+ complain (&startsymbol_location, fatal,
+ _("the start symbol %s is a token"),
+ startsymbol->tag);
+}
+
+/*---------------------------------.
+| Initialize relation graph nodes. |
+`---------------------------------*/
+
+static void
+init_prec_nodes (void)
+{
+ int i;
+ prec_nodes = xcalloc (nsyms, sizeof *prec_nodes);
+ for (i = 0; i < nsyms; ++i)
+ {
+ prec_nodes[i] = xmalloc (sizeof *prec_nodes[i]);
+ symgraph *s = prec_nodes[i];
+ s->id = i;
+ s->succ = 0;
+ s->pred = 0;
+ }
+}
+
+/*----------------.
+| Create a link. |
+`----------------*/
+
+static symgraphlink *
+symgraphlink_new (graphid id, symgraphlink *next)
+{
+ symgraphlink *l = xmalloc (sizeof *l);
+ l->id = id;
+ l->next = next;
+ return l;
+}
+
+
+/*------------------------------------------------------------------.
+| Register the second symbol of the precedence relation, and return |
+| whether this relation is new. Use only in register_precedence. |
+`------------------------------------------------------------------*/
+
+static bool
+register_precedence_second_symbol (symgraphlink **first, graphid sym)
+{
+ if (!*first || sym < (*first)->id)
+ *first = symgraphlink_new (sym, *first);
+ else
+ {
+ symgraphlink *slist = *first;
+
+ while (slist->next && slist->next->id <= sym)
+ slist = slist->next;
+
+ if (slist->id == sym)
+ /* Relation already present. */
+ return false;
+
+ slist->next = symgraphlink_new (sym, slist->next);
+ }
+ return true;
+}
+
+/*------------------------------------------------------------------.
+| Register a new relation between symbols as used. The first symbol |
+| has a greater precedence than the second one. |
+`------------------------------------------------------------------*/
+
+void
+register_precedence (graphid first, graphid snd)
+{
+ if (!prec_nodes)
+ init_prec_nodes ();
+ register_precedence_second_symbol (&(prec_nodes[first]->succ), snd);
+ register_precedence_second_symbol (&(prec_nodes[snd]->pred), first);
+}
+
+
+/*---------------------------------------.
+| Deep clear a linked / adjacency list). |
+`---------------------------------------*/
+
+static void
+linkedlist_free (symgraphlink *node)
+{
+ if (node)
+ {
+ while (node->next)
+ {
+ symgraphlink *tmp = node->next;
+ free (node);
+ node = tmp;
+ }
+ free (node);
+ }
+}
+
+/*----------------------------------------------.
+| Clear and destroy association tracking table. |
+`----------------------------------------------*/
+
+static void
+assoc_free (void)
+{
+ int i;
+ for (i = 0; i < nsyms; ++i)
+ {
+ linkedlist_free (prec_nodes[i]->pred);
+ linkedlist_free (prec_nodes[i]->succ);
+ free (prec_nodes[i]);
+ }
+ free (prec_nodes);
+}
+
+/*---------------------------------------.
+| Initialize association tracking table. |
+`---------------------------------------*/
+
+static void
+init_assoc (void)
+{
+ graphid i;
+ used_assoc = xcalloc(nsyms, sizeof(*used_assoc));
+ for (i = 0; i < nsyms; ++i)
+ used_assoc[i] = false;
+}
+
+/*------------------------------------------------------------------.
+| Test if the associativity for the symbols is defined and useless. |
+`------------------------------------------------------------------*/
+
+static inline bool
+is_assoc_useless (symbol *s)
+{
+ return s
+ && s->assoc != undef_assoc
+ && s->assoc != precedence_assoc
+ && !used_assoc[s->number];
+}
+
+/*-------------------------------.
+| Register a used associativity. |
+`-------------------------------*/
+
+void
+register_assoc (graphid i, graphid j)
+{
+ if (!used_assoc)
+ init_assoc ();
+ used_assoc[i] = true;
+ used_assoc[j] = true;
+}
+
+/*--------------------------------------------------.
+| Print a warning for unused precedence relations. |
+`--------------------------------------------------*/
+
+void
+print_precedence_warnings (void)
+{
+ int i;
+ if (!prec_nodes)
+ init_prec_nodes ();
+ if (!used_assoc)
+ init_assoc ();
+ for (i = 0; i < nsyms; ++i)
+ {
+ symbol *s = symbols[i];
+ if (s
+ && s->prec != 0
+ && !prec_nodes[i]->pred
+ && !prec_nodes[i]->succ)
+ {
+ if (is_assoc_useless (s))
+ complain (&s->location, Wprecedence,
+ _("useless precedence and associativity for %s"), s->tag);
+ else if (s->assoc == precedence_assoc)
+ complain (&s->location, Wprecedence,
+ _("useless precedence for %s"), s->tag);
+ }
+ else if (is_assoc_useless (s))
+ complain (&s->location, Wprecedence,
+ _("useless associativity for %s, use %%precedence"), s->tag);
+ }
+ free (used_assoc);
+ assoc_free ();
projects / bison.git / blobdiff