diff options
Diffstat (limited to 'Parser/grammar.c')
| -rw-r--r-- | Parser/grammar.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/Parser/grammar.c b/Parser/grammar.c new file mode 100644 index 0000000..ad9c2b0 --- /dev/null +++ b/Parser/grammar.c @@ -0,0 +1,207 @@ +/* Grammar implementation */ + +#include <stdio.h> +#include <ctype.h> + +#include "PROTO.h" +#include "malloc.h" +#include "assert.h" +#include "token.h" +#include "grammar.h" + +extern int debugging; + +grammar * +newgrammar(start) + int start; +{ + grammar *g; + + g = NEW(grammar, 1); + if (g == NULL) + fatal("no mem for new grammar"); + g->g_ndfas = 0; + g->g_dfa = NULL; + g->g_start = start; + g->g_ll.ll_nlabels = 0; + g->g_ll.ll_label = NULL; + return g; +} + +dfa * +adddfa(g, type, name) + grammar *g; + int type; + char *name; +{ + dfa *d; + + RESIZE(g->g_dfa, dfa, g->g_ndfas + 1); + if (g->g_dfa == NULL) + fatal("no mem to resize dfa in adddfa"); + d = &g->g_dfa[g->g_ndfas++]; + d->d_type = type; + d->d_name = name; + d->d_nstates = 0; + d->d_state = NULL; + d->d_initial = -1; + d->d_first = NULL; + return d; /* Only use while fresh! */ +} + +int +addstate(d) + dfa *d; +{ + state *s; + + RESIZE(d->d_state, state, d->d_nstates + 1); + if (d->d_state == NULL) + fatal("no mem to resize state in addstate"); + s = &d->d_state[d->d_nstates++]; + s->s_narcs = 0; + s->s_arc = NULL; + return s - d->d_state; +} + +void +addarc(d, from, to, lbl) + dfa *d; + int lbl; +{ + state *s; + arc *a; + + assert(0 <= from && from < d->d_nstates); + assert(0 <= to && to < d->d_nstates); + + s = &d->d_state[from]; + RESIZE(s->s_arc, arc, s->s_narcs + 1); + if (s->s_arc == NULL) + fatal("no mem to resize arc list in addarc"); + a = &s->s_arc[s->s_narcs++]; + a->a_lbl = lbl; + a->a_arrow = to; +} + +int +addlabel(ll, type, str) + labellist *ll; + int type; + char *str; +{ + int i; + label *lb; + + for (i = 0; i < ll->ll_nlabels; i++) { + if (ll->ll_label[i].lb_type == type && + strcmp(ll->ll_label[i].lb_str, str) == 0) + return i; + } + RESIZE(ll->ll_label, label, ll->ll_nlabels + 1); + if (ll->ll_label == NULL) + fatal("no mem to resize labellist in addlabel"); + lb = &ll->ll_label[ll->ll_nlabels++]; + lb->lb_type = type; + lb->lb_str = str; /* XXX strdup(str) ??? */ + return lb - ll->ll_label; +} + +/* Same, but rather dies than adds */ + +int +findlabel(ll, type, str) + labellist *ll; + int type; + char *str; +{ + int i; + label *lb; + + for (i = 0; i < ll->ll_nlabels; i++) { + if (ll->ll_label[i].lb_type == type /*&& + strcmp(ll->ll_label[i].lb_str, str) == 0*/) + return i; + } + fprintf(stderr, "Label %d/'%s' not found\n", type, str); + abort(); +} + +static void +translabel(g, lb) + grammar *g; + label *lb; +{ + int i; + + if (debugging) + printf("Translating label %s ...\n", labelrepr(lb)); + + if (lb->lb_type == NAME) { + for (i = 0; i < g->g_ndfas; i++) { + if (strcmp(lb->lb_str, g->g_dfa[i].d_name) == 0) { + if (debugging) + printf("Label %s is non-terminal %d.\n", + lb->lb_str, + g->g_dfa[i].d_type); + lb->lb_type = g->g_dfa[i].d_type; + lb->lb_str = NULL; + return; + } + } + for (i = 0; i < (int)N_TOKENS; i++) { + if (strcmp(lb->lb_str, tok_name[i]) == 0) { + if (debugging) + printf("Label %s is terminal %d.\n", + lb->lb_str, i); + lb->lb_type = i; + lb->lb_str = NULL; + return; + } + } + printf("Can't translate NAME label '%s'\n", lb->lb_str); + return; + } + + if (lb->lb_type == STRING) { + if (isalpha(lb->lb_str[1])) { + char *p, *strchr(); + if (debugging) + printf("Label %s is a keyword\n", lb->lb_str); + lb->lb_type = NAME; + lb->lb_str++; + p = strchr(lb->lb_str, '\''); + if (p) + *p = '\0'; + } + else { + if (lb->lb_str[2] == lb->lb_str[0]) { + int type = (int) tok_1char(lb->lb_str[1]); + if (type != OP) { + lb->lb_type = type; + lb->lb_str = NULL; + } + else + printf("Unknown OP label %s\n", + lb->lb_str); + } + else + printf("Can't translate STRING label %s\n", + lb->lb_str); + } + } + else + printf("Can't translate label '%s'\n", labelrepr(lb)); +} + +void +translatelabels(g) + grammar *g; +{ + int i; + + printf("Translating labels ...\n"); + /* Don't translate EMPTY */ + for (i = EMPTY+1; i < g->g_ll.ll_nlabels; i++) + translabel(g, &g->g_ll.ll_label[i]); +} |