From: Akim Demaille <akim@epita.fr>
Date: Sun, 26 May 2002 20:25:52 +0000 (+0000)
Subject: * src/state.h (state_t): `solved_conflicts' is a new member.
X-Git-Tag: BISON-1_49b~214
X-Git-Url: https://git.saurik.com/bison.git/commitdiff_plain/b408954b40e74d85ee90544ea7e296dbc99356c9
* src/state.h (state_t): `solved_conflicts' is a new member.
* src/LR0.c (new_state): Set it to 0.
* src/conflicts.h, src/conflicts.c (print_conflicts)
(free_conflicts, solve_conflicts): Rename as...
(conflicts_print, conflicts_free, conflicts_solve): these.
Adjust callers.
* src/conflicts.c (enum conflict_resolution_e)
(solved_conflicts_obstack): New, used by...
(log_resolution): this.
Adjust to attach the conflict resolution to each state.
Complete the description with the precedence/associativity
information.
(resolve_sr_conflict): Adjust.
* src/print.c (print_state): Output its solved_conflicts.
* tests/conflicts.at (Unresolved SR Conflicts)
(Solved SR Conflicts): Exercise --report=all.
---
diff --git a/ChangeLog b/ChangeLog
index 4a450cbc..980b2193 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,22 @@
+2002-05-26 Akim Demaille <akim@epita.fr>
+
+ * src/state.h (state_t): `solved_conflicts' is a new member.
+ * src/LR0.c (new_state): Set it to 0.
+ * src/conflicts.h, src/conflicts.c (print_conflicts)
+ (free_conflicts, solve_conflicts): Rename as...
+ (conflicts_print, conflicts_free, conflicts_solve): these.
+ Adjust callers.
+ * src/conflicts.c (enum conflict_resolution_e)
+ (solved_conflicts_obstack): New, used by...
+ (log_resolution): this.
+ Adjust to attach the conflict resolution to each state.
+ Complete the description with the precedence/associativity
+ information.
+ (resolve_sr_conflict): Adjust.
+ * src/print.c (print_state): Output its solved_conflicts.
+ * tests/conflicts.at (Unresolved SR Conflicts)
+ (Solved SR Conflicts): Exercise --report=all.
+
2002-05-26 Akim Demaille <akim@epita.fr>
* src/LR0.c, src/derives.c, src/gram.c, src/gram.h, src/lalr.c,
diff --git a/NEWS b/NEWS
index 0d083b56..e4acf388 100644
--- a/NEWS
+++ b/NEWS
@@ -73,7 +73,7 @@ Changes in version 1.49b:
* Semantic parser
This old option, which has been broken for ages, is removed.
-* New translations
+* New translation
Croatian, thanks to Denis Lackovic.
* Incorrect token definitions
@@ -87,9 +87,14 @@ Changes in version 1.49b:
* Reports
In addition to --verbose, bison supports --report=THINGS, which
produces additional information:
-
- `itemset' complete the core item sets with their closure
- `lookahead' explicitly associate lookaheads to items
+ - itemset
+ complete the core item sets with their closure
+ - lookahead
+ explicitly associate lookaheads to items
+ - solved
+ describe shift/reduce conflicts solving.
+ Bison used to systematically output this information on top of
+ the report. Solved conflicts are now attached to their states.
Changes in version 1.35, 2002-03-25:
diff --git a/TODO b/TODO
index 89c5a070..607366b3 100644
--- a/TODO
+++ b/TODO
@@ -40,22 +40,6 @@ When implementing multiple-%union support, bare the following in mind:
Provide better assistance for understanding the conflicts by providing
a sample text exhibiting the (LALR) ambiguity.
-* report
-Solved conflicts should not be reported in the beginning of the file.
-Rather they should be reported within each state description. Also,
-now that the symbol providing the precedence of a rule is kept, it is
-possible to explain why a conflict was solved this way. E.g., instead
-of
-
- Conflict in state 8 between rule 2 and token '+' resolved as reduce.
-
-we can (in state 8) report something like
-
- Conflict between rule 2 and token '+' resolved as reduce
- because '*' < '+'.
-
-or something like that.
-
* Coding system independence
Paul notes:
diff --git a/src/LR0.c b/src/LR0.c
index 269a8b87..efe9589a 100644
--- a/src/LR0.c
+++ b/src/LR0.c
@@ -200,8 +200,9 @@ new_state (symbol_number_t symbol, size_t core_size, item_number_t *core)
p = STATE_ALLOC (core_size);
p->accessing_symbol = symbol;
p->number = nstates;
- p->nitems = core_size;
+ p->solved_conflicts = NULL;
+ p->nitems = core_size;
memcpy (p->items, core, core_size * sizeof (core[0]));
/* If this is the eoftoken, and this is not the initial state, then
diff --git a/src/conflicts.c b/src/conflicts.c
index df3c931d..0ba2e5ac 100644
--- a/src/conflicts.c
+++ b/src/conflicts.c
@@ -35,22 +35,93 @@
/* -1 stands for not specified. */
int expected_conflicts = -1;
static char *conflicts = NULL;
+struct obstack solved_conflicts_obstack;
static bitset shiftset;
static bitset lookaheadset;
+
+enum conflict_resolution_e
+ {
+ shift_resolution,
+ reduce_resolution,
+ left_resolution,
+ right_resolution,
+ nonassoc_resolution,
+ };
+
+
static inline void
-log_resolution (state_t *state, int LAno, int token, const char *resolution)
+log_resolution (int lookahead, int token,
+ enum conflict_resolution_e resolution)
{
- if (report_flag & report_states)
- obstack_fgrow4 (&output_obstack,
- _("\
-Conflict in state %d between rule %d and token %s resolved as %s.\n"),
- state->number,
- LArule[LAno]->number,
- symbols[token]->tag,
- resolution);
+ if (report_flag & report_solved_conflicts)
+ {
+ /* The description of the resolution. */
+ switch (resolution)
+ {
+ case shift_resolution:
+ case left_resolution:
+ obstack_fgrow2 (&solved_conflicts_obstack,
+ _("\
+ Conflict between rule %d and token %s resolved as shift"),
+ LArule[lookahead]->number,
+ symbols[token]->tag);
+ break;
+ case reduce_resolution:
+ case right_resolution:
+ obstack_fgrow2 (&solved_conflicts_obstack,
+ _("\
+ Conflict between rule %d and token %s resolved as reduce"),
+ LArule[lookahead]->number,
+ symbols[token]->tag);
+ break;
+ case nonassoc_resolution:
+ obstack_fgrow2 (&solved_conflicts_obstack,
+ _("\
+ Conflict between rule %d and token %s resolved as an error"),
+ LArule[lookahead]->number,
+ symbols[token]->tag);
+ break;
+ }
+
+ /* The reason. */
+ switch (resolution)
+ {
+ case shift_resolution:
+ obstack_fgrow2 (&solved_conflicts_obstack,
+ " (%s < %s)",
+ LArule[lookahead]->prec->tag,
+ symbols[token]->tag);
+ break;
+
+ case reduce_resolution:
+ obstack_fgrow2 (&solved_conflicts_obstack,
+ " (%s < %s)",
+ symbols[token]->tag,
+ LArule[lookahead]->prec->tag);
+ break;
+
+ case left_resolution:
+ obstack_printf (&solved_conflicts_obstack,
+ " (%%left %s)",
+ symbols[token]->tag);
+ break;
+
+ case right_resolution:
+ obstack_fgrow1 (&solved_conflicts_obstack,
+ " (%%right %s)",
+ symbols[token]->tag);
+ break;
+ case nonassoc_resolution:
+ obstack_fgrow1 (&solved_conflicts_obstack,
+ " (%%nonassoc %s)",
+ symbols[token]->tag);
+ break;
+ }
+ obstack_sgrow (&solved_conflicts_obstack, ".\n");
+ }
}
@@ -112,12 +183,12 @@ resolve_sr_conflict (state_t *state, int lookahead)
The precedence of shifting is that of token i. */
if (symbols[i]->prec < redprec)
{
- log_resolution (state, lookahead, i, _("reduce"));
+ log_resolution (lookahead, i, reduce_resolution);
flush_shift (state, i);
}
else if (symbols[i]->prec > redprec)
{
- log_resolution (state, lookahead, i, _("shift"));
+ log_resolution (lookahead, i, shift_resolution);
flush_reduce (lookahead, i);
}
else
@@ -129,17 +200,17 @@ resolve_sr_conflict (state_t *state, int lookahead)
switch (symbols[i]->assoc)
{
case right_assoc:
- log_resolution (state, lookahead, i, _("shift"));
+ log_resolution (lookahead, i, right_resolution);
flush_reduce (lookahead, i);
break;
case left_assoc:
- log_resolution (state, lookahead, i, _("reduce"));
+ log_resolution (lookahead, i, left_resolution);
flush_shift (state, i);
break;
case non_assoc:
- log_resolution (state, lookahead, i, _("an error"));
+ log_resolution (lookahead, i, nonassoc_resolution);
flush_shift (state, i);
flush_reduce (lookahead, i);
/* Record an explicit error for this token. */
@@ -152,6 +223,12 @@ resolve_sr_conflict (state_t *state, int lookahead)
permanent errs structure for this state, to record them. */
state->errs = errs_dup (errp);
free (errp);
+
+ if (obstack_object_size (&solved_conflicts_obstack))
+ {
+ obstack_1grow (&solved_conflicts_obstack, '\0');
+ state->solved_conflicts = obstack_finish (&solved_conflicts_obstack);
+ }
}
@@ -195,13 +272,14 @@ set_conflicts (state_t *state)
}
void
-solve_conflicts (void)
+conflicts_solve (void)
{
size_t i;
conflicts = XCALLOC (char, nstates);
shiftset = bitset_create (ntokens, BITSET_FIXED);
lookaheadset = bitset_create (ntokens, BITSET_FIXED);
+ obstack_init (&solved_conflicts_obstack);
for (i = 0; i < nstates; i++)
set_conflicts (states[i]);
@@ -393,9 +471,10 @@ conflicts_print (void)
void
-free_conflicts (void)
+conflicts_free (void)
{
XFREE (conflicts);
bitset_free (shiftset);
bitset_free (lookaheadset);
+ obstack_free (&solved_conflicts_obstack, NULL);
}
diff --git a/src/conflicts.h b/src/conflicts.h
index 10f4d7ee..bd21253e 100644
--- a/src/conflicts.h
+++ b/src/conflicts.h
@@ -1,5 +1,5 @@
/* Find and resolve or report look-ahead conflicts for bison,
- Copyright 2000, 2001 Free Software Foundation, Inc.
+ Copyright (C) 2000, 2001, 2002 Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
@@ -22,10 +22,10 @@
# define CONFLICTS_H_
# include "state.h"
-void solve_conflicts PARAMS ((void));
+void conflicts_solve PARAMS ((void));
void conflicts_print PARAMS ((void));
void conflicts_output PARAMS ((FILE *out));
-void free_conflicts PARAMS ((void));
+void conflicts_free PARAMS ((void));
/* Were there conflicts? */
extern int expected_conflicts;
diff --git a/src/getargs.c b/src/getargs.c
index 25d042ce..b4f160f0 100644
--- a/src/getargs.c
+++ b/src/getargs.c
@@ -55,6 +55,7 @@ static const char * const report_args[] =
"state", "states",
"itemset", "itemsets",
"lookahead", "lookaheads",
+ "solved",
"all",
0
};
@@ -65,6 +66,7 @@ static const int report_types[] =
report_states, report_states,
report_states | report_itemsets, report_states | report_itemsets,
report_states | report_lookaheads, report_states | report_lookaheads,
+ report_states | report_solved_conflicts,
report_all
};
@@ -140,6 +142,7 @@ THINGS is a list of comma separated words that can include:\n\
`state' describe the states\n\
`itemset' complete the core item sets with their closure\n\
`lookahead' explicitly associate lookaheads to items\n\
+ `solved' describe shift/reduce conflicts solving\n\
`all' include all the above information\n\
`none' disable the report\n\
"), stream);
diff --git a/src/getargs.h b/src/getargs.h
index 76feac2d..8b0de9a4 100644
--- a/src/getargs.h
+++ b/src/getargs.h
@@ -43,6 +43,7 @@ enum
report_states = 1 << 0,
report_itemsets = 1 << 1,
report_lookaheads = 1 << 2,
+ report_solved_conflicts = 1 << 3,
report_all = ~0
};
diff --git a/src/main.c b/src/main.c
index d9461cc4..c0faa97a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -84,7 +84,7 @@ main (int argc, char *argv[])
lookahead is not enough to disambiguate the parsing. In file
conflicts. Also resolve s/r conflicts based on precedence
declarations. */
- solve_conflicts ();
+ conflicts_solve ();
conflicts_print ();
/* Output file names. */
@@ -107,7 +107,7 @@ main (int argc, char *argv[])
output ();
reduce_free ();
- free_conflicts ();
+ conflicts_free ();
free_nullable ();
free_derives ();
grammar_free ();
diff --git a/src/print.c b/src/print.c
index b99c233d..d8a4f008 100644
--- a/src/print.c
+++ b/src/print.c
@@ -364,6 +364,9 @@ print_state (FILE *out, state_t *state)
fputs ("\n\n", out);
print_core (out, state);
print_actions (out, state);
+ if ((report_flag & report_solved_conflicts)
+ && state->solved_conflicts)
+ fputs (state->solved_conflicts, out);
fputs ("\n\n", out);
}
diff --git a/src/state.h b/src/state.h
index c2282474..95b716d8 100644
--- a/src/state.h
+++ b/src/state.h
@@ -184,7 +184,12 @@ typedef struct state_s
short lookaheadsp;
int nlookaheads;
- /* Its items. */
+ /* If some conflicts were solved thanks to precedence/associativity,
+ a human readable description of the resolution. */
+ const char *solved_conflicts;
+
+ /* Its items. Must be last, since ITEMS can be arbitrarily large.
+ */
unsigned short nitems;
item_number_t items[1];
} state_t;
diff --git a/tests/conflicts.at b/tests/conflicts.at
index e436311f..6d546783 100644
--- a/tests/conflicts.at
+++ b/tests/conflicts.at
@@ -136,7 +136,7 @@ AT_DATA([input.y],
exp: exp OP exp | NUM;
]])
-AT_CHECK([bison input.y -o input.c -v], 0, [],
+AT_CHECK([bison input.y -o input.c --report=all], 0, [],
[input.y contains 1 shift/reduce conflict.
])
@@ -172,6 +172,8 @@ exp (6)
state 0
$axiom -> . exp $ (rule 0)
+ exp -> . exp OP exp (rule 1)
+ exp -> . NUM (rule 2)
NUM shift, and go to state 1
@@ -206,7 +208,9 @@ state 3
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
@@ -216,8 +220,8 @@ state 4
state 5
- exp -> exp . OP exp (rule 1)
- exp -> exp OP exp . (rule 1)
+ exp -> exp . OP exp [$, OP] (rule 1)
+ exp -> exp OP exp . [$, OP] (rule 1)
OP shift, and go to state 4
@@ -244,14 +248,11 @@ AT_DATA([input.y],
exp: exp OP exp | NUM;
]])
-AT_CHECK([bison input.y -o input.c -v], 0, [], [])
+AT_CHECK([bison input.y -o input.c --report=all], 0, [], [])
# Check the contents of the report.
AT_CHECK([cat input.output], [],
-[[Conflict in state 5 between rule 2 and token OP resolved as shift.
-
-
-Grammar
+[[Grammar
Number, Line, Rule
0 4 $axiom -> exp $
@@ -278,6 +279,8 @@ exp (6)
state 0
$axiom -> . exp $ (rule 0)
+ exp -> . exp OP exp (rule 1)
+ exp -> . NUM (rule 2)
NUM shift, and go to state 1
@@ -312,7 +315,9 @@ state 3
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
@@ -322,13 +327,14 @@ state 4
state 5
- exp -> exp . OP exp (rule 1)
- exp -> exp OP exp . (rule 1)
+ exp -> exp . OP exp [$] (rule 1)
+ exp -> exp OP exp . [$] (rule 1)
OP shift, and go to state 4
$default reduce using rule 1 (exp)
+ Conflict between rule 2 and token OP resolved as reduce (%right OP).
]])