Thread overview
[Issue 18375] std.getopt uses deprecated rwm operations for shared variables
Feb 05, 2018
Seb
Feb 05, 2018
ZombineDev
Feb 05, 2018
Seb
Dec 17, 2022
Iain Buclaw
February 05, 2018
https://issues.dlang.org/show_bug.cgi?id=18375

--- Comment #1 from Seb <greensunny12@gmail.com> ---
std.getopt test cases:

1) Passing and "just" triggering deprecation warnings


---
@system unittest
{
    shared real v;
    shared uint i;
    shared string[] arrString;
    shared int[] arrInt;

    auto args = ["program.name",
        "-v=2",
        "-i=10",
        "--arrString=a", "--arrString=b",
        "--arrInt=1", "--arrInt=2",
    ];
    getopt(args,
        "v", &v,
        "i", &i,
        "arrString", &arrString,
        "arrInt", &arrInt,
    );
    assert(v == 2);
    assert(i == 10);

    shared expectedArrString = ["a", "b"];
    assert(arrString == expectedArrString);
    shared expectedArrInt = [1, 2];
    assert(arrInt == expectedArrInt);
}
---

2) Completely failing

---
@system unittest
{
    shared string s;
    shared bool b;
    shared string[string] assocArrayString;
    shared double[string] assocArrayDouble;

    auto args = ["program.name",
        "-s=bar",
        "-b",
        "--assocArrayString=foo=bar,bar=1",
        "--assocArrayDouble=foo=1,bar=2",
    ];
    getopt(args,
        "s", &s,
        "b", &b,
        "assocArrayString", &assocArrayString,
        "assocArrayDouble", &assocArrayDouble,
    );

    assert(s == "bar");
    assert(b == 1);

    shared expectedAssocArrayString = ["foo": "bar", "bar": "1"];
    assert(assocArrayString == expectedAssocArrayString);
    shared expectedAssocArrayDouble = ["foo":1.0, "bar": 2];
    assert(assocArrayDouble == expectedAssocArrayDouble);
}
---

--
February 05, 2018
https://issues.dlang.org/show_bug.cgi?id=18375

ZombineDev <petar.p.kirov@gmail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |petar.p.kirov@gmail.com

--- Comment #2 from ZombineDev <petar.p.kirov@gmail.com> ---
All of these examples should *never* compile. The whole point of `shared` is to statically disallow accidental access shared mutable state. > 90% of all functions in phobos have no business touching `shared`/`__gshared` variables, especially `std.getopt`.

`std.getopt` can be safely used to set:
* function local variables
* (static) thread-local variables
* immutable global variables from shared static constructors (not sure if this
currently works, but it should be ok from memory model perspective)

I consider everything else to potentially trigger undefined behavior.

--
February 05, 2018
https://issues.dlang.org/show_bug.cgi?id=18375

--- Comment #3 from Seb <greensunny12@gmail.com> ---
>  immutable global variables from shared static constructors (not sure if this currently works, but it should be ok from memory model perspective)

No this doesn't work at the moment.


For future readers: it has been used by people before
(https://github.com/vibe-d/vibe.d/pull/2060).

--
December 17, 2022
https://issues.dlang.org/show_bug.cgi?id=18375

Iain Buclaw <ibuclaw@gdcproject.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P1                          |P3

--
December 13
https://issues.dlang.org/show_bug.cgi?id=18375

--- Comment #4 from dlangBugzillaToGithub <robert.schadek@posteo.de> ---
THIS ISSUE HAS BEEN MOVED TO GITHUB

https://github.com/dlang/dmd/issues/19379

DO NOT COMMENT HERE ANYMORE, NOBODY WILL SEE IT, THIS ISSUE HAS BEEN MOVED TO GITHUB

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