MIPS object attributes

[Joseph S. Myers]

Following the object attribute tagging discussion 
<http://gcc.gnu.org/ml/gcc/2007-06/msg00654.html> and my implementation of 
this in binutils, now checked in, here is a first patch to use 
.gnu_attribute in GCC.

This patch marks the MIPS floating-point ABI; the assigned values for MIPS 
.gnu_attribute can be found in include/elf/mips.h in the src repository; 
for the convention of which numbers take strings and which integers, and 
which are target-dependent or target-independent, see 
bfd/elf-attrs.c:gnu_obj_attrs_arg_type.

Once this is in I'll submit a separate patch to do much the same thing for 
Power, and other attributes (possibly including target-independent ones) 
may be allocated and output by GCC as and when it's found useful to output 
additional information.  For now the configure checks are target-dependent 
since the supported attributes are; I expect they'll move to 
target-independent when we have some target-independent attributes to 
record on all ELF targets.

A GDB patch to use this information from MIPS and Power objects should 
follow in due course.

Tested with no regressions with cross to mips-linux-gnu.  OK to commit?

2007-06-30  Joseph Myers  <joseph@codesourcery.com>

	* configure.ac: Check for .gnu_attribute on MIPS.
	* configure, config.in: Regenerate.
	* config/mips/mips.c (mips_file_start): If supported, output
	attribute for floating-point ABI.

Index: configure.ac
===================================================================
--- configure.ac	(revision 126119)
+++ configure.ac	(working copy)
@@ -2943,6 +2943,12 @@
       gcc_cv_as_mips_no_shared, [2,16,0], [-mno-shared], [nop],,
       [AC_DEFINE(HAVE_AS_NO_SHARED, 1,
 		 [Define if the assembler understands -mno-shared.])])
+
+    gcc_GAS_CHECK_FEATURE([.gnu_attribute support],
+      gcc_cv_as_mips_gnu_attribute, [2,18,0],,
+      [.gnu_attribute 4,1],,
+      [AC_DEFINE(HAVE_AS_GNU_ATTRIBUTE, 1,
+	  [Define if your assembler supports .gnu_attribute.])])
     ;;
 esac
 
Index: config/mips/mips.c
===================================================================
--- config/mips/mips.c	(revision 126119)
+++ config/mips/mips.c	(working copy)
@@ -6010,6 +6010,11 @@
 
   if (!TARGET_IRIX)
     {
+#ifdef HAVE_AS_GNU_ATTRIBUTE
+      fprintf (asm_out_file, "\t.gnu_attribute 4, %d\n",
+	       TARGET_HARD_FLOAT ? (TARGET_DOUBLE_FLOAT ? 1 : 2) : 3);
+#endif
+
       /* Generate a special section to describe the ABI switches used to
 	 produce the resultant binary.  This used to be done by the assembler
 	 setting bits in the ELF header's flags field, but we have run out of

-- 
Joseph S. Myers
joseph@codesourcery.com