Refactor the ELF support to allow ELF write suppport.

The refactoring allows better reuse of the ELF support and cleans up
some hacks from the generic file and archive handling improving the
separation of the file handling from the file format, ie ELF. The
handling of ELF object files and ELF object files inside archives
is cleaner.

The refactor cleaned up the symbol handling where the symbols now
reside in the ELF file object and references are take in symbol
pointer containers and symbol table containers.

The main purpose of the refactor is to allow support for creating
and writing ELF files.

Also added an rtems-syms command where special symbol support
can be added.

1 files changed, 55 insertions, 43 deletions

diff --git a/rld-files.h b/rld-files.h
index 976f60a..26c7723 100644
--- a/rld-files.h
+++ b/rld-files.h
@@ -1,10 +1,10 @@
 /*
- * Copyright (c) 2011, Chris Johns <chrisj@rtems.org> 
+ * Copyright (c) 2011, Chris Johns <chrisj@rtems.org>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
- * 
+ *
  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
@@ -26,7 +26,7 @@
  * handle. A handle is the object file with the specific file descriptor
  * created when the archive or object file was opened.
  *
- * 
+ *
  */
 
 #if !defined (_RLD_FILES_H_)
@@ -67,7 +67,7 @@ namespace rld
      * Container list of object files.
      */
     typedef std::list < object* > object_list;
-    
+
     /**
      * Split a path from a string with a delimiter to the path container. Add
      * only the paths that exist and ignore those that do not.
@@ -78,8 +78,8 @@ namespace rld
     /**
      * Make a path by joining the parts with required separator.
      */
-    void path_join (const std::string& path_, 
-                    const std::string& file_, 
+    void path_join (const std::string& path_,
+                    const std::string& file_,
                     std::string& joined);
 
     /**
@@ -91,7 +91,7 @@ namespace rld
      * Check the path is a directory.
      */
     bool check_directory (const std::string& path);
-    
+
     /**
      * Find the file given a container of paths and file names.
      *
@@ -99,7 +99,7 @@ namespace rld
      * @param name The name of the file to search for.
      * @param search_paths The container of paths to search.
      */
-    void find_file (std::string&       path, 
+    void find_file (std::string&       path,
                     const std::string& name,
                     paths&             search_paths);
 
@@ -323,15 +323,9 @@ namespace rld
       virtual int fd () const;
 
       /**
-       * The libelf reference. The ELF image could be in an archive container
-       * so set container to true to get the archive's reference.
+       * The ELF reference.
        */
-      virtual rld::elf::elf* elf (bool archive = false);
-
-      /**
-       * Set the libelf reference.
-       */
-      void set_elf (rld::elf::elf* elf);
+      elf::file& elf ();
 
       /**
        * A symbol in the image has been referenced.
@@ -353,21 +347,33 @@ namespace rld
       }
 
       /**
-       * Is the archive open ?
+       * Is the image open ?
        *
-       * @retval true The archive is open.
-       * @retval false The archive is not open.
+       * @retval true The image is open.
+       * @retval false The image is not open.
        */
       bool is_open () const {
         return fd () != -1;
       }
 
+      /**
+       * Is the image writable ?
+       *
+       * @retval true The image is writeable.
+       * @retval false The image is not writeable.
+       */
+      bool is_writeable () const {
+        return writeable;
+      }
+
     private:
+
       file      name_;       //< The name of the file.
       int       references_; //< The number of handles open.
       int       fd_;         //< The file descriptor of the archive.
-      elf::elf* elf_;        //< The libelf reference.
+      elf::file elf_;        //< The libelf reference.
       int       symbol_refs; //< The number of symbols references made.
+      bool      writeable;   //< The image is writable.
     };
 
     /**
@@ -396,6 +402,16 @@ namespace rld
       virtual ~archive ();
 
       /**
+       * Begin the ELF session.
+       */
+      void begin ();
+
+      /**
+       * End the ELF session.
+       */
+      void end ();
+
+      /**
        * Match the archive name.
        *
        * @param name The name of the archive to check.
@@ -413,7 +429,7 @@ namespace rld
        * Load objects.
        */
       void load_objects (objects& objs);
-      
+
       /**
        * Get the name.
        */
@@ -431,6 +447,7 @@ namespace rld
       void create (object_list& objects);
 
     private:
+
       /**
        * Read header.
        */
@@ -441,7 +458,7 @@ namespace rld
        */
       void add_object (objects&    objs,
                        const char* name,
-                       off_t       offset, 
+                       off_t       offset,
                        size_t      size);
 
       /**
@@ -528,7 +545,7 @@ namespace rld
       /**
        * Get the string from the string table.
        */
-      std::string get_string (int section, size_t offset);
+//      std::string get_string (int section, size_t offset);
 
       /**
        * References to the image.
@@ -546,12 +563,6 @@ namespace rld
       virtual int fd () const;
 
       /**
-       * The libelf reference. The ELF image could be in an archive container
-       * so set container to true to get the archive's reference.
-       */
-      virtual elf::elf* elf (bool archive = false);
-
-      /**
        * A symbol in the image has been referenced.
        */
       virtual void symbol_referenced ();
@@ -562,6 +573,7 @@ namespace rld
        */
       archive* get_archive ();
 
+#if 0
       /**
        * Number of sections in the object file.
        */
@@ -571,6 +583,7 @@ namespace rld
        * Section string index.
        */
       int section_strings () const;
+#endif
 
       /**
        * Return the unresolved symbol table for this object file.
@@ -580,14 +593,13 @@ namespace rld
       /**
        * Return the list external symbols.
        */
-      rld::symbols::list& external_symbols ();
+      rld::symbols::pointers& external_symbols ();
 
     private:
-      archive*            archive_;   //< Points to the archive if part of an
-                                      //  archive.
-      elf::elf_ehdr       ehdr;       //< The ELF header.
-      rld::symbols::table unresolved; //< This object's unresolved symbols.
-      rld::symbols::list  externals;  //< This object's external symbols.
+      archive*               archive_;   //< Points to the archive if part of
+                                         //  an archive.
+      rld::symbols::table    unresolved; //< This object's unresolved symbols.
+      rld::symbols::pointers externals;  //< This object's external symbols.
 
       /**
        * Cannot copy via a copy constructor.
@@ -644,22 +656,22 @@ namespace rld
       void add_libraries (paths& paths__);
 
       /**
-       * Being an ELF session on an archive.
+       * Being a session on an archive.
        */
       void archive_begin (const std::string& path);
 
       /**
-       * End an ELF session on an archive.
+       * End a session on an archive.
        */
       void archive_end (const std::string& path);
 
       /**
-       * Being ELF sessions on all archives.
+       * Being sessions on all archives.
        */
       void archives_begin ();
 
       /**
-       * End the archive elf sessions.
+       * End the archive sessions.
        */
       void archives_end ();
 
@@ -667,13 +679,13 @@ namespace rld
        * Collect the object names and add them to the cache.
        */
       void collect_object_files ();
-      
+
       /**
        * Collect the object file names by verifing the paths to the files are
        * valid or read the object file names contained in any archives.
        */
       void collect_object_files (const std::string& path);
-      
+
       /**
        * Load the symbols into the symbol table.
        *
@@ -691,12 +703,12 @@ namespace rld
        * Get the archives.
        */
       archives& get_archives ();
- 
+
       /**
        * Get the objects inlcuding those in archives.
        */
       objects& get_objects ();
- 
+
       /**
        * Get the added objects. Does not include the ones in th archives.
        */