dwarf-collector

[Roland McGrath <roland at redhat dot com>]

I fiddled dwarf_output on roland/dwarf-collector some more on Monday,
but forgot to post about it.  I did the value_dispatch stuff to get the
constructors passed the collector pointer.  I did one attr_value flavor
(strings) in the collector to maybe indicate how others would go.

But then it occurred to me that perhaps the collector's sets should contain
the value_foobar objects that value_dispatch points to, rather than have a
"new value_foobar" for each that actually just holds a pointer/reference
into a collector value_set.  I started hacking for that on top of
roland/dwarf-collector (0206412) but did not get it to the point of compiling.
Non-compiling unfinished patch below.

The concept is that dwarf_output::value_wrapper::make can
be defined with a separate overload for each flavor, and
those will return a pointer into a collector value_set.


Thanks,
Roland



diff --git a/libdw/c++/dwarf_output b/libdw/c++/dwarf_output
index 6c5fe51..f1a0128 100644  
--- a/libdw/c++/dwarf_output
+++ b/libdw/c++/dwarf_output
@@ -271,6 +271,8 @@ namespace elfutils
 
   class dwarf_output
   {
+    friend class dwarf_output_collector;
+
   public:
     typedef dwarf_data::source_file source_file;
     typedef dwarf_data::directory_table directory_table;
@@ -288,10 +290,6 @@ namespace elfutils
   protected:
 
     template<typename input>
-    static inline const std::string &
-    collect_string (dwarf_output_collector *, const input &);
-
-    template<typename input>
     static inline const range_list &
     collect (dwarf_output_collector *, const typename input::range_list &);
 
@@ -334,28 +332,18 @@ namespace elfutils
     struct value_wrapper
       : public dwarf_data::value<dwarf_output, dwarf_output_collector *>
     {
-      struct value_string : public value_dispatch
+      // XXX Generic case, goes away when all types complete(?)
+      template<typename flavor, typename input>
+      static inline value_dispatch *
+      make (flavor *&result, const input &x, dwarf_output_collector *c)
       {
-	const std::string &_m_str;
-
-	template<typename string>
-	inline value_string (const string &s, dwarf_output_collector *c)
-	  : _m_str (collect_string (c, s))
-	{}
+	return result = new flavor (x, c);
+      }
 
-	inline operator const std::string & () const
-	{
-	  return _m_str;
-	}
-
-	std::string to_string () const
-	{
-	  std::string result ("\"");
-	  result += _m_str;
-	  result += "\"";
-	  return result;
-	}
-      };
+      template<typename input>
+      static inline value_dispatch *make (value_string *result,
+					  const input &x,
+					  dwarf_output_collector *);
     };
 
   public:
@@ -580,16 +568,18 @@ namespace elfutils
     friend class dwarf_output;
 
   private:
-    subr::value_set<std::string> _m_strings;
+    subr::value_set<dwarf_output::value_wrapper::value_string> _m_strings;
     subr::value_set<dwarf_output::range_list> _m_ranges;
 
   };
 
   template<typename input>
-  inline const std::string &
-  dwarf_output::collect_string (dwarf_output_collector *c, const input &s)
+  inline dwarf_output::value_wrapper::value_dispatch *
+  dwarf_output::value_wrapper::make
+  (dwarf_output::value_wrapper::value_string *result,
+   const input &x, dwarf_output_collector *c)
   {
-    return c->_m_strings.add (s);
+    return c->_m_strings.add (x);
   }
 
   template<typename input>