2009-07-20 Pedro Alves <pedro@codesourcery.com>

	* features/gdb-target.dtd (target): Accept an optional 'osabi'
	element.
	(osabi): Define element.
	* features/mips-linux.xml (target): Add an osabi subelement set to
	GNU/Linux.
	* regformats/regdat.sh (xmlarch, xmlosabi): New variables.  Don't
	write the architecture into $xmltarget.  Store it in $xmlarch.
	Handle the 'osabi' type.  Handle outputting the osabi element of
	the target description.
	* regformats/reg-x86-64-linux.dat (osabi): Set to GNU/Linux.
	* regformats/reg-i386-linux.dat (osabi): Set to GNU/Linux.

	* target-descriptions.h (tdesc_osabi, set_tdesc_osabi): Declare.
	* target-descriptions.c (struct target_desc) <osabi>: New field.
	(tdesc_osabi): New function.
	(set_tdesc_osabi): New function.
	* xml-tdesc.c: Include osabi.h.
	(tdesc_end_osabi): New.
	(target_children): Parse "osabi" elements.
	* arch-utils.c (gdbarch_info_fill): Try to get the osabi from the
	target description if the user didn't override it or it is not
	extractable from the bfd.  If that still fails, fallback to the
	configured in default.
	* osabi.h (osabi_from_tdesc_string): Declare.
	* osabi.c (osabi_from_tdesc_string): New.
	(gdbarch_lookup_osabi): Return GDB_OSABI_UNKNOWN instead of
	GDB_OSABI_DEFAULT.

	* NEWS: Mention that target descriptions can now describe the
	target OS ABI.

2009-07-20  Pedro Alves  <pedro@codesourcery.com>

	* gdb.texinfo (Target Description Format): Mention the new <osabi>
	optional element.
	(subsection OS ABI): New subsection.

1 files changed, 29 insertions, 9 deletions

diff --git a/gdb/osabi.c b/gdb/osabi.c
index 778dedc..a8ecc8c 100644
--- a/gdb/osabi.c
+++ b/gdb/osabi.c
@@ -87,6 +87,30 @@ gdbarch_osabi_name (enum gdb_osabi osabi)
   return gdb_osabi_names[GDB_OSABI_INVALID];
 }
 
+/* Lookup the OS ABI corresponding to the specified target description
+   string.  */
+
+enum gdb_osabi
+osabi_from_tdesc_string (const char *name)
+{
+  int i;
+
+  for (i = 0; i < ARRAY_SIZE (gdb_osabi_names); i++)
+    if (strcmp (name, gdb_osabi_names[i]) == 0)
+      {
+	/* See note above: the name table matches the indices assigned
+	   to enum gdb_osabi.  */
+	enum gdb_osabi osabi = (enum gdb_osabi) i;
+
+	if (osabi == GDB_OSABI_INVALID)
+	  return GDB_OSABI_UNKNOWN;
+	else
+	  return osabi;
+      }
+
+  return GDB_OSABI_UNKNOWN;
+}
+
 /* Handler for a given architecture/OS ABI pair.  There should be only
    one handler for a given OS ABI each architecture family.  */
 struct gdb_osabi_handler  
@@ -205,10 +229,11 @@ gdbarch_lookup_osabi (bfd *abfd)
   if (user_osabi_state == osabi_user)
     return user_selected_osabi;
 
-  /* If we don't have a binary, return the default OS ABI (if set) or
-     unknown (otherwise).  */
+  /* If we don't have a binary, just return unknown.  The caller may
+     have other sources the OSABI can be extracted from, e.g., the
+     target description.  */
   if (abfd == NULL) 
-    return GDB_OSABI_DEFAULT;
+    return GDB_OSABI_UNKNOWN;
 
   match = GDB_OSABI_UNKNOWN;
   match_specific = 0;
@@ -269,12 +294,7 @@ gdbarch_lookup_osabi (bfd *abfd)
 	}
     }
 
-  /* If we didn't find a match, but a default was specified at configure
-     time, return the default.  */
-  if (GDB_OSABI_DEFAULT != GDB_OSABI_UNKNOWN && match == GDB_OSABI_UNKNOWN)
-    return GDB_OSABI_DEFAULT;
-  else
-    return match;
+  return match;
 }