A ::=[ ] c A ::=[ ] ] ]
Second derivation S ::=[ B C ::=[ A ::=[ B ::=[ A ::=[ . ] b A ::=[ ] ] ] c A ::=[ ] ] ]
First derivation S -> [ B -> [ A -> [ B . ] b A -> [ ] ] C -> [ A -> [ ] c A -> [ ] ] ]
Second derivation S -> [ B C -> [ A -> [ B -> [ A -> [ . ] b A -> [ ] ] ] c A -> [ ] ] ]
Reduce/reduce conflict on tokens b, c:
Example C . c b
First derivation S ::=[ C ::=[ A ::=[ C . ] c A ::=[ ] ] B ::=[ A ::=[ ] b A ::=[ ] ] ]
Second derivation S ::=[ C B ::=[ A ::=[ C ::=[ A ::=[ . ] c A ::=[ ] ] ] b A ::=[ ] ] ]
First derivation S -> [ C -> [ A -> [ C . ] c A -> [ ] ] B -> [ A -> [ ] b A -> [ ] ] ]
Second derivation S -> [ C B -> [ A -> [ C -> [ A -> [ . ] c A -> [ ] ] ] b A -> [ ] ] ]
]])
@@ -400,52 +400,52 @@ AT_BISON_CHECK_CEX([input.y], [], [],
input.y: warning: 6 reduce/reduce conflicts [-Wconflicts-rr]
Reduce/reduce conflict on token A:
First example . c A A $end
First derivation $accept ::=[ a ::=[ b ::=[ . ] d ::=[ c A A ] ] $end ]
First derivation $accept -> [ a -> [ b -> [ . ] d -> [ c A A ] ] $end ]
Second example . c A A $end
Second derivation $accept ::=[ a ::=[ c ::=[ . ] d ::=[ c A A ] ] $end ]
Second derivation $accept -> [ a -> [ c -> [ . ] d -> [ c A A ] ] $end ]
Reduce/reduce conflict on token A:
time limit exceeded: XXX
First example b . c A A $end
First derivation $accept ::=[ a ::=[ b d ::=[ a ::=[ b ::=[ . ] d ::=[ c A A ] ] ] ] $end ]
First derivation $accept -> [ a -> [ b d -> [ a -> [ b -> [ . ] d -> [ c A A ] ] ] ] $end ]
Second example b . A $end
Second derivation $accept ::=[ a ::=[ b d ::=[ c ::=[ . ] A ] ] $end ]
Second derivation $accept -> [ a -> [ b d -> [ c -> [ . ] A ] ] $end ]
Reduce/reduce conflict on token A:
time limit exceeded: XXX
First example c . c A A $end
First derivation $accept ::=[ a ::=[ c d ::=[ a ::=[ b ::=[ . ] d ::=[ c A A ] ] ] ] $end ]
First derivation $accept -> [ a -> [ c d -> [ a -> [ b -> [ . ] d -> [ c A A ] ] ] ] $end ]
Second example c . A $end
Second derivation $accept ::=[ a ::=[ c d ::=[ c ::=[ . ] A ] ] $end ]
Second derivation $accept -> [ a -> [ c d -> [ c -> [ . ] A ] ] $end ]
Shift/reduce conflict on token A:
time limit exceeded: XXX
First example b c . c A A $end
First derivation $accept ::=[ a ::=[ b d ::=[ a ::=[ c d ::=[ a ::=[ b ::=[ . ] d ::=[ c A A ] ] ] ] ] ] $end ]
First derivation $accept -> [ a -> [ b d -> [ a -> [ c d -> [ a -> [ b -> [ . ] d -> [ c A A ] ] ] ] ] ] $end ]
Second example b c . A
Second derivation a ::=[ b d ::=[ c . A ] ]
Second derivation a -> [ b d -> [ c . A ] ]
Reduce/reduce conflict on token A:
First example b c . c A A $end
First derivation $accept ::=[ a ::=[ b d ::=[ a ::=[ c d ::=[ a ::=[ b ::=[ . ] d ::=[ c A A ] ] ] ] ] ] $end ]
First derivation $accept -> [ a -> [ b d -> [ a -> [ c d -> [ a -> [ b -> [ . ] d -> [ c A A ] ] ] ] ] ] $end ]
Second example b c . A $end
Second derivation $accept ::=[ a ::=[ b d ::=[ a ::=[ c d ::=[ c ::=[ . ] A ] ] ] ] $end ]
Second derivation $accept -> [ a -> [ b d -> [ a -> [ c d -> [ c -> [ . ] A ] ] ] ] $end ]
Shift/reduce conflict on token A:
First example b c . A $end
First derivation $accept ::=[ a ::=[ b d ::=[ a ::=[ c d ::=[ c ::=[ . ] A ] ] ] ] $end ]
First derivation $accept -> [ a -> [ b d -> [ a -> [ c d -> [ c -> [ . ] A ] ] ] ] $end ]
Second example b c . A
Second derivation a ::=[ b d ::=[ c . A ] ]
Second derivation a -> [ b d -> [ c . A ] ]
Reduce/reduce conflict on token $end:
Example b d .
First derivation a ::=[ b d . ]
Second derivation a ::=[ b d ::=[ d . ] ]
First derivation a -> [ b d . ]
Second derivation a -> [ b d -> [ d . ] ]
Reduce/reduce conflict on token $end:
Example c d .
First derivation a ::=[ c d . ]
Second derivation a ::=[ c d ::=[ d . ] ]
First derivation a -> [ c d . ]
Second derivation a -> [ c d -> [ d . ] ]
input.y:5.4: warning: rule useless in parser due to conflicts [-Wother]
input.y:6.15: warning: rule useless in parser due to conflicts [-Wother]
@@ -475,8 +475,8 @@ AT_BISON_CHECK_CEX([input.y], [], [],
[[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
Shift/reduce conflict on token 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 ]
First derivation s -> [ a -> [ H i -> [ i J . ] J J ] ]
Second derivation s -> [ a -> [ H i J . J ] J ]
input.y:5.13-15: warning: rule useless in parser due to conflicts [-Wother]
]])
@@ -507,8 +507,8 @@ AT_BISON_CHECK_CEX([input.y], [], [],
[[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
Shift/reduce conflict on token D:
Example A a . D
First derivation s ::=[ A a a ::=[ b ::=[ c ::=[ . ] ] ] d ::=[ D ] ]
Second derivation s ::=[ A a d ::=[ . D ] ]
First derivation s -> [ A a a -> [ b -> [ c -> [ . ] ] ] d -> [ D ] ]
Second derivation s -> [ A a d -> [ . D ] ]
]])
@@ -537,9 +537,9 @@ AT_BISON_CHECK_CEX([input.y], [], [],
[[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
Shift/reduce conflict on token D:
First example A a . D E $end
First derivation $accept ::=[ s ::=[ A a a ::=[ b ::=[ c ::=[ . ] ] ] d ::=[ 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 ]
Second derivation $accept -> [ s -> [ A a d -> [ . D ] ] $end ]
]])

22
tests/diagnostics.at
View File

@@ -376,10 +376,12 @@ exp:^M
]],
[0],
[[input.y:11.9-11: <warning>warning:</warning> symbol FOO redeclared [<warning>-Wother</warning>]
11 | %token
11 | %token
<warning>FOO</warning>
| <warning>^~~</warning>
input.y:10.9-11: <note>note:</note> previous declaration
input.y:10.9-11: <note>note:</note> previous declaration
10 | %token
<note>FOO</note>
| <note>^~~</note>
input.y:13.5: <warning>warning:</warning> empty rule without %empty [<warning>-Wempty-rule</warning>]
13 | exp:
@@ -535,27 +537,27 @@ exp
[[input.y: <error>error:</error> shift/reduce conflicts: 4 found, 0 expected
Shift/reduce conflict on token "+":
Example <cex-0><cex-1><cex-leaf>exp</cex-leaf> <cex-leaf>"+"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-dot>•</cex-dot></cex-1> <cex-leaf>"+"</cex-leaf> <cex-leaf>exp</cex-leaf></cex-0>
Shift/reduce conflict on token "+":
First derivation <cex-0><cex-step>exp → [ </cex-step><cex-1><cex-step>exp → [ </cex-step><cex-leaf>exp</cex-leaf> <cex-leaf>"+"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-dot>•</cex-dot><cex-step> ]</cex-step></cex-1> <cex-leaf>"+"</cex-leaf> <cex-leaf>exp</cex-leaf><cex-step> ]</cex-step></cex-0>
Example <cex-0><cex-leaf>exp</cex-leaf> <cex-leaf>"+"</cex-leaf><cex-1> <cex-leaf>exp</cex-leaf> <cex-dot>•</cex-dot> <cex-leaf>"+"</cex-leaf> <cex-leaf>exp</cex-leaf></cex-1></cex-0>
First derivation <cex-0><cex-step>exp ::=[ </cex-step><cex-1><cex-step>exp ::=[ </cex-step><cex-leaf>exp</cex-leaf> <cex-leaf>"+"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-dot>•</cex-dot><cex-step> ]</cex-step></cex-1> <cex-leaf>"+"</cex-leaf> <cex-leaf>exp</cex-leaf><cex-step> ]</cex-step></cex-0>
Second derivation <cex-0><cex-step>exp → [ </cex-step><cex-leaf>exp</cex-leaf> <cex-leaf>"+"</cex-leaf><cex-1> <cex-step>exp → [ </cex-step><cex-leaf>exp</cex-leaf> <cex-dot>•</cex-dot> <cex-leaf>"+"</cex-leaf> <cex-leaf>exp</cex-leaf><cex-step> ]</cex-step></cex-1><cex-step> ]</cex-step></cex-0>
Shift/reduce conflict on token "else":
Example <cex-0><cex-leaf>"if"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"then"</cex-leaf><cex-1> <cex-leaf>"if"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"then"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-dot>•</cex-dot></cex-1> <cex-leaf>"else"</cex-leaf> <cex-leaf>exp</cex-leaf></cex-0>
Shift/reduce conflict on token "else":
First derivation <cex-0><cex-step>exp → [ </cex-step><cex-leaf>"if"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"then"</cex-leaf><cex-1> <cex-step>exp → [ </cex-step><cex-leaf>"if"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"then"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-dot>•</cex-dot><cex-step> ]</cex-step></cex-1> <cex-leaf>"else"</cex-leaf> <cex-leaf>exp</cex-leaf><cex-step> ]</cex-step></cex-0>
Example <cex-0><cex-leaf>"if"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"then"</cex-leaf><cex-1> <cex-leaf>"if"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"then"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-dot>•</cex-dot> <cex-leaf>"else"</cex-leaf> <cex-leaf>exp</cex-leaf></cex-1></cex-0>
First derivation <cex-0><cex-step>exp ::=[ </cex-step><cex-leaf>"if"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"then"</cex-leaf><cex-1> <cex-step>exp ::=[ </cex-step><cex-leaf>"if"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"then"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-dot>•</cex-dot><cex-step> ]</cex-step></cex-1> <cex-leaf>"else"</cex-leaf> <cex-leaf>exp</cex-leaf><cex-step> ]</cex-step></cex-0>
Second derivation <cex-0><cex-step>exp → [ </cex-step><cex-leaf>"if"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"then"</cex-leaf><cex-1> <cex-step>exp → [ </cex-step><cex-leaf>"if"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"then"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-dot>•</cex-dot> <cex-leaf>"else"</cex-leaf> <cex-leaf>exp</cex-leaf><cex-step> ]</cex-step></cex-1><cex-step> ]</cex-step></cex-0>
Shift/reduce conflict on token "+":
Example <cex-0><cex-1><cex-leaf>"if"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"then"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-dot>•</cex-dot></cex-1> <cex-leaf>"+"</cex-leaf> <cex-leaf>exp</cex-leaf></cex-0>
Shift/reduce conflict on token "+":
First derivation <cex-0><cex-step>exp → [ </cex-step><cex-1><cex-step>exp → [ </cex-step><cex-leaf>"if"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"then"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-dot>•</cex-dot><cex-step> ]</cex-step></cex-1> <cex-leaf>"+"</cex-leaf> <cex-leaf>exp</cex-leaf><cex-step> ]</cex-step></cex-0>
Example <cex-0><cex-leaf>"if"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"then"</cex-leaf><cex-1> <cex-leaf>exp</cex-leaf> <cex-dot>•</cex-dot> <cex-leaf>"+"</cex-leaf> <cex-leaf>exp</cex-leaf></cex-1></cex-0>
First derivation <cex-0><cex-step>exp ::=[ </cex-step><cex-1><cex-step>exp ::=[ </cex-step><cex-leaf>"if"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"then"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-dot>•</cex-dot><cex-step> ]</cex-step></cex-1> <cex-leaf>"+"</cex-leaf> <cex-leaf>exp</cex-leaf><cex-step> ]</cex-step></cex-0>
Second derivation <cex-0><cex-step>exp → [ </cex-step><cex-leaf>"if"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"then"</cex-leaf><cex-1> <cex-step>exp → [ </cex-step><cex-leaf>exp</cex-leaf> <cex-dot>•</cex-dot> <cex-leaf>"+"</cex-leaf> <cex-leaf>exp</cex-leaf><cex-step> ]</cex-step></cex-1><cex-step> ]</cex-step></cex-0>
Shift/reduce conflict on token "+":
Example <cex-0><cex-1><cex-leaf>"if"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"then"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"else"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-dot>•</cex-dot></cex-1> <cex-leaf>"+"</cex-leaf> <cex-leaf>exp</cex-leaf></cex-0>
Shift/reduce conflict on token "+":
First derivation <cex-0><cex-step>exp → [ </cex-step><cex-1><cex-step>exp → [ </cex-step><cex-leaf>"if"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"then"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"else"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-dot>•</cex-dot><cex-step> ]</cex-step></cex-1> <cex-leaf>"+"</cex-leaf> <cex-leaf>exp</cex-leaf><cex-step> ]</cex-step></cex-0>
Example <cex-0><cex-leaf>"if"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"then"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"else"</cex-leaf><cex-1> <cex-leaf>exp</cex-leaf> <cex-dot>•</cex-dot> <cex-leaf>"+"</cex-leaf> <cex-leaf>exp</cex-leaf></cex-1></cex-0>
First derivation <cex-0><cex-step>exp ::=[ </cex-step><cex-1><cex-step>exp ::=[ </cex-step><cex-leaf>"if"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"then"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"else"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-dot>•</cex-dot><cex-step> ]</cex-step></cex-1> <cex-leaf>"+"</cex-leaf> <cex-leaf>exp</cex-leaf><cex-step> ]</cex-step></cex-0>
Second derivation <cex-0><cex-step>exp → [ </cex-step><cex-leaf>"if"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"then"</cex-leaf> <cex-leaf>exp</cex-leaf> <cex-leaf>"else"</cex-leaf><cex-1> <cex-step>exp → [ </cex-step><cex-leaf>exp</cex-leaf> <cex-dot>•</cex-dot> <cex-leaf>"+"</cex-leaf> <cex-leaf>exp</cex-leaf><cex-step> ]</cex-step></cex-1><cex-step> ]</cex-step></cex-0>
]])

48
tests/report.at
View File

@@ -1539,33 +1539,33 @@ AT_CHECK([LC_ALL="$locale" bison -fno-caret -o input.cc -rall -Wcex --graph=inpu
input.y: warning: 3 reduce/reduce conflicts [-Wconflicts-rr]
Shift/reduce conflict on token "⊕":
Example exp "+" exp • "⊕" exp
First derivation exp ::=[ exp ::=[ exp "+" exp • ] "⊕" exp ]
Second derivation exp ::=[ exp "+" exp ::=[ exp • "⊕" exp ] ]
First derivation exp → [ exp → [ exp "+" exp • ] "⊕" exp ]
Second derivation exp → [ exp "+" exp → [ exp • "⊕" exp ] ]
Reduce/reduce conflict on tokens $end, "+", "⊕":
Example exp "+" exp •
First derivation exp ::=[ exp "+" exp • ]
Second derivation exp ::=[ exp "+" exp • ]
First derivation exp → [ exp "+" exp • ]
Second derivation exp → [ exp "+" exp • ]
Shift/reduce conflict on token "⊕":
Example exp "+" exp • "⊕" exp
First derivation exp ::=[ exp ::=[ exp "+" exp • ] "⊕" exp ]
Second derivation exp ::=[ exp "+" exp ::=[ exp • "⊕" exp ] ]
First derivation exp → [ exp → [ exp "+" exp • ] "⊕" exp ]
Second derivation exp → [ exp "+" exp → [ exp • "⊕" exp ] ]
Shift/reduce conflict on token "⊕":
Example exp "⊕" exp • "⊕" exp
First derivation exp ::=[ exp ::=[ exp "⊕" exp • ] "⊕" exp ]
Second derivation exp ::=[ exp "⊕" exp ::=[ exp • "⊕" exp ] ]
First derivation exp → [ exp → [ exp "⊕" exp • ] "⊕" exp ]
Second derivation exp → [ exp "⊕" exp → [ exp • "⊕" exp ] ]
Shift/reduce conflict on token "+":
Example exp "⊕" exp • "+" exp
First derivation exp ::=[ exp ::=[ exp "⊕" exp • ] "+" exp ]
Second derivation exp ::=[ exp "⊕" exp ::=[ exp • "+" exp ] ]
First derivation exp → [ exp → [ exp "⊕" exp • ] "+" exp ]
Second derivation exp → [ exp "⊕" exp → [ exp • "+" exp ] ]
Shift/reduce conflict on token "+":
Example exp "⊕" exp • "+" exp
First derivation exp ::=[ exp ::=[ exp "⊕" exp • ] "+" exp ]
Second derivation exp ::=[ exp "⊕" exp ::=[ exp • "+" exp ] ]
First derivation exp → [ exp → [ exp "⊕" exp • ] "+" exp ]
Second derivation exp → [ exp "⊕" exp → [ exp • "+" exp ] ]
input.y:6.3-13: warning: rule useless in parser due to conflicts [-Wother]
]])
@@ -1714,22 +1714,22 @@ State 7
2 exp: exp "+" exp •
1 exp: exp • "⊕" exp
Example exp "+" exp • "⊕" exp
First derivation exp ::=[ exp ::=[ exp "+" exp • ] "⊕" exp ]
Second derivation exp ::=[ exp "+" exp ::=[ exp • "⊕" exp ] ]
First derivation exp → [ exp → [ exp "+" exp • ] "⊕" exp ]
Second derivation exp → [ exp "+" exp → [ exp • "⊕" exp ] ]
Reduce/reduce conflict on tokens $end, "+", "⊕":
2 exp: exp "+" exp •
3 exp: exp "+" exp •
Example exp "+" exp •
First derivation exp ::=[ exp "+" exp • ]
Second derivation exp ::=[ exp "+" exp • ]
First derivation exp → [ exp "+" exp • ]
Second derivation exp → [ exp "+" exp • ]
Shift/reduce conflict on token "⊕":
3 exp: exp "+" exp •
1 exp: exp • "⊕" exp
Example exp "+" exp • "⊕" exp
First derivation exp ::=[ exp ::=[ exp "+" exp • ] "⊕" exp ]
Second derivation exp ::=[ exp "+" exp ::=[ exp • "⊕" exp ] ]
First derivation exp → [ exp → [ exp "+" exp • ] "⊕" exp ]
Second derivation exp → [ exp "+" exp → [ exp • "⊕" exp ] ]
@@ -1751,22 +1751,22 @@ State 8
1 exp: exp "⊕" exp •
1 exp: exp • "⊕" exp
Example exp "⊕" exp • "⊕" exp
First derivation exp ::=[ exp ::=[ exp "⊕" exp • ] "⊕" exp ]
Second derivation exp ::=[ exp "⊕" exp ::=[ exp • "⊕" exp ] ]
First derivation exp → [ exp → [ exp "⊕" exp • ] "⊕" exp ]
Second derivation exp → [ exp "⊕" exp → [ exp • "⊕" exp ] ]
Shift/reduce conflict on token "+":
1 exp: exp "⊕" exp •
2 exp: exp • "+" exp
Example exp "⊕" exp • "+" exp
First derivation exp ::=[ exp ::=[ exp "⊕" exp • ] "+" exp ]
Second derivation exp ::=[ exp "⊕" exp ::=[ exp • "+" exp ] ]
First derivation exp → [ exp → [ exp "⊕" exp • ] "+" exp ]
Second derivation exp → [ exp "⊕" exp → [ exp • "+" exp ] ]
Shift/reduce conflict on token "+":
1 exp: exp "⊕" exp •
3 exp: exp • "+" exp
Example exp "⊕" exp • "+" exp
First derivation exp ::=[ exp ::=[ exp "⊕" exp • ] "+" exp ]
Second derivation exp ::=[ exp "⊕" exp ::=[ exp • "+" exp ] ]
First derivation exp → [ exp → [ exp "⊕" exp • ] "+" exp ]
Second derivation exp → [ exp "⊕" exp → [ exp • "+" exp ] ]
]])