steven-michaud

Running Third Party Kernel Extensions on Virtualization Framework macOS Guest VMs

As of macOS 12 (Monterey), Apple's Virtualization framework has nice support for macOS guest virtual machines, but with severe limitations: For example you can't install a macOS guest on Intel Macs, install guests with newer versions of macOS than the host, copy and paste between the host and the guest, or install third party kernel extensions in the guest. As usual for Apple, the functionality they do support is nicely implemented, but they've left out so much that the result is only marginally useful -- at least compared to

JunyuKuang

let overrideCatalystScaleFactor: Void = {
    guard let sceneViewClass = NSClassFromString("UINSSceneView") as? NSObject.Type else {
        return
    }
    if sceneViewClass.instancesRespond(to: NSSelectorFromString("scaleFactor")) {
        // old
        swizzleInstanceMethod(
            class: sceneViewClass,
            originalSelector: NSSelectorFromString("scaleFactor"),
            swizzledSelector: #selector(swizzle_scaleFactor)

macshome

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The Wisdom of Quinn

Informative DevForum posts from everyone's favorite DTS member.

(Arranged newest to oldest)

jart

RMS NOTATION TUTORIAL

BEHAVIOR

  =: write-only
  +: read/writeable
  &: earlyclobber (impacts register sharing, defensive copying, etc.)
  %: commutative
  ,: groups alternative constraints
  ?: discourages group of constraints

fay59

Here's a list of mildly interesting things about the C language that I learned mostly by consuming Clang's ASTs. Although surprises are getting sparser, I might continue to update this document over time.

There are many more mildly interesting features of C++, but the language is literally known for being weird, whereas C is usually considered smaller and simpler, so this is (almost) only about C.

1. Combined type and variable/field declaration, inside a struct scope [https://godbolt.org/g/Rh94Go]

struct foo {
   struct bar {
 int x;

saagarjha

// Dynamic library that pauses a short lived program during launch so that a
// debugger can attach to it. To use it, compile it on macOS:
//     clang -dynamiclib pause4debug.c -o pause4debug.dylib
// On Linux:
//     gcc -shared -fPIC pause4debug.c -o pause4debug.so
// To use it, make the dynamic linker inject it using DYLD_INSERT_LIBRARIES or
// LD_PRELOAD, depending on your platform. On macOS:
//     DYLD_INSERT_LIBRARIES=/path/to/pause4debug.dylib debugme
// On Linux,
//     LD_PRELOAD=/path/to/pause4debug.so debugme

saagarjha

cd() {
	# Set the current directory to the 0th history item
	cd_history[0]=$PWD
	if [[ $1 == -h ]]; then
		for i in ${!cd_history[@]}; do
			echo $i: "${cd_history[$i]}"
		done
		return
	elif [[ $1 =~ ^-[0-9]+ ]]; then
		builtin cd "${cd_history[${1//-}]}" || # Remove the argument's dash

smileyborg

// UICollectionView Objective-C example

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
        
    NSIndexPath *selectedIndexPath = [[self.collectionView indexPathsForSelectedItems] firstObject];
    if (selectedIndexPath != nil) {
        id<UIViewControllerTransitionCoordinator> coordinator = self.transitionCoordinator;
        if (coordinator != nil) {
            [coordinator animateAlongsideTransition:^(id<UIViewControllerTransitionCoordinatorContext> context) {

saagarjha

function postUpdatedxkcdIfNecessary() {
	var properties = PropertiesService.getUserProperties();
	
	var latestComic = JSON.parse(UrlFetchApp.fetch("http://xkcd.com/info.0.json").getContentText());
	
	if (latestComic["num"] > properties.getProperty("lastComic")) {
		var title = latestComic["title"];
		var imageURL = latestComic["img"];
		var altText = latestComic["alt"];
		var number = latestComic["num"];

saagarjha

#!/bin/sh

if [ $# == 1 ]; then
	git fetch origin pull/$1/head:pr-$1
	git checkout pr-$1
elif [ $# == 2 ]; then
	git fetch $1 pull/$2/head:pr-$2
	git checkout pr-$2
else
	echo "Usage: git test-pr [remote] pr#"