crashes on function with no appropriate return value

[zhendongsu]

$ tis-interpreter.sh test.c
test.c:3:[kernel] warning: Body of function foo falls-through and cannot find an appropriate return value
test.c:3:[kernel] failure: Found return without value in function foo
[kernel] Current source was: test.c:3
         The full backtrace is:
         Raised at file "src/kernel_services/plugin_entry_points/log.ml", line 586, characters 30-31
         Called from file "src/kernel_services/plugin_entry_points/log.ml", line 580, characters 9-16
         Re-raised at file "src/kernel_services/plugin_entry_points/log.ml", line 583, characters 15-16
         Called from file "src/kernel_internals/typing/oneret.ml", line 248, characters 8-87
         Called from file "src/kernel_internals/typing/oneret.ml", line 356, characters 22-54
         Called from file "src/kernel_internals/typing/oneret.ml", line 363, characters 13-35
         Called from file "src/kernel_services/ast_queries/file.ml", line 884, characters 6-26
         Called from file "list.ml", line 73, characters 12-15
         Called from file "src/kernel_services/ast_queries/file.ml", line 1135, characters 5-43
         Called from file "src/kernel_services/ast_queries/file.ml", line 1572, characters 2-22
         Called from file "src/kernel_services/ast_queries/file.ml", line 1659, characters 4-27
         Called from file "src/kernel_services/ast_data/ast.ml", line 113, characters 2-28
         Called from file "src/kernel_services/ast_data/ast.ml", line 125, characters 53-71
         Called from file "src/kernel_internals/runtime/boot.ml", line 31, characters 6-20
         Called from file "src/kernel_services/cmdline_parameters/cmdline.ml", line 783, characters 2-9
         Called from file "src/kernel_services/cmdline_parameters/cmdline.ml", line 813, characters 18-64
         Called from file "src/kernel_services/cmdline_parameters/cmdline.ml", line 224, characters 4-8

         Frama-C aborted: internal error.
         Please report at https://github.com/TrustInSoft/tis-interpreter/issues
$ 
$ cat test.c
struct S { int x; };

struct S foo () {} 

int main ()
{
  return 0; 
}
$