From 86598ebfa13479b4ba3b6b7a9de25c3e497ff57e Mon Sep 17 00:00:00 2001
From: Mark Wielaard <mjw@redhat.com>
Date: Wed, 16 Sep 2009 12:22:04 +0200
Subject: Clean up dwflpp::translate_location workaround for
 DW_AT_data_member_location.

Do the same workaround as loc2c-test.c does. Just treat a constant member
location offset as a DW_OP_plus_uconst and call c_translate_location for it.
Also Remove c_translate_add_offset.

* dwflpp.cxx (dwflpp::translate_location): Check elfutils version and only
  do workaround for elfutils < 0.142.
* loc2c.h (c_translate_add_offset): Removed.
* loc2c.c (c_translate_add_offset): Likewise.
---
 dwflpp.cxx | 23 +++++++++++------------
 loc2c.c    | 34 ----------------------------------
 loc2c.h    |  7 -------
 3 files changed, 11 insertions(+), 53 deletions(-)

diff --git a/dwflpp.cxx b/dwflpp.cxx
index 10127c61..ee13d0b2 100644
--- a/dwflpp.cxx
+++ b/dwflpp.cxx
@@ -1674,21 +1674,20 @@ dwflpp::translate_location(struct obstack *pool,
 {
 
   /* DW_AT_data_member_location, can be either constant offsets
-     (struct member fields), or full blown location expressions. */
+     (struct member fields), or full blown location expressions.
+     In older elfutils, dwarf_getlocation_addr would not handle the
+     constant for us, but newer ones do.  For older ones, we work
+     it by faking an expression, which is what newer ones do. */
+#if !_ELFUTILS_PREREQ (0,142)
   if (dwarf_whatattr (attr) == DW_AT_data_member_location)
     {
-      unsigned int form = dwarf_whatform (attr);
-      if (form == DW_FORM_data1 || form == DW_FORM_data2
-	  || form == DW_FORM_sdata || form == DW_FORM_udata)
-	{
-	  Dwarf_Sword off;
-	  if (dwarf_formsdata (attr, &off) != 0)
-	    throw semantic_error (string ("dwarf_formsdata failed, ")
-				  + string (dwarf_errmsg (-1)), e->tok);
-	  c_translate_add_offset (pool, 1, NULL, off, tail);
-	  return *tail;
-	}
+      Dwarf_Op offset_loc = { .atom = DW_OP_plus_uconst };
+      if (dwarf_formudata (attr, &offset_loc.number) == 0)
+        return c_translate_location (pool, &loc2c_error, this,
+                                     &loc2c_emit_address, 1, 0, pc,
+                                     &offset_loc, 1, NULL, NULL);
     }
+#endif
 
   Dwarf_Op *expr;
   size_t len;
diff --git a/loc2c.c b/loc2c.c
index d4cb4666..5cf59691 100644
--- a/loc2c.c
+++ b/loc2c.c
@@ -1711,40 +1711,6 @@ c_translate_pointer_store (struct obstack *pool, int indent,
   // XXX: what about multiple-location lvalues?
 }
 
-
-/* Translate a fragment to add an offset to the currently calculated
-   address of the input location. Used for struct fields. Only works
-   when location is already an actual base address.
-*/
-
-void
-c_translate_add_offset (struct obstack *pool, int indent, const char *comment,
-                        Dwarf_Sword off, struct location **input)
-{
-  indent++;
-  if (comment == NULL || comment[0] == '\0')
-    comment = "field offset";
-  switch ((*input)->type)
-    {
-    case loc_address:
-      obstack_printf (pool, "%*saddr += " SFORMAT "; // %s\n",
-		      indent * 2 + 2, "", off, comment);
-      *input = (*input)->next = new_synthetic_loc (pool, *input, false);
-    break;
-
-    case loc_register:
-      FAIL (*input, N_("cannot add offset of object in register"));
-      break;
-    case loc_noncontiguous:
-      FAIL (*input, N_("cannot add offset of noncontiguous object"));
-      break;
-
-    default:
-      abort ();
-      break;
-    }
-}
-
 /* Determine the element stride of an array type.  */
 static Dwarf_Word
 array_stride (Dwarf_Die *typedie, struct location *origin)
diff --git a/loc2c.h b/loc2c.h
index 449d4499..8bc59d29 100644
--- a/loc2c.h
+++ b/loc2c.h
@@ -87,13 +87,6 @@ c_translate_pointer_store (struct obstack *pool, int indent,
                            Dwarf_Die *typedie, struct location **input,
                            const char *rvalue);
 
-/* Translate a fragment to add an offset to the currently calculated
-   address of the input location. Used for struct fields. Only works
-   when location is already an actual base address. */
-void
-c_translate_add_offset (struct obstack *pool, int indent, const char *comment,
-			Dwarf_Sword off, struct location **input);
-
 /* Translate a C fragment for a direct argument VALUE.  On errors, call FAIL,
    which should not return.  Any later errors will use FAIL and FAIL_ARG from
    this translate call.  On success, return the fragment created. */
-- 
cgit