Add support for new functionality in the msp430 backend of GCC.

This functionality will generate a new GNU object attribute for the "data region"
has been added. This object attribute is used
mark whether the compiler has generated code assuming that data could be in the
upper or lower memory regions.

Code which assumes data is always in the lower memory region is incompatible
with code which uses the full memory range for data.

The patch also adds a new assembler directive ".mspabi_attribute" to handle the
existing MSPABI object attributes. GCC will now emit both .gnu_attribute and
.mspabi_attribute directives to indicate what options the source file was
compiled with.

The assembler will now check the values set in these directives against the
options that the it has been invoked with. If there is a discrepancy, the
assembler will exit with an error.

bfd	* elf32-msp430.c (elf32_msp430_merge_mspabi_attributes): Rename to..
	(elf32_msp430_merge_msp430_attributes): Add support for merging the GNU
	object attribute for data region.

binutils* readelf.c (display_msp430_gnu_attribute): New.
	(process_arch_specific): Use msp430 specific handler for GNU
	attributes.

gas	* config/tc-msp430.c (md_parse_option): Set lower_data_region_only to
	FALSE if the data region is set to "upper", "either" or "none".
	(msp430_object_attribute): New.
	(md_pseudo_table): Handle .mspabi_attribute and .gnu_attribute.
	(msp430_md_end): Replace hard-coded attribute values with enums.
	Handle data region object attribute.
	* doc/as.texi: Document MSP430 Data Region object attribute.
	* doc/c-msp430.texi: Document the .mspabi_attribute directive.
	* testsuite/gas/msp430/attr-430-small-bad.d: New test.
	* testsuite/gas/msp430/attr-430-small-bad.l: New test.
	* testsuite/gas/msp430/attr-430-small-good.d: New test.
	* testsuite/gas/msp430/attr-430-small.s: New test.
	* testsuite/gas/msp430/attr-430x-large-any-bad.d: New test.
	* testsuite/gas/msp430/attr-430x-large-any-bad.l: New test.
	* testsuite/gas/msp430/attr-430x-large-any-good.d: New test.
	* testsuite/gas/msp430/attr-430x-large-any.s: New test.
	* testsuite/gas/msp430/attr-430x-large-lower-bad.d: New test.
	* testsuite/gas/msp430/attr-430x-large-lower-bad.l: New test.
	* testsuite/gas/msp430/attr-430x-large-lower-good.d: New test.
	* testsuite/gas/msp430/attr-430x-large-lower.s: New test.
	* testsuite/gas/msp430/msp430.exp: Run new tests.

include	* elf/msp430.h: Add enums for MSPABI and GNU object attribute tag names
	and values.

ld	* testsuite/ld-msp430-elf/attr-gnu-main.s: New test.
	* testsuite/ld-msp430-elf/attr-gnu-obj.s: New test.
	* testsuite/ld-msp430-elf/attr-gnu-region-lower-upper.d: New test.
	* testsuite/ld-msp430-elf/attr-gnu-region-lower.d: New test.
	* testsuite/ld-msp430-elf/attr-gnu-region-upper.d: New test.
	* testsuite/ld-msp430-elf/msp430-elf.exp: Run new tests.

1 files changed, 59 insertions, 28 deletions

diff --git a/bfd/elf32-msp430.c b/bfd/elf32-msp430.c
index 4dcc8d4..d581dbc 100644
--- a/bfd/elf32-msp430.c
+++ b/bfd/elf32-msp430.c
@@ -2408,15 +2408,15 @@ data_model (int model)
     }
 }
 
-/* Merge MSPABI object attributes from IBFD into OBFD.
+/* Merge MSPABI and GNU object attributes from IBFD into OBFD.
    Raise an error if there are conflicting attributes.  */
 
 static bfd_boolean
-elf32_msp430_merge_mspabi_attributes (bfd *ibfd, struct bfd_link_info *info)
+elf32_msp430_merge_msp430_attributes (bfd *ibfd, struct bfd_link_info *info)
 {
   bfd *obfd = info->output_bfd;
-  obj_attribute *in_attr;
-  obj_attribute *out_attr;
+  obj_attribute *in_msp_attr, *in_gnu_attr;
+  obj_attribute *out_msp_attr, *out_gnu_attr;
   bfd_boolean result = TRUE;
   static bfd * first_input_bfd = NULL;
 
@@ -2435,45 +2435,48 @@ elf32_msp430_merge_mspabi_attributes (bfd *ibfd, struct bfd_link_info *info)
     {
       _bfd_elf_copy_obj_attributes (ibfd, obfd);
 
-      out_attr = elf_known_obj_attributes_proc (obfd);
+      out_msp_attr = elf_known_obj_attributes_proc (obfd);
 
       /* Use the Tag_null value to indicate that
 	 the attributes have been initialized.  */
-      out_attr[0].i = 1;
+      out_msp_attr[0].i = 1;
 
       first_input_bfd = ibfd;
       return TRUE;
     }
 
-  in_attr = elf_known_obj_attributes_proc (ibfd);
-  out_attr = elf_known_obj_attributes_proc (obfd);
+  in_msp_attr = elf_known_obj_attributes_proc (ibfd);
+  out_msp_attr = elf_known_obj_attributes_proc (obfd);
+  in_gnu_attr = elf_known_obj_attributes (ibfd) [OBJ_ATTR_GNU];
+  out_gnu_attr = elf_known_obj_attributes (obfd) [OBJ_ATTR_GNU];
 
   /* The ISAs must be the same.  */
-  if (in_attr[OFBA_MSPABI_Tag_ISA].i != out_attr[OFBA_MSPABI_Tag_ISA].i)
+  if (in_msp_attr[OFBA_MSPABI_Tag_ISA].i != out_msp_attr[OFBA_MSPABI_Tag_ISA].i)
     {
       _bfd_error_handler
 	/* xgettext:c-format */
 	(_("error: %pB uses %s instructions but %pB uses %s"),
-	 ibfd, isa_type (in_attr[OFBA_MSPABI_Tag_ISA].i),
-	 first_input_bfd, isa_type (out_attr[OFBA_MSPABI_Tag_ISA].i));
+	 ibfd, isa_type (in_msp_attr[OFBA_MSPABI_Tag_ISA].i),
+	 first_input_bfd, isa_type (out_msp_attr[OFBA_MSPABI_Tag_ISA].i));
       result = FALSE;
     }
 
   /* The code models must be the same.  */
-  if (in_attr[OFBA_MSPABI_Tag_Code_Model].i !=
-      out_attr[OFBA_MSPABI_Tag_Code_Model].i)
+  if (in_msp_attr[OFBA_MSPABI_Tag_Code_Model].i
+      != out_msp_attr[OFBA_MSPABI_Tag_Code_Model].i)
     {
       _bfd_error_handler
 	/* xgettext:c-format */
 	(_("error: %pB uses the %s code model whereas %pB uses the %s code model"),
-	 ibfd, code_model (in_attr[OFBA_MSPABI_Tag_Code_Model].i),
-	 first_input_bfd, code_model (out_attr[OFBA_MSPABI_Tag_Code_Model].i));
+	 ibfd, code_model (in_msp_attr[OFBA_MSPABI_Tag_Code_Model].i),
+	 first_input_bfd,
+	 code_model (out_msp_attr[OFBA_MSPABI_Tag_Code_Model].i));
       result = FALSE;
     }
 
   /* The large code model is only supported by the MSP430X.  */
-  if (in_attr[OFBA_MSPABI_Tag_Code_Model].i == 2
-      && out_attr[OFBA_MSPABI_Tag_ISA].i != 2)
+  if (in_msp_attr[OFBA_MSPABI_Tag_Code_Model].i == 2
+      && out_msp_attr[OFBA_MSPABI_Tag_ISA].i != 2)
     {
       _bfd_error_handler
 	/* xgettext:c-format */
@@ -2483,41 +2486,69 @@ elf32_msp430_merge_mspabi_attributes (bfd *ibfd, struct bfd_link_info *info)
     }
 
   /* The data models must be the same.  */
-  if (in_attr[OFBA_MSPABI_Tag_Data_Model].i !=
-      out_attr[OFBA_MSPABI_Tag_Data_Model].i)
+  if (in_msp_attr[OFBA_MSPABI_Tag_Data_Model].i
+      != out_msp_attr[OFBA_MSPABI_Tag_Data_Model].i)
     {
       _bfd_error_handler
 	/* xgettext:c-format */
 	(_("error: %pB uses the %s data model whereas %pB uses the %s data model"),
-	 ibfd, data_model (in_attr[OFBA_MSPABI_Tag_Data_Model].i),
-	 first_input_bfd, data_model (out_attr[OFBA_MSPABI_Tag_Data_Model].i));
+	 ibfd, data_model (in_msp_attr[OFBA_MSPABI_Tag_Data_Model].i),
+	 first_input_bfd,
+	 data_model (out_msp_attr[OFBA_MSPABI_Tag_Data_Model].i));
       result = FALSE;
     }
 
   /* The small code model requires the use of the small data model.  */
-  if (in_attr[OFBA_MSPABI_Tag_Code_Model].i == 1
-      && out_attr[OFBA_MSPABI_Tag_Data_Model].i != 1)
+  if (in_msp_attr[OFBA_MSPABI_Tag_Code_Model].i == 1
+      && out_msp_attr[OFBA_MSPABI_Tag_Data_Model].i != 1)
     {
       _bfd_error_handler
 	/* xgettext:c-format */
 	(_("error: %pB uses the small code model but %pB uses the %s data model"),
 	 ibfd, first_input_bfd,
-	 data_model (out_attr[OFBA_MSPABI_Tag_Data_Model].i));
+	 data_model (out_msp_attr[OFBA_MSPABI_Tag_Data_Model].i));
       result = FALSE;
     }
 
   /* The large data models are only supported by the MSP430X.  */
-  if (in_attr[OFBA_MSPABI_Tag_Data_Model].i > 1
-      && out_attr[OFBA_MSPABI_Tag_ISA].i != 2)
+  if (in_msp_attr[OFBA_MSPABI_Tag_Data_Model].i > 1
+      && out_msp_attr[OFBA_MSPABI_Tag_ISA].i != 2)
     {
       _bfd_error_handler
 	/* xgettext:c-format */
 	(_("error: %pB uses the %s data model but %pB only uses MSP430 instructions"),
-	 ibfd, data_model (in_attr[OFBA_MSPABI_Tag_Data_Model].i),
+	 ibfd, data_model (in_msp_attr[OFBA_MSPABI_Tag_Data_Model].i),
 	 first_input_bfd);
       result = FALSE;
     }
 
+  /* Just ignore the data region unless the large memory model is in use.
+     We have already checked that ibfd and obfd use the same memory model.  */
+  if ((in_msp_attr[OFBA_MSPABI_Tag_Code_Model].i
+       == OFBA_MSPABI_Val_Code_Model_LARGE)
+      && (in_msp_attr[OFBA_MSPABI_Tag_Data_Model].i
+	  == OFBA_MSPABI_Val_Data_Model_LARGE))
+    {
+      /* We cannot allow "lower region only" to be linked with any other
+	 values (i.e. ANY or NONE).
+	 Before this attribute existed, "ANY" region was the default.  */
+      bfd_boolean ibfd_lower_region_used
+	= (in_gnu_attr[Tag_GNU_MSP430_Data_Region].i
+	   == Val_GNU_MSP430_Data_Region_Lower);
+      bfd_boolean obfd_lower_region_used
+	= (out_gnu_attr[Tag_GNU_MSP430_Data_Region].i
+	   == Val_GNU_MSP430_Data_Region_Lower);
+      if (ibfd_lower_region_used != obfd_lower_region_used)
+	{
+	  _bfd_error_handler
+	    (_("error: %pB can use the upper region for data, "
+	       "but %pB assumes data is exclusively in lower memory"),
+	     ibfd_lower_region_used ? obfd : ibfd,
+	     ibfd_lower_region_used ? ibfd : obfd);
+	  result = FALSE;
+	}
+    }
+
   return result;
 }
 
@@ -2536,7 +2567,7 @@ elf32_msp430_merge_private_bfd_data (bfd *ibfd, struct bfd_link_info *info)
 			       max (bfd_get_mach (ibfd), bfd_get_mach (obfd)));
 #undef max
 
-  return elf32_msp430_merge_mspabi_attributes (ibfd, info);
+  return elf32_msp430_merge_msp430_attributes (ibfd, info);
 }
 
 static bfd_boolean