Add function to determine the scope where a variable is declared

diff --git a/symbol_table.c b/symbol_table.c
index 4e043d1..5d748f4 100644 (file)
--- a/symbol_table.c
+++ b/symbol_table.c
@@ -269,6 +269,36 @@ _mesa_symbol_table_iterator_next(struct _mesa_symbol_table_iterator *iter)
 }
 
 
+/**
+ * Determine the scope "distance" of a symbol from the current scope
+ *
+ * \return
+ * A non-negative number for the number of scopes between the current scope
+ * and the scope where a symbol was defined.  A value of zero means the current
+ * scope.  A negative number if the symbol does not exist.
+ */
+int
+_mesa_symbol_table_symbol_scope(struct _mesa_symbol_table *table,
+                               int name_space, const char *name)
+{
+    struct symbol_header *const hdr = find_symbol(table, name);
+    struct symbol *sym;
+
+    if (hdr != NULL) {
+       for (sym = hdr->symbols; sym != NULL; sym = sym->next_with_same_name) {
+         assert(sym->hdr == hdr);
+
+         if ((name_space == -1) || (sym->name_space == name_space)) {
+            assert(sym->depth <= table->depth);
+            return sym->depth - table->depth;
+         }
+       }
+    }
+
+    return -1;
+}
+
+
 void *
 _mesa_symbol_table_find_symbol(struct _mesa_symbol_table *table,
                                int name_space, const char *name)

diff --git a/symbol_table.h b/symbol_table.h
index d3f65e3..3a9994c 100644 (file)
--- a/symbol_table.h
+++ b/symbol_table.h
@@ -37,6 +37,9 @@ extern void _mesa_symbol_table_pop_scope(struct _mesa_symbol_table *table);
 extern int _mesa_symbol_table_add_symbol(struct _mesa_symbol_table *symtab,
     int name_space, const char *name, void *declaration);
 
+extern int _mesa_symbol_table_symbol_scope(struct _mesa_symbol_table *table,
+    int name_space, const char *name);
+
 extern void *_mesa_symbol_table_find_symbol(
     struct _mesa_symbol_table *symtab, int name_space, const char *name);