[Issue 7319] .bss section not used

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=7319

Marco Leise <Marco.Leise at gmx.de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|minor                       |normal

--- Comment #4 from Marco Leise <Marco.Leise at gmx.de> ---
Three years later and this is still open. I don't think it is the difficulty of
the problem. I'm raising this to 'normal'. Here is a test case that _should_
result in a few KiB executable, but creates a 7 MiB one. Every instantiation of
the templated structs adds 1 MiB. Some, but not all of these unnecessary .inits
are also accessible at runtime:

---------8<-------------

import std.typetuple;
import std.stdio;

struct StuffDefault(T) { T[1024 * 1024] m_data; }
struct StuffVoid(T) { T[1024 * 1024] m_data = void; }
struct StuffZero(T) { T[1024 * 1024] m_data = 0; }

void main(string[] args)
{
    alias Ts = TypeTuple!(
        StuffDefault!void,
        StuffVoid!void,
        StuffDefault!ubyte,
        StuffVoid!ubyte,
        StuffZero!ubyte,
        StuffVoid!char,
        StuffZero!char,
    );

    // .inits visible at runtime
    foreach (T; Ts) {
        writefln("Does %s have a superfluous init? %s",
                 T.stringof, typeid(T).init.ptr is null ? "no" : "YES");
    }
}

----------->8------------

Prints:

Does StuffDefault!void have a superfluous init? no
Does StuffVoid!void have a superfluous init? YES
Does StuffDefault!ubyte have a superfluous init? no
Does StuffVoid!ubyte have a superfluous init? YES
Does StuffZero!ubyte have a superfluous init? YES
Does StuffVoid!char have a superfluous init? YES
Does StuffZero!char have a superfluous init? YES

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