+AT_BISON_CHECK([-o input.c input.y])
+AT_CLEANUP
+
+
+## ---------------------------------------------- ##
+## Unreachable States After Conflict Resolution. ##
+## ---------------------------------------------- ##
+
+AT_SETUP([[Unreachable States After Conflict Resolution]])
+
+# If conflict resolution makes states unreachable, remove those states, report
+# rules that are then unused, and don't report conflicts in those states. Test
+# what happens when a nonterminal becomes useless as a result of state removal
+# since that causes lalr.o's goto map to be rewritten.
+
+AT_DATA([[input.y]],
+[[%output "input.c"
+%left 'a'
+
+%%
+
+start: resolved_conflict 'a' reported_conflicts 'a' ;
+
+/* S/R conflict resolved as reduce, so the state with item
+ * (resolved_conflict: 'a' . unreachable1) and all it transition successors are
+ * unreachable, and the associated production is useless. */
+resolved_conflict:
+ 'a' unreachable1
+ | %prec 'a'
+ ;
+
+/* S/R conflict that need not be reported since it is unreachable because of
+ * the previous conflict resolution. Nonterminal unreachable1 and all its
+ * productions are useless. */
+unreachable1:
+ 'a' unreachable2
+ |
+ ;
+
+/* Likewise for a R/R conflict and nonterminal unreachable2. */
+unreachable2: | ;
+
+/* Make sure remaining S/R and R/R conflicts are still reported correctly even
+ * when their states are renumbered due to state removal. */
+reported_conflicts:
+ 'a'
+ | 'a'
+ |
+ ;
+
+]])
+
+AT_BISON_CHECK([[--report=all input.y]], 0, [],
+[[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
+input.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
+input.y:12.5-20: warning: rule useless in parser due to conflicts [-Wother]
+input.y:20.5-20: warning: rule useless in parser due to conflicts [-Wother]
+input.y:21.4: warning: rule useless in parser due to conflicts [-Wother]
+input.y:25.13: warning: rule useless in parser due to conflicts [-Wother]
+input.y:25.16: warning: rule useless in parser due to conflicts [-Wother]
+input.y:31.5-7: warning: rule useless in parser due to conflicts [-Wother]
+input.y:32.4: warning: rule useless in parser due to conflicts [-Wother]
+]])
+
+AT_CHECK([[cat input.output]], 0,
+[[Rules useless in parser due to conflicts
+
+ 2 resolved_conflict: 'a' unreachable1
+
+ 4 unreachable1: 'a' unreachable2
+ 5 | %empty
+
+ 6 unreachable2: %empty
+ 7 | %empty
+
+ 9 reported_conflicts: 'a'
+ 10 | %empty
+
+
+State 4 conflicts: 1 shift/reduce
+State 5 conflicts: 1 reduce/reduce
+
+
+Grammar
+
+ 0 $accept: start $end
+
+ 1 start: resolved_conflict 'a' reported_conflicts 'a'
+
+ 2 resolved_conflict: 'a' unreachable1
+ 3 | %empty
+
+ 4 unreachable1: 'a' unreachable2
+ 5 | %empty
+
+ 6 unreachable2: %empty
+ 7 | %empty
+
+ 8 reported_conflicts: 'a'
+ 9 | 'a'
+ 10 | %empty
+
+
+Terminals, with rules where they appear
+
+$end (0) 0
+'a' (97) 1 2 4 8 9
+error (256)
+
+
+Nonterminals, with rules where they appear
+
+$accept (4)
+ on left: 0
+start (5)
+ on left: 1, on right: 0
+resolved_conflict (6)
+ on left: 2 3, on right: 1
+unreachable1 (7)
+ on left: 4 5, on right: 2
+unreachable2 (8)
+ on left: 6 7, on right: 4
+reported_conflicts (9)
+ on left: 8 9 10, on right: 1
+
+
+State 0
+
+ 0 $accept: . start $end
+ 1 start: . resolved_conflict 'a' reported_conflicts 'a'
+ 2 resolved_conflict: . 'a' unreachable1
+ 3 | . %empty ['a']
+
+ $default reduce using rule 3 (resolved_conflict)
+
+ start go to state 1
+ resolved_conflict go to state 2
+
+ Conflict between rule 3 and token 'a' resolved as reduce (%left 'a').
+
+
+State 1
+
+ 0 $accept: start . $end
+
+ $end shift, and go to state 3
+
+
+State 2
+
+ 1 start: resolved_conflict . 'a' reported_conflicts 'a'
+
+ 'a' shift, and go to state 4
+
+
+State 3
+
+ 0 $accept: start $end .
+
+ $default accept
+
+
+State 4
+
+ 1 start: resolved_conflict 'a' . reported_conflicts 'a'
+ 8 reported_conflicts: . 'a'
+ 9 | . 'a'
+ 10 | . %empty ['a']
+
+ 'a' shift, and go to state 5
+
+ 'a' [reduce using rule 10 (reported_conflicts)]
+
+ reported_conflicts go to state 6
+
+
+State 5
+
+ 8 reported_conflicts: 'a' . ['a']
+ 9 | 'a' . ['a']
+
+ 'a' reduce using rule 8 (reported_conflicts)
+ 'a' [reduce using rule 9 (reported_conflicts)]
+ $default reduce using rule 8 (reported_conflicts)
+
+
+State 6
+
+ 1 start: resolved_conflict 'a' reported_conflicts . 'a'
+
+ 'a' shift, and go to state 7
+
+
+State 7
+
+ 1 start: resolved_conflict 'a' reported_conflicts 'a' .
+
+ $default reduce using rule 1 (start)
+]])
+
+AT_DATA([[input-keep.y]],
+[[%define lr.keep-unreachable-state
+]])
+AT_CHECK([[cat input.y >> input-keep.y]])
+
+AT_BISON_CHECK([[input-keep.y]], 0, [],
+[[input-keep.y: warning: 2 shift/reduce conflicts [-Wconflicts-sr]
+input-keep.y: warning: 2 reduce/reduce conflicts [-Wconflicts-rr]
+input-keep.y:22.4: warning: rule useless in parser due to conflicts [-Wother]
+input-keep.y:26.16: warning: rule useless in parser due to conflicts [-Wother]
+input-keep.y:32.5-7: warning: rule useless in parser due to conflicts [-Wother]
+input-keep.y:33.4: warning: rule useless in parser due to conflicts [-Wother]
+]])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------ ##
+## Solved conflicts report for multiple reductions in a state. ##
+## ------------------------------------------------------------ ##
+
+AT_SETUP([[Solved conflicts report for multiple reductions in a state]])
+
+# Used to lose earlier solved conflict messages even within a single S/R/R.
+
+AT_DATA([[input.y]],
+[[%left 'a'
+%right 'b'
+%right 'c'
+%right 'd'
+%%
+start:
+ 'a'
+ | empty_a 'a'
+ | 'b'
+ | empty_b 'b'
+ | 'c'
+ | empty_c1 'c'
+ | empty_c2 'c'
+ | empty_c3 'c'
+ ;
+empty_a: %prec 'a' ;
+empty_b: %prec 'b' ;
+empty_c1: %prec 'c' ;
+empty_c2: %prec 'c' ;
+empty_c3: %prec 'd' ;
+]])
+AT_BISON_CHECK([[--report=all -o input.c input.y]], 0, [], [ignore])
+AT_CHECK([[cat input.output | sed -n '/^State 0$/,/^State 1$/p']], 0,
+[[State 0
+
+ 0 $accept: . start $end
+ 1 start: . 'a'
+ 2 | . empty_a 'a'
+ 3 | . 'b'
+ 4 | . empty_b 'b'
+ 5 | . 'c'
+ 6 | . empty_c1 'c'
+ 7 | . empty_c2 'c'
+ 8 | . empty_c3 'c'
+ 9 empty_a: . %empty ['a']
+ 10 empty_b: . %empty []
+ 11 empty_c1: . %empty []
+ 12 empty_c2: . %empty []
+ 13 empty_c3: . %empty ['c']
+
+ 'b' shift, and go to state 1
+
+ 'c' reduce using rule 13 (empty_c3)
+ $default reduce using rule 9 (empty_a)
+
+ start go to state 2
+ empty_a go to state 3
+ empty_b go to state 4
+ empty_c1 go to state 5
+ empty_c2 go to state 6
+ empty_c3 go to state 7
+
+ Conflict between rule 9 and token 'a' resolved as reduce (%left 'a').
+ Conflict between rule 10 and token 'b' resolved as shift (%right 'b').
+ Conflict between rule 11 and token 'c' resolved as shift (%right 'c').
+ Conflict between rule 12 and token 'c' resolved as shift (%right 'c').
+ Conflict between rule 13 and token 'c' resolved as reduce ('c' < 'd').
+
+
+State 1
+]])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------ ##
+## %nonassoc error actions for multiple reductions in a state. ##
+## ------------------------------------------------------------ ##
+
+# Used to abort when trying to resolve conflicts as %nonassoc error actions for
+# multiple reductions in a state.
+
+# For a %nonassoc error action token, used to print the first remaining
+# reduction on that token without brackets.
+
+AT_SETUP([[%nonassoc error actions for multiple reductions in a state]])
+
+AT_DATA([[input.y]],
+[[%nonassoc 'a' 'b' 'c'
+%%
+start:
+ 'a'
+ | empty_a 'a'
+ | 'b'
+ | empty_b 'b'
+ | 'c'
+ | empty_c1 'c'
+ | empty_c2 'c'
+ | empty_c3 'c'
+ ;
+empty_a: %prec 'a' ;
+empty_b: %prec 'b' ;
+empty_c1: %prec 'c' ;
+empty_c2: %prec 'c' ;
+empty_c3: %prec 'c' ;
+]])
+
+AT_BISON_CHECK([[--report=all -o input.c input.y]], 0, [], [ignore])
+AT_CHECK([[cat input.output | sed -n '/^State 0$/,/^State 1$/p']], 0,
+[[State 0
+
+ 0 $accept: . start $end
+ 1 start: . 'a'
+ 2 | . empty_a 'a'
+ 3 | . 'b'
+ 4 | . empty_b 'b'
+ 5 | . 'c'
+ 6 | . empty_c1 'c'
+ 7 | . empty_c2 'c'
+ 8 | . empty_c3 'c'
+ 9 empty_a: . %empty []
+ 10 empty_b: . %empty []
+ 11 empty_c1: . %empty []
+ 12 empty_c2: . %empty ['c']
+ 13 empty_c3: . %empty ['c']
+
+ 'a' error (nonassociative)
+ 'b' error (nonassociative)
+ 'c' error (nonassociative)
+
+ 'c' [reduce using rule 12 (empty_c2)]
+ 'c' [reduce using rule 13 (empty_c3)]
+
+ start go to state 1
+ empty_a go to state 2
+ empty_b go to state 3
+ empty_c1 go to state 4
+ empty_c2 go to state 5
+ empty_c3 go to state 6
+
+ Conflict between rule 9 and token 'a' resolved as an error (%nonassoc 'a').
+ Conflict between rule 10 and token 'b' resolved as an error (%nonassoc 'b').
+ Conflict between rule 11 and token 'c' resolved as an error (%nonassoc 'c').
+
+
+State 1
+]])
+AT_CLEANUP
+
+
+## -------------------- ##
+## %expect-rr non GLR. ##
+## -------------------- ##
+
+AT_SETUP([[%expect-rr non GLR]])
+
+AT_DATA([[1.y]],
+[[%expect-rr 0
+%%
+exp: 'a'
+]])
+
+AT_BISON_CHECK([[1.y]], [[0]], [],
+[[1.y: warning: %expect-rr applies only to GLR parsers [-Wother]
+]])
+
+AT_DATA([[2.y]],
+[[%expect-rr 1
+%%
+exp: 'a' | 'a';
+]])
+
+AT_BISON_CHECK([[2.y]], [[0]], [],
+[[2.y: warning: %expect-rr applies only to GLR parsers [-Wother]
+2.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
+2.y:3.12-14: warning: rule useless in parser due to conflicts [-Wother]
+]])
+
+AT_CLEANUP
+
+
+## ---------------------------------- ##
+## -W versus %expect and %expect-rr. ##
+## ---------------------------------- ##
+
+AT_SETUP([[-W versus %expect and %expect-rr]])
+
+AT_DATA([[sr-rr.y]],
+[[%glr-parser
+%%
+start: 'a' | A 'a' | B 'a' ;
+A: ;
+B: ;
+]])
+AT_DATA([[sr.y]],
+[[%glr-parser
+%%
+start: 'a' | A 'a' ;
+A: ;
+]])
+AT_DATA([[rr.y]],
+[[%glr-parser
+%%
+start: A | B ;
+A: ;
+B: ;
+]])
+
+AT_BISON_CHECK([[sr-rr.y]], [[0]], [[]],
+[[sr-rr.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
+sr-rr.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
+]])
+AT_BISON_CHECK([[-Wno-conflicts-sr sr-rr.y]], [[0]], [[]],
+[[sr-rr.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
+]])
+AT_BISON_CHECK([[-Wno-conflicts-rr sr-rr.y]], [[0]], [[]],
+[[sr-rr.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
+]])
+
+[
+# This is piece of code is rather complex for a simple task: try every
+# combinaison of (0 or 1 real SR) x (0 or 1 real RR) x (don't %expect
+# or %expect 0, 1, or 2 SR) x (don't %expect-rr or %expect-rr 0, 1, or 2
+# RR).
+
+# Number and types of genuine conflicts in the grammar.
+for gram in sr-rr sr rr; do
+ # Number of expected s/r conflicts.
+ for sr_exp_i in '' 0 1 2; do
+ # Number of expected r/r conflicts.
+ for rr_exp_i in '' 0 1 2; do
+ test -z "$sr_exp_i" && test -z "$rr_exp_i" && continue
+
+ # Build grammar file.
+ sr_exp=0
+ rr_exp=0
+ file=$gram
+ directives=
+ if test -n "$sr_exp_i"; then
+ sr_exp=$sr_exp_i
+ file=$file-expect-$sr_exp
+ directives="%expect $sr_exp"
+ fi
+ if test -n "$rr_exp_i"; then
+ rr_exp=$rr_exp_i
+ file=$file-expect-rr-$rr_exp
+ directives="$directives %expect-rr $rr_exp"
+ fi
+ file=$file.y
+ echo "$directives" > $file
+ cat $gram.y >> $file
+
+ # Number of found conflicts.
+ case $gram in
+ (sr) sr_count=1; rr_count=0;;
+ (rr) sr_count=0; rr_count=1;;
+ (sr-rr) sr_count=1; rr_count=1;;
+ esac
+
+ # Update number of expected conflicts: if %expect is given then
+ # %expect-rr defaults to 0, and vice-versa. Leave empty if
+ # nothing expected.
+ case $sr_exp_i:$rr_exp_i in
+ ?:) rr_exp_i=0;;
+ :?) sr_exp_i=0;;
+ esac
+
+ # Run tests.
+ if test $sr_count -eq $sr_exp && test $rr_count -eq $rr_exp; then
+ ]AT_BISON_CHECK([[-Wnone $file]])[
+ ]AT_BISON_CHECK([[-Werror $file]])[
+ else
+ {
+ if test -z "$sr_exp_i" && test "$sr_count" -ne 0; then
+ echo "warning: $sr_count shift/reduce conflicts"
+ elif test "$sr_exp_i" -ne "$sr_count"; then
+ echo "error: shift/reduce conflicts: $sr_count found, $sr_exp_i expected"
+ fi
+ if test -z "$rr_exp_i" && test "$rr_count" -ne 0; then
+ echo "warning: $rr_count reduce/reduce conflicts"
+ elif test "$rr_exp_i" -ne "$rr_count"; then
+ echo "error: reduce/reduce conflicts: $rr_count found, $rr_exp_i expected"
+ fi
+ } | sed -e "s/^/$file: /" > experr
+ ]AT_BISON_CHECK([[-Wnone $file]], [[1]], [[]], [[experr]])[
+ ]AT_BISON_CHECK([[-Werror $file]], [[1]], [[]], [[experr]])[
+ fi
+ done
+ done
+done]
+