adding check for duplicated symbols

BitKeeper/etc/logging_ok:
  Logging to logging@openlogging.org accepted

BitKeeper/etc/logging_ok

@@ -90,6 +90,7 @@ tonu@x153.internalnet
 tonu@x3.internalnet
 venu@myvenu.com
 venu@work.mysql.com
+vva@eagle.mysql.r18.ru
 vva@genie.(none)
 walrus@mysql.com
 wax@mysql.com

sql/gen_lex_hash.cc

@@ -200,19 +200,21 @@ void insert_sql_functions()
   }
 }
 
-void generate_find_structs()
+void calc_length()
 {
-  root_by_len= 0;
-  max_len=0;
-  size_t i;
-
   SYMBOL *cur, *end= symbols + array_elements(symbols);
   for (cur= symbols; cur < end; cur++)
     cur->length=(uchar) strlen(cur->name);
   end= sql_functions + array_elements(sql_functions);
   for (cur= sql_functions; cur<end; cur++)
     cur->length=(uchar) strlen(cur->name);
-  
+}
+
+void generate_find_structs()
+{
+  root_by_len= 0;
+  max_len=0;
+
   insert_symbols();
 
   root_by_len2= root_by_len;
@@ -351,6 +353,45 @@ static int get_options(int argc, char **argv)
   return(0);
 }
 
+int check_dup_symbols(SYMBOL *s1, SYMBOL *s2)
+{
+  if (s1->length!=s2->length || strncmp(s1->name,s2->name,s1->length))
+    return 0;
+
+  const char *err_tmpl= "\ngen_lex_hash fatal error : \
+Unfortunately gen_lex_hash can not generate a hash,\n since \
+your lex.h has duplicate definition for a symbol \"%s\"\n\n";
+  printf (err_tmpl,s1->name);
+  fprintf (stderr,err_tmpl,s1->name);
+
+  return 1;
+}
+
+int check_duplicates()
+{
+  SYMBOL *cur1, *cur2, *s_end, *f_end;
+
+  s_end= symbols + array_elements(symbols);
+  f_end= sql_functions + array_elements(sql_functions);
+
+  for (cur1= symbols; cur1<s_end; cur1++)
+  {
+    for (cur2= cur1+1; cur2<s_end; cur2++)
+      if (check_dup_symbols(cur1,cur2))
+	return 1;
+    for (cur2= sql_functions; cur2<f_end; cur2++)
+      if (check_dup_symbols(cur1,cur2))
+	return 1;
+  }
+
+  for (cur1= sql_functions; cur1<f_end; cur1++)
+    for (cur2= cur1+1; cur2< f_end; cur2++)
+      if (check_dup_symbols(cur1,cur2))
+	return 1;
+
+  return 0;
+}
+
 int main(int argc,char **argv)
 {
   MY_INIT(argv[0]);
@@ -376,6 +417,11 @@ int main(int argc,char **argv)
  a perfect\nhash function */\n\n");
   printf("#include \"lex.h\"\n\n");
 
+  calc_length();
+
+  if (check_duplicates())
+    exit(1);
+
   generate_find_structs();
   print_find_structs();