[Bug c++/63207] New: ICE in expand_expr_real_l when instantiating a template with a lambda that captures a const variable with a dependent initializer

["st at quanttec dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63207

            Bug ID: 63207
           Summary: ICE in expand_expr_real_l when instantiating a
                    template with a lambda that captures a const variable
                    with a dependent initializer
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: st at quanttec dot com

Compiling the following following code with the current trunk GCC results in an
ICE.

template <typename T>
struct Base {
  T value;
};

template <typename T>
struct Test : Base<T> {
  T test() {
    const int x = this->value;
    return ([&]{ return x; })();
  }
};

int main()  {
  Test<int> t;
  t.value = 0;
  return t.test();
}

g++ test.cpp --std=c++11 -Wall
test.cpp: In lambda function:
test.cpp:10:28: warning: âxâ is used uninitialized in this function
[-Wuninitialized]
     return ([&]{ return x; })();
                            ^
test.cpp:9:15: note: âxâ was declared here
     const int x = this->value;
               ^
test.cpp:10:28: internal compiler error: in expand_expr_real_1, at expr.c:9517
     return ([&]{ return x; })();
                            ^
0x8c96ba expand_expr_real_1(tree_node*, rtx_def*, machine_mode,
expand_modifier, rtx_def**, bool)
        ../../gcc/gcc/expr.c:9517
0x8d0dea store_expr(tree_node*, rtx_def*, int, bool)
        ../../gcc/gcc/expr.c:5338
0x8d8e4b expand_assignment(tree_node*, tree_node*, bool)
        ../../gcc/gcc/expr.c:5124
0x7e3b33 expand_gimple_stmt_1
        ../../gcc/gcc/cfgexpand.c:3274
0x7e3b33 expand_gimple_stmt
        ../../gcc/gcc/cfgexpand.c:3376
0x7e99d3 expand_gimple_basic_block
        ../../gcc/gcc/cfgexpand.c:5215
0x7eb86f execute
        ../../gcc/gcc/cfgexpand.c:5821