[Bug target/120900] C++ passes user aligned struct differently from C

[hjl.tools at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120900

--- Comment #9 from H.J. Lu <hjl.tools at gmail dot com> ---
C++ does

 /* If this is a typedef that names the class for linkage purposes
     (7.1.3p8), apply any attributes directly to the type.  */
  if (TREE_CODE (decl) == TYPE_DECL
      && OVERLOAD_TYPE_P (TREE_TYPE (decl))
      && decl == TYPE_NAME (TYPE_MAIN_VARIANT (TREE_TYPE (decl))))
    flags = ATTR_FLAG_TYPE_IN_PLACE;
  else  
    flags = 0;

  /* Set attributes here so if duplicate decl, will have proper attributes.  */
  cplus_decl_attributes (&decl, attributes, flags);

while C does

  /* Set attributes here so if duplicate decl, will have proper attributes.  */
  c_decl_attributes (&decl, attributes, 0);