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style: reduce: reduce scopes and other stylistic changes

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* src/reduce.c: Various stylistic changes:
Reduce scopes.
Prefer ++i to i++.
Prefer < to >.
This commit is contained in:
Akim Demaille
2015-01-12 18:23:09 +01:00
parent dfd5b89d01
commit c5da1a2adc
1 changed files with 64 additions and 67 deletions
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131
src/reduce.c
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@@ -39,7 +39,7 @@
#include "reduce.h"
#include "symtab.h"
/* Set of all nonterminals which are not useless. */
/* Set of all nonterminals whose language is not empty. */
static bitset N;
/* Set of all rules which have no useless nonterminals in their RHS. */
@@ -71,7 +71,7 @@ useful_production (rule_number r, bitset N0)
/* A production is useful if all of the nonterminals in its appear
in the set of useful nonterminals. */
for (rhsp = rules[r].rhs; *rhsp >= 0; ++rhsp)
for (rhsp = rules[r].rhs; 0 <= *rhsp; ++rhsp)
if (ISVAR (*rhsp) && !bitset_test (N0, *rhsp - ntokens))
return false;
return true;
@@ -85,14 +85,10 @@ useful_production (rule_number r, bitset N0)
static void
useless_nonterminals (void)
{
bitset Np, Ns;
rule_number r;
/* 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 = bitset_create (nvars, BITSET_FIXED);
bitset 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
@@ -112,8 +108,9 @@ useless_nonterminals (void)
while (1)
{
rule_number r;
bitset_copy (Np, N);
for (r = 0; r < nrules; r++)
for (r = 0; r < nrules; ++r)
if (!bitset_test (P, r)
&& useful_production (r, N))
{
@@ -122,9 +119,11 @@ useless_nonterminals (void)
}
if (bitset_equal_p (N, Np))
break;
Ns = Np;
Np = N;
N = Ns;
{
bitset Ns = Np;
Np = N;
N = Ns;
}
}
bitset_free (N);
N = Np;
@@ -134,8 +133,6 @@ useless_nonterminals (void)
static void
inaccessable_symbols (void)
{
bitset Vp, Vs, Pp;
/* Find out which productions are reachable and which symbols are
used. Starting with an empty set of productions and a set of
symbols which only has the start symbol in it, iterate over all
@@ -159,8 +156,8 @@ inaccessable_symbols (void)
terminals are printed (if running in verbose mode) so that the
user can know. */
Vp = bitset_create (nsyms, BITSET_FIXED);
Pp = bitset_create (nrules, BITSET_FIXED);
bitset Vp = bitset_create (nsyms, BITSET_FIXED);
bitset Pp = bitset_create (nrules, BITSET_FIXED);
/* If the start symbol isn't useful, then nothing will be useful. */
if (bitset_test (N, accept->content->number - ntokens))
@@ -171,31 +168,32 @@ inaccessable_symbols (void)
{
rule_number r;
bitset_copy (Vp, V);
for (r = 0; r < nrules; r++)
{
if (!bitset_test (Pp, r)
&& bitset_test (P, r)
&& bitset_test (V, rules[r].lhs->number))
{
item_number *rhsp;
for (rhsp = rules[r].rhs; *rhsp >= 0; rhsp++)
if (ISTOKEN (*rhsp) || bitset_test (N, *rhsp - ntokens))
bitset_set (Vp, *rhsp);
bitset_set (Pp, r);
}
}
for (r = 0; r < nrules; ++r)
if (!bitset_test (Pp, r)
&& bitset_test (P, r)
&& bitset_test (V, rules[r].lhs->number))
{
item_number *rhsp;
for (rhsp = rules[r].rhs; 0 <= *rhsp; ++rhsp)
if (ISTOKEN (*rhsp) || bitset_test (N, *rhsp - ntokens))
bitset_set (Vp, *rhsp);
bitset_set (Pp, r);
}
if (bitset_equal_p (V, Vp))
break;
Vs = Vp;
Vp = V;
V = Vs;
{
bitset Vs = Vp;
Vp = V;
V = Vs;
}
}
}
bitset_free (V);
V = Vp;
/* Tokens 0, 1, and 2 are internal to Bison. Consider them useful. */
/* These tokens (numbered 0, 1, and 2) are internal to Bison.
Consider them useful. */
bitset_set (V, endtoken->content->number); /* end-of-input token */
bitset_set (V, errtoken->content->number); /* error token */
bitset_set (V, undeftoken->content->number); /* some undefined token */
@@ -209,9 +207,8 @@ inaccessable_symbols (void)
nuseful_nonterminals = 0;
{
symbol_number i;
for (i = ntokens; i < nsyms; i++)
if (bitset_test (V, i))
nuseful_nonterminals++;
for (i = ntokens; i < nsyms; ++i)
nuseful_nonterminals += bitset_test (V, i);
}
nuseless_nonterminals = nvars - nuseful_nonterminals;
@@ -236,7 +233,7 @@ reduce_grammar_tables (void)
/* Report and flag useless productions. */
{
rule_number r;
for (r = 0; r < nrules; r++)
for (r = 0; r < nrules; ++r)
rules[r].useful = bitset_test (P, r);
grammar_rules_useless_report (_("rule useless in grammar"));
}
@@ -257,8 +254,8 @@ reduce_grammar_tables (void)
for (r = 0; r < nrules; ++r)
{
item_number *rhsp = rules[r].rhs;
for (/* Nothing. */; *rhsp >= 0; ++rhsp)
/* Nothing. */;
for (/* Nothing. */; 0 <= *rhsp; ++rhsp)
continue;
*rhsp = rule_number_as_item_number (r);
rules[r].number = r;
}
@@ -289,31 +286,33 @@ nonterminals_reduce (void)
afterwards. Kept for later report. */
symbol_number *nontermmap = xnmalloc (nvars, sizeof *nontermmap);
symbol_number n = ntokens;
symbol_number i;
for (i = ntokens; i < nsyms; i++)
if (bitset_test (V, i))
nontermmap[i - ntokens] = n++;
for (i = ntokens; i < nsyms; i++)
if (!bitset_test (V, i))
{
{
symbol_number n = ntokens;
symbol_number i;
for (i = ntokens; i < nsyms; ++i)
if (bitset_test (V, i))
nontermmap[i - ntokens] = n++;
if (symbols[i]->content->status != used)
complain (&symbols[i]->location, Wother,
_("nonterminal useless in grammar: %s"),
symbols[i]->tag);
}
for (i = ntokens; i < nsyms; ++i)
if (!bitset_test (V, i))
{
nontermmap[i - ntokens] = n++;
if (symbols[i]->content->status != used)
complain (&symbols[i]->location, Wother,
_("nonterminal useless in grammar: %s"),
symbols[i]->tag);
}
}
/* Shuffle elements of tables indexed by symbol number. */
{
symbol **symbols_sorted = xnmalloc (nvars, sizeof *symbols_sorted);
for (i = ntokens; i < nsyms; i++)
symbol_number i;
for (i = ntokens; i < nsyms; ++i)
symbols[i]->content->number = nontermmap[i - ntokens];
for (i = ntokens; i < nsyms; i++)
for (i = ntokens; i < nsyms; ++i)
symbols_sorted[nontermmap[i - ntokens] - ntokens] = symbols[i];
for (i = ntokens; i < nsyms; i++)
for (i = ntokens; i < nsyms; ++i)
symbols[i] = symbols_sorted[i - ntokens];
free (symbols_sorted);
}
@@ -323,7 +322,7 @@ nonterminals_reduce (void)
for (r = 0; r < nrules; ++r)
{
item_number *rhsp;
for (rhsp = rules[r].rhs; *rhsp >= 0; ++rhsp)
for (rhsp = rules[r].rhs; 0 <= *rhsp; ++rhsp)
if (ISVAR (*rhsp))
*rhsp = symbol_number_as_item_number (nontermmap[*rhsp
- ntokens]);
@@ -345,7 +344,7 @@ nonterminals_reduce (void)
void
reduce_output (FILE *out)
{
if (nuseless_nonterminals > 0)
if (0 < nuseless_nonterminals)
{
int i;
fprintf (out, "%s\n\n", _("Nonterminals useless in grammar"));
@@ -357,7 +356,7 @@ reduce_output (FILE *out)
{
bool b = false;
int i;
for (i = 0; i < ntokens; i++)
for (i = 0; i < ntokens; ++i)
if (reduce_token_unused_in_grammar (i))
{
if (!b)
@@ -369,7 +368,7 @@ reduce_output (FILE *out)
fputs ("\n\n", out);
}
if (nuseless_productions > 0)
if (0 < nuseless_productions)
grammar_rules_partial_print (out, _("Rules useless in grammar"),
rule_useless_in_grammar_p);
}
@@ -382,12 +381,12 @@ reduce_output (FILE *out)
static void
reduce_print (void)
{
if (nuseless_nonterminals > 0)
if (0 < nuseless_nonterminals)
complain (NULL, Wother, ngettext ("%d nonterminal useless in grammar",
"%d nonterminals useless in grammar",
nuseless_nonterminals),
nuseless_nonterminals);
if (nuseless_productions > 0)
if (0 < nuseless_productions)
complain (NULL, Wother, ngettext ("%d rule useless in grammar",
"%d rules useless in grammar",
nuseless_productions),
@@ -397,8 +396,6 @@ reduce_print (void)
void
reduce_grammar (void)
{
bool reduced;
/* Allocate the global sets used to compute the reduced grammar */
N = bitset_create (nvars, BITSET_FIXED);
@@ -409,8 +406,8 @@ reduce_grammar (void)
useless_nonterminals ();
inaccessable_symbols ();
reduced = (nuseless_nonterminals + nuseless_productions > 0);
if (!reduced)
/* Did we reduce something? */
if (!nuseless_nonterminals && !nuseless_productions)
return;
reduce_print ();
@@ -423,9 +420,9 @@ reduce_grammar (void)
/* First reduce the nonterminals, as they renumber themselves in the
whole grammar. If you change the order, nonterms would be
renumbered only in the reduced grammar. */
if (nuseless_nonterminals > 0)
if (0 < nuseless_nonterminals)
nonterminals_reduce ();
if (nuseless_productions > 0)
if (0 < nuseless_productions)
reduce_grammar_tables ();
if (trace_flag & trace_grammar)