/* Grammar implementation */

#include "Python.h"
#include "pgenheaders.h"

#include <ctype.h>

#include "token.h"
#include "grammar.h"

extern int Py_DebugFlag;

grammar *
newgrammar(int start)
{
 grammar *g;

 g = (grammar *)PyObject_MALLOC(sizeof(grammar));
 if (g == NULL)
 Py_FatalError("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;
 g->g_accel = 0;
 return g;
}

void
freegrammar(grammar *g)
{
 int i;
 for (i = 0; i < g->g_ndfas; i++) {
 free(g->g_dfa[i].d_name);
 for (int j = 0; j < g->g_dfa[i].d_nstates; j++)
 PyObject_FREE(g->g_dfa[i].d_state[j].s_arc);
 PyObject_FREE(g->g_dfa[i].d_state);
 }
 PyObject_FREE(g->g_dfa);
 for (i = 0; i < g->g_ll.ll_nlabels; i++)
 free(g->g_ll.ll_label[i].lb_str);
 PyObject_FREE(g->g_ll.ll_label);
 PyObject_FREE(g);
}

dfa *
adddfa(grammar *g, int type, const char *name)
{
 dfa *d;

 g->g_dfa = (dfa *)PyObject_REALLOC(g->g_dfa,
 sizeof(dfa) * (g->g_ndfas + 1));
 if (g->g_dfa == NULL)
 Py_FatalError("no mem to resize dfa in adddfa");
 d = &g->g_dfa[g->g_ndfas++];
 d->d_type = type;
 d->d_name = strdup(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(dfa *d)
{
 state *s;

 d->d_state = (state *)PyObject_REALLOC(d->d_state,
 sizeof(state) * (d->d_nstates + 1));
 if (d->d_state == NULL)
 Py_FatalError("no mem to resize state in addstate");
 s = &d->d_state[d->d_nstates++];
 s->s_narcs = 0;
 s->s_arc = NULL;
 s->s_lower = 0;
 s->s_upper = 0;
 s->s_accel = NULL;
 s->s_accept = 0;
 return Py_SAFE_DOWNCAST(s - d->d_state, intptr_t, int);
}

void
addarc(dfa *d, int from, int to, 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];
 s->s_arc = (arc *)PyObject_REALLOC(s->s_arc, sizeof(arc) * (s->s_narcs + 1));
 if (s->s_arc == NULL)
 Py_FatalError("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(labellist *ll, int type, const 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;
 }
 ll->ll_label = (label *)PyObject_REALLOC(ll->ll_label,
 sizeof(label) * (ll->ll_nlabels + 1));
 if (ll->ll_label == NULL)
 Py_FatalError("no mem to resize labellist in addlabel");
 lb = &ll->ll_label[ll->ll_nlabels++];
 lb->lb_type = type;
 lb->lb_str = strdup(str);
 if (Py_DebugFlag)
 printf("Label @ %8p, %d: %s\n", ll, ll->ll_nlabels,
 PyGrammar_LabelRepr(lb));
 return Py_SAFE_DOWNCAST(lb - ll->ll_label, intptr_t, int);
}

/* Same, but rather dies than adds */

int
findlabel(labellist *ll, int type, const char *str)
{
 int i;

 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);
 Py_FatalError("grammar.c:findlabel()");

 /* Py_FatalError() is declared with __attribute__((__noreturn__)).
 GCC emits a warning without "return 0;" (compiler bug!), but Clang is
 smarter and emits a warning on the return... */
#ifndef __clang__
 return 0; /* Make gcc -Wall happy */
#endif
}

/* Forward */
static void translabel(grammar *, label *);

void
translatelabels(grammar *g)
{
 int i;

#ifdef Py_DEBUG
 printf("Translating labels ...\n");
#endif
 /* 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(grammar *g, label *lb)
{
 int i;

 if (Py_DebugFlag)
 printf("Translating label %s ...\n", PyGrammar_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 (Py_DebugFlag)
 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;
 free(lb->lb_str);
 lb->lb_str = NULL;
 return;
 }
 }
 for (i = 0; i < (int)N_TOKENS; i++) {
 if (strcmp(lb->lb_str, _PyParser_TokenNames[i]) == 0) {
 if (Py_DebugFlag)
 printf("Label %s is terminal %d.\n",
 lb->lb_str, i);
 lb->lb_type = i;
 free(lb->lb_str);
 lb->lb_str = NULL;
 return;
 }
 }
 printf("Can't translate NAME label '%s'\n", lb->lb_str);
 return;
 }

 if (lb->lb_type == STRING) {
 if (isalpha(Py_CHARMASK(lb->lb_str[1])) ||
 lb->lb_str[1] == '_') {
 char *p;
 char *src;
 char *dest;
 size_t name_len;
 if (Py_DebugFlag)
 printf("Label %s is a keyword\n", lb->lb_str);
 lb->lb_type = NAME;
 src = lb->lb_str + 1;
 p = strchr(src, '\'');
 if (p)
 name_len = p - src;
 else
 name_len = strlen(src);
 dest = (char *)malloc(name_len + 1);
 if (!dest) {
 printf("Can't alloc dest '%s'\n", src);
 return;
 }
 strncpy(dest, src, name_len);
 dest[name_len] = '0円';
 free(lb->lb_str);
 lb->lb_str = dest;
 }
 else if (lb->lb_str[2] == lb->lb_str[0]) {
 int type = (int) PyToken_OneChar(lb->lb_str[1]);
 if (type != OP) {
 lb->lb_type = type;
 free(lb->lb_str);
 lb->lb_str = NULL;
 }
 else
 printf("Unknown OP label %s\n",
 lb->lb_str);
 }
 else if (lb->lb_str[2] && lb->lb_str[3] == lb->lb_str[0]) {
 int type = (int) PyToken_TwoChars(lb->lb_str[1],
 lb->lb_str[2]);
 if (type != OP) {
 lb->lb_type = type;
 free(lb->lb_str);
 lb->lb_str = NULL;
 }
 else
 printf("Unknown OP label %s\n",
 lb->lb_str);
 }
 else if (lb->lb_str[2] && lb->lb_str[3] && lb->lb_str[4] == lb->lb_str[0]) {
 int type = (int) PyToken_ThreeChars(lb->lb_str[1],
 lb->lb_str[2],
 lb->lb_str[3]);
 if (type != OP) {
 lb->lb_type = type;
 free(lb->lb_str);
 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",
 PyGrammar_LabelRepr(lb));
}