2009-01-19 Andrew Stubbs <ams@codesourcery.com>

	bfd/
	* elf-attrs.c (vendor_set_obj_attr_contents): Support tag ordering.
	* elf-bfd.h (elf_backend_data): Add obj_attrs_order.
	* elf32-arm.c (elf32_arm_obj_attrs_order): New function.
	(elf_backend_obj_attrs_order): New define.
	* elfxx-target.h (elf_backend_obj_attrs_order): New define.
	(elfNN_bed): Add elf_backend_obj_attrs_order.

	gas/testsuite/
	* gas/arm/attr-order.d: New file.
	* gas/arm/attr-order.s: New file.

5 files changed, 44 insertions, 1 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 65300c1..c2cc5e3 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,5 +1,14 @@
 2009-01-19  Andrew Stubbs  <ams@codesourcery.com>
 
+	* elf-attrs.c (vendor_set_obj_attr_contents): Support tag ordering.
+	* elf-bfd.h (elf_backend_data): Add obj_attrs_order.
+	* elf32-arm.c (elf32_arm_obj_attrs_order): New function.
+	(elf_backend_obj_attrs_order): New define.
+	* elfxx-target.h (elf_backend_obj_attrs_order): New define.
+	(elfNN_bed): Add elf_backend_obj_attrs_order.
+
+2009-01-19  Andrew Stubbs  <ams@codesourcery.com>
+
 	* elf-attrs.c (is_default_attr): Substitute magic numbers with macros.
 	(obj_attr_size): Likewise.
 	(write_obj_attribute): Likewise.
diff --git a/bfd/elf-attrs.c b/bfd/elf-attrs.c
index 1e8076b..e60053b 100644
--- a/bfd/elf-attrs.c
+++ b/bfd/elf-attrs.c
@@ -189,7 +189,12 @@ vendor_set_obj_attr_contents (bfd *abfd, bfd_byte *contents, bfd_vma size,
 
   attr = elf_known_obj_attributes (abfd)[vendor];
   for (i = 4; i < NUM_KNOWN_OBJ_ATTRIBUTES; i++)
-    p = write_obj_attribute (p, i, &attr[i]);
+    {
+      int tag = i;
+      if (get_elf_backend_data (abfd)->obj_attrs_order)
+	tag = get_elf_backend_data (abfd)->obj_attrs_order (i);
+      p = write_obj_attribute (p, tag, &attr[tag]);
+    }
 
   for (list = elf_other_obj_attributes (abfd)[vendor];
        list;
diff --git a/bfd/elf-bfd.h b/bfd/elf-bfd.h
index c0d8c8a..35dc018 100644
--- a/bfd/elf-bfd.h
+++ b/bfd/elf-bfd.h
@@ -1167,6 +1167,12 @@ struct elf_backend_data
   /* The section type to use for an attributes section.  */
   unsigned int obj_attrs_section_type;
 
+  /* This function determines the order in which any attributes are written.
+     It must be defined for input in the range 4..NUM_KNOWN_OBJ_ATTRIBUTES-1
+     (this range is used in order to make unity easy).  The returned value is
+     the actual tag number to place in the input position.  */
+  int (*obj_attrs_order) (int);
+
   /* This is TRUE if the linker should act like collect and gather
      global constructors and destructors by name.  This is TRUE for
      MIPS ELF because the Irix 5 tools can not handle the .init
diff --git a/bfd/elf32-arm.c b/bfd/elf32-arm.c
index bf1f06f..5fdd138 100644
--- a/bfd/elf32-arm.c
+++ b/bfd/elf32-arm.c
@@ -8149,6 +8149,24 @@ elf32_arm_obj_attrs_arg_type (int tag)
     return (tag & 1) != 0 ? ATTR_TYPE_FLAG_STR_VAL : ATTR_TYPE_FLAG_INT_VAL;
 }
 
+/* The ABI defines that Tag_conformance should be emitted first, and that
+   Tag_nodefaults should be second (if either is defined).  This sets those
+   two positions, and bumps up the position of all the remaining tags to
+   compensate.  */
+static int
+elf32_arm_obj_attrs_order (int num)
+{
+  if (num == 4)
+    return Tag_conformance;
+  if (num == 5)
+    return Tag_nodefaults;
+  if ((num - 2) < Tag_nodefaults)
+    return num - 2;
+  if ((num - 1) < Tag_conformance)
+    return num - 1;
+  return num;
+}
+
 /* Read the architecture from the Tag_also_compatible_with attribute, if any.
    Returns -1 if no architecture could be read.  */
 
@@ -12292,6 +12310,7 @@ const struct elf_size_info elf32_arm_size_info =
 #define elf_backend_obj_attrs_arg_type		elf32_arm_obj_attrs_arg_type
 #undef  elf_backend_obj_attrs_section_type
 #define elf_backend_obj_attrs_section_type	SHT_ARM_ATTRIBUTES
+#define elf_backend_obj_attrs_order	elf32_arm_obj_attrs_order
 
 #include "elf32-target.h"
 
diff --git a/bfd/elfxx-target.h b/bfd/elfxx-target.h
index 811dbf5..4aa8dd4 100644
--- a/bfd/elfxx-target.h
+++ b/bfd/elfxx-target.h
@@ -461,6 +461,9 @@
 #ifndef elf_backend_obj_attrs_section_type
 #define elf_backend_obj_attrs_section_type		SHT_GNU_ATTRIBUTES
 #endif
+#ifndef elf_backend_obj_attrs_order
+#define elf_backend_obj_attrs_order		NULL
+#endif
 #ifndef elf_backend_post_process_headers
 #define elf_backend_post_process_headers	NULL
 #endif
@@ -720,6 +723,7 @@ static struct elf_backend_data elfNN_bed =
   elf_backend_obj_attrs_section,
   elf_backend_obj_attrs_arg_type,
   elf_backend_obj_attrs_section_type,
+  elf_backend_obj_attrs_order,
   elf_backend_collect,
   elf_backend_type_change_ok,
   elf_backend_may_use_rel_p,