[csl-arm] EABI object attributes

[Paul Brook <paul at codesourcery dot com>]

The attached patch adds makes the Arm backend output assembly directives for 
more EABI object attributes. Some of these are necessary because the default 
value is actively incorrect (so a linker could/should refuse to link the 
objects), others are just nice to have.

Some of the attributes (eg. size of enums any wchar_t) can be reported as "not 
used" itstead of the actual value. However there doesn't seem to be a way to 
get this usage infomation, so we output the value whether they are used or 
not.

Tested with cross to arm-none-eabi.
Applied to branches/csl/arm-4_1.

Paul

2006-04-02  Paul Brook  <paul@codesourcery.com>

	* gcc/config/arm/arm.c (arm_file_start): Output additional object
	attribute directives.

Index: gcc/config/arm/arm.c
===================================================================
--- gcc/config/arm/arm.c	(revision 112606)
+++ gcc/config/arm/arm.c	(working copy)
@@ -14973,6 +14973,8 @@ arm_asm_output_labelref (FILE *stream, c
 static void
 arm_file_start (void)
 {
+  int val;
+
   if (TARGET_UNIFIED_ASM)
     asm_fprintf (asm_out_file, "\t.syntax unified\n");
 
@@ -15011,6 +15013,8 @@ arm_file_start (void)
 	      fpu_name = "maverick";
 	      break;
 	    case FPUTYPE_VFP:
+	      if (TARGET_HARD_FLOAT)
+		asm_fprintf (asm_out_file, "\t.eabi_attribute 27, 3\n");
 	      if (TARGET_HARD_FLOAT_ABI)
 		asm_fprintf (asm_out_file, "\t.eabi_attribute 28, 1\n");
 	      fpu_name = "vfp";
@@ -15020,6 +15024,50 @@ arm_file_start (void)
 	    }
 	}
       asm_fprintf (asm_out_file, "\t.fpu %s\n", fpu_name);
+
+      /* Some of these attributes only apply when the corresponding features
+         are used.  However we don't have any easy way of figuring this out.
+	 Conservatively record the setting that would have been used.  */
+
+      /* Tag_ABI_PCS_wchar_t.  */
+      asm_fprintf (asm_out_file, "\t.eabi_attribute 18, %d\n",
+		   (int)WCHAR_TYPE_SIZE / BITS_PER_UNIT);
+
+      /* Tag_ABI_FP_rounding.  */
+      if (flag_rounding_math)
+	asm_fprintf (asm_out_file, "\t.eabi_attribute 19, 1\n");
+      if (!flag_unsafe_math_optimizations)
+	{
+	  /* Tag_ABI_FP_denomal.  */
+	  asm_fprintf (asm_out_file, "\t.eabi_attribute 20, 1\n");
+	  /* Tag_ABI_FP_exceptions.  */
+	  asm_fprintf (asm_out_file, "\t.eabi_attribute 21, 1\n");
+	}
+      /* Tag_ABI_FP_user_exceptions.  */
+      if (flag_signaling_nans)
+	asm_fprintf (asm_out_file, "\t.eabi_attribute 22, 1\n");
+      /* Tag_ABI_FP_number_model.  */
+      asm_fprintf (asm_out_file, "\t.eabi_attribute 23, %d\n", 
+		   flag_finite_math_only ? 1 : 3);
+
+      /* Tag_ABI_align8_needed.  */
+      asm_fprintf (asm_out_file, "\t.eabi_attribute 24, 1\n");
+      /* Tag_ABI_align8_preserved.  */
+      asm_fprintf (asm_out_file, "\t.eabi_attribute 25, 1\n");
+      /* Tag_ABI_enum_size.  */
+      asm_fprintf (asm_out_file, "\t.eabi_attribute 26, %d\n",
+		   flag_short_enums ? 1 : 2);
+
+      /* Tag_ABI_optimization_goals.  */
+      if (optimize_size)
+	val = 4;
+      else if (optimize >= 2)
+	val = 2;
+      else if (optimize)
+	val = 1;
+      else
+	val = 6;
+      asm_fprintf (asm_out_file, "\t.eabi_attribute 30, %d\n", val);
     }
   default_file_start();
 }