[Issue 19196] DMD thinks storage size for pointer or dynamic array is unknown

[Issue 19196] DMD thinks storage size for pointer or dynamic array isn't always known

Aug 27, 2018

Abscissa

Aug 27, 2018

Sep 06, 2018

github-bugzilla@puremagic.com

Dec 17, 2022

Iain Buclaw

Dec 13

dlangBugzillaToGithub

https://issues.dlang.org/show_bug.cgi?id=19196 Abscissa <bus_dlangzilla@semitwist.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Summary|DMD thinks storage size of |DMD thinks storage size for |dynamic array is unknown |pointer or dynamic array is | |unknown --- Comment #1 from Abscissa <bus_dlangzilla@semitwist.com> --- Same result if "Foo!(A)[]" is changed to "Foo!(A)*" --

https://issues.dlang.org/show_bug.cgi?id=19196 Abscissa <bus_dlangzilla@semitwist.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Blocks| |340 Referenced Issues: https://issues.dlang.org/show_bug.cgi?id=340 [Issue 340] [Tracker] Forward reference bugs and other order-of-declaration issues --

August 27, 2018

[Issue 19196] DMD thinks storage size for pointer or dynamic array isn't always known

Posted by |

Permalink

https://issues.dlang.org/show_bug.cgi?id=19196

| <dhasenan@gmail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dhasenan@gmail.com

--- Comment #2 from | <dhasenan@gmail.com> ---
Reduced testcase that doesn't rely on phobos:

---
struct Foo(T)
{
    alias F = typeof(T.tupleof);
}

struct B
{
        // Error: struct `test.A` no size because of forward reference
        Foo!(B)[] arr;
}
---

In typesem.d:3495, we call `mt.sym.size(e.loc);`. We use it as a shortcut to run semantic analysis on the type before getting the type tuple. This results in a bad error message, but it's straightforward to improve that error message.

Obviously, some stuff won't fly, so we can't glibly leave everything to a later semantic step. The fix required to make this work fully is to run minimal semantic analysis during tupleof, lazily finish that semantic analysis, and only error out then.

That would catch the obvious problem of:

---
struct Foo
{
  static if (!hasElaborateDestructor!B) ~this() {}
}
struct B
{
  Foo foo;
}
---

But would let the original example compile.

Unfortunately, that level of change is beyond me at the moment.

--

https://issues.dlang.org/show_bug.cgi?id=19196 --- Comment #4 from github-bugzilla@puremagic.com --- Commit pushed to master at https://github.com/dlang/dmd https://github.com/dlang/dmd/commit/379446e0f059d25e8da909bf5373f861af5069c5 Improve diagnostic with forward references and tupleof When using tupleof in a template forward reference context, dmd emitted an error message complaining that it could not calculate the size of the struct. This happened even in cases when the size was not obviously required. To make things less confusing and workarounds more obvious, the error message now explicitly says that tupleof is the problem. Relates to (but doesn't fix) issue 19196. --

https://issues.dlang.org/show_bug.cgi?id=19196 Iain Buclaw <ibuclaw@gdcproject.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Priority|P1 |P3 --

https://issues.dlang.org/show_bug.cgi?id=19196 --- Comment #5 from dlangBugzillaToGithub <robert.schadek@posteo.de> --- THIS ISSUE HAS BEEN MOVED TO GITHUB https://github.com/dlang/dmd/issues/19480 DO NOT COMMENT HERE ANYMORE, NOBODY WILL SEE IT, THIS ISSUE HAS BEEN MOVED TO GITHUB --

Forums