die_name.patch

diff --git a/dwflpp.cxx b/dwflpp.cxx
index c2fdb05f5..96d55490e 100644
--- a/dwflpp.cxx
+++ b/dwflpp.cxx
@@ -2892,7 +2892,7 @@ dwflpp::find_variable_and_frame_base (vector<Dwarf_Die>& scopes,
            // version is recent enough to not need this workaround if
            // we would see an imported unit.
            if (dwarf_tag (vardie) == DW_TAG_variable
-               && strcmp (dwarf_diename (vardie), local.c_str ()) == 0
+               && strcmp (dwarf_diename (vardie) ?: "<unknown>", local.c_str ()) == 0
                && (dwarf_attr_integrate (vardie, DW_AT_external, &attr_mem)
                    != NULL)
                && ((dwarf_attr_integrate (vardie, DW_AT_const_value, &attr_mem)
diff --git a/loc2stap.cxx b/loc2stap.cxx
index 74e753187..efc78cc57 100644
--- a/loc2stap.cxx
+++ b/loc2stap.cxx
@@ -1510,7 +1510,7 @@ max_fetch_size (Dwarf_Die *die)
   if (cu == NULL)
     throw SEMANTIC_ERROR(std::string("cannot determine compilation unit "
                                     "address size from ")
-                        + dwarf_diename (die)
+                        + (dwarf_diename (die) ?: "<anonymous>")
                         + " " + dwarf_errmsg (-1));
 
   return address_size;
diff --git a/tapsets.cxx b/tapsets.cxx
index 1fed5dfd6..0ec71ebda 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -12605,7 +12605,7 @@ tracepoint_query::handle_query_type(Dwarf_Die * type)
   if (!dwarf_hasattr(type, DW_AT_name))
     return DWARF_CB_OK;
 
-  std::string name(dwarf_diename(type));
+  std::string name(dwarf_diename(type) ?: "<unknown type>");
 
   if (!dw.function_name_matches_pattern(name, "stapprobe_" + tracepoint)
       || startswith(name, "stapprobe_template_"))