/* Compute look-ahead criteria for Bison.
- Copyright (C) 1984, 1986, 1989, 2000, 2001, 2002
+ Copyright (C) 1984, 1986, 1989, 2000, 2001, 2002, 2003, 2004
Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
/* Compute how to make the finite state machine deterministic; find
- which rules need lookahead in each state, and which lookahead
+ which rules need look-ahead in each state, and which look-ahead
tokens they accept. */
#include "system.h"
{
int ri = state_reduction_find (s, r);
goto_list *sp = MALLOC (sp, 1);
- sp->next = lookback[(s->reductions->lookaheads - LA) + ri];
+ sp->next = lookback[(s->reductions->look_ahead_tokens - LA) + ri];
sp->value = gotono;
- lookback[(s->reductions->lookaheads - LA) + ri] = sp;
+ lookback[(s->reductions->look_ahead_tokens - LA) + ri] = sp;
}
for (rulep = derives[symbol1 - ntokens]; *rulep; rulep++)
{
- int done;
+ bool done;
int length = 1;
item_number *rp;
state *s = states[from_state[i]];
add_lookback_edge (s, *rulep, i);
length--;
- done = 0;
+ done = false;
while (!done)
{
- done = 1;
+ done = true;
rp--;
/* JF added rp>=ritem && I hope to god its right! */
if (rp >= ritem && ISVAR (*rp))
edge[nedges++] = map_goto (states1[--length],
item_number_as_symbol_number (*rp));
if (nullable[*rp - ntokens])
- done = 0;
+ done = false;
}
}
}
static void
-compute_lookaheads (void)
+compute_look_ahead_tokens (void)
{
size_t i;
goto_list *sp;
}
-/*-----------------------------------------------------------.
-| Count the number of lookaheads required for S (NLOOKAHEADS |
-| member). |
-`-----------------------------------------------------------*/
+/*-----------------------------------------------------.
+| Count the number of look-ahead tokens required for S |
+| (N_LOOK_AHEAD_TOKENS member). |
+`-----------------------------------------------------*/
static int
-state_lookaheads_count (state *s)
+state_look_ahead_tokens_count (state *s)
{
int k;
- int nlookaheads = 0;
+ int n_look_ahead_tokens = 0;
reductions *rp = s->reductions;
transitions *sp = s->transitions;
- /* We need a lookahead either to distinguish different
+ /* We need a look-ahead either to distinguish different
reductions (i.e., there are two or more), or to distinguish a
reduction from a shift. Otherwise, it is straightforward,
and the state is `consistent'. */
if (rp->num > 1
|| (rp->num == 1 && sp->num &&
!TRANSITION_IS_DISABLED (sp, 0) && TRANSITION_IS_SHIFT (sp, 0)))
- nlookaheads += rp->num;
+ n_look_ahead_tokens += rp->num;
else
s->consistent = 1;
break;
}
- return nlookaheads;
+ return n_look_ahead_tokens;
}
-/*----------------------------------------------.
-| Compute LA, NLA, and the lookaheads members. |
-`----------------------------------------------*/
+/*-----------------------------------------------------.
+| Compute LA, NLA, and the look_ahead_tokens members. |
+`-----------------------------------------------------*/
static void
initialize_LA (void)
state_number i;
bitsetv pLA;
- /* Compute the total number of reductions requiring a lookahead. */
+ /* Compute the total number of reductions requiring a look-ahead. */
nLA = 0;
for (i = 0; i < nstates; i++)
- nLA += state_lookaheads_count (states[i]);
+ nLA += state_look_ahead_tokens_count (states[i]);
/* Avoid having to special case 0. */
if (!nLA)
nLA = 1;
pLA = LA = bitsetv_create (nLA, ntokens, BITSET_FIXED);
CALLOC (lookback, nLA);
- /* Initialize the members LOOKAHEADS for each state which reductions
- require lookaheads. */
+ /* Initialize the members LOOK_AHEAD_TOKENS for each state whose reductions
+ require look-ahead tokens. */
for (i = 0; i < nstates; i++)
{
- int count = state_lookaheads_count (states[i]);
+ int count = state_look_ahead_tokens_count (states[i]);
if (count)
{
- states[i]->reductions->lookaheads = pLA;
+ states[i]->reductions->look_ahead_tokens = pLA;
pLA += count;
}
}
}
-/*---------------------------------------.
-| Output the lookaheads for each state. |
-`---------------------------------------*/
+/*----------------------------------------------.
+| Output the look-ahead tokens for each state. |
+`----------------------------------------------*/
static void
-lookaheads_print (FILE *out)
+look_ahead_tokens_print (FILE *out)
{
state_number i;
int j, k;
- fprintf (out, "Lookaheads: BEGIN\n");
+ fprintf (out, "Look-ahead tokens: BEGIN\n");
for (i = 0; i < nstates; ++i)
{
reductions *reds = states[i]->reductions;
bitset_iterator iter;
- int nlookaheads = 0;
+ int n_look_ahead_tokens = 0;
- if (reds->lookaheads)
+ if (reds->look_ahead_tokens)
for (k = 0; k < reds->num; ++k)
- if (reds->lookaheads[k])
- ++nlookaheads;
+ if (reds->look_ahead_tokens[k])
+ ++n_look_ahead_tokens;
- fprintf (out, "State %d: %d lookaheads\n",
- i, nlookaheads);
+ fprintf (out, "State %d: %d look-ahead tokens\n",
+ i, n_look_ahead_tokens);
- if (reds->lookaheads)
+ if (reds->look_ahead_tokens)
for (j = 0; j < reds->num; ++j)
- BITSET_FOR_EACH (iter, reds->lookaheads[j], k, 0)
+ BITSET_FOR_EACH (iter, reds->look_ahead_tokens[j], k, 0)
{
fprintf (out, " on %d (%s) -> rule %d\n",
k, symbols[k]->tag,
reds->rules[j]->number);
};
}
- fprintf (out, "Lookaheads: END\n");
+ fprintf (out, "Look-ahead tokens: END\n");
}
void
initialize_F ();
build_relations ();
compute_FOLLOWS ();
- compute_lookaheads ();
+ compute_look_ahead_tokens ();
if (trace_flag & trace_sets)
- lookaheads_print (stderr);
+ look_ahead_tokens_print (stderr);
}
{
state_number s;
for (s = 0; s < nstates; ++s)
- states[s]->reductions->lookaheads = NULL;
+ states[s]->reductions->look_ahead_tokens = NULL;
bitsetv_free (LA);
}
projects / bison.git / blobdiff