• d-bugmail puremagic.com (35/35) Apr 16 2022 https://issues.dlang.org/show_bug.cgi?id=23024

d-bugmail puremagic.com writes:

https://issues.dlang.org/show_bug.cgi?id=23024

          Issue ID: 23024
           Summary: Large static array causes access violation on Windows
                    with DMD
           Product: D
           Version: D2
          Hardware: x86
                OS: Windows
            Status: NEW
          Severity: major
          Priority: P1
         Component: dmd
          Assignee: nobody puremagic.com
          Reporter: andy.pj.hanson gmail.com

This program breaks on Windows when compiled with DMD:

```
import core.stdc.stdio : printf;

static ulong[0x100000] data;

extern(C) void main() {
        foreach (immutable size_t i; 0 .. data.length) {
                printf("Write to data[%llu]\n", i);
                data[i] = 42;
        }
        printf("Success\n");
}
```

The issue is an access violation. 
`dmd -m64 a.d && .\a.exe` fails before writing data[1007].
`dmd -m64 -g a.d && .\a.exe` fails before writing data[6].

(Removing the -m64 doesn't help. The difference with `-g` may be related to
https://issues.dlang.org/show_bug.cgi?id=21763 .)

`ldc2 a.d && .\a.exe` succeeds. And both dmd and ldc2 work on Linux.

I'm testing this on a VMWare virtual machine in case that matters.

Tested with dmd `v2.099.1-dirty`.

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