2004-07-07  Guilherme Destefani <gd@helixbrasil.com>

	Adding linker script command TEMPORARY
	Useful to use a temporary symbol just for calculation,
	that's not stored in the bfd backend

--- ld/ld.texinfo	2004-04-12 19:56:35.000000000 +0000
+++ ld/ld.texinfo	2004-07-07 21:59:50.000000000 +0000
@@ -2632,6 +2632,7 @@
 @menu
 * Simple Assignments::		Simple Assignments
 * PROVIDE::			PROVIDE
+* TEMPORARY::			TEMPORARY
 @end menu
 
 @node Simple Assignments
@@ -2724,6 +2725,16 @@
 If the program references @samp{etext} but does not define it, the
 linker will use the definition in the linker script.
 
+@node TEMPORARY
+@subsection TEMPORARY
+@cindex TEMPORARY
+In some cases, it is desirable for a linker script to use a name
+ just to hold a value without sending a symbol to the bfd backend.
+The @code{TEMPORARY} keyword may be used to define that type of variable.
+The syntax is:
+@code{TEMPORARY(@var{symbol} = @var{expression})}.
+
+
 @node SECTIONS
 @section SECTIONS Command
 @kindex SECTIONS
--- ld/ldexp.c	2004-03-03 20:24:34.000000000 +0000
+++ ld/ldexp.c	2004-07-07 21:59:50.000000000 +0000
@@ -456,7 +456,8 @@
 	   bfd_vma dot)
 {
   etree_value_type result;
-
+  temporary_variable_list_type *temporary;
+	
   result.valid_p = FALSE;
   
   switch (tree->type.node_code)
@@ -494,6 +495,10 @@
 	  if (allocation_done != lang_first_phase_enum)
 	    result = new_rel_from_section (dot, current_section);
 	}
+    else if ( (temporary = lang_temporary_lookup(tree->name.name) ) )
+    {
+      result = new_abs(temporary->value);
+    }
       else if (allocation_done != lang_first_phase_enum)
 	{
 	  struct bfd_link_hash_entry *h;
@@ -657,6 +662,7 @@
     case etree_assign:
     case etree_provide:
     case etree_provided:
+    case etree_temporary:
       if (tree->assign.dst[0] == '.' && tree->assign.dst[1] == 0)
 	{
 	  /* Assignment to dot can only be done during allocation.  */
@@ -698,6 +704,12 @@
 				  current_section, allocation_done,
 				  dot, dotp);
 	  if (result.valid_p)
+     {
+       if(tree->type.node_class == etree_temporary)
+       {
+         lang_temporary_set(tree->assign.dst,result.value);
+	   }
+        else
 	    {
 	      bfd_boolean create;
 	      struct bfd_link_hash_entry *h;
@@ -734,6 +746,7 @@
 		    tree->type.node_class = etree_provided;
 		}
 	    }
+     }
 	}
       break;
 
@@ -871,6 +884,21 @@
   return n;
 }
 
+/* Handle TEMPORARY.  */
+
+etree_type *
+exp_temporary (const char *dst, etree_type *src)
+{
+  etree_type *n;
+
+  n = stat_alloc (sizeof (n->assign));
+  n->assign.type.node_code = '=';
+  n->assign.type.node_class = etree_temporary;
+  n->assign.src = src;
+  n->assign.dst = dst;
+  return n;
+}
+
 /* Handle ASSERT.  */
 
 etree_type *
--- ld/ldexp.h	2004-01-14 21:07:52.000000000 +0000
+++ ld/ldexp.h	2004-07-07 21:59:50.000000000 +0000
@@ -40,6 +40,7 @@
     etree_assign,
     etree_provide,
     etree_provided,
+    etree_temporary,
     etree_undef,
     etree_unspec,
     etree_value,
@@ -126,6 +127,8 @@
   (int, const char *, etree_type *);
 etree_type *exp_provide
   (const char *, etree_type *);
+etree_type *exp_temporary
+  (const char *, etree_type *);
 etree_type *exp_assert
   (etree_type *, const char *);
 void exp_print_tree
--- ld/ldgram.y	2004-03-03 20:24:34.000000000 +0000
+++ ld/ldgram.y	2004-07-07 22:05:11.183145976 +0000
@@ -147,7 +147,7 @@
 %type <name>  filename
 %token CHIP LIST SECT ABSOLUTE  LOAD NEWLINE ENDWORD ORDER NAMEWORD ASSERT_K
 %token FORMAT PUBLIC DEFSYMEND BASE ALIAS TRUNCATE REL
-%token INPUT_SCRIPT INPUT_MRI_SCRIPT INPUT_DEFSYM CASE EXTERN START
+%token INPUT_SCRIPT INPUT_MRI_SCRIPT INPUT_DEFSYM CASE EXTERN START TEMPORARY
 %token <name> VERS_TAG VERS_IDENTIFIER
 %token GLOBAL LOCAL VERSIONK INPUT_VERSION_SCRIPT
 %token KEEP
@@ -611,6 +611,10 @@
 		{
 		  lang_add_assignment (exp_provide ($3, $5));
 		}
+	|	TEMPORARY '(' NAME '=' mustbe_exp ')'
+		{
+		  lang_add_assignment (exp_temporary ($3, $5));
+		}
 	;
 
 
--- ld/ldlang.c	2004-04-12 19:56:36.000000000 +0000
+++ ld/ldlang.c	2004-07-07 21:59:50.000000000 +0000
@@ -643,6 +643,55 @@
   return lookup;
 }
 
+/*	A temporary variable can be used to store a value without
+	saving it on the bfd backends
+	The syntax to declare a a temporary variable is:
+	TEMPORARAY ( VARNAME = EXPRESSION );
+	Then the value can be used later on like any other symbol.
+	The linker use a liked list to store those values in memory.
+*/
+
+static temporary_variable_list_type *lang_temporary_list = NULL;
+static temporary_variable_list_type **lang_temporary_list_tail = &lang_temporary_list;
+
+temporary_variable_list_type *lang_temporary_lookup(char const *const name)
+{
+  temporary_variable_list_type *temp;
+
+  if (name == NULL)
+    return NULL;
+
+  for (temp = lang_temporary_list; temp != NULL; temp = temp->next)
+    if (strcmp (temp->name, name) == 0)
+		break;
+  return temp;
+}
+
+temporary_variable_list_type *lang_temporary_set(char const *const name, bfd_vma value)
+{
+  temporary_variable_list_type *temp;
+
+  if (! name[0] )
+	  return NULL;
+	
+  if ( (temp = lang_temporary_lookup (name)) )
+	  /*Reuse element already defined*/
+	  free (temp->name);
+  else
+  {
+	  /*Allocate a new element and link it to list*/
+	  temp = xmalloc(sizeof(temporary_variable_list_type));
+	  temp->next = NULL;
+	  
+	  *lang_temporary_list_tail = temp;
+	  lang_temporary_list_tail = &temp->next;
+  }
+
+  temp->name = xstrdup(name);
+  temp->value = value;
+  return temp;  
+}
+
 static void
 lang_map_flags (flagword flag)
 {
--- ld/ldlang.h	2004-04-12 19:56:36.000000000 +0000
+++ ld/ldlang.h	2004-07-07 21:59:50.000000000 +0000
@@ -103,6 +103,14 @@
   const char *name;
 } lang_output_statement_type;
 
+/* Used to store temporary link script variables in memory*/
+typedef struct temporary_variable_list_struct
+{
+    struct temporary_variable_list_struct *next;
+    bfd_vma value;
+    char *name;	
+} temporary_variable_list_type;
+
 /* Section types specified in a linker script.  */
 
 enum section_type
@@ -426,6 +434,10 @@
   (const char *const, bfd_boolean);
 extern lang_memory_region_type *lang_memory_region_default
   (asection *);
+extern temporary_variable_list_type *lang_temporary_lookup
+  (char const *const);
+extern temporary_variable_list_type *lang_temporary_set
+  (char const *const, bfd_vma);
 extern void lang_map
   (void);
 extern void lang_set_flags
--- ld/ldlex.l	2004-04-12 19:56:36.000000000 +0000
+++ ld/ldlex.l	2004-07-07 22:08:07.602326184 +0000
@@ -268,6 +268,7 @@
 <BOTH,SCRIPT>"INPUT"			{ RTOKEN(INPUT);}
 <EXPRESSION,BOTH,SCRIPT>"GROUP"		{ RTOKEN(GROUP);}
 <EXPRESSION,BOTH,SCRIPT>"DEFINED"		{ RTOKEN(DEFINED);}
+<EXPRESSION,BOTH,SCRIPT>"TEMPORARY"		{ RTOKEN(TEMPORARY); }
 <BOTH,SCRIPT>"CREATE_OBJECT_SYMBOLS"	{ RTOKEN(CREATE_OBJECT_SYMBOLS);}
 <BOTH,SCRIPT>"CONSTRUCTORS"		{ RTOKEN( CONSTRUCTORS);}
 <BOTH,SCRIPT>"FORCE_COMMON_ALLOCATION" { RTOKEN(FORCE_COMMON_ALLOCATION);}
--- ld/ldexp.c	2004-07-07 22:26:51.276778088 -0300
+++ ld/ldexp.c	2004-07-07 22:25:06.401721520 -0300
@@ -989,6 +989,11 @@
       exp_print_tree (tree->assign.src);
       fprintf (config.map_file, ")");
       break;
+    case etree_temporary:
+      fprintf (config.map_file, "TEMPORARY (%s, ", tree->assign.dst);
+      exp_print_tree (tree->assign.src);
+      fprintf (config.map_file, ")");
+      break;
     case etree_binary:
       fprintf (config.map_file, "(");
       exp_print_tree (tree->binary.lhs);