Merge remote-tracking branch 'origin/maint'

* origin/maint:
  tests: split a large test case into several smaller ones
  package: a bit of trouble shooting indications
  doc: liby's main arms the internationalization
  bison: avoid warnings from static code analysis
  c++: fix the use of destructors when variants are enabled
  style: tests: simplify the handling of some C++ tests
  c++: symbols can be empty, so use it
  c++: variants: don't leak the lookahead in error recovery
  c++: provide a means to clear symbols
  c++: clean up the handling of empty symbols
  c++: comment and style changes
  c++: variants: comparing addresses of typeid.name() is undefined
  c++: locations: complete the API and fix comments
  build: do not clean figure sources in make clean

src/scan-code.l

@@ -711,7 +711,7 @@ handle_action_dollar (symbol_list *rule, char *text, location dollar_loc)
                       "]b4_rhs_value(%d, %d, ", effective_rule_length, n);
       obstack_quote (&obstack_for_string, type_name);
       obstack_sgrow (&obstack_for_string, ")[");
-      if (n > 0)
+      if (0 < n)
         symbol_list_n_get (effective_rule, n)->action_props.is_value_used =
           true;
       break;

src/symlist.c

@@ -21,7 +21,6 @@
 #include <config.h>
 #include "system.h"
 
-#include "complain.h"
 #include "symlist.h"
 
 /*--------------------------------------.
@@ -174,22 +173,17 @@ symbol_list *
 symbol_list_n_get (symbol_list *l, int n)
 {
   int i;
-
-  if (n < 0)
-    return NULL;
-
+  aver (0 <= n);
   for (i = 0; i < n; ++i)
     {
       l = l->next;
-      if (l == NULL
-          || (l->content_type == SYMLIST_SYMBOL && l->content.sym == NULL))
-        return NULL;
+      aver (l);
     }
-
+  aver (l->content_type == SYMLIST_SYMBOL);
+  aver (l->content.sym);
   return l;
 }
 
-
 /*--------------------------------------------------------------.
 | Get the data type (alternative in the union) of the value for |
 | symbol N in symbol list L.                                    |
@@ -198,21 +192,14 @@ symbol_list_n_get (symbol_list *l, int n)
 uniqstr
 symbol_list_n_type_name_get (symbol_list *l, location loc, int n)
 {
-  l = symbol_list_n_get (l, n);
-  if (!l)
-    {
-      complain (&loc, complaint, _("invalid $ value: $%d"), n);
-      return NULL;
-    }
-  aver (l->content_type == SYMLIST_SYMBOL);
-  return l->content.sym->content->type_name;
+  return symbol_list_n_get (l, n)->content.sym->content->type_name;
 }
 
 bool
 symbol_list_null (symbol_list *node)
 {
-  return !node ||
-    (node->content_type == SYMLIST_SYMBOL && !(node->content.sym));
+  return (!node
+          || (node->content_type == SYMLIST_SYMBOL && !node->content.sym));
 }
 
 void

src/symlist.h

@@ -116,7 +116,10 @@ void symbol_list_free (symbol_list *list);
 /** Return the length of \c l. */
 int symbol_list_length (symbol_list const *l);
 
-/** Get item \c n in symbol list \c l.  */
+/** Get item \c n in symbol list \c l.
+ ** \pre  0 <= n
+ ** \post res != NULL
+ **/
 symbol_list *symbol_list_n_get (symbol_list *l, int n);
 
 /* Get the data type (alternative in the union) of the value for