warnings: introduce -Wprecedence

[bison.git] / src / symtab.c

diff --git a/src/symtab.c b/src/symtab.c
index 3028df9fb5f84708a820b7e2f1f81a3818b9cfff..d3ad2fbbdfc4babffcde095f12ba5e78459cc894 100644 (file)
--- a/src/symtab.c
+++ b/src/symtab.c
@@ -52,6 +52,12 @@ location startsymbol_location;
 
 static symgraph **prec_nodes;
 
+/*-----------------------------------.
+| Store which associativity is used. |
+`-----------------------------------*/
+
+bool *used_assoc = NULL;
+
 /*---------------------------------.
 | Create a new symbol, named TAG.  |
 `---------------------------------*/
@@ -1051,6 +1057,45 @@ register_precedence (graphid first, graphid snd)
 }
 
 
+/*---------------------------------------.
+| 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.  |
 `--------------------------------------------------*/
@@ -1061,15 +1106,25 @@ 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
-          && s->assoc == precedence_assoc)
-        complain (&s->location, Wother,
-                  _("useless precedence for %s"), s->tag);
+          && !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);
     }
 }