cpython/Parser/grammar.c

210 lines
3.8 KiB
C

/* Grammar implementation */
#include "pgenheaders.h"
#include <ctype.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();
}
/* Forward */
static void translabel PROTO((grammar *, label *));
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]);
}
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));
}