[Issue 14131] New: va_copy is broken on posix X86_64

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=14131

          Issue ID: 14131
           Summary: va_copy is broken on posix X86_64
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Linux
            Status: NEW
          Keywords: wrong-code
          Severity: major
          Priority: P1
         Component: DMD
          Assignee: nobody at puremagic.com
          Reporter: yebblies at gmail.com

This code fails on posix X86_64 because va_copy doesn't properly copy the
argument pointer, instead aliasing the original.

void copya(int a, string format, ...)
{
    va_list ap;
    va_start(ap, format);

    va_list ap2;
    va_copy(ap2, ap);

    auto a1 = va_arg!int(ap);
    auto a2 = va_arg!int(ap);
    auto a3 = va_arg!int(ap);

    assert(a1 == 0x11111111);
    assert(a2 == 0x22222222);
    assert(a3 == 0x33333333);

    auto b1 = va_arg!int(ap2);
    auto b2 = va_arg!int(ap2);
    auto b3 = va_arg!int(ap2);

    assert(b1 == 0x11111111);
    assert(b2 == 0x22222222);
    assert(b3 == 0x33333333);

    va_end(ap);
    va_end(ap2);
}

void testCopy()
{
    copya(0, "", 0x11111111, 0x22222222, 0x33333333);
}

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