[Bug c++/77592] gcc accepts delegated constructor with circular reference

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77592

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Gawain Bolton from comment #0)
> Compilation segfaults using gcc v5.3, v6.1 and gcc HEAD 7.0.0 20160913

Compilation works fine, the executable segfaults, due to a stack overflow.

The standard says your code is "ill-formed, no diagnostic required" so
compilers aren't required to reject the code, but it would be nice to diagnose
it.

Clang does:

circ.cc:10:7: error: constructor for 'T' creates a delegation cycle
[-Wdelegating-ctor-cycles]
    : T(i,s)
      ^
circ.cc:3:5: note: it delegates to
    T(const int i,
    ^
circ.cc:8:5: note: which delegates to
    T(const char * s,
    ^


And EDG does:

"circ.cc", line 10: error: constructor delegates directly or indirectly to
          itself
      : T(i,s)
        ^