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.

 
AAPL
$102.42
Apple Inc.
+0.17
MSFT
$45.28
Microsoft Corpora
+0.40
GOOG
$569.86
Google Inc.
+0.66

MacTech Search:
Community Search:

Software Updates via MacUpdate

VueScan 9.4.41 - Scanner software with a...
VueScan is a scanning program that works with most high-quality flatbed and film scanners to produce scans that have excellent color fidelity and color balance. VueScan is easy to use, and has... Read more
Cloud 3.0.0 - File sharing from your men...
Cloud is simple file sharing for the Mac. Drag a file from your Mac to the CloudApp icon in the menubar and we take care of the rest. A link to the file will automatically be copied to your clipboard... Read more
LibreOffice 4.3.1.2 - Free Open Source o...
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
SlingPlayer Plugin 3.3.20.505 - Browser...
SlingPlayer is the screen interface software that works hand-in-hand with the hardware inside the Slingbox to make your TV viewing experience just like that at home. It features an array of... Read more
Get Lyrical 3.8 - Auto-magically adds ly...
Get Lyrical auto-magically add lyrics to songs in iTunes. You can choose either a selection of tracks, or the current track. Or turn on "Active Tagging" to get lyrics for songs as you play them.... Read more
Viber 4.2.2 - Send messages and make cal...
Viber lets you send free messages and make free calls to other Viber users, on any device and network, in any country! Viber syncs your contacts, messages and call history with your mobile device,... Read more
Cocktail 7.6 - General maintenance and o...
Cocktail is a general purpose utility for OS X that lets you clean, repair and optimize your Mac. It is a powerful digital toolset that helps hundreds of thousands of Mac users around the world get... Read more
LaunchBar 6.1 - Powerful file/URL/email...
LaunchBar is an award-winning productivity utility that offers an amazingly intuitive and efficient way to search and access any kind of information stored on your computer or on the Web. It provides... Read more
Maya 2015 - Professional 3D modeling and...
Maya is an award-winning software and powerful, integrated 3D modeling, animation, visual effects, and rendering solution. Because Maya is based on an open architecture, all your work can be scripted... Read more
BBEdit 10.5.12 - Powerful text and HTML...
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

Latest Forum Discussions

See All

Fire in the Hole Review
Fire in the Hole Review By Rob Thomas on August 29th, 2014 Our Rating: :: WALK THE PLANKUniversal App - Designed for iPhone and iPad Seafoam’s Fire in the Hole looks like a bright, 8-bit throwback, but there’s not enough booty to... | Read more »
Dodo Master Review
Dodo Master Review By Jordan Minor on August 29th, 2014 Our Rating: :: NEST EGGiPad Only App - Designed for the iPad Dodo Master is tough but fair, and that’s what makes it a joy to play.   | Read more »
Motorsport Manager Review
Motorsport Manager Review By Lee Hamlet on August 29th, 2014 Our Rating: :: MARVELOUS MANAGEMENTUniversal App - Designed for iPhone and iPad Despite its depth and sense of tactical freedom, Motorsport Manager is one of the most... | Read more »
Motorsport Manager – Beginner Tips, Tric...
The world of Motorsport management can be an unforgiving and merciless one, so to help with some of the stress that comes with running a successful race team, here are a few hints and tips to leave your opponents in the dust. | Read more »
Baseball Battle Review
Baseball Battle Review By Jennifer Allen on August 29th, 2014 Our Rating: :: SIMPLE HITTINGUniversal App - Designed for iPhone and iPad Simple and cute, Baseball Battle is a fairly fun baseball game for those looking for something... | Read more »
Checkmark 2.1 Update Released, and it’s...
Checkmark 2.1 Update Released, and it’s on Sale for a Limited Time Posted by Jessica Fisher on August 29th, 2014 [ permalink ] | Read more »
The Walking Dead Pinball Review
The Walking Dead Pinball Review By Blake Grundman on August 29th, 2014 Our Rating: :: DECISIONS, DECISIONS...Universal App - Designed for iPhone and iPad Zen Studios is at it again, taking a property that would never seem to work... | Read more »
Stupeflix Has Released a Major Update fo...
Stupeflix Has Released a Major Update for Replay Posted by Jessica Fisher on August 29th, 2014 [ permalink ] iPhone App - Designed for the iPhone, compatible with the iPad | Read more »
ALONE… Review
ALONE… Review By Jennifer Allen on August 29th, 2014 Our Rating: :: MINIMALISTIC AND TOUGHUniversal App - Designed for iPhone and iPad Tough yet satisfying, ALONE… is a challenging endless flyer with some suitably sensitive... | Read more »
Hyperlapse Review
Hyperlapse Review By Jennifer Allen on August 28th, 2014 Our Rating: :: SPEEDY VIDEO SNAPSUniversal App - Designed for iPhone and iPad Want to make a great time-lapse video quickly? Hyperlapse is perfect for that.   | Read more »

Price Scanner via MacPrices.net

13-inch 1.4GHz MacBook Air on sale for $899,...
Adorama has the new 2014 13″ 1.4GHz/128GB MacBook Air on sale for $899.99 including free shipping plus NY & NJ tax only. Their price is $100 off MSRP. Read more
It’s Official: Apple Issues Invitations To Se...
Apple has issued one of its characteristically cryptic press invitations for a special event to be held at the Flint Center for the Performing Arts in hometown Cupertino on Sept. 9, 2014 at 10:00 am... Read more
Tablet Shipments To See First On-year Decline...
TrendForce analyst Caroline Chen notes that when the iPad launched in 2010, it was an instant hit and spurred a tablet PC revolution, with tablets so popular that that notebook PC sales stagnated and... Read more
SOBERLINK Releases Apple iOS Compatible Handh...
Cypress, California based SOBERLINK, Inc., creator of the first handheld Breathalyzer designed to improve recovery outcomes, continues to show prominence in the mobile alcohol monitoring space with... Read more
New 21″ 1.4GHz iMac on sale again for $999, s...
Best Buy has the new 21″ 1.4GHz iMac on sale for $999.99 on their online store. Their price is $100 off MSRP. Choose free shipping or free local store pick up. Price is for online orders only, in-... Read more
Smartphone Outlook Remains Strong for 2014, U...
According to a new mobile phone forecast from the International Data Corporation (IDC) Worldwide Quarterly Mobile Phone Tracker, more than 1.25 billion smartphones will be shipped worldwide in 2014,... Read more
Save up to $60 with Apple refurbished iPod to...
The Apple Store has Apple Certified Refurbished 5th generation iPod touches available starting at $149. Apple’s one-year warranty is included with each model, and shipping is free. Many, but not all... Read more
12-Inch MacBook Air Coming in 4Q14 or 2015 –...
Digitimes’ Aaron Lee and Joseph Tsai report that according to Taiwan-based upstream supply chain insiders, Apple plans to launch a thinner MacBook model either at year end 2014 or in 2015, and that... Read more
Sapphire Screen “Most Wanted” iPhone 6 New Fe...
According to the ‘uSell.com iPhone Most Wanted Survey’ — a representative survey of 1,000 U.S. smartphone users conducted by used iPhone marketplace uSell.com — close to half of all smartphone users... Read more
The iPad’s Real Competitive Challenger (Not S...
It’s been my contention for some time that the iPad is suffering from something of an identity crisis, and I suspect that may be a factor in slackening sales this year. Apple can’t seem to decide... Read more

Jobs Board

*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* 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* 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
Senior Event Manager, *Apple* Retail Market...
…This senior level position is responsible for leading and imagining the Apple Retail Team's global event strategy. Delivering an overarching brand story; in-store, Read more
*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.