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.

17 files changed, 252 insertions, 4 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index abb8bf0..41bcaa3 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,27 @@
+2019-10-07  Jozef Lawrynowicz  <jozef.l@mittosystems.com>
+
+	* 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.
+
 2019-10-07  Jan Beulich  <jbeulich@suse.com>
 
 	* config/tc-i386.c (check_string): Make reported operand number
diff --git a/gas/config/tc-msp430.c b/gas/config/tc-msp430.c
index 56d2024..41413f0 100644
--- a/gas/config/tc-msp430.c
+++ b/gas/config/tc-msp430.c
@@ -689,6 +689,8 @@ static bfd_boolean do_unknown_interrupt_nops = TRUE;
 static bfd_boolean move_data = FALSE;
 #define OPTION_DATA_REGION 'r'
 static bfd_boolean upper_data_region_in_use = FALSE;
+/* The default is to use the lower region only.  */
+static bfd_boolean lower_data_region_only = TRUE;
 
 enum
 {
@@ -1473,6 +1475,13 @@ md_parse_option (int c, const char * arg)
       if (strcmp (arg, "upper") == 0
 	  || strcmp (arg, "either") == 0)
 	upper_data_region_in_use = TRUE;
+      if (strcmp (arg, "upper") == 0
+	  || strcmp (arg, "either") == 0
+	  /* With data-region=none, the compiler has generated code assuming
+	     data could be in the upper region, but nothing has been explicitly
+	     placed there.  */
+	  || strcmp (arg, "none") == 0)
+	lower_data_region_only = FALSE;
       return 1;
     }
 
@@ -1598,6 +1607,120 @@ msp430_refsym (int arg ATTRIBUTE_UNUSED)
   (void) symbol_find_or_make (sym_name);
 }
 
+/* Handle a .mspabi_attribute or .gnu_attribute directive.
+   attr_type is 0 for .mspabi_attribute or 1 for .gnu_attribute.
+   This is only used for validating the attributes in the assembly file against
+   the options gas has been invoked with.  If the attributes and options are
+   compatible then we add the attributes to the assembly file in
+   msp430_md_end.  */
+static void
+msp430_object_attribute (int attr_type)
+{
+  char tag_name_s[32];
+  char tag_value_s[32];
+  int tag_name, tag_value;
+  /* First operand is the tag name, second is the tag value e.g.
+     ".mspabi_attribute 4, 2".  */
+  input_line_pointer = extract_operand (input_line_pointer, tag_name_s, 32);
+  input_line_pointer = extract_operand (input_line_pointer, tag_value_s, 32);
+  tag_name = atoi (tag_name_s);
+  tag_value = atoi (tag_value_s);
+  /* If the attribute directive is present, the tag_value should never be set
+     to 0.  */
+  if (tag_name == 0 || tag_value == 0)
+    as_bad (_("bad arguments \"%s\" and/or \"%s\" in %s directive"),
+	      tag_name_s, tag_value_s, (attr_type ? ".gnu_attribute"
+					: ".mspabi_attribute"));
+  else if (attr_type == 0)
+    /* Handle .mspabi_attribute.  */
+    switch (tag_name)
+      {
+      case OFBA_MSPABI_Tag_ISA:
+	switch (tag_value)
+	  {
+	  case OFBA_MSPABI_Val_ISA_MSP430:
+	    if (target_is_430x ())
+	      as_bad (_("file was compiled for the 430 ISA but the %s ISA is "
+			"selected"), (target_is_430xv2 () ? "430X" : "430Xv2"));
+	    break;
+	  case OFBA_MSPABI_Val_ISA_MSP430X:
+	    if (!target_is_430x ())
+	      as_bad (_("file was compiled for the 430X ISA but the 430 ISA is "
+			"selected"));
+	    break;
+	  default:
+	    as_bad (_("unknown MSPABI build attribute value '%d' for "
+		      "OFBA_MSPABI_Tag_ISA(%d) in .mspabi_attribute directive"),
+		    tag_value, OFBA_MSPABI_Tag_ISA);
+	    break;
+	  }
+	break;
+      case OFBA_MSPABI_Tag_Code_Model:
+	/* Fall through.  */
+      case OFBA_MSPABI_Tag_Data_Model:
+	/* FIXME: Might we want to set the memory model to large if the assembly
+	   file has the large model attribute, but -ml has not been passed?  */
+	switch (tag_value)
+	  {
+	  case OFBA_MSPABI_Val_Code_Model_SMALL:
+	    if (large_model)
+	      as_bad (_("file was compiled for the small memory model, but the "
+			"large memory model is selected"));
+	    break;
+	  case OFBA_MSPABI_Val_Code_Model_LARGE:
+	    if (!large_model)
+	      as_bad (_("file was compiled for the large memory model, "
+			"but the small memory model is selected"));
+	    break;
+	  default:
+	    as_bad (_("unknown MSPABI build attribute value '%d' for %s(%d) "
+		      "in .mspabi_attribute directive"), tag_value,
+		    (tag_name == OFBA_MSPABI_Tag_Code_Model
+		     ? "OFBA_MSPABI_Tag_Code_Model"
+		     : "OFBA_MSPABI_Tag_Data_Model"),
+		    (tag_name == OFBA_MSPABI_Tag_Code_Model
+		     ? OFBA_MSPABI_Tag_Code_Model
+		     : OFBA_MSPABI_Tag_Data_Model));
+	    break;
+	  }
+	break;
+      default:
+	as_bad (_("unknown MSPABI build attribute tag '%d' in "
+		  ".mspabi_attribute directive"), tag_name);
+	break;
+      }
+  else if (attr_type == 1)
+    /* Handle .gnu_attribute.  */
+    switch (tag_name)
+      {
+      case Tag_GNU_MSP430_Data_Region:
+	/* This attribute is only applicable in the large memory model.  */
+	if (!large_model)
+	  break;
+	switch (tag_value)
+	  {
+	  case Val_GNU_MSP430_Data_Region_Lower:
+	    if (!lower_data_region_only)
+	      as_bad (_("file was compiled assuming all data will be in the "
+			"lower memory region, but the upper region is in use"));
+	    break;
+	  case Val_GNU_MSP430_Data_Region_Any:
+	    if (lower_data_region_only)
+	      as_bad (_("file was compiled assuming data could be in the upper "
+			"memory region, but the lower data region is "
+			"exclusively in use"));
+	    break;
+	  default:
+	    as_bad (_("unknown GNU build attribute value '%d' for "
+		      "Tag_GNU_MSP430_Data_Region(%d) in .gnu_attribute "
+		      "directive"), tag_value, Tag_GNU_MSP430_Data_Region);
+	  }
+      }
+  else
+    as_bad (_("internal: unexpected argument '%d' to msp430_object_attribute"),
+	    attr_type);
+}
+
 const pseudo_typeS md_pseudo_table[] =
 {
   {"arch", msp430_set_arch, OPTION_MMCU},
@@ -1611,6 +1734,8 @@ const pseudo_typeS md_pseudo_table[] =
   {"refsym", msp430_refsym, 0},
   {"comm", msp430_comm, 0},
   {"lcomm", msp430_lcomm, 0},
+  {"mspabi_attribute", msp430_object_attribute, 0},
+  {"gnu_attribute", msp430_object_attribute, 1},
   {NULL, NULL, 0}
 };
 
@@ -4919,7 +5044,7 @@ msp430_fix_adjustable (struct fix *fixp ATTRIBUTE_UNUSED)
   return FALSE;
 }
 
-/* Set the contents of the .MSP430.attributes section.  */
+/* Set the contents of the .MSP430.attributes and .GNU.attributes sections.  */
 
 void
 msp430_md_end (void)
@@ -4936,14 +5061,27 @@ msp430_md_end (void)
 	as_warn (_(WARN_NOP_AT_EOF));
     }
 
+  /* We have already emitted an error if any of the following attributes
+     disagree with the attributes in the input assembly file.  See
+     msp430_object_attribute.  */
   bfd_elf_add_proc_attr_int (stdoutput, OFBA_MSPABI_Tag_ISA,
-			     target_is_430x () ? 2 : 1);
+			     target_is_430x () ? OFBA_MSPABI_Val_ISA_MSP430X
+			     : OFBA_MSPABI_Val_ISA_MSP430);
 
   bfd_elf_add_proc_attr_int (stdoutput, OFBA_MSPABI_Tag_Code_Model,
-			     large_model ? 2 : 1);
+			     large_model ? OFBA_MSPABI_Val_Code_Model_LARGE
+			     : OFBA_MSPABI_Val_Code_Model_SMALL);
 
   bfd_elf_add_proc_attr_int (stdoutput, OFBA_MSPABI_Tag_Data_Model,
-			     large_model ? 2 : 1);
+			     large_model ? OFBA_MSPABI_Val_Code_Model_LARGE
+			     : OFBA_MSPABI_Val_Code_Model_SMALL);
+
+  /* The data region GNU attribute is ignored for the small memory model.  */
+  if (large_model)
+    bfd_elf_add_obj_attr_int (stdoutput, OBJ_ATTR_GNU,
+			      Tag_GNU_MSP430_Data_Region, lower_data_region_only
+			      ? Val_GNU_MSP430_Data_Region_Lower
+			      : Val_GNU_MSP430_Data_Region_Any);
 }
 
 /* Returns FALSE if there is a msp430 specific reason why the
diff --git a/gas/doc/as.texi b/gas/doc/as.texi
index b4598e8..93e80f9 100644
--- a/gas/doc/as.texi
+++ b/gas/doc/as.texi
@@ -7585,6 +7585,23 @@ The vector ABI used by this object file.  The value will be:
 @end itemize
 @end table
 
+@subsection MSP430 Attributes
+
+@table @r
+@item Tag_GNU_MSP430_Data_Region (4)
+The data region used by this object file.  The value will be:
+
+@itemize @bullet
+@item
+0 for files not using the large memory model.
+@item
+1 for files which have been compiled with the condition that all
+data is in the lower memory region, i.e. below address 0x10000.
+@item
+2 for files which allow data to be placed in the full 20-bit memory range.
+@end itemize
+@end table
+
 @node Defining New Object Attributes
 @section Defining New Object Attributes
 
diff --git a/gas/doc/c-msp430.texi b/gas/doc/c-msp430.texi
index 516c0038..3691f21 100644
--- a/gas/doc/c-msp430.texi
+++ b/gas/doc/c-msp430.texi
@@ -322,6 +322,18 @@ exist purely for pulling in object files from archives.  Note that
 this reloc is not sufficient to prevent garbage collection; use a
 KEEP() directive in the linker file to preserve such objects.
 
+@cindex @code{mspabi_attribute} directive, MSP430
+@item .mspabi_attribute
+This directive tells the assembler what the MSPABI build attributes for this
+file are.  This is used for validating the command line options passed to
+the assembler against the options the original source file was compiled with.
+The expected format is:
+@samp{.mspabi_attribute tag_name, tag_value}
+For example, to set the tag @code{OFBA_MSPABI_Tag_ISA} to @code{MSP430X}:
+@samp{.mspabi_attribute 4, 2}
+
+See the @cite{MSP430 EABI, document slaa534} for the details on tag names and
+values.
 @end table
 
 @node MSP430 Opcodes
diff --git a/gas/testsuite/gas/msp430/attr-430-small-bad.d b/gas/testsuite/gas/msp430/attr-430-small-bad.d
new file mode 100644
index 0000000..302ba57
--- /dev/null
+++ b/gas/testsuite/gas/msp430/attr-430-small-bad.d
@@ -0,0 +1,4 @@
+#name: Error when 430 ISA and small memory model object attributes conflict with options
+#source: attr-430-small.s
+#as: -mdata-region=none -ml
+#error_output: attr-430-small-bad.l
diff --git a/gas/testsuite/gas/msp430/attr-430-small-bad.l b/gas/testsuite/gas/msp430/attr-430-small-bad.l
new file mode 100644
index 0000000..c339ecf
--- /dev/null
+++ b/gas/testsuite/gas/msp430/attr-430-small-bad.l
@@ -0,0 +1,4 @@
+[^:]*: Assembler messages:
+[^:]*:1: Error: file was compiled for the 430 ISA but the 430X ISA is selected
+[^:]*:2: Error: file was compiled for the small memory model, but the large memory model is selected
+[^:]*:3: Error: file was compiled for the small memory model, but the large memory model is selected
diff --git a/gas/testsuite/gas/msp430/attr-430-small-good.d b/gas/testsuite/gas/msp430/attr-430-small-good.d
new file mode 100644
index 0000000..5f3137f
--- /dev/null
+++ b/gas/testsuite/gas/msp430/attr-430-small-good.d
@@ -0,0 +1,6 @@
+#name: 430 ISA and small memory model object attributes
+#source: attr-430-small.s
+#as: -mcpu=msp430
+#objdump: -t
+
+#pass
diff --git a/gas/testsuite/gas/msp430/attr-430-small.s b/gas/testsuite/gas/msp430/attr-430-small.s
new file mode 100644
index 0000000..2bdb1db
--- /dev/null
+++ b/gas/testsuite/gas/msp430/attr-430-small.s
@@ -0,0 +1,3 @@
+.mspabi_attribute 4, 1 ; OFBA_MSPABI_Tag_ISA == 430
+.mspabi_attribute 6, 1 ; OFBA_MSPABI_Tag_Code_Model == Small
+.mspabi_attribute 8, 1 ; OFBA_MSPABI_Tag_Data_Model == Small
diff --git a/gas/testsuite/gas/msp430/attr-430x-large-any-bad.d b/gas/testsuite/gas/msp430/attr-430x-large-any-bad.d
new file mode 100644
index 0000000..6793f7c
--- /dev/null
+++ b/gas/testsuite/gas/msp430/attr-430x-large-any-bad.d
@@ -0,0 +1,4 @@
+#name: Error when 430X ISA, large memory model and any data region object attributes conflict with options
+#source: attr-430x-large-any.s
+#as: -mcpu=msp430 -ml
+#error_output: attr-430x-large-any-bad.l
diff --git a/gas/testsuite/gas/msp430/attr-430x-large-any-bad.l b/gas/testsuite/gas/msp430/attr-430x-large-any-bad.l
new file mode 100644
index 0000000..c7f2282
--- /dev/null
+++ b/gas/testsuite/gas/msp430/attr-430x-large-any-bad.l
@@ -0,0 +1,3 @@
+[^:]*: Assembler messages:
+[^:]*:1: Error: file was compiled for the 430X ISA but the 430 ISA is selected
+[^:]*:4: Error: file was compiled assuming data could be in the upper memory region, but the lower data region is exclusively in use
diff --git a/gas/testsuite/gas/msp430/attr-430x-large-any-good.d b/gas/testsuite/gas/msp430/attr-430x-large-any-good.d
new file mode 100644
index 0000000..603aab1
--- /dev/null
+++ b/gas/testsuite/gas/msp430/attr-430x-large-any-good.d
@@ -0,0 +1,6 @@
+#name: 430X ISA, large memory model and any data region object attributes
+#source: attr-430x-large-any.s
+#as: -ml -mdata-region=none
+#objdump: -t
+
+#pass
diff --git a/gas/testsuite/gas/msp430/attr-430x-large-any.s b/gas/testsuite/gas/msp430/attr-430x-large-any.s
new file mode 100644
index 0000000..593c171
--- /dev/null
+++ b/gas/testsuite/gas/msp430/attr-430x-large-any.s
@@ -0,0 +1,4 @@
+.mspabi_attribute 4, 2 ; OFBA_MSPABI_Tag_ISA == 430x
+.mspabi_attribute 6, 2 ; OFBA_MSPABI_Tag_Code_Model == Large
+.mspabi_attribute 8, 2 ; OFBA_MSPABI_Tag_Data_Model == Large
+.gnu_attribute 4, 2 ; Tag_GNU_MSP430_Data_Region == Any
diff --git a/gas/testsuite/gas/msp430/attr-430x-large-lower-bad.d b/gas/testsuite/gas/msp430/attr-430x-large-lower-bad.d
new file mode 100644
index 0000000..fb7e5ca
--- /dev/null
+++ b/gas/testsuite/gas/msp430/attr-430x-large-lower-bad.d
@@ -0,0 +1,4 @@
+#name: Error when 430X ISA, large memory model and lower data region object attributes conflict with options
+#source: attr-430x-large-lower.s
+#as: -mdata-region=none -mcpu=msp430 -ml
+#error_output: attr-430x-large-lower-bad.l
diff --git a/gas/testsuite/gas/msp430/attr-430x-large-lower-bad.l b/gas/testsuite/gas/msp430/attr-430x-large-lower-bad.l
new file mode 100644
index 0000000..a21b640
--- /dev/null
+++ b/gas/testsuite/gas/msp430/attr-430x-large-lower-bad.l
@@ -0,0 +1,3 @@
+[^:]*: Assembler messages:
+[^:]*:1: Error: file was compiled for the 430X ISA but the 430 ISA is selected
+[^:]*:4: Error: file was compiled assuming all data will be in the lower memory region, but the upper region is in use
diff --git a/gas/testsuite/gas/msp430/attr-430x-large-lower-good.d b/gas/testsuite/gas/msp430/attr-430x-large-lower-good.d
new file mode 100644
index 0000000..c4a395c
--- /dev/null
+++ b/gas/testsuite/gas/msp430/attr-430x-large-lower-good.d
@@ -0,0 +1,6 @@
+#name: 430X ISA, large memory model and lower data region object attributes
+#source: attr-430x-large-lower.s
+#as: -ml
+#objdump: -t
+
+#pass
diff --git a/gas/testsuite/gas/msp430/attr-430x-large-lower.s b/gas/testsuite/gas/msp430/attr-430x-large-lower.s
new file mode 100644
index 0000000..4ab0b5d
--- /dev/null
+++ b/gas/testsuite/gas/msp430/attr-430x-large-lower.s
@@ -0,0 +1,4 @@
+.mspabi_attribute 4, 2 ; OFBA_MSPABI_Tag_ISA == 430x
+.mspabi_attribute 6, 2 ; OFBA_MSPABI_Tag_Code_Model == Large
+.mspabi_attribute 8, 2 ; OFBA_MSPABI_Tag_Data_Model == Large
+.gnu_attribute 4, 1 ; Tag_GNU_MSP430_Data_Region == Lower
diff --git a/gas/testsuite/gas/msp430/msp430.exp b/gas/testsuite/gas/msp430/msp430.exp
index 9c7a197..ef3164d 100644
--- a/gas/testsuite/gas/msp430/msp430.exp
+++ b/gas/testsuite/gas/msp430/msp430.exp
@@ -46,4 +46,10 @@ if [expr [istarget "msp430-*-*"]]  then {
     run_dump_test "preinit-array"
     run_dump_test "init-array"
     run_dump_test "fini-array"
+    run_dump_test "attr-430-small-bad"
+    run_dump_test "attr-430-small-good"
+    run_dump_test "attr-430x-large-lower-bad"
+    run_dump_test "attr-430x-large-lower-good"
+    run_dump_test "attr-430x-large-any-bad"
+    run_dump_test "attr-430x-large-any-good"
 }