| /* Parser accelerator module */ |
| |
| #include <stdio.h> |
| |
| #include "PROTO.h" |
| #include "grammar.h" |
| #include "token.h" |
| #include "malloc.h" |
| |
| static void |
| fixstate(g, d, s) |
| grammar *g; |
| dfa *d; |
| state *s; |
| { |
| arc *a; |
| int k; |
| int *accel; |
| int nl = g->g_ll.ll_nlabels; |
| s->s_accept = 0; |
| accel = NEW(int, nl); |
| for (k = 0; k < nl; k++) |
| accel[k] = -1; |
| a = s->s_arc; |
| for (k = s->s_narcs; --k >= 0; a++) { |
| int lbl = a->a_lbl; |
| label *l = &g->g_ll.ll_label[lbl]; |
| int type = l->lb_type; |
| if (a->a_arrow >= (1 << 7)) { |
| printf("XXX too many states!\n"); |
| continue; |
| } |
| if (ISNONTERMINAL(type)) { |
| dfa *d1 = finddfa(g, type); |
| int ibit; |
| if (type - NT_OFFSET >= (1 << 7)) { |
| printf("XXX too high nonterminal number!\n"); |
| continue; |
| } |
| for (ibit = 0; ibit < g->g_ll.ll_nlabels; ibit++) { |
| if (testbit(d1->d_first, ibit)) { |
| if (accel[ibit] != -1) |
| printf("XXX ambiguity!\n"); |
| accel[ibit] = a->a_arrow | (1 << 7) | |
| ((type - NT_OFFSET) << 8); |
| } |
| } |
| } |
| else if (lbl == EMPTY) |
| s->s_accept = 1; |
| else if (lbl >= 0 && lbl < nl) |
| accel[lbl] = a->a_arrow; |
| } |
| while (nl > 0 && accel[nl-1] == -1) |
| nl--; |
| for (k = 0; k < nl && accel[k] == -1;) |
| k++; |
| if (k < nl) { |
| int i; |
| s->s_accel = NEW(int, nl-k); |
| if (s->s_accel == NULL) { |
| fprintf(stderr, "no mem to add parser accelerators\n"); |
| exit(1); |
| } |
| s->s_lower = k; |
| s->s_upper = nl; |
| for (i = 0; k < nl; i++, k++) |
| s->s_accel[i] = accel[k]; |
| } |
| DEL(accel); |
| } |
| |
| static void |
| fixdfa(g, d) |
| grammar *g; |
| dfa *d; |
| { |
| state *s; |
| int j; |
| s = d->d_state; |
| for (j = 0; j < d->d_nstates; j++, s++) |
| fixstate(g, d, s); |
| } |
| |
| void |
| addaccelerators(g) |
| grammar *g; |
| { |
| dfa *d; |
| int i; |
| #ifdef DEBUG |
| printf("Adding parser accellerators ...\n"); |
| #endif |
| d = g->g_dfa; |
| for (i = g->g_ndfas; --i >= 0; d++) |
| fixdfa(g, d); |
| g->g_accel = 1; |
| #ifdef DEBUG |
| printf("Done.\n"); |
| #endif |
| } |