code_asm: add ability to align the code

[wtfsck]

#207

[marcospampi]

is there any workaround you recommend?

[Tyler-IN]

Would be nice to have some alignment directives without having to run the encoder to get the instruction (data) sizes.

[Tyler-IN]

    internal static void int3_align(this Assembler c, int alignment)
    {
        if (c.Instructions.Count == 0)
            return;
        var cw = new SizingCodeWriter();
        c.Assemble(cw, 0);
        var length = cw.Length;
        var pad = alignment - length % alignment;
        for (var i = 0; i < pad; ++i)
            c.int3();
    }
    internal static void nop_align(this Assembler c, int alignment)
    {
        if (c.Instructions.Count == 0)
            return;
        var cw = new SizingCodeWriter();
        c.Assemble(cw, 0);
        var length = cw.Length;
        var pad = alignment - length % alignment;
        if (pad > 0)
            c.nop(pad);
    }

public sealed class SizingCodeWriter : CodeWriter
{
    public int Length { get; private set; }
    public override void WriteByte(byte value) => ++Length;
    public void Reset() => Length = 0;
}

These are some mediocre hacks that serve good enough for my use cases.

[Tyler-IN]

Tried that first; came out to 0 every time. Looks like it gets set during encoding.

…

On Sat, Jan 28, 2023, 4:43 AM Marco Spampinato ***@***.***> wrote: Would be nice to have some alignment directives without having to run the encoder to get the instruction (data) sizes. You evildoer using C# 😂 now seriously, the code assembler struct/impl is backed up by a vector of Instruction(s), as far as I know you can query the instruction length, so the current byte size could be computed, am I right? — Reply to this email directly, view it on GitHub <#210 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AIC7PYC7PNN74EFEUKYFVGTWUTS5HANCNFSM5GTESTNQ> . You are receiving this because you commented.Message ID: ***@***.***>