[Issue 24440] multiple multidimensional array appends broke in 2.107 on Windows

Mar 17, 2024

Ivan Kazmenko

Mar 17, 2024

Ivan Kazmenko

[Issue 24440] [REG 2.107] multiple multidimensional array appends broke in 2.107 on Windows

Mar 17, 2024

Ivan Kazmenko

Mar 31, 2024

Ivan Kazmenko

https://issues.dlang.org/show_bug.cgi?id=24440 --- Comment #1 from Ivan Kazmenko <gassa@mail.ru> --- Created attachment 1911 --> https://issues.dlang.org/attachment.cgi?id=1911&action=edit reduced example --

https://issues.dlang.org/show_bug.cgi?id=24440 --- Comment #2 from Ivan Kazmenko <gassa@mail.ru> --- With Linux, it's just "segmentation fault" with 2.107. Correctly goes to assert(false) with 2.106. --

https://issues.dlang.org/show_bug.cgi?id=24440 --- Comment #3 from Ivan Kazmenko <gassa@mail.ru> --- Originally got hit by it in my toy language project which I use to teach parallel computing. It maintains a three-dimensional array to store queues of messages between different simulated processes. For now, circumvented the issue by transforming it to a two-dimensional array of structs containing arrays. https://github.com/GassaFM/interpr/commit/b959bb7870 Still, multidimensional arrays are a pretty core language feature. Can I expect it would work again at some point?.. Ivan Kazmenko. --

April 19, 2024

[Issue 24440] [REG 2.107] multiple multidimensional array appends broke in 2.107

Posted by Yui Hosaka

Permalink

Yui Hosaka

Permalink

https://issues.dlang.org/show_bug.cgi?id=24440

Yui Hosaka <hos@hos.ac> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hos@hos.ac

--- Comment #4 from Yui Hosaka <hos@hos.ac> ---
Sorry if this is unrelated, but I'm trying to add an example with similar behavior. The following code, given `1000 1000` on the first line and 1000 tokens in each of the subsequence 1000 lines from standard input, fails to run successfully and it is just "Segmentation fault" (DMD>=2.107.0, WSL2).


```
import std.conv, std.stdio, std.string;

void main() {
  string[] tokens = readln.chomp.split;
  const M = tokens[0].to!int;
  const N = tokens[1].to!int;
  auto A = new string[][](M, N);
  foreach (x; 0 .. M) {
    tokens = readln.chomp.split;
    foreach (y; 0 .. N) {
      A[x][y] = tokens[y];
    }
  }
}
```

For further info, I found this at when solving a problem at
https://yukicoder.me/ - my submission link:
https://yukicoder.me/submissions/974786 where I see that when the input is
smaller the segmentation fault does not happen (RE (Runtime Error) vs WA (Wrong
Answer)).

--

https://issues.dlang.org/show_bug.cgi?id=24440 Tim <tim.dlang@t-online.de> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |tim.dlang@t-online.de --- Comment #5 from Tim <tim.dlang@t-online.de> --- This looks like the same problem as in issue 24498. The expression `new long [][][](n, n)` creates memory, which is not scanned by the GC, but contains pointers. The GC will free the inner arrays and the program crashes, when they are accessed. --

https://issues.dlang.org/show_bug.cgi?id=24440 Tim <tim.dlang@t-online.de> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution|--- |DUPLICATE --- Comment #6 from Tim <tim.dlang@t-online.de> --- *** This issue has been marked as a duplicate of issue 24498 *** --

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