https://issues.dlang.org/show_bug.cgi?id=21690
Issue ID: 21690
Summary: Unable to dynamic cast extern(C++) classes
Product: D
Version: D2
Hardware: x86_64
OS: Linux
Status: NEW
Severity: critical
Priority: P1
Component: dmd
Assignee: nob...@puremagic.com
Reporter: thomas.bock...@gmail.com
Since 2.067.1, the program below outputs:
D cast was dynamic.
C++ cast was static.
The extern(C++) class casts need to be dynamic, just like the extern(D) casts:
///////////////////////////////////////////////
module app;
import std.stdio;
@safe:
extern(D) {
abstract class DA {
char foo();
}
class DB : DA {
override char foo() { return 'B'; }
}
class DC : DA {
override char foo() { return 'C'; }
}
}
extern(C++) {
abstract class CA {
char foo();
}
class CB : CA {
override char foo() { return 'b'; }
}
class CC : CA {
override char foo() { return 'c'; }
}
}
void main() {
DB db = new DB;
DA da = db;
DC dc = cast(DC) da;
writeln((dc is null)? "D cast was dynamic." : "D cast was static.");
CB cb = new CB;
CA ca = cb;
CC cc = cast(CC) ca;
writeln((cc is null)? "C++ cast was dynamic." : "C++ cast was static.");
return;
}
///////////////////////////////////////////////
This is a critical bug, as the results of accessing an incorrectly typed class
object could, in the general case, be almost anything, including memory
corruption.
--
