digitalmars.D.bugs - [Issue 10785] New: Interface diamond covariance causes silent breakage
- d-bugmail puremagic.com (39/39) Aug 08 2013 http://d.puremagic.com/issues/show_bug.cgi?id=10785
- d-bugmail puremagic.com (39/39) Aug 11 2013 http://d.puremagic.com/issues/show_bug.cgi?id=10785
- d-bugmail puremagic.com (8/9) Aug 11 2013 http://d.puremagic.com/issues/show_bug.cgi?id=10785
- d-bugmail puremagic.com (8/8) Aug 11 2013 http://d.puremagic.com/issues/show_bug.cgi?id=10785
http://d.puremagic.com/issues/show_bug.cgi?id=10785 Summary: Interface diamond covariance causes silent breakage Product: D Version: D1 & D2 Platform: All OS/Version: All Status: NEW Severity: major Priority: P2 Component: DMD AssignedTo: nobody puremagic.com ReportedBy: default_357-line yahoo.de 17:01:53 PDT --- Consider this code: interface A { A foo(); } interface A1 : A { A1 foo(); } interface A2 : A { A2 foo(); } class C : A1, A2 { override C foo() { return new C; } } void main() { A2 x = new C; A2 y = x.foo(); // y.classinfo.name should be "A2" here; instead, it is "A1". The vtables also don't match up (not that there's significant vtables in this example, but, you know) assert(y.classinfo.name.find("A2") != -1); // fails // Further issues: this should be a no-op, but it isn't. A2 z = cast(A2) cast(A) y; assert(z.classinfo.name == y.classinfo.name); // fails too } The problem seems to be that whatever magic the compiler does to make interface covariance work fails in the case where it has to satisfy the same interface via two covariant child interfaces at once. I suspect this would either require A2.foo to be filled with a stub that does the conversion of C to A2, or a compiletime error. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Aug 08 2013
http://d.puremagic.com/issues/show_bug.cgi?id=10785 Infiltrator <lt.infiltrator gmail.com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |lt.infiltrator gmail.com PDT --- This also affects non-diamond configurations: http://dpaste.dzfl.pl/e9df03f9 ---------------------- import std.stdio; interface A1 { A1 foo(); } interface A2 { A2 foo(); } class C1 : A1, A2 { override C1 foo() { return new C1; } } interface B1 { B1 foo(); } interface B2 { B2 foo(); } class C2 : B2, B1 { override C2 foo() { return new C2; } } void main() { A2 x = new C1; A2 y = x.foo(); writefln("X: %s", x.classinfo); writefln("Y: %s", y.classinfo); B2 a = new C2; B2 b = a.foo(); writefln("A: %s", a.classinfo); writefln("B: %s", b.classinfo); } ----------------------- Application output: X: f230.A2 Y: f230.A1 A: f230.B2 B: f230.B2 -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Aug 11 2013
http://d.puremagic.com/issues/show_bug.cgi?id=10785 22:40:21 PDT ---This also affects non-diamond configurations:Thanks, filed as 10806. Not sure whether to mark this as a duplicate. (10806 is the more general bug) -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Aug 11 2013
http://d.puremagic.com/issues/show_bug.cgi?id=10785 PDT --- non-diamond is fixed. Somebody more knowledgeable in dmd can make the duplicate decision. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Aug 11 2013