e: 'e' | /* Nothing. */;
]])
-AT_CHECK([bison input.y -o input.c])
+AT_CHECK([bison input.y -o input.c], 0, [],
+[[input.y:4.8: warning: rule never reduced because of conflicts: e: /* empty */
+]])
AT_CLEANUP
+
## ------------------- ##
## %nonassoc and eof. ##
## ------------------- ##
# Specify the output files to avoid problems on different file systems.
AT_CHECK([bison input.y -o input.c])
-AT_CHECK([$CC $CFLAGS $CPPFLAGS input.c -o input], 0, [], [ignore])
+AT_COMPILE([input])
-AT_CHECK([./input '0<0'])
+AT_PARSER_CHECK([./input '0<0'])
# FIXME: This is an actual bug, but a new one, in the sense that
# no one has ever spotted it! The messages are *wrong*: there should
# be nothing there, it should be expected eof.
-AT_CHECK([./input '0<0<0'], [1], [],
+AT_PARSER_CHECK([./input '0<0<0'], [1], [],
[parse error, unexpected '<', expecting '<' or '>'
])
-AT_CHECK([./input '0>0'])
-AT_CHECK([./input '0>0>0'], [1], [],
+AT_PARSER_CHECK([./input '0>0'])
+AT_PARSER_CHECK([./input '0>0>0'], [1], [],
[parse error, unexpected '>', expecting '<' or '>'
])
-AT_CHECK([./input '0<0>0'], [1], [],
+AT_PARSER_CHECK([./input '0<0>0'], [1], [],
[parse error, unexpected '>', expecting '<' or '>'
])
]])
AT_CHECK([bison input.y -o input.c --report=all], 0, [],
-[input.y contains 1 shift/reduce conflict.
+[input.y: warning: 1 shift/reduce conflict
])
# Check the contents of the report.
Grammar
- 0 $axiom: exp $
+ 0 $accept: exp $end
1 exp: exp OP exp
2 | NUM
Terminals, with rules where they appear
-$ (0) 0
+$end (0) 0
error (256)
NUM (258) 2
OP (259) 1
Nonterminals, with rules where they appear
-$axiom (5)
+$accept (5)
on left: 0
exp (6)
on left: 1 2, on right: 0 1
state 0
- $axiom -> . exp $ (rule 0)
- exp -> . exp OP exp (rule 1)
- exp -> . NUM (rule 2)
+ 0 $accept: . exp $end
+ 1 exp: . exp OP exp
+ 2 | . NUM
- NUM shift, and go to state 1
-
- exp go to state 2
+ NUM shift, and go to state 1
+ exp go to state 2
state 1
- exp -> NUM . (rule 2)
-
- $default reduce using rule 2 (exp)
+ 2 exp: NUM .
+ $default reduce using rule 2 (exp)
state 2
- $axiom -> exp . $ (rule 0)
- exp -> exp . OP exp (rule 1)
-
- $ shift, and go to state 3
- OP shift, and go to state 4
+ 0 $accept: exp . $end
+ 1 exp: exp . OP exp
+ $end shift, and go to state 3
+ OP shift, and go to state 4
state 3
- $axiom -> exp $ . (rule 0)
+ 0 $accept: exp $end .
- $default accept
+ $default accept
state 4
- exp -> . exp OP exp (rule 1)
- exp -> exp OP . exp (rule 1)
- exp -> . NUM (rule 2)
-
- NUM shift, and go to state 1
+ 1 exp: . exp OP exp
+ 1 | exp OP . exp
+ 2 | . NUM
- exp go to state 5
+ NUM shift, and go to state 1
+ exp go to state 5
state 5
- exp -> exp . OP exp [$, OP] (rule 1)
- exp -> exp OP exp . [$, OP] (rule 1)
-
- OP shift, and go to state 4
-
- OP [reduce using rule 1 (exp)]
- $default reduce using rule 1 (exp)
-
+ 1 exp: exp . OP exp [$end, OP]
+ 1 | exp OP exp . [$end, OP]
+ OP shift, and go to state 4
+ OP [reduce using rule 1 (exp)]
+ $default reduce using rule 1 (exp)
]])
AT_CLEANUP
-## --------------------- ##
-## Solved SR Conflicts. ##
-## --------------------- ##
-AT_SETUP([Solved SR Conflicts])
+## ----------------------- ##
+## Resolved SR Conflicts. ##
+## ----------------------- ##
+
+AT_SETUP([Resolved SR Conflicts])
AT_KEYWORDS([report])
AT_DATA([input.y],
[[%token NUM OP
-%right OP
+%left OP
%%
exp: exp OP exp | NUM;
]])
-AT_CHECK([bison input.y -o input.c --report=all], 0, [], [])
+AT_CHECK([bison input.y -o input.c --report=all])
# Check the contents of the report.
AT_CHECK([cat input.output], [],
[[Grammar
- 0 $axiom: exp $
+ 0 $accept: exp $end
1 exp: exp OP exp
2 | NUM
Terminals, with rules where they appear
-$ (0) 0
+$end (0) 0
error (256)
NUM (258) 2
OP (259) 1
Nonterminals, with rules where they appear
-$axiom (5)
+$accept (5)
on left: 0
exp (6)
on left: 1 2, on right: 0 1
state 0
- $axiom -> . exp $ (rule 0)
- exp -> . exp OP exp (rule 1)
- exp -> . NUM (rule 2)
-
- NUM shift, and go to state 1
+ 0 $accept: . exp $end
+ 1 exp: . exp OP exp
+ 2 | . NUM
- exp go to state 2
+ NUM shift, and go to state 1
+ exp go to state 2
state 1
- exp -> NUM . (rule 2)
-
- $default reduce using rule 2 (exp)
+ 2 exp: NUM .
+ $default reduce using rule 2 (exp)
state 2
- $axiom -> exp . $ (rule 0)
- exp -> exp . OP exp (rule 1)
-
- $ shift, and go to state 3
- OP shift, and go to state 4
+ 0 $accept: exp . $end
+ 1 exp: exp . OP exp
+ $end shift, and go to state 3
+ OP shift, and go to state 4
state 3
- $axiom -> exp $ . (rule 0)
+ 0 $accept: exp $end .
- $default accept
+ $default accept
state 4
- exp -> . exp OP exp (rule 1)
- exp -> exp OP . exp (rule 1)
- exp -> . NUM (rule 2)
-
- NUM shift, and go to state 1
+ 1 exp: . exp OP exp
+ 1 | exp OP . exp
+ 2 | . NUM
- exp go to state 5
+ NUM shift, and go to state 1
+ exp go to state 5
state 5
- exp -> exp . OP exp [$] (rule 1)
- exp -> exp OP exp . [$] (rule 1)
+ 1 exp: exp . OP exp [$end, OP]
+ 1 | exp OP exp . [$end, OP]
- OP shift, and go to state 4
+ $default reduce using rule 1 (exp)
+ Conflict between rule 1 and token OP resolved as reduce (%left OP).
+]])
- $default reduce using rule 1 (exp)
+AT_CLEANUP
- Conflict between rule 2 and token OP resolved as reduce (%right OP).
+## -------------------------------- ##
+## Defaulted Conflicted Reduction. ##
+## -------------------------------- ##
+
+# When there are RR conflicts, some rules are disabled. Usually it is
+# simply displayed as:
+#
+# $end reduce using rule 3 (num)
+# $end [reduce using rule 4 (id)]
+#
+# But when `reduce 3' is the default action, we'd produce:
+#
+# $end [reduce using rule 4 (id)]
+# $default reduce using rule 3 (num)
+#
+# In this precise case (a reduction is masked by the default
+# reduction), we make the `reduce 3' explicit:
+#
+# $end reduce using rule 3 (num)
+# $end [reduce using rule 4 (id)]
+# $default reduce using rule 3 (num)
+#
+# Maybe that's not the best display, but then, please propose something
+# else.
+
+AT_SETUP([Defaulted Conflicted Reduction])
+AT_KEYWORDS([report])
+
+AT_DATA([input.y],
+[[%%
+exp: num | id;
+num: '0';
+id : '0';
+%%
+]])
+AT_CHECK([bison input.y -o input.c --report=all], 0, [],
+[[input.y: warning: 1 reduce/reduce conflict
+input.y:4.4-8: warning: rule never reduced because of conflicts: id: '0'
+]])
+
+# Check the contents of the report.
+AT_CHECK([cat input.output], [],
+[[Rules never reduced
+
+ 4 id: '0'
+
+
+State 1 contains 1 reduce/reduce conflict.
+
+
+Grammar
+
+ 0 $accept: exp $end
+
+ 1 exp: num
+ 2 | id
+
+ 3 num: '0'
+
+ 4 id: '0'
+
+
+Terminals, with rules where they appear
+
+$end (0) 0
+'0' (48) 3 4
+error (256)
+
+
+Nonterminals, with rules where they appear
+
+$accept (4)
+ on left: 0
+exp (5)
+ on left: 1 2, on right: 0
+num (6)
+ on left: 3, on right: 1
+id (7)
+ on left: 4, on right: 2
+
+
+state 0
+
+ 0 $accept: . exp $end
+ 1 exp: . num
+ 2 | . id
+ 3 num: . '0'
+ 4 id: . '0'
+
+ '0' shift, and go to state 1
+
+ exp go to state 2
+ num go to state 3
+ id go to state 4
+
+
+state 1
+
+ 3 num: '0' . [$end]
+ 4 id: '0' . [$end]
+
+ $end reduce using rule 3 (num)
+ $end [reduce using rule 4 (id)]
+ $default reduce using rule 3 (num)
+
+
+state 2
+
+ 0 $accept: exp . $end
+
+ $end shift, and go to state 5
+
+
+state 3
+
+ 1 exp: num .
+
+ $default reduce using rule 1 (exp)
+
+
+state 4
+
+ 2 exp: id .
+
+ $default reduce using rule 2 (exp)
+
+
+state 5
+
+ 0 $accept: exp $end .
+
+ $default accept
]])
AT_CLEANUP
]])
AT_CHECK([bison input.y -o input.c], 1, [],
-[input.y contains 1 shift/reduce conflict.
-expected 0 shift/reduce conflicts
+[input.y: warning: 1 shift/reduce conflict
+input.y: expected 0 shift/reduce conflicts
])
AT_CLEANUP
exp: exp OP exp | NUM;
]])
-AT_CHECK([bison input.y -o input.c], 0)
+AT_CHECK([bison input.y -o input.c])
AT_CLEANUP
]])
AT_CHECK([bison input.y -o input.c], 1, [],
-[input.y contains 1 shift/reduce conflict.
-expected 2 shift/reduce conflicts
+[input.y: warning: 1 shift/reduce conflict
+input.y: expected 2 shift/reduce conflicts
])
AT_CLEANUP
projects / bison.git / blobdiff