Re: [PATCH 2.5/4 v2] GAS: Make new fake labels when cloning a symbol

["Maciej W. Rozycki" <macro at codesourcery dot com>]

On Mon, 1 Nov 2010, Richard Sandiford wrote:

> Sounds good, but please don't let it get in the way of applying this patch
> (when the time comes).  The change above seems entirely in keeping with
> the way that abs_symbol is initialised.

 This is the version I applied.

2010-12-01  Maciej W. Rozycki  <macro@codesourcery.com>

	* symbols.h (dot_symbol): New declaration.
	(dot_symbol_init): New prototype.
	* symbols.c (dot_symbol): New variable.
	(symbol_clone): Assert it's not dot_symbol being cloned.
	(dot_symbol_init): New function.
	(symbol_clone_if_forward_ref): Create a new temporary symbol
	when trying to clone dot_symbol.
	* expr.c (current_location): Refer to dot_symbol instead of
	making a new temporary symbol.
	* read.c (read_a_source_file): Update dot_symbol as we go.
	* as.c (main): Call dot_symbol_init.

 Thanks,

  Maciej

binutils-gas-dot.diff
Index: binutils-fsf-trunk-quilt/gas/symbols.c
===================================================================
--- binutils-fsf-trunk-quilt.orig/gas/symbols.c	2010-12-01 21:05:48.000000000 +0000
+++ binutils-fsf-trunk-quilt/gas/symbols.c	2010-12-01 21:05:48.000000000 +0000
@@ -48,6 +48,7 @@ static struct hash_control *local_hash;
 symbolS *symbol_rootP;
 symbolS *symbol_lastP;
 symbolS abs_symbol;
+symbolS dot_symbol;
 
 #ifdef DEBUG_SYMS
 #define debug_verify_symchain verify_symbol_chain
@@ -557,6 +558,9 @@ symbol_clone (symbolS *orgsymP, int repl
   symbolS *newsymP;
   asymbol *bsymorg, *bsymnew;
 
+  /* Make sure we never clone the dot special symbol.  */
+  gas_assert (orgsymP != &dot_symbol);
+
   /* Running local_symbol_convert on a clone that's not the one currently
      in local_hash would incorrectly replace the hash entry.  Thus the
      symbol must be converted here.  Note that the rest of the function
@@ -658,8 +662,13 @@ symbol_clone_if_forward_ref (symbolS *sy
 	  || add_symbol != symbolP->sy_value.X_add_symbol
 	  || op_symbol != symbolP->sy_value.X_op_symbol)
 	{
-	  symbolP = symbol_clone (symbolP, 0);
-	  symbolP->sy_resolving = 0;
+	  if (symbolP != &dot_symbol)
+	    {
+	      symbolP = symbol_clone (symbolP, 0);
+	      symbolP->sy_resolving = 0;
+	    }
+	  else
+	    symbolP = symbol_temp_new_now ();
 	}
 
       symbolP->sy_value.X_add_symbol = add_symbol;
@@ -2749,6 +2758,17 @@ symbol_begin (void)
   if (LOCAL_LABELS_FB)
     fb_label_init ();
 }
+
+void
+dot_symbol_init (void)
+{
+  dot_symbol.bsym = bfd_make_empty_symbol (stdoutput);
+  if (dot_symbol.bsym == NULL)
+    as_fatal ("bfd_make_empty_symbol: %s", bfd_errmsg (bfd_get_error ()));
+  dot_symbol.bsym->name = ".";
+  dot_symbol.sy_forward_ref = 1;
+  dot_symbol.sy_value.X_op = O_constant;
+}
 
 int indent_level;
 
Index: binutils-fsf-trunk-quilt/gas/expr.c
===================================================================
--- binutils-fsf-trunk-quilt.orig/gas/expr.c	2010-12-01 21:05:48.000000000 +0000
+++ binutils-fsf-trunk-quilt/gas/expr.c	2010-12-01 21:05:48.000000000 +0000
@@ -705,7 +705,7 @@ current_location (expressionS *expressio
   else
     {
       expressionp->X_op = O_symbol;
-      expressionp->X_add_symbol = symbol_temp_new_now ();
+      expressionp->X_add_symbol = &dot_symbol;
       expressionp->X_add_number = 0;
     }
 }
Index: binutils-fsf-trunk-quilt/gas/symbols.h
===================================================================
--- binutils-fsf-trunk-quilt.orig/gas/symbols.h	2010-12-01 21:05:41.000000000 +0000
+++ binutils-fsf-trunk-quilt/gas/symbols.h	2010-12-01 21:05:48.000000000 +0000
@@ -28,6 +28,7 @@ extern symbolS *symbol_rootP;	/* all the
 extern symbolS *symbol_lastP;	/* last struct symbol we made, or NULL */
 
 extern symbolS abs_symbol;
+extern symbolS dot_symbol;
 
 extern int symbol_table_frozen;
 
@@ -60,6 +61,7 @@ symbolS *symbol_temp_make (void);
 symbolS *colon (const char *sym_name);
 void local_colon (int n);
 void symbol_begin (void);
+void dot_symbol_init (void);
 void symbol_print_statistics (FILE *);
 void symbol_table_insert (symbolS * symbolP);
 valueT resolve_symbol_value (symbolS *);
Index: binutils-fsf-trunk-quilt/gas/read.c
===================================================================
--- binutils-fsf-trunk-quilt.orig/gas/read.c	2010-12-01 21:05:41.000000000 +0000
+++ binutils-fsf-trunk-quilt/gas/read.c	2010-12-01 21:05:48.000000000 +0000
@@ -629,6 +629,7 @@ read_a_source_file (char *name)
 	  was_new_line = is_end_of_line[(unsigned char) input_line_pointer[-1]];
 	  if (was_new_line)
 	    {
+	      symbol_set_value_now (&dot_symbol);
 #ifdef md_start_line_hook
 	      md_start_line_hook ();
 #endif
@@ -1128,6 +1129,7 @@ read_a_source_file (char *name)
       md_after_pass_hook ();
 #endif
     }
+  symbol_set_value_now (&dot_symbol);
 
  quit:
 
Index: binutils-fsf-trunk-quilt/gas/as.c
===================================================================
--- binutils-fsf-trunk-quilt.orig/gas/as.c	2010-12-01 21:05:41.000000000 +0000
+++ binutils-fsf-trunk-quilt/gas/as.c	2010-12-01 21:05:48.000000000 +0000
@@ -1181,6 +1181,8 @@ main (int argc, char ** argv)
   output_file_create (out_file_name);
   gas_assert (stdoutput != 0);
 
+  dot_symbol_init ();
+
 #ifdef tc_init_after_args
   tc_init_after_args ();
 #endif