X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/aa7815f5c6e8e07a85e47df9cd7b579468969efb..eeeb962b:/src/reduce.c diff --git a/src/reduce.c b/src/reduce.c index c2efee93..a95b4bbd 100644 --- a/src/reduce.c +++ b/src/reduce.c @@ -1,5 +1,5 @@ /* Grammar reduction for Bison. - Copyright 1988, 1989, 2000 Free Software Foundation, Inc. + Copyright 1988, 1989, 2000, 2001 Free Software Foundation, Inc. This file is part of Bison, the GNU Compiler Compiler. @@ -29,7 +29,6 @@ #include "getargs.h" #include "files.h" #include "gram.h" -#include "xalloc.h" #include "complain.h" #include "reduce.h" #include "reader.h" @@ -101,7 +100,7 @@ useful_production (int i, BSet N0) /* A production is useful if all of the nonterminals in its appear in the set of useful nonterminals. */ - for (r = &ritem[rrhs[i]]; *r > 0; r++) + for (r = &ritem[rule_table[i].rhs]; *r > 0; r++) if (ISVAR (n = *r)) if (!BITISSET (N0, n - ntokens)) return FALSE; @@ -117,7 +116,7 @@ static void useless_nonterminals (void) { BSet Np, Ns; - int i, n; + 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. */ @@ -140,7 +139,6 @@ useless_nonterminals (void) saved to be used when finding useful productions: only productions in this set will appear in the final grammar. */ - n = 0; while (1) { for (i = WORDSIZE (nvars) - 1; i >= 0; i--) @@ -151,7 +149,7 @@ useless_nonterminals (void) { if (useful_production (i, N)) { - SETBIT (Np, rlhs[i] - ntokens); + SETBIT (Np, rule_table[i].lhs - ntokens); SETBIT (P, i); } } @@ -171,7 +169,7 @@ static void inaccessable_symbols (void) { BSet Vp, Vs, Pp; - int i, n; + int i; short t; rule r; @@ -202,39 +200,33 @@ inaccessable_symbols (void) Pp = XCALLOC (unsigned, WORDSIZE (nrules + 1)); /* If the start symbol isn't useful, then nothing will be useful. */ - if (!BITISSET (N, start_symbol - ntokens)) - goto end_iteration; - - SETBIT (V, start_symbol); - - n = 0; - while (1) + if (BITISSET (N, start_symbol - ntokens)) { - for (i = WORDSIZE (nsyms) - 1; i >= 0; i--) - Vp[i] = V[i]; - for (i = 1; i <= nrules; i++) + SETBIT (V, start_symbol); + + while (1) { - if (!BITISSET (Pp, i) && BITISSET (P, i) && BITISSET (V, rlhs[i])) + for (i = WORDSIZE (nsyms) - 1; i >= 0; i--) + Vp[i] = V[i]; + for (i = 1; i <= nrules; i++) { - for (r = &ritem[rrhs[i]]; *r >= 0; r++) + if (!BITISSET (Pp, i) + && BITISSET (P, i) + && BITISSET (V, rule_table[i].lhs)) { - if (ISTOKEN (t = *r) || BITISSET (N, t - ntokens)) - { + for (r = &ritem[rule_table[i].rhs]; *r >= 0; r++) + if (ISTOKEN (t = *r) || BITISSET (N, t - ntokens)) SETBIT (Vp, t); - } + SETBIT (Pp, i); } - SETBIT (Pp, i); } + if (bits_equal (V, Vp, WORDSIZE (nsyms))) + break; + Vs = Vp; + Vp = V; + V = Vs; } - if (bits_equal (V, Vp, WORDSIZE (nsyms))) - { - break; - } - Vs = Vp; - Vp = V; - V = Vs; } -end_iteration: XFREE (V); V = Vp; @@ -258,8 +250,8 @@ end_iteration: /* A token that was used in %prec should not be warned about. */ for (i = 1; i < nrules; i++) - if (rprecsym[i] != 0) - SETBIT (V1, rprecsym[i]); + if (rule_table[i].precsym != 0) + SETBIT (V1, rule_table[i].precsym); } static void @@ -282,15 +274,15 @@ reduce_grammar_tables (void) np++; if (pn != np) { - rlhs[np] = rlhs[pn]; + rule_table[np].lhs = rule_table[pn].lhs; rline[np] = rline[pn]; - rprec[np] = rprec[pn]; - rassoc[np] = rassoc[pn]; - rrhs[np] = rrhs[pn]; - if (rrhs[np] != ni) + rule_table[np].prec = rule_table[pn].prec; + rule_table[np].assoc = rule_table[pn].assoc; + rule_table[np].rhs = rule_table[pn].rhs; + if (rule_table[np].rhs != ni) { - pi = rrhs[np]; - rrhs[np] = ni; + pi = rule_table[np].rhs; + rule_table[np].rhs = ni; while (ritem[pi] >= 0) ritem[ni++] = ritem[pi++]; ritem[ni++] = -np; @@ -322,7 +314,7 @@ reduce_grammar_tables (void) { if (!BITISSET (P, pn)) { - rlhs[pn] = -1; + rule_table[pn].lhs = -1; } } } @@ -371,11 +363,11 @@ reduce_grammar_tables (void) for (i = 1; i <= nrules; i++) { /* Ignore the rules disabled above. */ - if (rlhs[i] >= 0) - rlhs[i] = nontermmap[rlhs[i]]; - if (ISVAR (rprecsym[i])) + if (rule_table[i].lhs >= 0) + rule_table[i].lhs = nontermmap[rule_table[i].lhs]; + if (ISVAR (rule_table[i].precsym)) /* Can this happen? */ - rprecsym[i] = nontermmap[rprecsym[i]]; + rule_table[i].precsym = nontermmap[rule_table[i].precsym]; } for (r = ritem; *r; r++) @@ -391,21 +383,25 @@ reduce_grammar_tables (void) } } -static void -print_results (void) + +/*-----------------------------------------------------------------. +| Ouput the detailed results of the reductions. For FILE.output. | +`-----------------------------------------------------------------*/ + +void +reduce_output (FILE *out) { int i; -/* short j; JF unused */ rule r; bool b; if (nuseless_nonterminals > 0) { - fputs (_("Useless nonterminals:"), foutput); - fputs ("\n\n", foutput); + fprintf (out, _("Useless nonterminals:")); + fprintf (out, "\n\n"); for (i = ntokens; i < nsyms; i++) if (!BITISSET (V, i)) - fprintf (foutput, " %s\n", tags[i]); + fprintf (out, " %s\n", tags[i]); } b = FALSE; for (i = 0; i < ntokens; i++) @@ -414,79 +410,82 @@ print_results (void) { if (!b) { - fputs ("\n\n", foutput); - fprintf (foutput, _("Terminals which are not used:")); - fputs ("\n\n", foutput); + fprintf (out, "\n\n"); + fprintf (out, _("Terminals which are not used:")); + fprintf (out, "\n\n"); b = TRUE; } - fprintf (foutput, " %s\n", tags[i]); + fprintf (out, " %s\n", tags[i]); } } if (nuseless_productions > 0) { - fputs ("\n\n", foutput); - fprintf (foutput, _("Useless rules:")); - fputs ("\n\n", foutput); + fprintf (out, "\n\n"); + fprintf (out, _("Useless rules:")); + fprintf (out, "\n\n"); for (i = 1; i <= nrules; i++) - { - if (!BITISSET (P, i)) - { - fprintf (foutput, "#%-4d ", i); - fprintf (foutput, "%s :\t", tags[rlhs[i]]); - for (r = &ritem[rrhs[i]]; *r >= 0; r++) - { - fprintf (foutput, " %s", tags[*r]); - } - fprintf (foutput, ";\n"); - } - } + if (!BITISSET (P, i)) + { + fprintf (out, "#%-4d ", i); + fprintf (out, "%s :\t", tags[rule_table[i].lhs]); + for (r = &ritem[rule_table[i].rhs]; *r >= 0; r++) + fprintf (out, " %s", tags[*r]); + fprintf (out, ";\n"); + } } if (nuseless_nonterminals > 0 || nuseless_productions > 0 || b) - fputs ("\n\n", foutput); + fprintf (out, "\n\n"); } -#if 0 /* XXX currently unused. */ static void -dump_grammar (void) +dump_grammar (FILE *out) { int i; rule r; - fprintf (foutput, - "ntokens = %d, nvars = %d, nsyms = %d, nrules = %d, nitems = %d\n\n", - ntokens, nvars, nsyms, nrules, nitems); - fprintf (foutput, _("Variables\n---------\n\n")); - fprintf (foutput, _("Value Sprec Sassoc Tag\n")); + fprintf (out, "REDUCED GRAMMAR\n\n"); + fprintf (out, + "ntokens = %d, nvars = %d, nsyms = %d, nrules = %d, nitems = %d\n\n", + ntokens, nvars, nsyms, nrules, nitems); + fprintf (out, _("Variables\n---------\n\n")); + fprintf (out, _("Value Sprec Sassoc Tag\n")); for (i = ntokens; i < nsyms; i++) - fprintf (foutput, "%5d %5d %5d %s\n", i, sprec[i], sassoc[i], tags[i]); - fprintf (foutput, "\n\n"); - fprintf (foutput, _("Rules\n-----\n\n")); + fprintf (out, "%5d %5d %5d %s\n", i, sprec[i], sassoc[i], tags[i]); + fprintf (out, "\n\n"); + fprintf (out, _("Rules\n-----\n\n")); for (i = 1; i <= nrules; i++) { - fprintf (foutput, "%-5d(%5d%5d)%5d : (@%-5d)", - i, rprec[i], rassoc[i], rlhs[i], rrhs[i]); - for (r = &ritem[rrhs[i]]; *r > 0; r++) - fprintf (foutput, "%5d", *r); - fprintf (foutput, " [%d]\n", -(*r)); + fprintf (out, "%-5d(%5d%5d)%5d : (@%-5d)", + i, + rule_table[i].prec, + rule_table[i].assoc, + rule_table[i].lhs, + rule_table[i].rhs); + for (r = &ritem[rule_table[i].rhs]; *r > 0; r++) + fprintf (out, "%5d", *r); + fprintf (out, " [%d]\n", -(*r)); } - fprintf (foutput, "\n\n"); - fprintf (foutput, _("Rules interpreted\n-----------------\n\n")); + fprintf (out, "\n\n"); + fprintf (out, _("Rules interpreted\n-----------------\n\n")); for (i = 1; i <= nrules; i++) { - fprintf (foutput, "%-5d %s :", i, tags[rlhs[i]]); - for (r = &ritem[rrhs[i]]; *r > 0; r++) - fprintf (foutput, " %s", tags[*r]); - fprintf (foutput, "\n"); + fprintf (out, "%-5d %s :", i, tags[rule_table[i].lhs]); + for (r = &ritem[rule_table[i].rhs]; *r > 0; r++) + fprintf (out, " %s", tags[*r]); + fputc ('\n', out); } - fprintf (foutput, "\n\n"); + fprintf (out, "\n\n"); } -#endif +/*-------------------------------. +| Report the results to STDERR. | +`-------------------------------*/ + static void -print_notices (void) +reduce_print (void) { if (yacc_flag && nuseless_productions) fprintf (stderr, _("%d rules never reduced\n"), nuseless_productions); @@ -528,42 +527,37 @@ reduce_grammar (void) reduced = (bool) (nuseless_nonterminals + nuseless_productions > 0); - if (verbose_flag) - print_results (); - - if (reduced == FALSE) - goto done_reducing; + if (!reduced) + return; - print_notices (); + reduce_print (); if (!BITISSET (N, start_symbol - ntokens)) fatal (_("Start symbol %s does not derive any sentence"), tags[start_symbol]); reduce_grammar_tables (); -#if 0 - if (verbose_flag) + + if (trace_flag) { - fprintf (foutput, "REDUCED GRAMMAR\n\n"); - dump_grammar (); + dump_grammar (stderr); + + fprintf (stderr, "reduced %s defines %d terminals, %d nonterminals\ +, and %d productions.\n", + infile, ntokens, nvars, nrules); } -#endif - - if (statistics_flag) - fprintf (stderr, _("reduced %s defines %d terminal%s, %d nonterminal%s\ -, and %d production%s.\n"), - infile, - ntokens, - (ntokens == 1 ? "" : "s"), - nvars, - (nvars == 1 ? "" : "s"), - nrules, - (nrules == 1 ? "" : "s")); - -done_reducing: - /* Free the global sets used to compute the reduced grammar */ +} + +/*-----------------------------------------------------------. +| Free the global sets used to compute the reduced grammar. | +`-----------------------------------------------------------*/ + +void +reduce_free (void) +{ XFREE (N); XFREE (V); + XFREE (V1); XFREE (P); }