TweetFollow Us on Twitter

Oct 97 Factory Floor

Volume Number: 13 (1997)
Issue Number: 10
Column Tag: From The Factory Floor

A CodeWarrior Rhapsody Update: Part One

by Dave Mark, ©1997 by Metrowerks, Inc., all rights reserved.

Berardino E. Baratta is Vice President, Research and Development for Metrowerks Corp. With the Metrowerks R&D department quickly approaching 100, he has little time left for doing actual coding but he does still sneak it in (mostly by working on it late at night, or early in the morning, depending on how you look at it). Most recently having done compiler and linker modifications for PalmPilot Release 3. He also tries to spend as much time as possible with his wife and young son.

Andreas Hommel is currently the C/C++ front end and 68K back end/linker architect at Metrowerks. After finishing his masters degree in computer science, Andreas did some contract programming in the desktop publishing area and also published several games on the Macintosh and Amiga. He has been with Metrowerks for three and a half years.

Andreas lives in a small country village about 20 kilometers north of Hamburg, Germany with his wife, two Australian Shepherd dogs, and two arabian horses. When he is not coding, riding horses or walking his dogs Andreas likes travelling, playing a good video game, and driving really fast on the Autobahn. He also likes cooking and fine red wines (in particular Californian Cabernets).

Bob Campbell is the enginer responsible for the Mac OS and Rhapsody, PowerPC code generators. Prior to joining Metrowerks, he worked for Apple Computer for 8 years. To relieve the stress of programming he rides in bicycle races on the weekends.

Since starting at Metrowerks in early 1996, Lawrence You has been helping shape the CodeWarrior debugging architecture for non-Mac OS targets, including Rhapsody. He has been a longtime Macintosh developer, also working for Apple and Taligent.

As you read this column, the finishing touches are being applied, as CodeWarrior Pro 2 gets ready to ship. Hopefully, you've all had a chance to bang on the first Rhapsody pre-release and you're chomping at the bit to get your apps ported using Latitude and the first native-yellow box version of CodeWarrior. This month's interview is with the CodeWarrior Rhapsody team. It is the first half of a two parter. The second half will be featured in next month's issue.

Dave: What's the current state of Metrowerks' Rhapsody development tools?

Berardino Baratta: By the time you read this, CodeWarrior Professional Release 2 will have shipped. The Pro 2 release will show the fruit of our current labors (oh, the joys of printed publications and their built-in time delays).

We plan on having a release of our C/C++ PowerPC compiler with support for generating mixed C/C++/Objective-C binaries for native Yellow Box, which builds on the first pre-release version of Objective-C support that we shipped on Pro 1. We will also be shipping a pre-release version of both our IDE and Debugger hosted on Rhapsody as native Yellow Box applications. This port will be done using our Metrowerks Latitude porting library, which forces us to "eat our own dogfood", so to speak.

The new Apple OS architecture forced us to come up with a debug kernel solution that didn't involve MetroNub, as MetroNub was designed strictly for Mac OS and wouldn't port to Rhapsody. For that we ported a piece of technology that came out of the ashes of the Taligent project.

We've also modified our x86 code generator to emit Mach-O executables, so that when Apple releases their version of Yellow Box for x86, CodeWarrior users can target building binaries for that version without having to change toolsets.

Dave: What's the status of the Objective-C compiler?

Andreas Hommel: The basic Objective-C support is pretty much complete. We actually shipped a pre-release of our Objective-C front-end on the CodeWarrior Pro 1 CD (in Pre-Release:1.9b1 MacOS plugins.sit). This compiler comes with a mini runtime that lets you use Objective-C under Mac OS. Objective-C is actually a relative small extension to ANSI C (or C++) and a lot of the real advanced functionality, such as remote messaging, comes from NeXT's foundation framework. As you've seen in recent issues of MacTech, the OpenStep environment gives you a way to start learning the Objective-C syntax until Apple ships the first developer's release of Rhapsody.

Dave: What about support for modern Objective-C syntax?

Andreas Hommel: We still have to add support for the modern Objective-C syntax. The classic Objective-C syntax is based on Smalltalk and it looks a little weird to C/C++ or Java programmers. The modern syntax is much closer to C++ or Java. So, for example, instead of writing code like this:

@implementation MyClass : NSObject
{
     int m;
}

- (void)set:(int)i
{
     m=i;
}

- (void)print
{
     printf("m = %d\n",m);
}
@end

int main()
{
     MyClass *my;

     my=[[MyClass alloc] init];
     [my set:123];
     [my print];
     [my dealloc];

     return 0;
}

You will soon be able to write code like this:

@implementation MyClass : NSObject
{
     int m;
}

void set(int i)
{
     m=i;
}

void print()
{
     printf("m = %d\n",m);
}
@end

int main()
{
     MyClass *my;

     my=(new MyClass)->init();
     my->set(123);
     my->print();
     delete my;

     return 0;
}

The latter, modern form looks a lot more familiar to C++ programmers. We will support this as a real modern syntax specification falls into place.

Dave: What changes were required in the code generators to support Rhapsody?

Bob Campbell: As far as ABI changes go, Mach for PowerPC changes some of the runtime model from the Mac OS ABI. While the usage of registers when calling functions is almost exactly the same, the Mach model does not have a "TOC" pointer. This changes the way that global variables are addressed, as well as the way that routines in shared libraries are called.

There are a lot of reasons for the changes to the ABI. Unfortunately, it would probably take an entire article just to explain the underlying logic behind the current Mach-based ABI design. For now, I think it would be useful to see an overview. If we get the chance, we'll explore these issues in more detail in a future column.

Addressing global variables, in Mac OS addressing an external global variable requires an indirection via a TOC pointer, as follows:

    lwz r4,x(RTOC)
    lwz r4,0(r4)

In Mach (using the static model), this would be done by breaking the first instruction up into two. The first loads the high half of the address, which is then used as a base register with the low half of the address to load the actual data:

    lis r4,HA(L_x$non_lazy_ptr)
    lwz r4,LO(L_x$non_lazy_ptr)(r4)
    lwz r4,0(r4)

Note "HA" is the high 16 bits of the address adjusted for the case where the low 16 bits when treated as signed becomes a negative value. It is possible to use the HI function but in this cause it would require more instructions:

    lis r4,HI(L_x$non_lazy_ptr)
    ori r4,r4,LO(L_x$non_lazy_ptr)
    lwz r4,0(r4)
    lwz r4,0(r4)

When we are using the dynamic model we need to use a base register to insure position independant code so it becomes:

    ; set up PIC base register
    mflr  r0        ; save the return address
    bl    L_pic_base  ; put pc of next instruction in lr
      L_pic_base:
    mflr  r3        ; setup r3 as a base register
...
    addis r4,r3,HA(L_x$non_lazy_ptr-L_pic_base)
    lwz   r4,LO(L_x$non_lazy_ptr-L_pic_base)(r4)
    lwz   r4,0(r4)
...
    mtlr  r0        ; restore return address
    blr

Another example is of differences in calling external functions. In the Mac OS case, there may need to be a reload of the TOC pointer so it inserts a nop which the linker may fill with an instruction. In the Mach case, the reload of the TOC is not needed.

extern void x(void);

void y(void)
{
    x();
}

.y:
    mflr  r0
    stw   r0,0(r1)
    stwu  r1,-64(r1)
    bl    .x
    nop      ; slot for restoring the TOC pointer if needed
    lwz   r0,72(r1)
    addi  r1,r1,64
    mtlr  r0
    blr

becomes:

_y:
    mflr  r0
    stw   r0,0(r1)
    stwu  r1,-64(r1)
    bl    L_x$stub
    lwz   r0,72(r1)
    addi  r1,r1,64
    mtlr  r0
    blr

Dave: What about object formats?

Bob Campbell: The object format defined by Apple for Rhapsody is Mach-O. It is a very different from the object format that Metrowerks uses for Mac OS.

One big difference is that in our Mac OS object format we let our linker resolve things which the Mach-O object format requires be resolved at compile time. For example, in our current object files we start the address for each function at zero and let the linker resolve the addresses. For Mach-O we must assign each function and variable a unique address before the object file is written.

I would like to point out that these are the ABIs and Object Formats that are being used for the initial release of Rhapsody. Once the initial version is out the door we will start looking for ways to improve the performance of the dynamic model.

Dave: What's the linker strategy for Mach-O?

Berardino Baratta: For this part of the equation, we decided early on, after discussions with core Apple/NeXT engineers, that NeXT had developed some very good linker technology, and it made the most sense to license that technology so we could convert that command line linker into a CodeWarrior plugin for use under our IDE. This allows us to concentrate our resources on the rest of our tools and not in trying to replicate the excellent linker optimizations that the NeXT linker implements. This helps reduce the method call overhead penalty that the ObjectiveC runtime imposes.

Dave: What can you tell me about porting the IDE to Rhapsody?

Berardino Baratta: Technically, we don't have to do anything to port our IDE to Rhapsody as it will run just fine inside of the Blue Box (Apple's solution that allow users to run their existing application inside of Rhapsody). Of course, that would be too easy. So, as I said before, we're using Latitude to solve this part of the equation. This solution involved a two step process.

First, we ported our IDE to run under Latitude hosted on SunOS, as at the time Latitude for Rhapsody was still under development. This cleaned up any issues in the IDE that were not supported under Latitude, and validated the core of Latitude with another large sourcebase.

Next, we rebuilt the IDE under Latitude for Rhapsody, giving David Hempling and the other Latitude engineers a large sourcebase with which to validate their port of Latitude for Rhapsody. If all went well, then you should be seeing the results of this work on Pro 2, as a pre-release version of the Metrowerks IDE running native on Rhapsody in the Yellow Box.

In the future, we're going to use the native hooks in Latitude to add in Yellow Box specific functionality that will make sure that the IDE is, from the user's standpoint, a fully native Yellow Box application.

Dave: Will there be any integration between CodeWarrior and InterfaceBuilder?

Berardino Baratta: Yes, we're working together with Apple to fully support InterfaceBuilder (IB), but this work is not scheduled to begin until after our IDE is up and stable under Rhapsody. Our goal is to replace ProjectBuilder, in order to provide seamless support between IB and the Metrowerks IDE.

Next month, we'll finish up this interview, starting with Lawrence You's discussion of yellow box debugging plans.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Tunnelblick 3.8.2a - GUI for OpenVPN.
Tunnelblick is a free, open source graphic user interface for OpenVPN on OS X. It provides easy control of OpenVPN client and/or server connections. It comes as a ready-to-use application with all... Read more
calibre 4.17.0 - Complete e-book library...
Calibre is a complete e-book library manager. Organize your collection, convert your books to multiple formats, and sync with all of your devices. Let Calibre be your multi-tasking digital librarian... Read more
MacPilot 11.1.4 - $15.96
MacPilot gives you the power of UNIX and the simplicity of Macintosh, which means a phenomenal amount of untapped power in your hands! Use MacPilot to unlock over 1,200 features, and access them all... Read more
Transmission 3.00 - Popular BitTorrent c...
Transmission is a fast, easy, and free multi-platform BitTorrent client. Transmission sets initial preferences so things "just work", while advanced features like watch directories, bad peer blocking... Read more
Doom 3 1.3.1 - First-person shooter acti...
A massive demonic invasion has overwhelmed the Union Aerospace Corporation's (UAC) Mars Research Facility, leaving only chaos and horror in its wake. As one of only a few survivors, you must fight... Read more
Box Sync 4.0.8004 - Online synchronizati...
Box Sync gives you a hard-drive in the Cloud for online storage. Note: You must first sign up to use Box. What if the files you need are on your laptop -- but you're on the road with your iPhone? No... Read more
LibreOffice 6.4.4.2 - Free, open-source...
LibreOffice is an office suite (word processor, spreadsheet, presentations, drawing tool) compatible with other major office suites. The Document Foundation is coordinating development and... Read more
Day One 4.14 - Maintain a daily journal.
Day One is an easy, great-looking way to use a journal / diary / text-logging application. Day One is well designed and extremely focused to encourage you to write more through quick Menu Bar entry,... Read more
MenuMeters 2.0.7 - CPU, memory, disk, an...
MenuMeters is a set of CPU, memory, disk, and network monitoring tools for Mac OS X. Although there are numerous other programs which do the same thing, none had quite the feature set I was looking... Read more
Doxie 2.12.2 - Scan, share, and store do...
Introducing Doxie, the new, modern paper scanner that's so simple, it'll revolutionize the way you think about sharing and storing docs and photos forever. Doxie is ultra-portable, fully automatic,... Read more

Latest Forum Discussions

See All

SINoALICE, Yoko Taro and Pokelabo's...
Yoko Taro and developer Pokelabo's SINoALICE has now opened for pre-registration over on the App Store. It's already amassed 1.5 million Android pre-registrations, and it's currently slated to launch on July 1st. [Read more] | Read more »
Masketeers: Idle Has Fallen's lates...
Masketeers: Idle Has Fallen is the latest endeavour from Appxplore, the folks behind Crab War, Thor: War of Tapnarok and Light A Way. It's an idle RPG that's currently available for Android in Early Access and will head to iOS at a later date. [... | Read more »
Evil Hunter Tycoon celebrates 2 million...
Evil Hunter Tycoon has proved to be quite the hit since launching back in March, with its most recent milestone being 2 million downloads. To celebrate the achievement, developer Super Planet has released a new updated called Darkness' Front Yard... | Read more »
Peak's Edge is an intriguing roguel...
Peak's Edge is an upcoming roguelike puzzle game from developer Kenny Sun that's heading for both iOS and Android on June 4th as a free-to-play title. It will see players rolling a pyramid shape through a variety of different levels. [Read more] | Read more »
Clash Royale: The Road to Legendary Aren...
Supercell recently celebrated its 10th anniversary and their best title, Clash Royale, is as good as it's ever been. Even for lapsed players, returning to the game is as easy as can be. If you want to join us in picking the game back up, we've put... | Read more »
The Magic Gladiator class arrives in MU...
The Magic Gladiator class is now available in MU Origin 2 following the most recent patch. It also marks the start of Abyss Season 11 and the introduction of Couple Skills and Couple Dungeons. [Read more] | Read more »
The 5 Best Racing Games
With KartRider Rush+ making a splash this past week, we figured it was high time we updated our list of the best mobile racing games out there. From realistic racing sims to futuristic arcade racers (and even racing management games!), check out... | Read more »
KartRider Rush+ Guide - Tips for new rac...
KartRider Rush+ continues to be a surprisingly refreshing and fun kart racer that's entirely free-to-play. The main reason for this is just how high its skill ceiling is. Check out the video above if you're curious to know what top level play looks... | Read more »
KartRider Rush+ might be good, actually?
It's hard to find good racing games on mobile. Most of them are free-to-play, and free-to-play racers generally suck. Even Nintendo couldn't put together a competent Mario Kart game, opting instead for a weird score chaser that resembles--but feels... | Read more »
LifeAfter, NetEase's popular surviv...
A new map will be making its way into NetEase's popular survival game LifeAfter. The map is set to arrive on May 28th and will introduce a volcano that's teetering on the verge of eruption, bringing a host of added challenges to the game. [Read... | Read more »

Price Scanner via MacPrices.net

Memorial Day Weekend Sale: Take $300 off thes...
Apple resellers are offering $300 discounts on select 16″ MacBook Pros as part of their Memorial Day Weekend 2020 sales. Prices start at $2099: – 16″ 2.6GHz 6-Core Space Gray MacBook Pro: $2099 at... Read more
Best Memorial Day Weekend 2020 Apple AirPods...
Apple resellers are offering discounts ranging up to $50 off MSRP on AirPods as part of their Memorial Day Weekend 2020 sales. These are the best deals today on various AirPods models. See our... Read more
Memorial Day Weekend Sale: 10″ Apple iPads fo...
Amazon is offering new 10.2″ iPads for $80-$100 off Apple’s MSRP as part of their Memorial Day Weekend 2020 sale, with prices starting at only $249. These are the same iPads sold by Apple in their... Read more
Memorial Day Weekend Sale: 2020 Apple iPhone...
Sprint is offering Apple’s new 2020 64GB iPhone SE for $0 per month for 18 months as part of their Memorial Day Weekend 2020 sale. New line of service and trade-in required. Offer is valid from 5/22/... Read more
Amazon’s popular $100 Apple Watch Series 5 di...
Amazon has Apple Watch Series 5 GPS + Cellular models on sale for up to $100 off Apple’s MSRP today. Shipping is free. These are the same Apple Watch models sold by Apple in their retail and online... Read more
2020 13″ 4-Core MacBook Air on sale for $949,...
Apple reseller Adorama has the new 2020 13″ 1.1GHz 4-Core Space Gray MacBook Air on sale today for $949 shipped. Their price is $50 off Apple’s MSRP, and it’s the lowest price currently available for... Read more
Apple Retail Chief Announces Staggered Reopen...
NEWS: 05.20.20 – In the midst of a global pandemic, after its retail outlets were shuttered temporarily in mid-March as a mitigation measure enacted by Apple during the peak of the spread of COVID-19... Read more
Apple’s Pro Display XDR models in stock today...
Abt Electronics has Apple’s new 32″ Pro Display XDR models in stock and on sale today for up to $305 off MSRP. Shipping is free. Their prices are currently the lowest available for these new models... Read more
Apple restocks refurbished iPhone 8 for $339
Apple has restocked Apple Certified Refurbished 64GB iPhone 8 models for only $339. Apple dropped their price on this phone last month by $160, from $499 to $339. Each refurbished iPhone comes with a... Read more
New at AT&T: 50% off iPhone 11 for new cu...
AT&T is offering a 50% off the 64GB iPhone 11 for new customers who switch to AT&T and open a new line of service. Discount applied over a 30 month period The fine print: “iPhone 11 64GB for... Read more

Jobs Board

Cub Foods - *Apple* Valley - Now Hiring Par...
Cub Foods - Apple Valley - Now Hiring Part Time! United States of America, Minnesota, Apple Valley New Retail Operations Post Date 5 days ago Requisition # Read more
Senior Data Engineer - *Apple* - Theorem, L...
Job Summary Apple is seeking an experienced, detail-minded data engineeringconsultant to join our worldwide business development and strategy team. If you are Read more
Cub Foods - *Apple* Valley - Now Hiring Par...
Cub Foods - Apple Valley - Now Hiring Part Time! United States of America, Minnesota, Apple Valley New Retail Operations Post Date 4 days ago Requisition # Read more
Medical Screener - *Apple* Hill - Evenings...
Medical Screener - Apple Hill - Evenings Tracking Code D-MS-AH-E Job Description Medical Screener - Temporary We Are Hiring: WellSpan Health has a temporary Medical Read more
*Apple* Systems Administrator - Solidus Tech...
Solidus is searching for an Apple Systems Engineer. The engineer will be responsible for desktop and server infrastructure. This includes support for operating Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.