mayoff

Using LLVM's libfuzzer with Swift

Background

Of the many tools available for fuzzing, I've found that LLVM's libfuzzer is the easiest to use for Swift on macOS. Other tools seem to have a list of requirements taht are difficult to meet. libfuzzer on the other hand is built into LLVM and is available on macOS in the custom Swift toolchains: https://www.swift.org/download/

In this document I'll describe how to use libfuzzer with Swift and Swift Packages.

I used this setup to fuzz an SVG Renderer package that I am building. I was able to find and fix a number of bugs in my SVG parsing code using libfuzzer in basically no time at all.

mayoff

import Cocoa
import MetalKit

@NSApplicationMain
class AppDelegate: NSObject, NSApplicationDelegate, MTKViewDelegate {
    weak var window: NSWindow!
    weak var metalView: MTKView!
    let device = MTLCreateSystemDefaultDevice()!
    var commandQueue: MTLCommandQueue!
    var pipelineState: MTLRenderPipelineState!

mayoff

#!/bin/sh

defaults read com.apple.finder CreateDesktop > /dev/null 2>&1
enabled=$?

if [ "$1" = "off" ]; then
	if [ $enabled -eq 1 ]; then
		defaults write com.apple.finder CreateDesktop false
		osascript -e 'tell application "Finder" to quit'
		open -a Finder

mayoff

• http://courses.cms.caltech.edu/cs179/
• http://www.amd.com/Documents/GCN_Architecture_whitepaper.pdf
• https://community.arm.com/graphics/b/blog
• http://cdn.imgtec.com/sdk-documentation/PowerVR+Hardware.Architecture+Overview+for+Developers.pdf
• http://cdn.imgtec.com/sdk-documentation/PowerVR+Series5.Architecture+Guide+for+Developers.pdf
• https://www.imgtec.com/blog/a-look-at-the-powervr-graphics-architecture-tile-based-rendering/
• https://www.imgtec.com/blog/the-dr-in-tbdr-deferred-rendering-in-rogue/
• http://developer.amd.com/tools-and-sdks/opencl-zone/amd-accelerated-parallel-processing-app-sdk/opencl-optimization-guide/#50401334_pgfId-412605
• https://fgiesen.wordpress.com/2011/07/09/a-trip-through-the-graphics-pipeline-2011-index/
• https://community.arm.com/graphics/b/documents/posts/moving-mobile-graphics#siggraph2015

mayoff

 a:  AM/PM
 A:	0~86399999 (Millisecond of Day)
 
 c/cc:	1~7 (Day of Week)
 ccc:	Sun/Mon/Tue/Wed/Thu/Fri/Sat
 cccc:	Sunday/Monday/Tuesday/Wednesday/Thursday/Friday/Saturday
 
 d:	1~31 (0 padded Day of Month)
 D:	1~366 (0 padded Day of Year) 
 

mayoff

import AppKit

public extension NSBezierPath {

    public var CGPath: CGPath {
        let path = CGMutablePath()
        var points = [CGPoint](repeating: .zero, count: 3)
        for i in 0 ..< self.elementCount {
            let type = self.element(at: i, associatedPoints: &points)
            switch type {

mayoff

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mayoff

#if os(iOS)
    import UIKit
#else
    import AppKit
#endif

let view = UIView(frame: CGRectMake(0, 0, 400, 300))
view.backgroundColor = UIColor.redColor()

let button = UIButton(type: .Custom)