digitalmars.D.bugs - [Issue 18597] New: more unsafe unaligned pointer errors
- d-bugmail puremagic.com (59/59) Mar 12 2018 https://issues.dlang.org/show_bug.cgi?id=18597
https://issues.dlang.org/show_bug.cgi?id=18597 Issue ID: 18597 Summary: more unsafe unaligned pointer errors Product: D Version: D2 Hardware: All OS: All Status: NEW Severity: normal Priority: P1 Component: dmd Assignee: nobody puremagic.com Reporter: bugzilla digitalmars.com ag0aep6g gmail.com writes: //////////////////////////////// test.d //////////////////////////////// safe: struct Victim { bool alive = true; ~this() { alive = false; } } align(1) struct Unaligned { align(1): ubyte filler; Victim* p; } pragma(msg, Unaligned.sizeof); void main() { enum N = 100; Unaligned[N] hosts; foreach (n; 0..N) { version (original) hosts[n].p = new Victim; else version (variation1) hosts[n] = Unaligned(0, new Victim); else version (variation2) { Unaligned u = { p: new Victim }; hosts[n] = u; } else static assert(false); assert(hosts[n].p.alive); } // Unaligned.p is invisible to the GC due to alignment void trustedCollect() trusted { import core.memory; GC.collect(); } trustedCollect(); foreach (n; 0..N) assert(hosts[n].p.alive); // Dangling pointer! } //////////////////////////////////////////////////////////////////////// These should all fail with the same error: dmd -version=original test.d dmd -version=variation1 test.d dmd -version=variation2 test.d The different versions effectively do the same thing, just with different syntax. --
Mar 12 2018