conflicts involving multiple reductions.
* src/conflicts.c (resolve_sr_conflict): Don't assign the error action
set for a state here or Bison will abort if it is reassigned on a
later conflicted reduction in the same state.
Similarly, don't finalize and assign the solved conflicts report here
or it will be lost if it is reassigned on a later conflicted reduction
in the same state.
(set_conflicts): Instead, assign them both here after all S/R conflicts
in the state have been fully examined.
* src/print.c (shift_set): Rename to...
(no_reduce_set): ... this.
(print_reductions): Update for rename, and add %nonassoc error action
tokens to no_reduce_set so that, when printing the first remaining
reduction on an error action token, the reduction is enclosed in
brackets.
(print_results): Update for rename.
* tests/conflicts.at (Solved conflicts report for multiple reductions
in a state): New test case.
(%nonassoc error actions for multiple reductions in a state): New test
case.
* src/main.c (main): Don't depend on C99 features.
+2007-07-17 Joel E. Denny <jdenny@ces.clemson.edu>
+
+ Improve handling of multiple S/R conflicts in the same state and of S/R
+ conflicts involving multiple reductions.
+ * src/conflicts.c (resolve_sr_conflict): Don't assign the error action
+ set for a state here or Bison will abort if it is reassigned on a
+ later conflicted reduction in the same state.
+ Similarly, don't finalize and assign the solved conflicts report here
+ or it will be lost if it is reassigned on a later conflicted reduction
+ in the same state.
+ (set_conflicts): Instead, assign them both here after all S/R conflicts
+ in the state have been fully examined.
+ * src/print.c (shift_set): Rename to...
+ (no_reduce_set): ... this.
+ (print_reductions): Update for rename, and add %nonassoc error action
+ tokens to no_reduce_set so that, when printing the first remaining
+ reduction on an error action token, the reduction is enclosed in
+ brackets.
+ (print_results): Update for rename.
+ * tests/conflicts.at (Solved conflicts report for multiple reductions
+ in a state): New test case.
+ (%nonassoc error actions for multiple reductions in a state): New test
+ case.
+
+ * src/main.c (main): Don't depend on C99 features.
+
2007-07-16 Joel E. Denny <jdenny@ces.clemson.edu>
* build-aux/.cvsignore: Add compile.
/*------------------------------------------------------------------.
| Turn off the shift recorded for the specified token in the |
| specified state. Used when we resolve a shift-reduce conflict in |
-| favor of the reduction. |
+| favor of the reduction or as an error (%nonassoc). |
`------------------------------------------------------------------*/
static void
/*--------------------------------------------------------------------.
-| Turn off the reduce recorded for the specified token for the |
-| specified lookahead. Used when we resolve a shift-reduce conflict |
-| in favor of the shift. |
+| Turn off the reduce recorded for the specified token in the |
+| specified lookahead set. Used when we resolve a shift-reduce |
+| conflict in favor of the shift or as an error (%nonassoc). |
`--------------------------------------------------------------------*/
static void
| |
| RULENO is the number of the lookahead bitset to consider. |
| |
-| ERRORS can be used to store discovered explicit errors. |
+| ERRORS and NERRS can be used to store discovered explicit |
+| errors. |
`------------------------------------------------------------------*/
static void
-resolve_sr_conflict (state *s, int ruleno, symbol **errors)
+resolve_sr_conflict (state *s, int ruleno, symbol **errors, int *nerrs)
{
symbol_number i;
reductions *reds = s->reductions;
rule *redrule = reds->rules[ruleno];
int redprec = redrule->prec->prec;
bitset lookahead_tokens = reds->lookahead_tokens[ruleno];
- int nerrs = 0;
for (i = 0; i < ntokens; i++)
if (bitset_test (lookahead_tokens, i)
flush_shift (s, i);
flush_reduce (lookahead_tokens, i);
/* Record an explicit error for this token. */
- errors[nerrs++] = symbols[i];
+ errors[(*nerrs)++] = symbols[i];
break;
}
}
-
- if (nerrs)
- {
- /* Some tokens have been explicitly made errors. Allocate a
- permanent errs structure for this state, to record them. */
- state_errs_set (s, nerrs, errors);
- }
-
- if (obstack_object_size (&solved_conflicts_obstack))
- {
- obstack_1grow (&solved_conflicts_obstack, '\0');
- s->solved_conflicts = obstack_finish (&solved_conflicts_obstack);
- }
}
int i;
transitions *trans = s->transitions;
reductions *reds = s->reductions;
+ int nerrs = 0;
if (s->consistent)
return;
for (i = 0; i < reds->num; ++i)
if (reds->rules[i]->prec && reds->rules[i]->prec->prec
&& !bitset_disjoint_p (reds->lookahead_tokens[i], lookahead_set))
- resolve_sr_conflict (s, i, errors);
+ resolve_sr_conflict (s, i, errors, &nerrs);
+
+ if (nerrs)
+ {
+ /* Some tokens have been explicitly made errors. Allocate a
+ permanent errs structure for this state, to record them. */
+ state_errs_set (s, nerrs, errors);
+ }
+ if (obstack_object_size (&solved_conflicts_obstack))
+ {
+ obstack_1grow (&solved_conflicts_obstack, '\0');
+ s->solved_conflicts = obstack_finish (&solved_conflicts_obstack);
+ }
/* Loop over all rules which require lookahead in this state. Check
for conflicts not resolved above. */
{
if (!bitset_disjoint_p (reds->lookahead_tokens[i], lookahead_set))
conflicts[s->number] = 1;
-
bitset_or (lookahead_set, lookahead_set, reds->lookahead_tokens[i]);
}
}
timevar_push (TV_CONFLICTS);
conflicts_solve ();
{
- state_number old_to_new[nstates];
+ state_number *old_to_new = xnmalloc (nstates, sizeof *old_to_new);
state_number nstates_old = nstates;
state_remove_unreachable_states (old_to_new);
lalr_update_state_numbers (old_to_new, nstates_old);
conflicts_update_state_numbers (old_to_new, nstates_old);
+ free (old_to_new);
}
conflicts_print ();
timevar_pop (TV_CONFLICTS);
#include "symtab.h"
#include "tables.h"
-static bitset shift_set;
+static bitset no_reduce_set;
#if 0
static void
if (yydefact[s->number] != 0)
default_rule = &rules[yydefact[s->number] - 1];
- bitset_zero (shift_set);
+ bitset_zero (no_reduce_set);
FOR_EACH_SHIFT (trans, i)
- bitset_set (shift_set, TRANSITION_SYMBOL (trans, i));
+ bitset_set (no_reduce_set, TRANSITION_SYMBOL (trans, i));
+ for (i = 0; i < s->errs->num; ++i)
+ if (s->errs->symbols[i])
+ bitset_set (no_reduce_set, s->errs->symbols[i]->number);
/* Compute the width of the lookahead token column. */
if (default_rule)
if (reds->lookahead_tokens)
for (i = 0; i < ntokens; i++)
{
- bool count = bitset_test (shift_set, i);
+ bool count = bitset_test (no_reduce_set, i);
for (j = 0; j < reds->num; ++j)
if (bitset_test (reds->lookahead_tokens[j], i))
for (i = 0; i < ntokens; i++)
{
bool defaulted = false;
- bool count = bitset_test (shift_set, i);
+ bool count = bitset_test (no_reduce_set, i);
for (j = 0; j < reds->num; ++j)
if (bitset_test (reds->lookahead_tokens[j], i))
if (report_flag & report_itemsets)
new_closure (nritems);
/* Storage for print_reductions. */
- shift_set = bitset_create (ntokens, BITSET_FIXED);
+ no_reduce_set = bitset_create (ntokens, BITSET_FIXED);
for (i = 0; i < nstates; i++)
print_state (out, states[i]);
- bitset_free (shift_set);
+ bitset_free (no_reduce_set);
if (report_flag & report_itemsets)
free_closure ();
int
main (int argc, const char *argv[])
{
- input = argc <= 1 ? "" : argv[1];
+ input = argc <= 1 ? "" : argv[1];
return yyparse ();
}
]])
state 7
1 start: resolved_conflict 'a' reported_conflicts 'a' .
-
+
$default reduce using rule 1 (start)
]])
AT_CLEANUP
+
+
+## ------------------------------------------------------------ ##
+## Solved conflicts report for multiple reductions in a state. ##
+## ------------------------------------------------------------ ##
+
+AT_SETUP([[Solved conflicts report for multiple reductions in a state]])
+
+# Used to lose earlier solved conflict messages even within a single S/R/R.
+
+AT_DATA([[input.y]],
+[[%left 'a'
+%right 'b'
+%right 'c'
+%right 'd'
+%%
+start:
+ 'a'
+ | empty_a 'a'
+ | 'b'
+ | empty_b 'b'
+ | 'c'
+ | empty_c1 'c'
+ | empty_c2 'c'
+ | empty_c3 'c'
+ ;
+empty_a: %prec 'a' ;
+empty_b: %prec 'b' ;
+empty_c1: %prec 'c' ;
+empty_c2: %prec 'c' ;
+empty_c3: %prec 'd' ;
+]])
+AT_CHECK([[bison --report=all -o input.c input.y]], 0, [], [ignore])
+AT_CHECK([[cat input.output | sed -n '/^state 0$/,/^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: . ['a']
+ 10 empty_b: . []
+ 11 empty_c1: . []
+ 12 empty_c2: . []
+ 13 empty_c3: . ['c']
+
+ 'b' shift, and go to state 1
+
+ 'c' reduce using rule 13 (empty_c3)
+ $default reduce using rule 9 (empty_a)
+
+ start go to state 2
+ empty_a go to state 3
+ empty_b go to state 4
+ empty_c1 go to state 5
+ empty_c2 go to state 6
+ empty_c3 go to state 7
+
+ Conflict between rule 9 and token 'a' resolved as reduce (%left 'a').
+ Conflict between rule 10 and token 'b' resolved as shift (%right 'b').
+ Conflict between rule 11 and token 'c' resolved as shift (%right 'c').
+ Conflict between rule 12 and token 'c' resolved as shift (%right 'c').
+ Conflict between rule 13 and token 'c' resolved as reduce ('c' < 'd').
+
+
+state 1
+]])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------ ##
+## %nonassoc error actions for multiple reductions in a state. ##
+## ------------------------------------------------------------ ##
+
+# Used to abort when trying to resolve conflicts as %nonassoc error actions for
+# multiple reductions in a state.
+
+# For a %nonassoc error action token, used to print the first remaining
+# reduction on that token without brackets.
+
+AT_SETUP([[%nonassoc error actions for multiple reductions in a state]])
+
+AT_DATA([[input.y]],
+[[%nonassoc 'a' 'b' 'c'
+%%
+start:
+ 'a'
+ | empty_a 'a'
+ | 'b'
+ | empty_b 'b'
+ | 'c'
+ | empty_c1 'c'
+ | empty_c2 'c'
+ | empty_c3 'c'
+ ;
+empty_a: %prec 'a' ;
+empty_b: %prec 'b' ;
+empty_c1: %prec 'c' ;
+empty_c2: %prec 'c' ;
+empty_c3: %prec 'c' ;
+]])
+
+AT_CHECK([[bison --report=all -o input.c input.y]], 0, [], [ignore])
+AT_CHECK([[cat input.output | sed -n '/^state 0$/,/^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: . []
+ 10 empty_b: . []
+ 11 empty_c1: . []
+ 12 empty_c2: . ['c']
+ 13 empty_c3: . ['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
projects / bison.git / commitdiff
