static void
s_pop(stack *s)
{
if (s_empty(s))
Py_FatalError("s_pop: parser stack underflow -- FATAL");
s->s_top++;
}
static int
shift(stack *s, int type, char *str, int newstate, int lineno, int col_offset)
{
int err;
assert(!s_empty(s));
err = PyNode_AddChild(s->s_top->s_parent, type, str, lineno, col_offset);
if (err)
return err;
s->s_top->s_state = newstate;
return 0;
}
static int
push(stack *s, int type, dfa *d, int newstate, int lineno, int col_offset)
{
int err;
node *n;
n = s->s_top->s_parent;
assert(!s_empty(s));
err = PyNode_AddChild(n, type, (char *)NULL, lineno, col_offset);
if (err)
return err;
s->s_top->s_state = newstate;
return s_push(s, d, CHILD(n, NCH(n)-1));
}
static int
shift(register stack *s, int type, char *str, int newstate, int lineno, int col_offset)
{
int err;
assert(!s_empty(s));
err = PyNode_AddChild(s->s_top->s_parent, type, str, lineno, col_offset);
// pgbovine
//printf("shift->PyNode_AddChild: '%s' L:%d,C:%d\n", str, lineno, col_offset);
if (err)
return err;
s->s_top->s_state = newstate;
return 0;
}
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;
}
}
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;
}
