parser_state *
PyParser_New(grammar *g, int start)
{
parser_state *ps;
DBP("Attempting to create new PyParser\n");
if (!g->g_accel)
PyGrammar_AddAccelerators(g);
DBP("Added grammar accelerators\n");
ps = (parser_state *)PyMem_MALLOC(sizeof(parser_state));
DBP("Created parser state\n");
if (ps == NULL)
return NULL;
ps->p_grammar = g;
#ifdef PY_PARSER_REQUIRES_FUTURE_KEYWORD
ps->p_flags = 0;
#endif
ps->p_tree = PyNode_New(start);
if (ps->p_tree == NULL) {
PyMem_FREE(ps);
return NULL;
}
s_reset(&ps->p_stack);
(void) s_push(&ps->p_stack, PyGrammar_FindDFA(g, start), ps->p_tree);
DBP("Created PyParser!!\n");
return ps;
}
parser_state *
PyParser_New(grammar *g, int start)
{
parser_state *ps;
if (!g->g_accel)
PyGrammar_AddAccelerators(g);
ps = PyMem_NEW(parser_state, 1);
if (ps == NULL)
return NULL;
ps->p_grammar = g;
ps->p_generators = 0;
ps->p_tree = PyNode_New(start);
if (ps->p_tree == NULL) {
PyMem_DEL(ps);
return NULL;
}
s_reset(&ps->p_stack);
(void) s_push(&ps->p_stack, PyGrammar_FindDFA(g, start), ps->p_tree);
return ps;
}
int
PyParser_AddToken(parser_state *ps, int type, char *str,
int lineno, int col_offset, int *expected_ret)
{
int ilabel;
int err;
D(printf("Token %s/'%s' ... ", _PyParser_TokenNames[type], str));
/* Find out which label this token is */
ilabel = classify(ps, type, str);
if (ilabel < 0)
return E_SYNTAX;
/* Loop until the token is shifted or an error occurred */
for (;;) {
/* Fetch the current dfa and state */
dfa *d = ps->p_stack.s_top->s_dfa;
state *s = &d->d_state[ps->p_stack.s_top->s_state];
D(printf(" DFA '%s', state %d:",
d->d_name, ps->p_stack.s_top->s_state));
/* Check accelerator */
if (s->s_lower <= ilabel && ilabel < s->s_upper) {
int x = s->s_accel[ilabel - s->s_lower];
if (x != -1) {
if (x & (1<<7)) {
/* Push non-terminal */
int nt = (x >> 8) + NT_OFFSET;
int arrow = x & ((1<<7)-1);
dfa *d1 = PyGrammar_FindDFA(
ps->p_grammar, nt);
if ((err = push(&ps->p_stack, nt, d1,
arrow, lineno, col_offset)) > 0) {
D(printf(" MemError: push\n"));
return err;
}
D(printf(" Push ...\n"));
continue;
}
/* Shift the token */
if ((err = shift(&ps->p_stack, type, str,
x, lineno, col_offset)) > 0) {
D(printf(" MemError: shift.\n"));
return err;
}
D(printf(" Shift.\n"));
/* Pop while we are in an accept-only state */
while (s = &d->d_state
[ps->p_stack.s_top->s_state],
s->s_accept && s->s_narcs == 1) {
D(printf(" DFA '%s', state %d: "
"Direct pop.\n",
d->d_name,
ps->p_stack.s_top->s_state));
#ifdef PY_PARSER_REQUIRES_FUTURE_KEYWORD
#if 0
if (d->d_name[0] == 'i' &&
strcmp(d->d_name,
"import_stmt") == 0)
future_hack(ps);
#endif
#endif
s_pop(&ps->p_stack);
if (s_empty(&ps->p_stack)) {
D(printf(" ACCEPT.\n"));
return E_DONE;
}
d = ps->p_stack.s_top->s_dfa;
}
return E_OK;
}
}
static void
calcfirstset(grammar *g, dfa *d)
{
int i, j;
state *s;
arc *a;
int nsyms;
int *sym;
int nbits;
static bitset dummy;
bitset result;
int type;
dfa *d1;
label *l0;
if (Py_DebugFlag)
printf("Calculate FIRST set for '%s'\n", d->d_name);
if (dummy == NULL)
dummy = newbitset(1);
if (d->d_first == dummy) {
fprintf(stderr, "Left-recursion for '%s'\n", d->d_name);
return;
}
if (d->d_first != NULL) {
fprintf(stderr, "Re-calculating FIRST set for '%s' ???\n",
d->d_name);
}
d->d_first = dummy;
l0 = g->g_ll.ll_label;
nbits = g->g_ll.ll_nlabels;
result = newbitset(nbits);
sym = (int *)PyObject_MALLOC(sizeof(int));
if (sym == NULL)
Py_FatalError("no mem for new sym in calcfirstset");
nsyms = 1;
sym[0] = findlabel(&g->g_ll, d->d_type, (char *)NULL);
s = &d->d_state[d->d_initial];
for (i = 0; i < s->s_narcs; i++) {
a = &s->s_arc[i];
for (j = 0; j < nsyms; j++) {
if (sym[j] == a->a_lbl)
break;
}
if (j >= nsyms) { /* New label */
sym = (int *)PyObject_REALLOC(sym,
sizeof(int) * (nsyms + 1));
if (sym == NULL)
Py_FatalError(
"no mem to resize sym in calcfirstset");
sym[nsyms++] = a->a_lbl;
type = l0[a->a_lbl].lb_type;
if (ISNONTERMINAL(type)) {
d1 = PyGrammar_FindDFA(g, type);
if (d1->d_first == dummy) {
fprintf(stderr,
"Left-recursion below '%s'\n",
d->d_name);
}
else {
if (d1->d_first == NULL)
calcfirstset(g, d1);
mergebitset(result,
d1->d_first, nbits);
}
}
else if (ISTERMINAL(type)) {
addbit(result, a->a_lbl);
}
}
}
d->d_first = result;
if (Py_DebugFlag) {
printf("FIRST set for '%s': {", d->d_name);
for (i = 0; i < nbits; i++) {
if (testbit(result, i))
printf(" %s", PyGrammar_LabelRepr(&l0[i]));
}
printf(" }\n");
}
PyObject_FREE(sym);
}
int
PyParser_AddToken(register parser_state *ps, register int type, char *str,
int lineno, int *expected_ret)
{
register int ilabel;
int err;
D(printf("Token %s/'%s' ... ", _PyParser_TokenNames[type], str));
/* Find out which label this token is */
ilabel = classify(ps, type, str);
if (ilabel < 0)
return E_SYNTAX;
/* Loop until the token is shifted or an error occurred */
for (;;) {
/* Fetch the current dfa and state */
register dfa *d = ps->p_stack.s_top->s_dfa;
register state *s = &d->d_state[ps->p_stack.s_top->s_state];
D(printf(" DFA '%s', state %d:",
d->d_name, ps->p_stack.s_top->s_state));
/* Check accelerator */
if (s->s_lower <= ilabel && ilabel < s->s_upper) {
register int x = s->s_accel[ilabel - s->s_lower];
if (x != -1) {
if (x & (1<<7)) {
/* Push non-terminal */
int nt = (x >> 8) + NT_OFFSET;
int arrow = x & ((1<<7)-1);
dfa *d1 = PyGrammar_FindDFA(
ps->p_grammar, nt);
if ((err = push(&ps->p_stack, nt, d1,
arrow, lineno)) > 0) {
D(printf(" MemError: push\n"));
return err;
}
D(printf(" Push ...\n"));
continue;
}
/* Shift the token */
if ((err = shift(&ps->p_stack, type, str,
x, lineno)) > 0) {
D(printf(" MemError: shift.\n"));
return err;
}
D(printf(" Shift.\n"));
/* Pop while we are in an accept-only state */
while (s = &d->d_state
[ps->p_stack.s_top->s_state],
s->s_accept && s->s_narcs == 1) {
D(printf(" DFA '%s', state %d: "
"Direct pop.\n",
d->d_name,
ps->p_stack.s_top->s_state));
if (d->d_name[0] == 'i' &&
strcmp(d->d_name,
"import_stmt") == 0)
future_hack(ps);
s_pop(&ps->p_stack);
if (s_empty(&ps->p_stack)) {
D(printf(" ACCEPT.\n"));
return E_DONE;
}
d = ps->p_stack.s_top->s_dfa;
}
return E_OK;
}
}
if (s->s_accept) {
if (d->d_name[0] == 'i' &&
strcmp(d->d_name, "import_stmt") == 0)
future_hack(ps);
/* Pop this dfa and try again */
s_pop(&ps->p_stack);
D(printf(" Pop ...\n"));
if (s_empty(&ps->p_stack)) {
D(printf(" Error: bottom of stack.\n"));
return E_SYNTAX;
}
continue;
}
/* Stuck, report syntax error */
D(printf(" Error.\n"));
if (expected_ret) {
if (s->s_lower == s->s_upper - 1) {
/* Only one possible expected token */
*expected_ret = ps->p_grammar->
g_ll.ll_label[s->s_lower].lb_type;
}
else
*expected_ret = -1;
}
return E_SYNTAX;
}
