Bug 22124 – Corrupted closure when compiling with -preview=dip1000

The following program will segfault when compiled with -preview=dip1000, but not otherwise: /////////////// test.d ////////////// import core.thread; static import std.parallelism; // ??? struct Elem { uint[16] pad; } Elem[] arr; void main(string[] args) { arr = new Elem[1]; fun1(); } void fun1() { fun2(); } void fun2() { fun3(); } void fun3() { foreach (ref elem; arr) fun4(elem); } void fun4(ref Elem elem) { auto pelem = &elem; auto thread = new Thread({ assert(&elem is pelem); }); thread.start(); } /////////////////////////////////////

(In reply to Vladimir Panteleev from comment #0) > The following program will segfault Assert, not segfault.

Probably a combination of issue 20150 and/or issue 21912. See also my thread example in: https://forum.dlang.org/thread/[email protected] A closure should be created on the heap for the stackframe of fun4, but dmd doesn't do that because Thread's constructor is `pure` so the delegate becomes `scope`. We can make the parameter in the constructor explicitly `return scope`, but considering issue 21912, that might not be enough.

@dkorpel created dlang/druntime pull request #3520 "Fix issue 22124 - Corrupted closure with -dip1000 " fixing this issue: - Fix issue 22124 - Corrupted closure with -dip1000 - Add test case for issue 22124 https://github.com/dlang/druntime/pull/3520

@dkorpel created dlang/druntime pull request #3550 "Add test case for issue 22124" mentioning this issue: - Add test case for issue 22124 https://github.com/dlang/druntime/pull/3550

dlang/druntime pull request #3550 "Add test case for issue 22124" was merged into master: - b4006f2b7a6dd8357f8f87bb3cad606078dfa9d7 by dkorpel: Fix issue 22124 - Corrupted closure when compiling with -preview=dip1000 https://github.com/dlang/druntime/pull/3550