• via Digitalmars-d-bugs (43/43) Sep 27 2016 https://issues.dlang.org/show_bug.cgi?id=16555

via Digitalmars-d-bugs <digitalmars-d-bugs puremagic.com> writes:

https://issues.dlang.org/show_bug.cgi?id=16555

          Issue ID: 16555
           Summary: Stack corruption when calling multi-parameter outer
                    function from nested function
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Linux
            Status: NEW
          Keywords: wrong-code
          Severity: normal
          Priority: P1
         Component: dmd
          Assignee: nobody puremagic.com
          Reporter: bugzilla kyllingen.net

When a nested function calls an outer function with a large number of
parameters, the first argument becomes corrupted.

Test case:

    void outer(
        double x,
        double a, double b, double c, double d,
        double e, double f, double g, double h)
    {
        import std.stdio;
        writefln("x=%s a=%s b=%s c=%s d=%s e=%s f=%s g=%s h=%s",
            x, a, b, c, d, e, f, g, h);
    }

    void main()
    {
        void inner(double x)
        {
            outer(x, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0);
        }

        inner(999.0);
    }

Here, the value of x in outer() is garbage.  That is, the program SHOULD print:

    x=999 a=1 b=2 c=3 d=4 e=5 f=6 g=7 h=8

But instead, it prints something like:

    x=6.95253e-310 a=1 b=2 c=3 d=4 e=5 f=6 g=7 h=8

Reducing the number of parameters of outer() makes the problem go away.  Also,
interestingly, if the program is compiled with -O or -inline, the correct
behaviour is restored.

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