February 8, 2015
Last week I posted about BuildSettingExtractor, a utility that makes it easy to pull the build settings out of an Xcode project file and into xcconfig build configuration files. (The post also mentions some xcconfig file benefits with links to ‘how to’ information. Read the earlier post here.)
I also wanted BuildSettingExtractor to be useful for anyone who wants to learn more about the build settings in their projects. To that end, the latest version, available on github, generates build setting descriptions gleaned from the installed version of Xcode.
For example:
// Framework Search Paths
//
// This is a list of paths to folders containing frameworks to be
// searched by the compiler for both included or imported header
// files when compiling C, Objective-C, C++, or Objective-C++, and by
// the linker for frameworks used by the product. Paths are delimited
// by whitespace, so any paths with spaces in them need to be
// properly quoted. [-F]
FRAMEWORK_SEARCH_PATHS = $(DEVELOPER_FRAMEWORKS_DIR) $(inherited)
// Info.plist File
//
// This is the project-relative path to the plist file that contains
// the Info.plist information used by bundles.
INFOPLIST_FILE = BuildSettingExtractorTests/BuildSettingExtractorTests-Info.plist
Inline Build Setting Info
To learn more about build settings, Apple provides the Build Setting Reference (Apple developer documentation links are notoriously fragile, just search for the document) as well as Quick Help in Xcode when a build setting is selected. (In Xcode choose View > Utilities > Show Quick Help Inspector (Cmd-Opt-2))
In addition to these ways of learning more, BuildSettingExtractor gleans the build setting info from Xcode and puts it inline in the generated xcconfig files. This has a few benefits:
- Read about each build setting without selecting setting one by one in Xcode
- Read about only the build settings currently set in your project and targets
- Information about build settings is available wherever you are looking at the xcconfig file: github, text editors, diff tools, etc.
What if I don’t want this lovely but verbose feature?
If you want BuildSettingExtractor to generate pithy xcconfig files without the build setting info, Choose BuildSettingExtractor > Preferences… (Command-,) for the new preferences sheet and turn it off.
Happy Building! (and a call for help)
I hope you find BuildSettingExtractor useful, either as a learning tool, or to get rolling with xcconfig files. If you do find it useful, please spread the word about it: https://github.com/dempseyatgithub/BuildSettingExtractor.
As for the call for help, if you would like to help out with a basic app icon for BuildSettingExtractor, the utility can emerge from the primordial world of the generic app icon. Contact me if you are interested. •
Categories: Mac, Software Development, iOS
January 31, 2015
The most recent NSScreencast covered using build configuration files to specify build settings in Xcode. (Episode #154)
Using build configuration files—or xcconfig files as they are known—has some definite benefits. However, as seen in the screencast, the initial process of copying the current build settings out of an Xcode project into xcconfig files is tedious and potentially error-prone.
Nuthin’ fancy. Drop an xcodeproj file on it—it spits out xcconfig files.
To aid in that initial extraction process, I wrote a utility app called BuildSettingExtractor. It is available on github at https://github.com/dempseyatgithub/BuildSettingExtractor.
The app is a simple droplet utility: drop an xcodeproj file on it, choose a destination folder, BuildSettingExtractor will extract the build settings from the project and generate xcconfig files.
A set of files is generated for each target in the project and for the project itself. Each set of files includes one xcconfig file per build configuration and one xcconfig file of shared settings. For example, a typical Xcode project will generate nine xcconfig files: three sets of files for the app target, test target, and project with three files for Debug, Release and Shared in each set.
I hope you find BuildSettingExtractor useful. Even if you are just curious about project build settings, this is an easy way to inspect a project’s build settings without fear of accidentally changing them.
A little more about xcconfig files
By default, Xcode stores all build configuration settings in the project file itself. However, you can tell Xcode to base a build configuration’s settings on a build configuration file instead.
A build configuration file is a text file of key-value pairs. An xcconfig file can also contain comments and include other xcconfig files.
//
// Project-Debug.xcconfig
//
#include "Project-Shared.xcconfig” // Include other xcconfig files
// An xcconfig file is a text file of key-value pairs.
// Use comments to record why you are using certain build values.
// The /*comment*/ and #comment styles are not valid in an xcconfig file.
COPY_PHASE_STRIP = NO
GCC_DYNAMIC_NO_PIC = NO
GCC_OPTIMIZATION_LEVEL = 0
GCC_PREPROCESSOR_DEFINITIONS = DEBUG=1 $(inherited)
GCC_SYMBOLS_PRIVATE_EXTERN = NO
MTL_ENABLE_DEBUG_INFO = YES
ONLY_ACTIVE_ARCH = YES
There are some benefits to using xcconfig files:
- Build settings are not in project file—this removes one source of project file merge conflicts
- Build settings can be documented using comments
- An xcconfig file of shared settings can be included in each build configuration
There are also potential drawbacks to using xcconfig files. One potential pitfall is that the build settings for a configuration are based on the xcconfig file—but settings set in Xcode override the xcconfig file settings. This can leave you with unexpected build behavior because an errant build setting set in Xcode is overriding the xcconfig file setting.
This issue is compounded by the fact that when new Xcode versions update project settings, the settings are added to the project, not to an xcconfig file. So when using xcconfig files, some vigilance is required to keep an eye out for build settings being added to the project. These stray build settings should be moved from the project to the appropriate xcconfig file.
What Next?
BuildSettingExtractor generates xcconfig files from a project—it does not set your project up to use them. Here are few resources that walk through that process:
I was inspired to release BuildSettingExtractor by Episode #154 of NSScreencast. The episode is a step by step demo walking through the process.
By the way, if you aren’t familiar with NSScreencast, I recommend taking a look. Ben Scheirman (@subdigital) presents weekly bite-sized screencasts covering a wide range of development topics. Some screencasts are free and some, like Episode #154, require a subscription. __(Ben also plays guitar with James Dempsey and the Breakpoints, but that has yet to be the subject of a screencast.)
The blog post Using xcconfig Files For Your Xcode Project by Jont Olof Lyttkens (@jontolof) explains how to set up a project to use xcconfig files in Xcode 6.
Finally, Building the Build System by Rob Napier (@cocoaphony) is an older post, written for an older version of Xcode, but the overall concepts and explanation of the benefits are still relevant.
In each of these walkthroughs, instead making a bunch of xcconfig files by hand and then copying and pasting from the project into the correct file, you would use BuildSettingExtractor instead. •
Categories: Mac, Software Development, iOS
November 10, 2014
The response to Backtrace has been fantastic, and I wanted to thank everyone who has shown their support by purchasing the album and helping to spread the word. You made Backtrace the #1 comedy album on iTunes in the US, UK, and Canada. You also made it debut at #5 on the Billboard Comedy Album Chart. I cannot thank you all enough!
Since releasing Backtrace last month, I’ve gotten numerous requests for the lyrics to the songs.
For the rest of November, I’ll post lyrics to a song a day (or thereabouts) and we’ll make our way through the album. I’ll be tweeting when each song page goes live as well as some of my favorite lyrics. You can follow me at @jamesdempsey .
Each song page contains its liner notes—lyrics, song notes, and full credits for the very talented people who brought these songs to life. Below are links to the liner notes for each song – each link will go live as Lyrical November progresses.
And of course, If you haven’t checked out Backtrace on iTunes, I invite you to give it a listen.
Modelin’ Man
Almost Dropped My iPhone
Model View Controller
Gonna Needa Pasteboard
The Accessibility Song
The Liki Song (Minawana Meika La’a Likiko)
The Designated Initializer (Got the Better of Me)
The Fetch Spec Song
Goto Fail
Hold Me, Use Me, Release Me
Endian Reservations
I Love View
Anti-Patterns
Model View Controller (Legacy Mix)
Relationships
The Liki Song (Greybeard Mix)
Categories: Mac, Music, Software Development, iOS
October 28, 2014
It’s been a busy few weeks with Apple announcements and Backtrace, our new album of iOS and Mac development songs, hitting the Billboard charts. I’ve updated my iOS Device Summary to include the recently announced iPads.
Check out the iOS Device Summary page for the rationale behind the summary as well as PDF downloads—including optimized files for printing.
The new iOS devices introduced this fall presented some challenges for the summary chart:
The iPad mini 2 and iPad mini 3 have identical processors and screens. The devices appear on the chart as a single entry, split to reflect the different supported OS versions.
We have not seen a revised iPod touch in two years. With the traditional Apple fall events behind us, it is unlikely we will see a significant update until next fall at the earliest. Since the iPod touch line ends at the A5 chip and the multiple-model iPhones start at the A6 chip, these have been combined into a single row.
Finally, the new A8X chip pushes the number of columns to the limit, so I’ve dropped the ARM chip and the iPhone 3GS and 3rd Generation iPod touch from the chart.
Since the chart is starting to have trouble cleanly representing devices on a single page, I am looking at more dynamic ways of presenting this information in the future.
Until then, I hope you find this version of the summary chart helpful. •
Check out the iOS Device Summary page to learn more and download printable PDFs of the summary.
And check out Backtrace, the only album of iOS and Mac development tunes ever on the Billboard charts.
Categories: Apple, Software Development, iOS
October 14, 2014
We are beyond thrilled to announce the release of Backtrace,
the debut album from James Dempsey and the Breakpoints.
It feels great for this to be finally out in the world.
We hope you love every track.
And if you do, please don’t keep it to yourself.
We hope you spread the word.
(tweet, facebook, review and blog like the wind!)
Now available for download worldwide via iTunes
Categories: Mac, Music, iOS
