Developer Tools

Tools you’ll love to use.

The Xcode developer tools package provides everything you need to create great applications for Mac, iPhone, and iPad.

Xcode is tightly integrated with the Cocoa and Cocoa Touch frameworks, creating a productive and easy-to-use development environment that is powerful enough to be the same tools used by Apple to produce Mac OS X and iOS. The Xcode toolset includes the amazing Xcode IDE, with the Interface Builder design tool and Apple LLVM compiler fully integrated. The Instruments analysis tool is also included, along with dozens of other supporting developer tools.

Xcode IDE

Designed from the ground up to take advantage of the newest Apple technologies, Xcode integrates all the tools you need. The unified interface smoothly transitions from composing source code, to debugging, and even to designing your next stunning user interface, all within the same window.
The Xcode workspace is all about keeping you focused. As you type, Live Issues will immediately alert you to coding mistakes, displaying a message bubble beside your code for more detail. Hit the Run button to launch your Mac app, or upload the app to your test device, and immediately start debugging. Hover the mouse pointer above a variable to inspect its value at runtime, never having lost your place in the editor.
By working closely with the developer web portal, Xcode provisions new iOS devices with a single click, can securely sign and archive your Mac or iOS app, and directly submit it to the App Store. Learn more about what’s new in Xcode 4

Apple LLVM Compiler

Apple’s next generation compiler technology, the Apple LLVM compiler, does more than build your app. Apple LLVM technology is integrated into the entire development experience. The same parser used to build C/C++ and Objective-C powers Xcode’s indexing engine, providing incredibly accurate code completions. As you work, Apple LLVM is constantly evaluating what you type, identifying coding mistakes that Xcode shows as Live Issues, and thinking ahead for ways to Fix-it for you. Other compilers can tell you what is wrong — Apple LLVM can make it right.

Instruments for Performance and Behavior Analysis

A world-class Mac OS X or iOS application provides a great user experience, and that means more than beautiful images and intuitive design. Great applications must feel fast, respond quickly, and impress with smooth animations. To help make your app great, the Xcode developer tools include Instruments, a truly unique application that helps you track down performance bottlenecks in your Mac OS X and iOS apps.
Instruments collects data such as disk, memory, or CPU usage in real time, either on your Mac or remotely from a connected iPhone. The collected data is graphically displayed as tracks over time, making it easy to pinpoint problem areas, then drill down to the offending lines of code.
Instruments helps guarantee your gorgeous user interface will be accompanied by equally impressive responsiveness.

iOS Simulator

The iOS Simulator runs your application in much the same way as an actual iOS device. Because it is quick to launch and debug, the iOS Simulator makes for a perfect test bed to make sure your user interface works the way you intend, your network calls are correct, and that the views change correctly when the phone rotates. You can even simulate touch gestures by using the mouse. The iOS Simulator is a great time saver.

Xcode is the complete toolset for building Mac OS X and iOS applications — and with Xcode 4, the tools have been redesigned to be faster, easier to use, and more helpful than ever before. The Xcode IDE understands your project’s every detail, identifies mistakes in both syntax and logic, and will even fix your code for you. Quite simply, Xcode 4 will help you write better code.

Xcode 4 has a brand new user interface, built upon proven technologies that Apple itself uses to build Mac OS X and iOS, and that have produced over a quarter million Mac OS X and iOS apps.

Single Window

As an experienced Xcode user, the first thing you will notice about Xcode 4 is that the many windows used to perform the development tasks you work on every day have been consolidated into a single window. The Xcode 4 work area has several unique UI elements that make it easy to work on many different tasks, even multiple projects, without cluttering your work area. Your editor is always front and center.

Navigators

On the left side is a collection of navigators, including the list of files in your project, sorted symbols, a central search interface, issue tracking, debugging data with compressible stack traces, active and inactive breakpoints, and a persistent collection of logs. The unified navigator UI provides live filtering of content and search results, so you can focus on your current task.

Jump Bar

At the top of every editor pane is a path bar showing the relative location of your current file. Click any location in the path to immediately jump to any other file at that level. This is the Jump Bar, and it is so efficient you may wish to dedicate your entire desktop to source code, quickly jumping from file to file.

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Take a closer look

Interface Builder is Built-in

In Xcode 4, Interface Builder has been completely integrated within the Xcode IDE –– there is no separate application.
Selecting an interface file (.nib/.xib) in your project will open the IB editor within Xcode. Opening the right-hand Utility area will show the full complement of interface inspectors, as well as the library of controls and UI objects. Drag a control from the library, and drop onto the canvas, to layout your Mac OS X or iOS application.

The best part: you can drag connections directly from the UI design to the source code. Xcode 4’s new split editor layout makes it easy to wire up your actions and outlets simply by dragging a connection to existing code –– one gesture and you’re done. Don’t yet have the code ready to connect? Xcode will create a new outlet or action for you, just drag to an empty space in your source file and Xcode will generate the code.

 

Assistant

Whether writing code, or designing an interface, no change happens in isolation. Even the smallest edit can have a cascading effect throughout your project. You often need to see more than just your current file; you need to see related documents as well.
With the new Xcode Assistant, the two-pane editor layout in Xcode 4 becomes dramatically more powerful. When you turn on Assistant, the IDE will anticipate which other files you need to see, as you work. Editing a new derived class? The Assistant will show you the code for the class you are inheriting. Writing new implementation code? The Assistant will automatically show you the corresponding header. When designing an interface, the Assistant will show you the appropriate controller, making drag-and-drop code connections extremely simple. Data model designing will bring up the classes that back your models — all automatically.

Apple LLVM Compiler 2.0

Apple LLVM is the next-generation compiler technology powering Xcode 4. Based on the vibrant open source LLVM.org project led by Apple engineers, the Apple LLVM compiler is modern thinking, tuned for iPhone, iPad, and the multi-core Mac.

Apple LLVM is fast. It compiles code twice as quickly as GCC, yet produces applications that also run faster. The compiler was built from the ground up as a set of highly optimized libraries, easy to extend, easy to optimize, and designed for today’s modern chip architectures. In Xcode 4, the full Apple LLVM compiler stack — from the front end parser, to the back end code optimizer — has great support for C, Objective-C, and C++.

Syntax highlighting, code completion, and every other index-driven feature is handled by the LLVM parser. If the compiler knows about a symbol, so does the Xcode IDE. C, C++, and Objective-C are all accurately understood at editing time, exactly as they are when building.

Fix-it and Live Issues

The Apple LLVM engine is constantly working in the background to understand your code. In the editor, the new Live Issues feature uses that understanding to alert you to coding mistakes as you type. Just like a word processor highlights spelling errors, Xcode 4 highlights common coding mistakes, without the need to click ‘build’ first.

Fix the problem automatically

Beyond just reporting errors, the IDE is intelligent enough to fix the problem for you. In many cases Xcode will not only report an error, it will present a solution as well. Click the error to see the available Fit-its, such as correcting an assignment to a comparison, repairing a misspelled symbol, or appending a missing semicolon. A single keyboard shortcut will instantly have the error repaired, and let you continue coding.
Fix-it is a great as-you-type companion to the rigorous testing performed by the Analyze feature. The Xcode static analyzer will walk through thousands of potential code paths, looking for places where code, while valid, would behave in unexpected ways, such memory allocation mistakes, never-hit case statements, or improperly constructed loops.
Together, Fix-it and the Xcode Analyze feature will find bugs long before your users.

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Version Editor

The new Version editor in Xcode 4 makes it easy to see any two versions of your source code, side by side, in a live editor. More importantly, the Version editor is a new way to think of source control management in an IDE, because the comparison view is also a timeline. Drag the slider in the middle and you travel back in time through your project, comparing any two versions.
The Version editor can also show you a detailed log of past events, and track blame for past check-ins. Complex SCM commands are managed for you behind the scenes. It is even possible to manage multiple projects within a single Xcode 4 workspace, one project managed in Subversion, the other in Git, all updated automatically.

New Debugger

Xcode 4 introduces LLDB, a brand new debugging engine contributed by Apple to the LLVM.org open source project. Like LLVM, the new LLDB engine is designed from the ground up to consume much less memory, and be a rocket when it comes to performance.
The new LLDB debugging engine is the perfect fit for the new Xcode 4 debugging interface. When your app is running, the navigator will show a stack trace you can expand or compress to show or hide stack frames as you debug. As you step through, you can even lock onto a single thread then click “continue” and follow that specific thread of execution. Multicore debugging in Xcode 4 is now as easy as multicore coding with blocks and Grand Central Dispatch.

Instruments for Xcode 4

Instruments has a streamlined interface, complete with the new Jump Bar, and stack compression from Xcode 4’s UI. Using Xcode4’s new launch schemes, it is easier than ever to create a robust test harness to run your app in Instruments. That includes launching Instruments in “deferred mode”, keeping the data collection UI off screen and saving system resources for running and metering your application.
New data collection instruments are also available, including OpenGL ES for tracking iPhone graphics performance, new memory allocation monitoring that can find unintended memory growth, Time Profiler on iOS for collecting samples with very low overhead, and complete System Trace for insight into how all system processes interact.
Instruments covers even more ground, has even lower overhead, and is more useful than ever before.