TweetFollow Us on Twitter

Aug 99 Factory Floor

Volume Number: 15 (1999)
Issue Number: 8
Column Tag: From the Factory Floor

Richard Atwell, Mac OS Debugger

by Richard Atwell and Dave Mark, ©1999 by Metrowerks, Inc., all rights reserved.

This month, we'll hear from Richard Atwell, a key member of Metrowerks' Debugger team. Richard will fill us in on the latest and greatest in Macintosh CodeWarrior debugging.

Richard Alexander David Atwell, aka ratwell, is the Mac OS Debugger Engineer at Metrowerks and is responsible for making MetroNub do nasty things to Mac OS so you can debug your code. Before joining Metrowerks, Richard worked for the Apple Education Consultant Program in Canada. He can be reached at <ratwell@metrowerks.com>.

Dave: Richard, tell me about your role at Metrowerks?

Richard: I work on Mac OS Debugging along with Ken Ryall, our Debugger Architect and our Java debugger engineers. Ken and I are responsible for adding support in CodeWarrior's integrated debugger for emerging Mac OS technologies.

Dave: I know you are working on the debugger for Mac OS X. Tell me about that.

Richard: CodeWarrior runs on Mac OS, Windows, Solaris and now Linux. Before we could deliver a version that ran on Mac OS X, developers needed to be able to debug applications that ran on the new operating system. At the time, the only remote debugger that we had was the Mac->Win debugger that lets you debug targets that run on a Win32 machine from a Mac running the IDE, but there wasn't much that we could reuse for the new OS. So with help from Apple we decided to leverage the debugger built into Mac OS X called gdb.

gdb is the command line debugging tool that is indigenous to UNIX based operating systems like Mac OS X. We discovered that NeXT/Apple had been modifying gdb over the years to meet their own needs but had kept it up to date with the open-source gdb version. All that we needed to do was hide the gdb command line interface from the developer and allow it to be controlled from the IDE.

With Apple's assistance we created a remote debugger for CodeWarrior running on Mac OS 8 that allows you to debug applications on a second Mac running Mac OS X over TCP/IP. gdb is running behind the scenes on Mac OS X but all the developer sees is a simple control panel like application that allows you to set the IP address and port of the machine that is running the IDE and a button to start/stop gdb.

Dave: Tell me about the new Mac OS 8 remote debugger? Is it similar to what Metrowerks did with the Mac->Win cross debugger?

Richard: Yes. For Windows we have an application called MWRemote that is run on the target machine and it acts as the middleman between the IDE running on the host Mac and Windows where your target runs.

For Mac->Mac debugging, we needed to write a similar application to run on the target machine. On the Pro 5 Tools CD in the "Other Metrowerks Tools" folder you'll find an application called MetroNub Remote 2.0. By running this application on a second Mac that has the MetroNub extension installed, you can debug applications remotely.

To operate it, run MetroNub Remote 2.0 and configure it with an IP address and port. This is a necessary security precaution to prevent "unfriendly" IDEs from debugging and essentially running programs on your Mac. Once the remote machine is setup, you configure the IDE for remote debugging by entering an IP address and port in the MetroNub settings preference panel. You next specify the path on the remote machine where the target is to be executed from and you're ready to debug the application just as you would if it were running on the same machine as the IDE.

Dave: What's new with Pro 5's integrated debugger?

Richard: We've added a lot of value to the debugger with Pro 5. The debugger in the IDE has an improved variables view that is better at displaying variable values for the supported languages. There is also a new widget at the top that toggles between two new variable modes: All and Auto. When the widget is toggled from All to Auto the view displays only the variables that are in the scope of the statement block where the program counter lies. Before we added this it was often awkward having to scroll the view down to the bottom to see the variables that you were interested in.

Remote debugging support for Mac OS 8 and Mac OS X is a large addition as we've already mentioned. Remote debugging is advantageous when you are short of screen real estate, wish to debug a system version earlier than the one you usually develop on, debug on another OS, or simply wish to stay independent of the program crashes that can interrupt your development cycle.

Dave: How about remote Java debugging?

Richard: Remote debugging of Java is now possible with Pro 5. In previous releases the MetroNub plug-in was used to debug Mac OS and Java programs. With Pro 5 our Java engineers have created a new debugger plug-in called SunJavaPlugin which uses the debugging facilities built-into Apple's MRJ. Debugging is done over TCP/IP when debugging on a local machine so making it work in the remote case required little extra development effort.

Dave: Is it possible to debug Java on other platforms?

Richard: Yes. Any Java VM that supports Sun's debugger API can be debugged remotely as long as both machines have TCP/IP services. We've also implemented a remote debugger for Win32 that lets you debug from one Win32 machine to another for the first time.

Dave: Aside from remote debugging, what else is new?

Richard: There is now an ability to control whether or not to attempt to automatically debug libraries that your program links against. There is a global setting for this that is used when there isn't a target, such as when you attach to an already running process. There is also a target-level setting to control this behavior.

We've changed the Debugger Setting panel that appears when you edit the preferences of your target. The field which previously specified the location of the host application has been changed to include the location of the remote folder where targets will execute from and also to include the location where code resources, shared libraries or DLLs that are used by your target can be found. The host application field has been relocated to a new panel called Runtime Settings.

We've also improved the reporting of libraries that are loaded by your application. You can now toggle whether the display of library loading messages appear in the log window with a checkbox. Previously this checkbox only applied if you were using the Mac->Win cross debugger.

To improve the debugging experience, there we've added a setting for a delay that can be adjusted which tells the IDE how often to refresh the contents of windows while you are debugging. This can also be set in the Debugger Settings panel.

Dave: How about Mac OS X and Carbon?

Richard: Mac OS X and Carbon are the hot programming topics today. Mac OS X has been making small leaps for about a year now and we've been making similar progress in order to keep from developing solutions with a short life span.

Our ultimate goal is to provide a Carbonized IDE that runs on the client version of Mac OS X. In the meantime we've been providing tools in staged releases.

Dave: What's been done for Carbon developers?

Richard: Carbon is Apple's programming model for Mac OS 8 and Mac OS X that allows developers to leverage the Mac OS toolbox based code they have developed over the last several years. Carbon is the only programming model on Mac OS X that doesn't require developers to completely rewrite their code. This makes Carbon very attractive to developers and we believe that CodeWarrior users are going to choose this development path over the others for most of their development needs.

Towards filling this demand we've been creating the tools that our customers require as the evolving Mac OS X technology allows us.

The first step we took was to release compiler and linker plug-ins with Pro 4 that created binaries in the Mac OS X native Mach-O execution. You could use these to create a separate target in your project that generated a Mach-O binary with which you could move over to Mac OS X and then debug it using gdb.

With the release of Mac OS X PR1 at WWDC this year, Pro 5 took the next logical step and made it possible to use the CodeWarrior integrated debugger for debugging applications on Mac OS X via remote debugging.

The Mac OS X remote debugger setup was specifically designed for debugging Carbon applications. Carbon applications can be PEF based just as they are now for Mac OS 8 or Mach-O based for Mac OS X. If you make applications that are PEF based using the Mac OS PPC Linker instead of the Mach-O linker, you can develop using a single target that you can then debug on Mac OS 8 or remotely on Mac OS X or Mac OS 8. If you app uses shared libraries for plug-ins or for code separation you'll have stick with PEF because Mach-O uses a different scheme for shared libraries that isn't supported by our debugger.

Dave: What's the word on AltiVec support?

Richard: AltiVec is an extension to the PowerPC architecture that provides 32 new 128-bit registers, 162 new instructions and a new execution unit within the AltiVec processor itself to complement the Branch, Integer and Floating Point units.

In addition, Apple and Motorola have introduced an AltiVec programming model for Mac developers in the form of an extension to the C language to support a new variable type called vector.

We've added the language support to our C/C++ compilers and added the necessary ABI changes to the linker. To the debugger, we've added support for displaying vectors variables just as we display any other type and we've added a third register window. Because AltiVec registers as so wide we've implemented a scrolling window to preserve screen real estate.

Dave: What's coming down the road?

Richard: Apple has revisited multi-processing with the introduction of Mac OS 8.6 using the MP hardware introduced a few years ago. For several releases we've had a version of MetroNub that was specifically designed for debugging MP tasks called "MetroNub for MP". Apple has dramatically changed their MP implementation with version 2.0 of the "Multiprocessing API Library" in Mac OS 8.6 and, as a result, the version of MetroNub for MP that shipped with Pro 5 is only compatible with MacOS 8.5.1 and earlier.

We're updating MetroNub for MP to support the new and improved MP library and the update will be available soon.

We're also planning to merge the two versions of MetroNub together. We originally split the extension into two separate versions because the old MP Library 1.4 had a huge memory overhead. Since the new library has a very low overheard of only 100K or so, we can merge the two versions together again. The merged extension will support MP debugging only on Mac OS 8.6 or later. If you want to debug MP Tasks on older versions of the OS, you can still use previous versions of CodeWarrior.

Another request that we've been listening to is to allow remote debugging of Mac applications from the IDE running on Win32 machines. After adding Win->Win and Mac->Mac debugging in Pro 5, we're now working on Win->Mac debugging for the next release. We hope this will encourage Windows developers to port their applications to Mac OS.

Dave: Any other changes on the CodeWarrior CDs?

Richard: We cleaned up the Mac OS Support folder by removing headers and libraries that belong to obsolete SDKs. We've also improved the layout by prominent placement of the OpenTransport and Universal folder that Apple provides. When new versions of these headers and libraries appear between CodeWarrior releases you'll easily be able to replace or add the new headers without having to walk the Mac OS Support folder hierarchy looking for the files that need to be removed.

We've also updated the MPW folder to the latest Tools CD from Apple and of course we've included versions of our MPW tools in that folder.

Finally, we've added a Sherlock index to the reference CD so all HTML and text documents have been searched along with the example code.
 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Apple Digital Camera RAW Compatibility 6...
Apple Digital Camera RAW Compatibility update adds RAW image compatibility to Aperture 3 and iPhoto '11. For more information on supported RAW formats, see this page. Version 6.03: This update adds... Read more
OmniGraffle Pro 6.1.4 - Create diagrams,...
OmniGraffle Pro helps you draw beautiful diagrams, family trees, flow charts, org charts, layouts, and (mathematically speaking) any other directed or non-directed graphs. We've had people use... Read more
OmniGraffle 6.1.4 - Create diagrams, flo...
OmniGraffle helps you draw beautiful diagrams, family trees, flow charts, org charts, layouts, and (mathematically speaking) any other directed or non-directed graphs. We've had people use Graffle to... Read more
MegaSeg 5.9.5 - Professional MP3 DJ appl...
MegaSeg is a complete solution for pro audio/video DJ mixing, radio automation, and music scheduling with rock-solid performance and an easy-to-use design. Mix with visual waveforms and Magic... Read more
MarsEdit 3.6.8 - Quick and convenient bl...
MarsEdit is a blog editor for OS X that makes editing your blog like writing email, with spell-checking, drafts, multiple windows, and even AppleScript support. It works with with most blog services... Read more
BBEdit 11.0.3 - Powerful text and HTML e...
BBEdit is the leading professional HTML and text editor for the Mac. Specifically crafted in response to the needs of Web authors and software developers, this award-winning product provides a... Read more
Microsoft Office Preview 15.8 - Popular...
Welcome to the new and modern Microsoft Office for Mac. You will receive regular updates automatically until the official release in the second half of 2015. With the redesigned Ribbon and your... Read more
Yosemite Cache Cleaner 9.0.5 - Clear cac...
Yosemite Cache Cleaner is an award-winning general purpose tool for OS X. YCC makes system maintenance simple with an easy point-and-click interface to many OS X functions. Novice and expert users... Read more
ExpanDrive 4.3.2 - Access cloud storage...
ExpanDrive builds cloud storage in every application, acts just like a USB drive plugged into your Mac. With ExpanDrive, you can securely access any remote file server directly from the Finder or... Read more
RapidWeaver 6.0.8 - Create template-base...
RapidWeaver is a next-generation Web design application to help you easily create professional-looking Web sites in minutes. No knowledge of complex code is required, RapidWeaver will take care of... Read more

Take a First Look at NaturalMotion’s Daw...
NaturalMotion has released a preview of their upcoming title, Dawn of Titans. Dawn of Titans immerses you in a world of fantasy as you build your kingdom, raise an army, and capture territories. The focus on this epic action strategy game was the... | Read more »
GDC 2015 – Warfriends is Something Famil...
GDC 2015 – Warfriends is Something Familiar That’s Also a Little Different Posted by Rob Rich on March 6th, 2015 [ permalink ] About Fun‘s upcoming Warfriends is quite the interesting hybrid. | Read more »
Bored? MyLeisure FreeTime Maximizer Will...
Bored? MyLeisure FreeTime Maximizer Will Take Care of That! Posted by Jessica Fisher on March 5th, 2015 [ permalink ] iPhone App - Designed for the iPhone, compatible with the iPad | Read more »
New Publisher Allstar Games Heads West w...
Allstar Games has announced its first mobile title designed for western audiences, Allstar Heroes. The game will be a massive online battle arena (MOBA) that offers dozens of heroes for you to collect and pit against your opponents. As each hero has... | Read more »
RAD Boarding Review
RAD Boarding Review By Jennifer Allen on March 5th, 2015 Our Rating: :: NEARLY RADUniversal App - Designed for iPhone and iPad RAD Boarding isn’t quite one of the greats, but it has potential.   | Read more »
Presenting the International Mobile Gami...
11th Annual International Mobile Gaming Awards ceremony, hosted by actress Allison Haislip, gathered mobile game developers and publishers from around the world. They chose 13 winners out of the 93 nominations. British studio USTWO won the the Grand... | Read more »
AG Drive Review
AG Drive Review By Tre Lawrence on March 5th, 2015 Our Rating: :: FUTURISTIC STREET RACING.Universal App - Designed for iPhone and iPad Futuristic racing… interstellar style.   | Read more »
GDC 2015 – Nightmare Guardians is an Int...
GDC 2015 – Nightmare Guardians is an Interesting Hybrid of MOBA and Lane Defense Posted by Rob Rich on March 5th, 2015 [ permalink ] I have to say that lane defense (i.e. | Read more »
Overkill 3 Review
Overkill 3 Review By Tre Lawrence on March 5th, 2015 Our Rating: :: WHO'S NEXT?Universal App - Designed for iPhone and iPad Cover system gameplay in the third-person.   Developer: Craneballs Price: Free Version Reviewed: 1.1.6... | Read more »
Warner Bros. Interactive Entertainment A...
Warner Bros. has some exciting games coming down the pipe! | Read more »

Price Scanner via MacPrices.net

16GB iPad mini 3 on sale for $349, save $50
 Walmart has the 16GB iPad mini 3 WiFi on sale on their online store for $349.99 including free shipping or free local store pickup. Their price is $50 off MSRP, and it’s the lowest price available... Read more
Save up to 15% with Apple refurbished Time Ca...
The Apple Store has certified refurbished Time Capsules available for up to $60 off MSRP. Apple’s one-year warranty is included with each Time Capsule, and shipping is free: - 2TB Time Capsule: $255... Read more
Save up to $105 on AppleCare Protection Plans
B&H Photo has 3-Year AppleCare Warranties on sale for up to $105 off MSRP including free shipping plus NY sales tax only: - Mac Laptops 15″ and Above: $244 $105 off MSRP - Mac Laptops 13″ and... Read more
Apple restocks refurbished 15-inch Retina Mac...
The Apple Store has restocked Apple Certified Refurbished 2014 15″ Retina MacBook Pros, available for up to $400 off the cost of new models. An Apple one-year warranty is included with each model,... Read more
Roundup of MacBook Air sale prices, models up...
B&H Photo has MacBook Airs on sale for up to $100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 11″ 128GB MacBook Air: $799 100 off MSRP - 11″ 256GB MacBook Air: $999 $100... Read more
New Firstrade Mobile App Enables On-The-Go Tr...
Firstrade Securities Inc. has announced its new mobile app, which gives investors immediate access to the company’s trading platform on all mobile devices. The app was developed in-house and was... Read more
Sonnet Introduces USB 3.0 + eSATA Thunderbolt...
Sonnet has announced the launch of its new USB 3.0 + eSATA Thunderbolt Adapter for easy connectivity to USB 3.0 devices and eSATA storage, and USB 3.0 + Gigabit Ethernet Thunderbolt Adapter for easy... Read more
Apple restocks refurbished 27-inch 5K iMacs f...
The Apple Store has restocked Apple Certified Refurbished 27″ 3.5GHz 5K iMacs for $2119 including free shipping. Their price is $380 off the cost of new models, and it’s the lowest price available... Read more
Free Clean Reader Mobile App Hides Swear Word...
The new Clean Reader app, now available in the Apple App Store and Google Play, delivers the opportunity of reading any book without being exposed to profanity. By selecting how clean they want their... Read more
Kinsa Launches “Groups” App to Monitor Illnes...
Kinsa, makers of the first FDA approved app-enabled smartphone thermometer thst won the 2013 Cleveland Clinic Medical Innovation Grand Prize and recently appeared in Apple’s “Parenthood” TV... Read more

Jobs Board

*Apple* Solutions Consultant - Retail Sales...
**Job Summary** As an Apple Solutions Consultant (ASC) you are the link between our customers and our products. Your role is to drive the Apple business in a retail Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Solutions Consultant - Retail Sales...
**Job Summary** As an Apple Solutions Consultant (ASC) you are the link between our customers and our products. Your role is to drive the Apple business in a retail Read more
Position Opening at *Apple* - Apple (United...
…Summary** As a Specialist, you help create the energy and excitement around Apple products, providing the right solutions and getting products into customers' hands. You Read more
Position Opening at *Apple* - Apple (United...
**Job Summary** The Apple Store is a retail environment like no other - uniquely focused on delivering amazing customer experiences. As an Expert, you introduce people Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.