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cpython/Parser/grammar1.c
Barry Warsaw b2e5794870 bpo-31338 (#3374)
* Add Py_UNREACHABLE() as an alias to abort().
* Use Py_UNREACHABLE() instead of assert(0)
* Convert more unreachable code to use Py_UNREACHABLE()
* Document Py_UNREACHABLE() and a few other macros.
2017-09-14 18:13:16 -07:00

61 lines
1.3 KiB
C

/* Grammar subroutines needed by parser */
#include "Python.h"
#include "pgenheaders.h"
#include "grammar.h"
#include "token.h"
/* Return the DFA for the given type */
dfa *
PyGrammar_FindDFA(grammar *g, int type)
{
dfa *d;
#if 1
/* Massive speed-up */
d = &g->g_dfa[type - NT_OFFSET];
assert(d->d_type == type);
return d;
#else
/* Old, slow version */
int i;
for (i = g->g_ndfas, d = g->g_dfa; --i >= 0; d++) {
if (d->d_type == type)
return d;
}
Py_UNREACHABLE();
#endif
}
const char *
PyGrammar_LabelRepr(label *lb)
{
static char buf[100];
if (lb->lb_type == ENDMARKER)
return "EMPTY";
else if (ISNONTERMINAL(lb->lb_type)) {
if (lb->lb_str == NULL) {
PyOS_snprintf(buf, sizeof(buf), "NT%d", lb->lb_type);
return buf;
}
else
return lb->lb_str;
}
else if (lb->lb_type < N_TOKENS) {
if (lb->lb_str == NULL)
return _PyParser_TokenNames[lb->lb_type];
else {
PyOS_snprintf(buf, sizeof(buf), "%.32s(%.32s)",
_PyParser_TokenNames[lb->lb_type], lb->lb_str);
return buf;
}
}
else {
Py_FatalError("invalid label");
return NULL;
}
}