[Bug c++/65284] [5 Regression] C++ lambda and auto return value causes ICE or gimple error

[aldyh at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65284

Aldy Hernandez <aldyh at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #34959|0                           |1
        is obsolete|                            |

--- Comment #7 from Aldy Hernandez <aldyh at gcc dot gnu.org> ---
Created attachment 34977
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34977&action=edit
smaller and simpler testcase

In cp_simplify_init_expr(), we are lowering part of the return
statement for the lambda function from this:

*NON_LVALUE_EXPR <this> = TARGET_EXPR <D.2173, <<< Unknown tree: aggr_init_expr
  4
  __comp_ctor 
  D.2173
  NON_LVALUE_EXPR <this> >>>>;

into:

<<< Unknown tree: aggr_init_expr
  4
  __comp_ctor 
  *NON_LVALUE_EXPR <this>        <-- notice we've dropped D.2173
  NON_LVALUE_EXPR <this> >>>;

This last blob cannot be stored into retval because the value of the
aggr_init_expr is a read from the constructor which has a void return type.