Fix test in anonymous_struct_prefix

I noticed a bad test in dwarf2/read.c:anonymous_struct_prefix:

   attr = dw2_linkage_name_attr (die, cu);
   const char *attr_name = attr->as_string ();
  if (attr == NULL || attr_name == NULL)
    return NULL;

Here, if attr==NULL, this will crash before the test can be executed.

This patch fixes the problem by hoisting the test.  I'm checking this
in as obvious.

diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index bc8b0883ed2c2e59510efcb487c10d4900468110..801917937ecbcf646cf1a70797a1e3bb135149cc 100644 (file)
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -17048,9 +17048,11 @@ anonymous_struct_prefix (struct die_info *die, struct dwarf2_cu *cu)
     return NULL;
 
   attr = dw2_linkage_name_attr (die, cu);
+  if (attr == nullptr)
+    return nullptr;
   const char *attr_name = attr->as_string ();
-  if (attr == NULL || attr_name == NULL)
-    return NULL;
+  if (attr_name == nullptr)
+    return nullptr;
 
   /* dwarf2_name had to be already called.  */
   gdb_assert (attr->canonical_string_p ());