[Bug c++/69251] New: [6 Regression] ICE (segmentation fault) in unify_array_domain on i686-linux-gnu

[doko at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69251

            Bug ID: 69251
           Summary: [6 Regression] ICE (segmentation fault) in
                    unify_array_domain on i686-linux-gnu
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: doko at gcc dot gnu.org
  Target Milestone: ---

trunk r232188, i686-linux-gnu, works with -O0

reduced test case:

template <typename, typename = int> class A;
struct B {
  int len;
  char name[];
};
template <class> struct C;
template <typename> struct D;
template <typename T, int N> struct D<T[N]>;
template <class T> struct F { typename D<T>::type type; };
template <class> struct G;
class H {
  template <class Source>
  H(Source &, typename C<G<typename F<Source>::type>>::type = 0);
};
template <class Char, class Traits> void operator<<(A<Char, Traits>, H);
class ErrnoLogMessage {
public:
  A<char> &stream();
};
B *inotify_handler_ievent {
ErrnoLogMessage().stream() << inotify_handler_ievent->name


$ g++ -c -O server.ii
server.ii: In instantiation of 'struct F<char []>':
server.ii:21:55:   recursively required by substitution of 'template<class
Char, class Traits> void operator<<(A<Char, Traits>, H) [with Char = char;
Traits = int]'
server.ii:21:55:   required from here
server.ii:9:51: internal compiler error: Segmentation fault
 template <class T> struct F { typename D<T>::type type; };
                                                   ^~~~

0x86c037a crash_signal
        ../../src/gcc/toplev.c:334
0x8225d7d unify_array_domain
        ../../src/gcc/cp/pt.c:19106
0x8224a80 unify
        ../../src/gcc/cp/pt.c:19662
0x8224f32 unify
        ../../src/gcc/cp/pt.c:19739
0x8225b4d get_partial_spec_bindings
        ../../src/gcc/cp/pt.c:20499
0x82229ae most_specialized_partial_spec
        ../../src/gcc/cp/pt.c:20771
0x822c400 instantiate_class_template_1
        ../../src/gcc/cp/pt.c:9713
0x822c400 instantiate_class_template(tree_node*)
        ../../src/gcc/cp/pt.c:10283
0x8292b3b complete_type(tree_node*)
        ../../src/gcc/cp/typeck.c:131
0x821b11d tsubst(tree_node*, tree_node*, int, tree_node*)
        ../../src/gcc/cp/pt.c:13328
0x8214da1 tsubst_decl
        ../../src/gcc/cp/pt.c:12014
0x821afb6 tsubst(tree_node*, tree_node*, int, tree_node*)
        ../../src/gcc/cp/pt.c:12697
0x822c63b instantiate_class_template_1
        ../../src/gcc/cp/pt.c:9997
0x822c63b instantiate_class_template(tree_node*)
        ../../src/gcc/cp/pt.c:10283
0x8292b3b complete_type(tree_node*)
        ../../src/gcc/cp/typeck.c:131
0x821b11d tsubst(tree_node*, tree_node*, int, tree_node*)
        ../../src/gcc/cp/pt.c:13328
0x821bbdb tsubst_template_arg
        ../../src/gcc/cp/pt.c:10296
0x82220c2 tsubst_template_args
        ../../src/gcc/cp/pt.c:11110
0x82225a5 tsubst_aggr_type
        ../../src/gcc/cp/pt.c:11307
0x821ac48 tsubst(tree_node*, tree_node*, int, tree_node*)
        ../../src/gcc/cp/pt.c:12776
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