* ld.texinfo (Expression Section): Describe treatment of numbers

and absolute symbols.
	* ldemul.c (after_open_default): Look up __ld_compatibility.
	* ldexp.c (fold_name): Convert absolute symbols to numbers when
	inside output section definitions, or when __ld_compatibility >= 221.
	(exp_fold_tree_1): Convert numbers to absolute when not in output
	section definition and __ld_compatibility < 221.  Don't always
	convert values outside an output section definition to absolute.
	* ldexp.h (uses_defined): Comment.
	* ldlang.c (ld_compatibility): New variable.
	* ldlang.h (ld_compatibility): Declare.
	* emultempl/aix.em, * emultempl/armcoff.em, * emultempl/beos.em,
	* emultempl/elf32.em, * emultempl/genelf.em, * emultempl/lnk960.em,
	* emultempl/m68kcoff.em, * emultempl/mmo.em, * emultempl/pe.em,
	* emultempl/pep.em, * emultempl/sunos.em, * emultempl/z80.em: Call
	after_open_default from after_open function.

ld/ChangeLog

@@ -1,3 +1,22 @@
+2010-12-20  Alan Modra  <amodra@gmail.com>
+
+	* ld.texinfo (Expression Section): Describe treatment of numbers
+	and absolute symbols.
+	* ldemul.c (after_open_default): Look up __ld_compatibility.
+	* ldexp.c (fold_name): Convert absolute symbols to numbers when
+	inside output section definitions, or when __ld_compatibility >= 221.
+	(exp_fold_tree_1): Convert numbers to absolute when not in output
+	section definition and __ld_compatibility < 221.  Don't always
+	convert values outside an output section definition to absolute.
+	* ldexp.h (uses_defined): Comment.
+	* ldlang.c (ld_compatibility): New variable.
+	* ldlang.h (ld_compatibility): Declare.
+	* emultempl/aix.em, * emultempl/armcoff.em, * emultempl/beos.em,
+	* emultempl/elf32.em, * emultempl/genelf.em, * emultempl/lnk960.em,
+	* emultempl/m68kcoff.em, * emultempl/mmo.em, * emultempl/pe.em,
+	* emultempl/pep.em, * emultempl/sunos.em, * emultempl/z80.em: Call
+	after_open_default from after_open function.
+
 2010-12-20  Alan Modra  <amodra@gmail.com>
 
 	PR ld/12001

ld/emultempl/aix.em

@@ -608,6 +608,8 @@ gld${EMULATION_NAME}_after_open (void)
   bfd_boolean r;
   struct set_info *p;
 
+  after_open_default ();
+
   /* Call ldctor_build_sets, after pretending that this is a
      relocatable link.  We do this because AIX requires relocation
      entries for all references to symbols, even in a final

ld/emultempl/armcoff.em

@@ -133,6 +133,8 @@ gld${EMULATION_NAME}_before_allocation (void)
 static void
 gld${EMULATION_NAME}_after_open (void)
 {
+  after_open_default ();
+
   if (strstr (bfd_get_target (link_info.output_bfd), "arm") == NULL)
     {
       /* The arm backend needs special fields in the output hash structure.

ld/emultempl/beos.em

@@ -376,6 +376,8 @@ gld_${EMULATION_NAME}_set_symbols (void)
 static void
 gld_${EMULATION_NAME}_after_open (void)
 {
+  after_open_default ();
+
   /* Pass the wacky PE command line options into the output bfd.
      FIXME: This should be done via a function, rather than by
      including an internal BFD header.  */

ld/emultempl/elf32.em

@@ -1059,6 +1059,8 @@ gld${EMULATION_NAME}_after_open (void)
   struct bfd_link_needed_list *needed, *l;
   struct elf_link_hash_table *htab;
 
+  after_open_default ();
+
   htab = elf_hash_table (&link_info);
   if (!is_elf_hash_table (htab))
     return;

ld/emultempl/genelf.em

@@ -35,6 +35,8 @@ gld${EMULATION_NAME}_after_open (void)
   asection *sec;
   asymbol **syms;
 
+  after_open_default ();
+
   if (link_info.relocatable)
     for (ibfd = link_info.input_bfds; ibfd != NULL; ibfd = ibfd->link_next)
       if ((syms = bfd_get_outsymbols (ibfd)) != NULL

ld/emultempl/lnk960.em

@@ -265,7 +265,7 @@ struct ld_emulation_xfer_struct ld_lnk960_emulation =
   lnk960_syslib,
   lnk960_hll,
   lnk960_after_parse,
-  NULL,			/* after_open */
+  after_open_default,
   lnk960_after_allocation,
   lnk960_set_output_arch,
   lnk960_choose_target,

ld/emultempl/m68kcoff.em

@@ -62,6 +62,8 @@ gld${EMULATION_NAME}_after_open (void)
 {
   bfd *abfd;
 
+  after_open_default ();
+
   if (! command_line.embedded_relocs
       || link_info.relocatable)
     return;

ld/emultempl/mmo.em

@@ -151,6 +151,7 @@ mmo_after_open (void)
 		   is->the_bfd);
 	}
     }
+  after_open_default ();
 }
 EOF
 

ld/emultempl/pe.em

@@ -1219,6 +1219,8 @@ debug_section_p (bfd *abfd ATTRIBUTE_UNUSED, asection *sect, void *obj)
 static void
 gld_${EMULATION_NAME}_after_open (void)
 {
+  after_open_default ();
+
 #ifdef DLL_SUPPORT
   if (pe_dll_extra_pe_debug)
     {

ld/emultempl/pep.em

@@ -1151,6 +1151,8 @@ debug_section_p (bfd *abfd ATTRIBUTE_UNUSED, asection *sect, void *obj)
 static void
 gld_${EMULATION_NAME}_after_open (void)
 {
+  after_open_default ();
+
   is_underscoring ();
 #ifdef DLL_SUPPORT
   if (pep_dll_extra_pe_debug)

ld/emultempl/sunos.em

@@ -366,6 +366,8 @@ gld${EMULATION_NAME}_after_open (void)
 {
   struct bfd_link_needed_list *needed, *l;
 
+  after_open_default ();
+
   /* We only need to worry about this when doing a final link.  */
   if (link_info.relocatable || link_info.shared)
     return;

ld/emultempl/z80.em

@@ -79,6 +79,8 @@ gldz80_after_open (void)
 {
   unsigned long mach_type;
 
+  after_open_default ();
+
   switch (result_mach_type)
     {
     case M_Z80STRICT:

ld/ld.texinfo

@@ -5503,17 +5503,17 @@ section relative symbols and for builtin functions that return an
 address, such as @code{ADDR}, @code{LOADADDR}, @code{ORIGIN} and
 @code{SEGMENT_START}.  Other terms are simply numbers, or are builtin
 functions that return a non-address value, such as @code{LENGTH}.
+One complication is that unless you assign @code{__ld_compatibility}
+a value of 221 or larger, numbers and absolute symbols are treated
+differently depending on their location, for compatibility with older
+versions of @code{ld}.  Expressions appearing outside an output
+section definition treat all numbers as absolute addresses.
+Expressions appearing inside an output section definition treat
+absolute symbols as numbers.  If @code{__ld_compatibility} is assigned
+a value larger than 221, then absolute symbols and numbers are simply
+treated as numbers everywhere.
 
-When the linker evaluates an expression, the result depends on where
-the expression is located in a linker script.  Expressions appearing
-outside an output section definitions are evaluated with all terms
-first being converted to absolute addresses before applying operators,
-and evaluate to an absolute address result.  Expressions appearing
-inside an output section definition are evaluated with more complex
-rules, but the aim is to treat terms as relative addresses and produce
-a relative address result.  In particular, an assignment of a number
-to a symbol results in a symbol relative to the output section with an
-offset given by the number.  So, in the following simple example,
+In the following simple example,
 
 @smallexample
 @group
@@ -5537,9 +5537,8 @@ address 0x100 in the first two assignments, then both @code{.} and
 @code{__data_start} are set to 0x10 relative to the @code{.data}
 section in the second two assignments.
 
-For expressions appearing inside an output section definition
-involving numbers, relative addresses and absolute addresses, ld
-follows these rules to evaluate terms:
+For expressions involving numbers, relative addresses and absolute
+addresses, ld follows these rules to evaluate terms:
 
 @itemize @bullet
 @item

ld/ldemul.c

@@ -226,6 +226,16 @@ after_parse_default (void)
 void
 after_open_default (void)
 {
+  struct bfd_link_hash_entry *h;
+
+  h = bfd_wrapped_link_hash_lookup (link_info.output_bfd,
+				    &link_info,
+				    "__ld_compatibility",
+				    FALSE, FALSE, TRUE);
+  if (h != NULL
+      && (h->type == bfd_link_hash_defined
+	  || h->type == bfd_link_hash_defweak))
+    ld_compatibility = h->u.def.value;
 }
 
 void

ld/ldexp.c

@@ -553,7 +553,9 @@ fold_name (etree_type *tree)
 			     " referenced in expression\n"),
 			   tree->name.name);
 		}
-	      else if (output_section == bfd_abs_section_ptr)
+	      else if (output_section == bfd_abs_section_ptr
+		       && (expld.section != bfd_abs_section_ptr
+			   || ld_compatibility >= 221))
 		new_number (h->u.def.value + h->u.def.section->output_offset);
 	      else
 		new_rel (h->u.def.value + h->u.def.section->output_offset,
@@ -700,7 +702,11 @@ exp_fold_tree_1 (etree_type *tree)
   switch (tree->type.node_class)
     {
     case etree_value:
-      new_number (tree->value.value);
+      if (expld.section == bfd_abs_section_ptr
+	  && ld_compatibility < 221)
+	new_abs (tree->value.value);
+      else
+	new_number (tree->value.value);
       expld.result.str = tree->value.str;
       break;
 
@@ -860,12 +866,6 @@ exp_fold_tree_1 (etree_type *tree)
       memset (&expld.result, 0, sizeof (expld.result));
       break;
     }
-
-  /* Any value not inside an output section statement is an
-     absolute value.  */
-  if (expld.result.valid_p
-      && expld.section == bfd_abs_section_ptr)
-    make_abs ();
 }
 
 void

ld/ldexp.h

@@ -127,6 +127,7 @@ struct ldexp_control {
   /* Working results.  */
   etree_value_type result;
   bfd_vma dot;
+  /* Set if an expression contains DEFINED().  */
   bfd_boolean uses_defined;
 
   /* Current dot and section passed to ldexp folder.  */

ld/ldlang.c

@@ -109,6 +109,7 @@ bfd_boolean delete_output_file_on_failure = FALSE;
 struct lang_phdr *lang_phdr_list;
 struct lang_nocrossrefs *nocrossref_list;
 bfd_boolean missing_file = FALSE;
+int ld_compatibility;
 
  /* Functions that traverse the linker script and might evaluate
     DEFINED() need to increment this.  */

ld/ldlang.h

@@ -469,6 +469,7 @@ extern bfd_boolean entry_from_cmdline;
 extern lang_statement_list_type file_chain;
 extern lang_statement_list_type input_file_chain;
 
+extern int ld_compatibility;
 extern int lang_statement_iteration;
 extern bfd_boolean missing_file;