Fix managing weak symbols.

Weak symbols where not being managed correctly. The symbols table
is now a class with externals and weaks as separate symtabs so
the externals can be searched first then the weaks and if not
found an unresolved error is raised. This was found creating
a libbsdport RAP file where the drivers in the all driver table
resolved to the weak symbols and so linking in nothing.

Fixing the weak symbols as found in the libbsdport library
triggered a new resolver bug. The object files now contain the
resolver state and this is used to determine if an object file
has been resolved or is currently being resolved avoiding
rescursive loops with dependent object files.

The resolver trace output is a little easier to read.

1 files changed, 31 insertions, 4 deletions

diff --git a/rld-files.h b/rld-files.h
index f579626..4b5362e 100644
--- a/rld-files.h
+++ b/rld-files.h
@@ -56,12 +56,12 @@ namespace rld
     /**
      * Container of archive files.
      */
-    typedef std::map < std::string, archive* > archives;
+    typedef std::map < const std::string, archive* > archives;
 
     /**
      * Container of object files.
      */
-    typedef std::map < std::string, object* > objects;
+    typedef std::map < const std::string, object* > objects;
 
     /**
      * Container list of object files.
@@ -700,7 +700,7 @@ namespace rld
       /**
        * Return the unresolved symbol table for this object file.
        */
-      symbols::table& unresolved_symbols ();
+      symbols::symtab& unresolved_symbols ();
 
       /**
        * Return the list external symbols.
@@ -741,13 +741,40 @@ namespace rld
        */
       const section& get_section (int index) const;
 
+      /**
+       * Set the object file's resolving flag.
+       */
+      void resolve_set ();
+
+      /**
+       * Clear the object file's resolving flag.
+       */
+      void resolve_clear ();
+
+      /**
+       * The resolving state.
+       */
+      bool resolving () const;
+
+      /**
+       * Set the object file resolved flag.
+       */
+      void resolved_set ();
+
+      /**
+       * The resolved state.
+       */
+      bool resolved () const;
+
     private:
       archive*          archive_;   //< Points to the archive if part of an
                                     //  archive.
       bool              valid_;     //< If true begin has run and finished.
-      symbols::table    unresolved; //< This object's unresolved symbols.
+      symbols::symtab   unresolved; //< This object's unresolved symbols.
       symbols::pointers externals;  //< This object's external symbols.
       sections          secs;       //< The sections.
+      bool              resolving_; //< The object is being resolved.
+      bool              resolved_;  //< The object has been resolved.
 
       /**
        * Cannot copy via a copy constructor.