PowerShell V2 and earlier never compiled a script, it was always interpreted via virtual “eval” methods in the parse tree. PowerShell V3 and later compile the parse tree (the AST) to a LINQ expression tree, which is then compiled to a bytecode, which is then interpreted. If the script is executed 16 times, the script … Read more
I am pretty sure this is a compiler bug. Nice find! Edit: it is not a bug, as Quartermeister demonstrates; dynamic might implement a weird true operator which might cause y to never be initialized. Here’s a minimal repro: class Program { static bool M(out int x) { x = 123; return true; } static … Read more
There are a lot of similarities between both implementations (and in my opinion: yes, they’re both “virtual machines”). For one thing, they’re both stack-based VM’s, with no notion of “registers” like we’re used to seeing in a modern CPU like the x86 or PowerPC. The evaluation of all expressions ((1 + 1) / 2) is … Read more
C# compiler does not give you any guarantees about tail-call optimizations because C# programs usually use loops and so they do not rely on the tail-call optimizations. So, in C#, this is simply a JIT optimization that may or may not happen (and you cannot rely on it). F# compiler is designed to handle functional … Read more
Now that Red Gate have started charging for the .NET Reflector tool you might want to check out these free alternatives instead… Telerik JustDecompile JetBrains dotPeek (Open Source) ILSpy
When the runtime executes a call instruction it’s making a call to an exact piece of code (method). There’s no question about where it exists. Once the IL has been JITted, the resulting machine code at the call site is an unconditional jmp instruction. By contrast, the callvirt instruction is used to call virtual methods … Read more
See my article on this very issue. Basically, beforefieldinit means “the type can be initialized at any point before any static fields are referenced.” In theory that means it can be very lazily initialized – if you call a static method which doesn’t touch any fields, the JIT doesn’t need to initialize the type. In … Read more
Here you go: internal class TaskCompletionSourceHolder { private readonly TaskCompletionSource<object[]> m_tcs; internal object Target { get; set; } internal EventInfo EventInfo { get; set; } internal Delegate Delegate { get; set; } internal TaskCompletionSourceHolder(TaskCompletionSource<object[]> tsc) { m_tcs = tsc; } private void SetResult(params object[] args) { // this method will be called from emitted IL … Read more
Disclosure: Harmony is a library that was written and is maintained by me, the author of this post. Harmony 2 is an open source library (MIT license) designed to replace, decorate or modify existing C# methods of any kind during runtime. It main focus is games and plugins written in Mono or .NET. It takes … Read more