From: Mark Wielaard <mjw@redhat.com>
Date: Tue, 9 Jul 2013 21:09:38 +0000 (+0200)
Subject: readelf: print actual DIE offsets of DW_OP_GNU_<type> ops.
X-Git-Tag: elfutils-0.156~7
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1ab6e78250293926e90bfe011ff7dc0d7bf311b7;p=thirdparty%2Felfutils.git

readelf: print actual DIE offsets of DW_OP_GNU_<type> ops.

Like DW_OP_GNU_parameter_ref the DW_OP_GNU type conversion ops
DW_OP_GNU_const_type, DW_OP_GNU_regval_type, DW_OP_GNU_deref_type,
DW_OP_GNU_convert and DW_OP_GNU_reinterpret take a CU relative offset
to a DIE (in these cases a DW_TAG_base_type). So handle the DIE offsets
just like in the DW_OP_GNU_parameter_ref case by adding the cu->start
if known (and -U hasn't been given). For DW_OP_GNU_convert and
DW_OP_GNU_reinterpret handle zero specially since it means to "untype"
the result and so isn't an actual DIE reference.

Signed-off-by: Mark Wielaard <mjw@redhat.com>
---

diff --git a/src/readelf.c b/src/readelf.c
index d6208cbde..119c10003 100644
--- a/src/readelf.c
+++ b/src/readelf.c
@@ -4042,10 +4042,13 @@ print_ops (Dwfl_Module *dwflmod, Dwarf *dbg, int indent, int indentrest,
 	  break;
 
 	case DW_OP_GNU_const_type:
-	  /* DIE offset, size plus block.  */
+	  /* uleb128 CU relative DW_TAG_base_type DIE offset, 1-byte
+	     unsigned size plus block.  */
 	  start = data;
 	  NEED (2);
 	  get_uleb128 (uleb, data); /* XXX check overrun */
+	  if (! print_unresolved_addresses && cu != NULL)
+	    uleb += cu->start;
 	  uint8_t usize = *(uint8_t *) data++;
 	  NEED (usize);
 	  printf ("%*s[%4" PRIuMAX "] %s [%6" PRIxMAX "] ",
@@ -4057,21 +4060,29 @@ print_ops (Dwfl_Module *dwflmod, Dwarf *dbg, int indent, int indentrest,
 	  break;
 
 	case DW_OP_GNU_regval_type:
+	  /* uleb128 register number, uleb128 CU relative
+	     DW_TAG_base_type DIE offset.  */
 	  start = data;
 	  NEED (2);
 	  get_uleb128 (uleb, data); /* XXX check overrun */
 	  get_uleb128 (uleb2, data); /* XXX check overrun */
-	  printf ("%*s[%4" PRIuMAX "] %s %" PRIu64 " %#" PRIx64 "\n",
+	  if (! print_unresolved_addresses && cu != NULL)
+	    uleb2 += cu->start;
+	  printf ("%*s[%4" PRIuMAX "] %s %" PRIu64 " [%6" PRIx64 "]\n",
 		  indent, "", (uintmax_t) offset, op_name, uleb, uleb2);
 	  CONSUME (data - start);
 	  offset += 1 + (data - start);
 	  break;
 
 	case DW_OP_GNU_deref_type:
+	  /* 1-byte unsigned size of value, uleb128 CU relative
+	     DW_TAG_base_type DIE offset.  */
 	  start = data;
 	  NEED (2);
 	  usize = *(uint8_t *) data++;
 	  get_uleb128 (uleb, data); /* XXX check overrun */
+	  if (! print_unresolved_addresses && cu != NULL)
+	    uleb += cu->start;
 	  printf ("%*s[%4" PRIuMAX "] %s %" PRIu8 " [%6" PRIxMAX "]\n",
 		  indent, "", (uintmax_t) offset,
 		  op_name, usize, uleb);
@@ -4081,9 +4092,13 @@ print_ops (Dwfl_Module *dwflmod, Dwarf *dbg, int indent, int indentrest,
 
 	case DW_OP_GNU_convert:
 	case DW_OP_GNU_reinterpret:
+	  /* uleb128 CU relative offset to DW_TAG_base_type, or zero
+	     for conversion to untyped.  */
 	  start = data;
 	  NEED (1);
 	  get_uleb128 (uleb, data); /* XXX check overrun */
+	  if (uleb != 0 && ! print_unresolved_addresses && cu != NULL)
+	    uleb += cu->start;
 	  printf ("%*s[%4" PRIuMAX "] %s [%6" PRIxMAX "]\n",
 		  indent, "", (uintmax_t) offset, op_name, uleb);
 	  CONSUME (data - start);