readelf: Print DIE offset in attribute reading error messages.

When processing large files it is useful to know the DIE offset if
printing of attributes fails (especially when redirecting the output).
With this change the error message looks like:

  eu-readelf: DIE [2aeb8ef1] cannot get attribute value: invalid DWARF

Signed-off-by: Mark Wielaard <mark@klomp.org>

diff --git a/src/ChangeLog b/src/ChangeLog
index 3b886a7bb34f67b2888f5caf5db39a5d8e5def16..d112cd2e5543813695f6019e4f7583272124ca3b 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,7 @@
+2017-10-03  Mark Wielaard  <mark@klomp.org>
+
+       * readelf.c (attr_callback): Print DIE offset in error messages.
+
 2017-11-03  Mark Wielaard  <mark@klomp.org>
 
        * readelf.c (print_ops): Handle DW_OP_GNU_variable_value. Print

diff --git a/src/readelf.c b/src/readelf.c
index 833884b532ab03bacd605bae59fadf1efb014ab8..e364583c8c580185e17d24e173599be0dbb72170 100644 (file)
--- a/src/readelf.c
+++ b/src/readelf.c
@@ -5935,13 +5935,15 @@ attr_callback (Dwarf_Attribute *attrp, void *arg)
 {
   struct attrcb_args *cbargs = (struct attrcb_args *) arg;
   const int level = cbargs->level;
+  Dwarf_Die *die = cbargs->die;
 
   unsigned int attr = dwarf_whatattr (attrp);
   if (unlikely (attr == 0))
     {
       if (!cbargs->silent)
-       error (0, 0, gettext ("cannot get attribute code: %s"),
-              dwarf_errmsg (-1));
+       error (0, 0, gettext ("DIE [%" PRIx64 "] "
+                             "cannot get attribute code: %s"),
+              dwarf_dieoffset (die), dwarf_errmsg (-1));
       return DWARF_CB_ABORT;
     }
 
@@ -5949,8 +5951,9 @@ attr_callback (Dwarf_Attribute *attrp, void *arg)
   if (unlikely (form == 0))
     {
       if (!cbargs->silent)
-       error (0, 0, gettext ("cannot get attribute form: %s"),
-              dwarf_errmsg (-1));
+       error (0, 0, gettext ("DIE [%" PRIx64 "] "
+                             "cannot get attribute form: %s"),
+              dwarf_dieoffset (die), dwarf_errmsg (-1));
       return DWARF_CB_ABORT;
     }
 
@@ -5964,8 +5967,9 @@ attr_callback (Dwarf_Attribute *attrp, void *arg)
            {
            attrval_out:
              if (!cbargs->silent)
-               error (0, 0, gettext ("cannot get attribute value: %s"),
-                      dwarf_errmsg (-1));
+               error (0, 0, gettext ("DIE [%" PRIx64 "] "
+                                     "cannot get attribute value: %s"),
+                      dwarf_dieoffset (die), dwarf_errmsg (-1));
              return DWARF_CB_ABORT;
            }
          char *a = format_dwarf_addr (cbargs->dwflmod, cbargs->addrsize,