* NEWS: Add item about discriminator support.

* dwarf2dbg.h (struct dwarf2_line_info): Add discriminator field.
	* dwarf2dbg.c (current): Add discriminator field.
	(dwarf2_where): Copy discriminator value.
	(dwarf2_consume_line_info): Set discriminator to 0.
	(dwarf2_directive_loc): Process discriminator sub-op.
	(out_leb128): New function.
	(process_entries): Output DW_LNE_set_discriminator.
	* doc/as.texinfo: Add discriminator operand to .loc directive.
	* testsuite/gas/lns/lns-common-1.d: Add test for discriminator.
	* testsuite/gas/lns/lns-common-1.s: Likewise.

gas/ChangeLog

@@ -1,3 +1,17 @@
+2009-04-24  Cary Coutant  <ccoutant@google.com>
+
+	* NEWS: Add item about discriminator support.
+	* dwarf2dbg.h (struct dwarf2_line_info): Add discriminator field.
+	* dwarf2dbg.c (current): Add discriminator field.
+	(dwarf2_where): Copy discriminator value.
+	(dwarf2_consume_line_info): Set discriminator to 0.
+	(dwarf2_directive_loc): Process discriminator sub-op.
+	(out_leb128): New function.
+	(process_entries): Output DW_LNE_set_discriminator.
+	* doc/as.texinfo: Add discriminator operand to .loc directive.
+	* testsuite/gas/lns/lns-common-1.d: Add test for discriminator.
+	* testsuite/gas/lns/lns-common-1.s: Likewise.
+
 2009-04-22  Nathan Sidwell  <nathan@codesourcery.com>
 
 	* config/tc-mips.c (macro_end, md_convert_frag): Use '%s' for

gas/NEWS

@@ -1,5 +1,8 @@
 -*- text -*-
 
+* Add support for the new discriminator column in the DWARF line table,
+  with a discriminator operand for the .loc directive.
+
 * Add support for Sunplus score architecture.
 
 * Add support for Lattice Mico32 (lm32) architecture.

gas/doc/as.texinfo

@@ -5108,6 +5108,10 @@ either 0 or 1.
 This directive will set the @code{isa} register in the @code{.debug_line}
 state machine to @var{value}, which must be an unsigned integer.
 
+@item discriminator @var{value}
+This directive will set the @code{discriminator} register in the @code{.debug_line}
+state machine to @var{value}, which must be an unsigned integer.
+
 @end table
 
 @node Loc_mark_labels

gas/dwarf2dbg.c

@@ -25,7 +25,8 @@
 
 	.file FILENO "file.c"
 	.loc  FILENO LINENO [COLUMN] [basic_block] [prologue_end] \
-	      [epilogue_begin] [is_stmt VALUE] [isa VALUE]
+	      [epilogue_begin] [is_stmt VALUE] [isa VALUE] \
+	      [discriminator VALUE]
 */
 
 #include "as.h"
@@ -194,7 +195,8 @@ bfd_boolean dwarf2_loc_mark_labels;
 /* Current location as indicated by the most recent .loc directive.  */
 static struct dwarf2_line_info current = {
   1, 1, 0, 0,
-  DWARF2_LINE_DEFAULT_IS_STMT ? DWARF2_FLAG_IS_STMT : 0
+  DWARF2_LINE_DEFAULT_IS_STMT ? DWARF2_FLAG_IS_STMT : 0,
+  0
 };
 
 /* The size of an address on the target.  */
@@ -331,6 +333,7 @@ dwarf2_where (struct dwarf2_line_info *line)
       line->column = 0;
       line->flags = DWARF2_FLAG_IS_STMT;
       line->isa = current.isa;
+      line->discriminator = current.discriminator;
     }
   else
     *line = current;
@@ -379,6 +382,7 @@ dwarf2_consume_line_info (void)
   current.flags &= ~(DWARF2_FLAG_BASIC_BLOCK
 		     | DWARF2_FLAG_PROLOGUE_END
 		     | DWARF2_FLAG_EPILOGUE_BEGIN);
+  current.discriminator = 0;
 }
 
 /* Called for each (preferably code) label.  If dwarf2_loc_mark_labels
@@ -581,6 +585,7 @@ dwarf2_directive_loc (int dummy ATTRIBUTE_UNUSED)
 
   current.filenum = filenum;
   current.line = line;
+  current.discriminator = 0;
 
 #ifndef NO_LISTING
   if (listing)
@@ -659,6 +664,18 @@ dwarf2_directive_loc (int dummy ATTRIBUTE_UNUSED)
 	      return;
 	    }
 	}
+      else if (strcmp (p, "discriminator") == 0)
+	{
+	  *input_line_pointer = c;
+	  value = get_absolute_expression ();
+	  if (value >= 0)
+	    current.discriminator = value;
+	  else
+	    {
+	      as_bad (_("discriminator less than zero"));
+	      return;
+	    }
+	}
       else
 	{
 	  as_bad (_("unknown .loc sub-directive `%s'"), p);
@@ -748,6 +765,14 @@ out_uleb128 (addressT value)
   output_leb128 (frag_more (sizeof_leb128 (value, 0)), value, 0);
 }
 
+/* Emit a signed "little-endian base 128" number.  */
+
+static void
+out_leb128 (addressT value)
+{
+  output_leb128 (frag_more (sizeof_leb128 (value, 1)), value, 1);
+}
+
 /* Emit a tuple for .debug_abbrev.  */
 
 static inline void
@@ -1208,6 +1233,14 @@ process_entries (segT seg, struct line_entry *e)
 	  out_uleb128 (column);
 	}
 
+      if (e->loc.discriminator != 0)
+	{
+	  out_opcode (DW_LNS_extended_op);
+	  out_leb128 (1 + sizeof_leb128 (e->loc.discriminator, 0));
+	  out_opcode (DW_LNE_set_discriminator);
+	  out_uleb128 (e->loc.discriminator);
+	}
+
       if (isa != e->loc.isa)
 	{
 	  isa = e->loc.isa;

gas/dwarf2dbg.h

@@ -34,6 +34,7 @@ struct dwarf2_line_info {
   unsigned int column;
   unsigned int isa;
   unsigned int flags;
+  unsigned int discriminator;
 };
 
 /* Implements the .file FILENO "FILENAME" directive.  FILENO can be 0

gas/testsuite/gas/lns/lns-common-1.d

@@ -21,6 +21,8 @@ Raw dump of debug contents of section \.debug_line:
   Special opcode .*: advance Address by .* to .* and Line by 1 to 6
   Set is_stmt to 1
   Special opcode .*: advance Address by .* to .* and Line by 1 to 7
+  Extended opcode 4: set Discriminator to 1
+  Special opcode .*: advance Address by .* to .* and Line by 0 to 7
   Advance PC by .* to .*
   Extended opcode 1: End of Sequence
 #...

gas/testsuite/gas/lns/lns-common-1.s

@@ -13,3 +13,5 @@
 	nop
 	.loc 1 7 is_stmt 1
 	nop
+	.loc 1 7 discriminator 1
+	nop