Resolve unresolved externals when loading object files.

Object files that depend on each other will cause an unresolved
external. The change lets object files load with unresolved
externals and will resolve them when the object file with the
external is loaded.

A common table of symbol strings and relocation records is maintained.
The symbol string is shared by each object file that is unresolved.
Each relocation record that references the symbol is held. The table
is a series of small blocks that compact as symbols are resolved. The
number of symbols left unresolved is typically small this design avoids
fragmentation of the heap memory.

1 files changed, 23 insertions, 8 deletions

diff --git a/rtl-sym.c b/rtl-sym.c
index 7e5eb03..0e29693 100644
--- a/rtl-sym.c
+++ b/rtl-sym.c
@@ -60,7 +60,9 @@ bool
 rtems_rtl_symbol_table_open (rtems_rtl_symbols_t* symbols,
                              size_t               buckets)
 {
-  symbols->buckets = calloc (buckets, sizeof (rtems_chain_control));
+  symbols->buckets = rtems_rtl_alloc_new (RTEMS_RTL_ALLOC_SYMBOL,
+                                          buckets * sizeof (rtems_chain_control),
+                                          true);
   if (!symbols->buckets)
   {
     rtems_rtl_set_error (ENOMEM, "no memory for global symbol table");
@@ -76,7 +78,7 @@ rtems_rtl_symbol_table_open (rtems_rtl_symbols_t* symbols,
 void
 rtems_rtl_symbol_table_close (rtems_rtl_symbols_t* symbols)
 {
-  free (symbols->buckets);
+  rtems_rtl_alloc_del (RTEMS_RTL_ALLOC_SYMBOL, symbols->buckets);
 }
 
 bool
@@ -123,7 +125,7 @@ rtems_rtl_symbol_global_add (rtems_rtl_obj_t*     obj,
 
   if (rtems_rtl_trace (RTEMS_RTL_TRACE_GLOBAL_SYM))
     printf ("rtl: global symbol add: %zi\n", count);
-  
+
   obj->global_size = count * sizeof (rtems_rtl_obj_sym_t);
   obj->global_table = rtems_rtl_alloc_new (RTEMS_RTL_ALLOC_SYMBOL,
                                            obj->global_size, true);
@@ -133,7 +135,7 @@ rtems_rtl_symbol_global_add (rtems_rtl_obj_t*     obj,
     rtems_rtl_set_error (ENOMEM, "no memory for global symbols");
     return false;
   }
-  
+
   symbols = rtems_rtl_global_symbols ();
 
   s = 0;
@@ -151,7 +153,7 @@ rtems_rtl_symbol_global_add (rtems_rtl_obj_t*     obj,
       void*   value;
     } copy_voidp;
     int b;
-    
+
     sym->name = (const char*) &esyms[s];
     s += strlen (sym->name) + 1;
     for (b = 0; b < sizeof (void*); ++b, ++s)
@@ -187,13 +189,13 @@ rtems_rtl_symbol_global_find (const char* name)
   {
     rtems_rtl_obj_sym_t* sym = (rtems_rtl_obj_sym_t*) node;
     /*
-     * Use the hash. I could add this to the symbol but it uses more memory..
+     * Use the hash. I could add this to the symbol but it uses more memory.
      */
     if (strcmp (name, sym->name) == 0)
       return sym;
     node = rtems_chain_next (node);
   }
-  
+
   return NULL;
 }
 
@@ -213,7 +215,20 @@ rtems_rtl_symbol_obj_find (rtems_rtl_obj_t* obj, const char* name)
 }
 
 void
-rtems_rtl_obj_symbol_erase (rtems_rtl_obj_t* obj)
+rtems_rtl_symbol_obj_add (rtems_rtl_obj_t* obj)
+{
+  rtems_rtl_symbols_t* symbols;
+  rtems_rtl_obj_sym_t* sym;
+  size_t               s;
+
+  symbols = rtems_rtl_global_symbols ();
+
+  for (s = 0, sym = obj->global_table; s < obj->global_syms; ++s, ++sym)
+    rtems_rtl_symbol_global_insert (symbols, sym);
+}
+
+void
+rtems_rtl_symbol_obj_erase (rtems_rtl_obj_t* obj)
 {
   if (obj->global_table)
   {