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One structure for states is enough, even though theoretically

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there are LR(0) states and LALR(1) states.
* src/lalr.h (state_t): Remove.
(state_table): Be state_t **, not state_t *.
* src/state.h (core, CORE_ALLOC): Rename as...
(state_t, STATE_ALLOC): this.
Add the LALR(1) members: shifts, reductions, errs.
* src/LR0.c (state_table): Rename as...
(state_hash): this, to avoid name clashes with the global
`state_table'.
* src/print_graph.c, src/LR0.c, src/LR0.h, src/conflicts.c
* src/lalr.c, src/lalr.h, src/output.c, src/print.c: Adjust.
This commit is contained in:
Akim Demaille
2001-12-10 08:45:22 +00:00
parent 74ffbcb6bf
commit f693ad146e
10 changed files with 149 additions and 141 deletions
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68
src/lalr.c
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@@ -36,7 +36,7 @@
/* All the decorated states, indexed by the state number. Warning:
there is a state_TABLE in LR0.c, but it is different and static.
*/
state_t *state_table = NULL;
state_t **state_table = NULL;
int tokensetsize;
short *LAruleno;
@@ -142,36 +142,33 @@ set_state_table (void)
/* NSTATES + 1 because lookahead for the pseudo state number NSTATES
might be used (see conflicts.c). It is too opaque for me to
provide a probably less hacky implementation. --akim */
state_table = XCALLOC (state_t, nstates + 1);
state_table = XCALLOC (state_t *, nstates + 1);
{
core *sp;
state_t *sp;
for (sp = first_state; sp; sp = sp->next)
{
state_table[sp->number].state = sp;
state_table[sp->number].accessing_symbol = sp->accessing_symbol;
}
state_table[sp->number] = sp;
}
{
shifts *sp;
for (sp = first_shift; sp; sp = sp->next)
state_table[sp->number].shifts = sp;
state_table[sp->number]->shifts = sp;
}
{
reductions *rp;
for (rp = first_reduction; rp; rp = rp->next)
state_table[rp->number].reductions = rp;
state_table[rp->number]->reductions = rp;
}
/* Pessimization, but simplification of the code: make sense all the
/* Pessimization, but simplification of the code: make sure all the
states have a shifts, even if reduced to 0 shifts. */
{
int i;
for (i = 0; i < nstates; i++)
if (!state_table[i].shifts)
state_table[i].shifts = shifts_new (0);
if (!state_table[i]->shifts)
state_table[i]->shifts = shifts_new (0);
}
/* Initializing the lookaheads members. Please note that it must be
@@ -183,25 +180,28 @@ set_state_table (void)
for (i = 0; i < nstates; i++)
{
int k;
reductions *rp = state_table[i].reductions;
shifts *sp = state_table[i].shifts;
reductions *rp = state_table[i]->reductions;
shifts *sp = state_table[i]->shifts;
state_table[i].lookaheads = count;
state_table[i]->lookaheads = count;
if (rp
&& (rp->nreds > 1 || (sp->nshifts && SHIFT_IS_SHIFT (sp, 0))))
count += rp->nreds;
else
state_table[i].consistent = 1;
state_table[i]->consistent = 1;
for (k = 0; k < sp->nshifts; k++)
if (SHIFT_IS_ERROR (sp, k))
{
state_table[i].consistent = 0;
state_table[i]->consistent = 0;
break;
}
}
state_table[nstates].lookaheads = count;
/* Seems to be needed by conflicts.c. */
state_table[nstates] = STATE_ALLOC (0);
state_table[nstates]->lookaheads = count;
}
}
@@ -214,7 +214,7 @@ initialize_LA (void)
short *np;
reductions *rp;
size_t nLA = state_table[nstates].lookaheads;
size_t nLA = state_table[nstates]->lookaheads;
if (!nLA)
nLA = 1;
@@ -224,8 +224,8 @@ initialize_LA (void)
np = LAruleno;
for (i = 0; i < nstates; i++)
if (!state_table[i].consistent)
if ((rp = state_table[i].reductions))
if (!state_table[i]->consistent)
if ((rp = state_table[i]->reductions))
for (j = 0; j < rp->nreds; j++)
*np++ = rp->rules[j];
}
@@ -249,7 +249,7 @@ set_goto_map (void)
for (sp = first_shift; sp; sp = sp->next)
for (i = sp->nshifts - 1; i >= 0 && SHIFT_IS_GOTO (sp, i); --i)
{
symbol = state_table[sp->shifts[i]].accessing_symbol;
symbol = state_table[sp->shifts[i]]->accessing_symbol;
if (ngotos == MAXSHORT)
fatal (_("too many gotos (max %d)"), MAXSHORT);
@@ -280,7 +280,7 @@ set_goto_map (void)
for (i = sp->nshifts - 1; i >= 0 && SHIFT_IS_GOTO (sp, i); --i)
{
state2 = sp->shifts[i];
symbol = state_table[state2].accessing_symbol;
symbol = state_table[state2]->accessing_symbol;
k = temp_map[symbol]++;
from_state[k] = state1;
@@ -340,18 +340,18 @@ initialize_F (void)
for (i = 0; i < ngotos; i++)
{
int stateno = to_state[i];
shifts *sp = state_table[stateno].shifts;
shifts *sp = state_table[stateno]->shifts;
int j;
for (j = 0; j < sp->nshifts && SHIFT_IS_SHIFT (sp, j); j++)
{
int symbol = state_table[sp->shifts[j]].accessing_symbol;
int symbol = state_table[sp->shifts[j]]->accessing_symbol;
SETBIT (F (i), symbol);
}
for (; j < sp->nshifts; j++)
{
int symbol = state_table[sp->shifts[j]].accessing_symbol;
int symbol = state_table[sp->shifts[j]]->accessing_symbol;
if (nullable[symbol])
edge[nedges++] = map_goto (stateno, symbol);
}
@@ -383,8 +383,8 @@ add_lookback_edge (int stateno, int ruleno, int gotono)
int found;
shorts *sp;
i = state_table[stateno].lookaheads;
k = state_table[stateno + 1].lookaheads;
i = state_table[stateno]->lookaheads;
k = state_table[stateno + 1]->lookaheads;
found = 0;
while (!found && i < k)
{
@@ -502,7 +502,7 @@ build_relations (void)
{
int nedges = 0;
int state1 = from_state[i];
int symbol1 = state_table[to_state[i]].accessing_symbol;
int symbol1 = state_table[to_state[i]]->accessing_symbol;
short *rulep;
for (rulep = derives[symbol1]; *rulep > 0; rulep++)
@@ -515,19 +515,19 @@ build_relations (void)
for (rp = ritem + rule_table[*rulep].rhs; *rp > 0; rp++)
{
shifts *sp = state_table[stateno].shifts;
shifts *sp = state_table[stateno]->shifts;
int j;
for (j = 0; j < sp->nshifts; j++)
{
stateno = sp->shifts[j];
if (state_table[stateno].accessing_symbol == *rp)
if (state_table[stateno]->accessing_symbol == *rp)
break;
}
states[length++] = stateno;
}
if (!state_table[stateno].consistent)
if (!state_table[stateno]->consistent)
add_lookback_edge (stateno, *rulep, i);
length--;
@@ -585,7 +585,7 @@ compute_lookaheads (void)
int i;
shorts *sp;
for (i = 0; i < state_table[nstates].lookaheads; i++)
for (i = 0; i < state_table[nstates]->lookaheads; i++)
for (sp = lookback[i]; sp; sp = sp->next)
{
int size = LA (i + 1) - LA (i);
@@ -595,7 +595,7 @@ compute_lookaheads (void)
}
/* Free LOOKBACK. */
for (i = 0; i < state_table[nstates].lookaheads; i++)
for (i = 0; i < state_table[nstates]->lookaheads; i++)
LIST_FREE (shorts, lookback[i]);
XFREE (lookback);