#include "reduce.h"
#include "reader.h"
#include "getargs.h"
+#include "bitset.h"
-typedef unsigned *BSet;
typedef short *rule;
/* Set of all nonterminals which are not useless. */
-static BSet N;
+static bitset N;
/* Set of all rules which have no useless nonterminals in their RHS. */
-static BSet P;
+static bitset P;
/* Set of all accessible symbols. */
-static BSet V;
+static bitset V;
/* Set of symbols used to define rule precedence (so they are
`useless', but no warning should be issued). */
-static BSet V1;
+static bitset V1;
static int nuseful_productions;
static int nuseless_productions;
static int nuseful_nonterminals;
int nuseless_nonterminals;
\f
-static bool
-bits_equal (BSet L, BSet R, int n)
-{
- int i;
-
- for (i = n - 1; i >= 0; i--)
- if (L[i] != R[i])
- return FALSE;
- return TRUE;
-}
-
-
-static int
-nbits (unsigned i)
-{
- int count = 0;
-
- while (i != 0)
- {
- i ^= (i & ((unsigned) (-(int) i)));
- ++count;
- }
- return count;
-}
-
-
-static int
-bits_size (BSet S, int n)
-{
- int i, count = 0;
-
- for (i = n - 1; i >= 0; i--)
- count += nbits (S[i]);
- return count;
-}
-\f
/*-------------------------------------------------------------------.
| Another way to do this would be with a set for each production and |
| then do subset tests against N0, but even for the C grammar the |
`-------------------------------------------------------------------*/
static bool
-useful_production (int i, BSet N0)
+useful_production (int i, bitset N0)
{
rule r;
short n;
/* A production is useful if all of the nonterminals in its appear
in the set of useful nonterminals. */
- for (r = &ritem[rules[i].rhs]; *r >= 0; r++)
- if (ISVAR (n = *r))
- if (!BITISSET (N0, n - ntokens))
- return FALSE;
+ for (r = rules[i].rhs; *r >= 0; r++)
+ if (ISVAR (n = *r) && !bitset_test (N0, n - ntokens))
+ return FALSE;
return TRUE;
}
static void
useless_nonterminals (void)
{
- BSet Np, Ns;
+ bitset Np, Ns;
int i;
/* N is set as built. Np is set being built this iteration. P is
set of all productions which have a RHS all in N. */
- Np = XCALLOC (unsigned, WORDSIZE (nvars));
+ Np = bitset_create (nvars, BITSET_FIXED);
+
/* The set being computed is a set of nonterminals which can derive
the empty string or strings consisting of all terminals. At each
while (1)
{
- for (i = WORDSIZE (nvars) - 1; i >= 0; i--)
- Np[i] = N[i];
- for (i = 1; i <= nrules; i++)
- {
- if (!BITISSET (P, i))
- {
- if (useful_production (i, N))
- {
- SETBIT (Np, rules[i].lhs - ntokens);
- SETBIT (P, i);
- }
- }
- }
- if (bits_equal (N, Np, WORDSIZE (nvars)))
+ bitset_copy (Np, N);
+ for (i = 1; i < nrules + 1; i++)
+ if (!bitset_test (P, i)
+ && useful_production (i, N))
+ {
+ bitset_set (Np, rules[i].lhs - ntokens);
+ bitset_set (P, i);
+ }
+ if (bitset_equal_p (N, Np))
break;
Ns = Np;
Np = N;
N = Ns;
}
- XFREE (N);
+ bitset_free (N);
N = Np;
}
static void
inaccessable_symbols (void)
{
- BSet Vp, Vs, Pp;
+ bitset Vp, Vs, Pp;
int i;
short t;
rule r;
terminals are printed (if running in verbose mode) so that the
user can know. */
- Vp = XCALLOC (unsigned, WORDSIZE (nsyms));
- Pp = XCALLOC (unsigned, WORDSIZE (nrules + 1));
+ Vp = bitset_create (nsyms, BITSET_FIXED);
+ Pp = bitset_create (nrules + 1, BITSET_FIXED);
/* If the start symbol isn't useful, then nothing will be useful. */
- if (BITISSET (N, start_symbol - ntokens))
+ if (bitset_test (N, start_symbol - ntokens))
{
- SETBIT (V, start_symbol);
+ bitset_set (V, start_symbol);
while (1)
{
- for (i = WORDSIZE (nsyms) - 1; i >= 0; i--)
- Vp[i] = V[i];
- for (i = 1; i <= nrules; i++)
+ bitset_copy (Vp, V);
+ for (i = 1; i < nrules + 1; i++)
{
- if (!BITISSET (Pp, i)
- && BITISSET (P, i)
- && BITISSET (V, rules[i].lhs))
+ if (!bitset_test (Pp, i)
+ && bitset_test (P, i)
+ && bitset_test (V, rules[i].lhs))
{
- for (r = &ritem[rules[i].rhs]; *r >= 0; r++)
- if (ISTOKEN (t = *r) || BITISSET (N, t - ntokens))
- SETBIT (Vp, t);
- SETBIT (Pp, i);
+ for (r = rules[i].rhs; *r >= 0; r++)
+ if (ISTOKEN (t = *r) || bitset_test (N, t - ntokens))
+ bitset_set (Vp, t);
+ bitset_set (Pp, i);
}
}
- if (bits_equal (V, Vp, WORDSIZE (nsyms)))
+ if (bitset_equal_p (V, Vp))
break;
Vs = Vp;
Vp = V;
}
}
- XFREE (V);
+ bitset_free (V);
V = Vp;
/* Tokens 0, 1, and 2 are internal to Bison. Consider them useful. */
- SETBIT (V, 0); /* end-of-input token */
- SETBIT (V, 1); /* error token */
- SETBIT (V, 2); /* some undefined token */
+ bitset_set (V, 0); /* end-of-input token */
+ bitset_set (V, 1); /* error token */
+ bitset_set (V, 2); /* some undefined token */
- XFREE (P);
+ bitset_free (P);
P = Pp;
- nuseful_productions = bits_size (P, WORDSIZE (nrules + 1));
+ nuseful_productions = bitset_count (P);
nuseless_productions = nrules - nuseful_productions;
nuseful_nonterminals = 0;
for (i = ntokens; i < nsyms; i++)
- if (BITISSET (V, i))
+ if (bitset_test (V, i))
nuseful_nonterminals++;
nuseless_nonterminals = nvars - nuseful_nonterminals;
/* A token that was used in %prec should not be warned about. */
- for (i = 1; i < nrules; i++)
+ for (i = 1; i < nrules + 1; i++)
if (rules[i].precsym != 0)
- SETBIT (V1, rules[i].precsym);
+ bitset_set (V1, rules[i].precsym);
}
static void
np = 0;
ni = 0;
- for (pn = 1; pn <= nrules; pn++)
- if (BITISSET (P, pn))
+ for (pn = 1; pn < nrules + 1; pn++)
+ if (bitset_test (P, pn))
{
np++;
if (pn != np)
rules[np].prec = rules[pn].prec;
rules[np].assoc = rules[pn].assoc;
rules[np].rhs = rules[pn].rhs;
- if (rules[np].rhs != ni)
+ if (rules[np].rhs - ritem != ni)
{
- pi = rules[np].rhs;
- rules[np].rhs = ni;
+ pi = rules[np].rhs - ritem;
+ rules[np].rhs = ritem + ni;
while (ritem[pi] >= 0)
ritem[ni++] = ritem[pi++];
ritem[ni++] = -np;
if (nuseless_productions > 0)
{
int pn;
- for (pn = 1; pn <= nrules; pn++)
- rules[pn].useful = BITISSET (P, pn);
+ for (pn = 1; pn < nrules + 1; pn++)
+ rules[pn].useful = bitset_test (P, pn);
}
}
nonterminals_reduce (void)
{
int i, n;
- rule r;
/* Map the nonterminals to their new index: useful first, useless
afterwards. Kept for later report. */
short *nontermmap = XCALLOC (short, nvars) - ntokens;
n = ntokens;
for (i = ntokens; i < nsyms; i++)
- if (BITISSET (V, i))
+ if (bitset_test (V, i))
nontermmap[i] = n++;
for (i = ntokens; i < nsyms; i++)
- if (!BITISSET (V, i))
+ if (!bitset_test (V, i))
nontermmap[i] = n++;
/* Replace all symbol numbers in valid data structures. */
- for (i = 1; i <= nrules; i++)
+ for (i = 1; i < nrules + 1; i++)
{
rules[i].lhs = nontermmap[rules[i].lhs];
if (ISVAR (rules[i].precsym))
bool b = FALSE;
int i;
for (i = 0; i < ntokens; i++)
- if (!BITISSET (V, i) && !BITISSET (V1, i))
+ if (!bitset_test (V, i) && !bitset_test (V1, i))
{
if (!b)
fprintf (out, "%s\n\n", _("Terminals which are not used:"));
{
int i;
fprintf (out, "%s\n\n", _("Useless rules:"));
- for (i = 1; i <= nrules; i++)
+ for (i = 1; i < nrules + 1; i++)
if (!rules[i].useful)
{
rule r;
fprintf (out, "#%-4d ", i - 1);
fprintf (out, "%s:", symbols[rules[i].lhs]->tag);
- for (r = &ritem[rules[i].rhs]; *r >= 0; r++)
+ for (r = rules[i].rhs; *r >= 0; r++)
fprintf (out, " %s", symbols[*r]->tag);
fputs (";\n", out);
}
fprintf (out, "\n\n");
fprintf (out, "Rules\n-----\n\n");
fprintf (out, "Num (Prec, Assoc, Useful, Ritem Range) Lhs -> Rhs (Ritem range) [Num]\n");
- for (i = 1; i <= nrules; i++)
+ for (i = 1; i < nrules + 1; i++)
{
int rhs_count = 0;
/* Find the last RHS index in ritems. */
- for (r = &ritem[rules[i].rhs]; *r >= 0; ++r)
+ for (r = rules[i].rhs; *r >= 0; ++r)
++rhs_count;
fprintf (out, "%3d (%2d, %2d, %2d, %2d-%2d) %2d ->",
i - 1,
rules[i].prec, rules[i].assoc, rules[i].useful,
- rules[i].rhs, rules[i].rhs + rhs_count - 1,
+ rules[i].rhs - ritem, rules[i].rhs - ritem + rhs_count - 1,
rules[i].lhs);
/* Dumped the RHS. */
- for (r = &ritem[rules[i].rhs]; *r >= 0; r++)
+ for (r = rules[i].rhs; *r >= 0; r++)
fprintf (out, "%3d", *r);
fprintf (out, " [%d]\n", -(*r) - 1);
}
fprintf (out, "\n\n");
fprintf (out, "Rules interpreted\n-----------------\n\n");
- for (i = 1; i <= nrules; i++)
+ for (i = 1; i < nrules + 1; i++)
{
fprintf (out, "%-5d %s :", i, symbols[rules[i].lhs]->tag);
- for (r = &ritem[rules[i].rhs]; *r >= 0; r++)
+ for (r = rules[i].rhs; *r >= 0; r++)
fprintf (out, " %s", symbols[*r]->tag);
fputc ('\n', out);
}
/* Allocate the global sets used to compute the reduced grammar */
- N = XCALLOC (unsigned, WORDSIZE (nvars));
- P = XCALLOC (unsigned, WORDSIZE (nrules + 1));
- V = XCALLOC (unsigned, WORDSIZE (nsyms));
- V1 = XCALLOC (unsigned, WORDSIZE (nsyms));
+ N = bitset_create (nvars, BITSET_FIXED);
+ P = bitset_create (nrules + 1, BITSET_FIXED);
+ V = bitset_create (nsyms, BITSET_FIXED);
+ V1 = bitset_create (nsyms, BITSET_FIXED);
useless_nonterminals ();
inaccessable_symbols ();
reduced = (bool) (nuseless_nonterminals + nuseless_productions > 0);
-
if (!reduced)
return;
reduce_print ();
- if (!BITISSET (N, start_symbol - ntokens))
+ if (!bitset_test (N, start_symbol - ntokens))
fatal (_("Start symbol %s does not derive any sentence"),
symbols[start_symbol]->tag);
void
reduce_free (void)
{
- XFREE (N);
- XFREE (V);
- XFREE (V1);
- XFREE (P);
+ bitset_free (N);
+ bitset_free (V);
+ bitset_free (V1);
+ bitset_free (P);
}
projects / bison.git / blobdiff