TweetFollow Us on Twitter

Debugging Pascal
Volume Number:2
Issue Number:9
Column Tag:Intermediate Mac'ing

Debugging with LightSpeed Pascal

By David E. Smith, Editor & Publisher

The Boston Expo this week promises to offer a world of new Mac products of particular interest to developers. Many of these products will revolutionize how software is done on the Mac, so it is time to take stock and review the software development process on the Mac.

Where to Begin

The first step in the product development cycle is to get information. This means getting a copy of Inside Macintosh by Addison Wesley, volumes 1-3 and soon volume 4. I prefer the hard bound all in one edition (great for dropping on bugs ). Next some Mac hardware is in order. A Mac Plus with a two meg upgrade from MacMemory is a must. A hard disk, scsi type, is helpful. The DataFrame 20 has been reported as a "safe" buy, reliable, few problems. A new round of 60 to 100 meg drives is also appearing in the $2500 range. Hardware and book in hand, it's time to reach for the check book and buy additional information. Apple's software supplements and technical notes are a must, from Apple's mailing facility. For referencing the ROM, there is TOM's Program's little ROM reference deck. Finally, don't forget the MacTutor subscription!

Utilities are important. No programmer should be without Fedit Plus, Mac Nosy 2.1, TMON or Heap Show. Both Fedit Plus and Mac Nosy 2.1 are new versions being shown at Boston. All four of these products are available from MacTutor as well as other technical software outlets. Heap Show is a very valuable little utility that allows you to analyze heap use in your program, find dangling handles and pointers, and help you prevent heap fragmentation. It is one of the most valuable of utilities yet is also the least known.

Now loaded with documentation from IM, supplements and back issues of MacTutor, the next step is finding out what it all means. For this, the only way to go is to sign up for Dave Wilson's Macintosh Programming Class. This is Apple's official introduction to Mac Programming and it is indispensible. I just finished the class and I really learned a lot about the Mac that I either didn't know or didn't understand correctly. Dave is a master teacher and well versed in the Mac hacker's world. Cost is not cheap at $1,000, but it's well worth the price if your part of a company project. Six months after you're well along in development, thanks to Dave Wilson, you can then sign up for Scott Kanaster's Mac College to get the bugs out of your project. But we're getting ahead of ourselves. First you must decide on a development system.

HFS Changes Development Environment

Under MFS, the Mac supported a number of traditional development systems. The Aztec C 1.06G is preferred by Unix programmers because it preserves much of the Unix flavor of software development within the Mac interface. Consulair C and TML Pascal both present a similar Mac User Interface for software development using the traditional Edit/Compile/Link process. Under MFS, this traditional approach worked fine. However, under HFS, this approach breaks down because development systems must devise various methods of finding include files and trap files now arranged in different directories. The real problem is that HFS really makes the traditional approach of edit, compile and link obsolete. It simply takes too much time to run a program, bomb a program, debug a program, edit, compile, link and try again, when dealing with such a highly interactive and dynamic environment as Macintosh. Servant may ease this problem when available, by bringing a user configurable integrated environment to seperate programs not originally designed to be integrated, making a kind of user constructable LightSpeed environment, with the added advantage that you select the tools to install.

Solving the HFS Problem

The new world of development systems now coming out for the Mac solve the HFS problem by creating a development environment, in which all the files necessary to support the program development cycle is known to the system. These new systems are MPW from Apple, which brings Object Pascal and MacApp in a strong Unix style environment with scripts; TML Pascal 2.0, which also supports Object Pascal and units; and the newest product, LightSpeed C & Pascal, which create a "Project" that bundles files together dramatically speeding up compile and link. Let's focus on LightSpeed Pascal as this product typlifies the new "environment" approach that the Mac interface encourages.

Integrated Tools Speeds Debugging

Mac programming is primarily a process of "discovering" what the Mac ROMS will let you do and how they let you do it. Because of this, re-running programs over and over to experiment is a primary debugging task. With traditional edit, compile and link systems, this process takes several minutes. Make five change and test cycles and you've used up the better part of an hour! With the concept of a "Project", all files are loaded and available, compilation is virtually instant as only the necessary compilation is done, everything else is pre-compiled. Finally, linking is automatic since the project knows both what to link, and what needs to be re-linked after a change. The editing and executing environment are the same, so you can both edit, and execute your program from the same shell, switching back and forth with a click of the mouse between your program's window and menus, and LightSpeed Pascal's windows and menus. Source is always available for editing and source code debugging is fully supported. The result is faster turn-around time in the edit, compile, execute, bomb, re-edit cycle. Instead of several minutes, new attempts are created and tested in seconds. An interactive environment that produces fully compiled double-clickable applications, DA's and drivers.

How it works

The key to LightSpeed Pascal is the project concept. A project is a window and a file that contains a list of all filenames associated with a particular program effort. It also contains compiler and linker information that allows only changed code to be re-compiled and linked dynamically. Since libraries and include files don't have to be re-loaded and compiled as they do on traditional systems, the project approach makes fast turn-around of the compile and link process.

We write a program within our project environment with the LightSpeed Pascal "system". This system includes a multi-file editor. Our editing window is always available, even while our program is running. A build command creates a final application for us that is a fully compiled stand alone program we can move to any disk. For MDS ".REL" files, we can convert them to our project library format with a converter utility, provided. The compiler is fully Lisa and TML Pascal compatible. We compiled last month's keyboard sleuth program without any problem. The system does not have an assembler, so assembly code still must be assembled using MDS or Consulair C systems, and then converted for loading into our project.

The Debugging Process

If your frustrated at trying to marry your development system with MacsBug and TMON, then you'll really appreciate the LightsBug debugging window. Debugging is the key to this system. The system automatically debugs your source code as you type, checking for syntax errors on entry. Instant compilation checks again for normal compilation errors. Finally, running the program again checks for run-time errors. At any time, if an error occurs, you can change the source, look at the debugger window, try some parameter values in the observe window, or change variable values in the instant window. To see what your program is doing, modify the source, set breakpoints and run again. Watch your window while you also watch the debug window! The debug window is automatically linked to the point where your program stopped, showing the heap trail, register values and your global variables. A single click on a global variable, and bang! The debugger shows you a hex and ascii memory dump at the location of the variable.

Figure 1 shows the many windows of LightSpeed Pascal. Our own program window is also available! The project window lists our library, source and include files. Compiler options are set for each file by clicking in the box next to the file name. We change the link order for our project by simply dragging the file name up or down in the project window. No more editing of a link file!

Our source code is shown in another window, and we can open a window for each of our source segments. The observe window allows us to monitor the value of a variable as our program executes. The Instant window allows us to execute program source code or trap calls instantly to observe their effects. If we get what we want, we can paste the line into our source window. Text and drawing have the same purpose they did under MacPascal, but even more important, our own toolbox created windows from our running program are available and clickable along with each of the other windows shown in figure 1.

In figure 2, we see how the observe window works. Here, we've placed a breakpoint at the putstring(s) statement in the source window. After running, our program is now stopped at the break, and the value of s is shown in bold in the observe window. Note that in the LightsBug window, we instantly have the base address of the variable s and can observe it's value in both hex and ascii.

In figure 3, we now change the value of s in the instant window. As we do this, the observe window shows the new value of S, and the LightsBug window shows the new hex and ascii values for s in memory.

In figure 5, we now wish to change the value that is assigned to s directly in memory where our source code lives. We do this by clicking edit and another little debug dialog box opens allowing us to enter a new value directly into memory. As we do this, the LightsBug window shows that what used to be "there!" is now "fere!". This also changes our source code and when we run the program, as figure 6 shows, the new source code value is shown being assigned to s during execution.

Figure 7 shows that our program window exists along with LightSpeed Pascal's windows and we can swtich back and forth by clicking on the spray can (for debugging!).

Finally a Decent Manual

For some reason, Mac development systems have shipped with manuals that assume you already know every language command by heart. Very few even have a simple language definition. If you don't already know C or Pascal, forget it! The LightSpeed manuals are very well done, very large and provide a clear description of the language syntax and commands much like normal manuals on other computers have traditionally done. It is a mystery to me why it has taken this long for decent manuals to be shipped with Mac development environments.

Reaction

I personally think these products will revolutionize how software is done on the Mac. The time saved in testing and re-running programs under development is so tremendous that no one will settle for the large development time required of traditional edit, compile, and link systems. The Mac takes more time anyway in the learning curve of the ROM functions, so anything we can gain in the development cycle is extremely important. But most of all, LightSpeed Pascal will be very popular because no one will want to live without source level debugging with LightsBug if they don't have to. The debugging capabilities will cause people to stop and think if they really need all the overhead of MPW after all.

 
AAPL
$112.94
Apple Inc.
+1.16
MSFT
$47.98
Microsoft Corpora
+0.32
GOOG
$524.87
Google Inc.
+8.52

MacTech Search:
Community Search:

Software Updates via MacUpdate

NeoOffice 2014.6 - Mac-tailored, OpenOff...
NeoOffice is a complete office suite for OS X. With NeoOffice, users can view, edit, and save OpenOffice documents, PDF files, and most Microsoft Word, Excel, and PowerPoint documents. NeoOffice 3.x... Read more
LibreOffice 4.3.5.2 - 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
CleanApp 5.0.0 Beta 5 - Application dein...
CleanApp is an application deinstaller and archiver.... Your hard drive gets fuller day by day, but do you know why? CleanApp 5 provides you with insights how to reclaim disk space. There are... Read more
Monolingual 1.6.2 - Remove unwanted OS X...
Monolingual is a program for removing unnecesary language resources from OS X, in order to reclaim several hundred megabytes of disk space. It requires a 64-bit capable Intel-based Mac and at least... Read more
NetShade 6.1 - Browse privately using an...
NetShade is an Internet security tool that conceals your IP address on the web. NetShade routes your Web connection through either a public anonymous proxy server, or one of NetShade's own dedicated... Read more
calibre 2.13 - Complete e-library manage...
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
Mellel 3.3.7 - Powerful word processor w...
Mellel is the leading word processor for OS X and has been widely considered the industry standard since its inception. Mellel focuses on writers and scholars for technical writing and multilingual... Read more
ScreenFlow 5.0.1 - Create screen recordi...
Save 10% with the exclusive MacUpdate coupon code: AFMacUpdate10 Buy now! ScreenFlow is powerful, easy-to-use screencasting software for the Mac. With ScreenFlow you can record the contents of your... Read more
Simon 4.0 - Monitor changes and crashes...
Simon monitors websites and alerts you of crashes and changes. Select pages to monitor, choose your alert options, and customize your settings. Simon does the rest. Keep a watchful eye on your... Read more
BBEdit 11.0.2 - 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

Latest Forum Discussions

See All

This Week at 148Apps: December 15-19, 20...
Happy Holidays from 148Apps!   How do you know what apps are worth your time and money? Just look to the review team at 148Apps. We sort through the chaos and find the apps you’re looking for. The ones we love become Editor’s Choice, standing out... | Read more »
New Version of Tempo Smart Calendar Help...
New Version of Tempo Smart Calendar Helps You Plan Your Day Without Opening the App Posted by Jessica Fisher on December 22nd, 2014 [ permalink ] | Read more »
Sparkle - Advanced Cross-Synthesis (Mus...
Sparkle - Advanced Cross-Synthesis 1.0 Device: iOS Universal Category: Music Price: $6.99, Version: 1.0 (iTunes) Description: Sparkle is a tool for advanced spectral hybridizations made of several algorithms that operate on frequency... | Read more »
DICETINY is coming to iOS in 2015
DICETINY is coming to iOS in 2015 Posted by Jessica Fisher on December 22nd, 2014 [ permalink ] Fakedice has announced that they’re bringing their digital board game DICETINY to iOS. | Read more »
It Came From Canada: The Witcher Battle...
The Witcher 3: Wild Hunt may still be a few months away, but very soon players will be able to get a new taste of the acclaimed Polish RPG on their mobile devices with The Witcher Battle Arena. While it trades open-world exploration for compact... | Read more »
The Babies Get Lost Again in the New Azt...
The Babies Get Lost Again in the New Aztec Ruins Update for Light in the Dark Posted by Jessica Fisher on December 22nd, 2014 [ permalink ] | Read more »
Living Room 3D for IKEA Makes All In-App...
Living Room 3D for IKEA Makes All In-App Purchases Free Until 2015 Posted by Jessica Fisher on December 22nd, 2014 [ permalink ] | Read more »
Crossbow Warrior – The Legend of William...
Crossbow Warrior – The Legend of William Tell Review By Lee Hamlet on December 22nd, 2014 Our Rating: :: MISSES THE MARKUniversal App - Designed for iPhone and iPad Crossbow Warrior details the entertaining adventures of legendary... | Read more »
A New Update Races onto Asphalt 8: Airbo...
A New Update Races onto Asphalt 8: Airborne Posted by Jessica Fisher on December 22nd, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Workflow: Powerful Automation Made Simpl...
Workflow: Powerful Automation Made Simple Review By Campbell Bird on December 22nd, 2014 Our Rating: :: GO WITH THE FLOWUniversal App - Designed for iPhone and iPad This powerful app lets users accomplish multiple tasks at touch of... | Read more »

Price Scanner via MacPrices.net

13-inch 2.4GHz Retina MacBook Pro (Apple refu...
The Apple Store has previous-generation Apple Certified Refurbished 13″ 2.4GHz/128GB Retina MacBook Pros available for $999. Apple’s one-year warranty is standard, and shipping is free: - 13″ 2.4GHz/... Read more
Apple resellers offer free overnight shipping
The Apple Store is now offering free next-day shipping on all in stock items if ordered before 12/23/14 at 10:00am PT. Local store pickup is also available within an hour of ordering for any in stock... Read more
Holiday sales continue: MacBook Airs for up t...
 B&H Photo has 2014 MacBook Airs on sale for up to $120 off MSRP, for a limited time, for the Thanksgiving/Christmas Holiday shopping season. Shipping is free, and B&H charges NY sales tax... Read more
Holiday sale continues: 13-inch Retina MacBoo...
 B&H Photo has new 13″ MacBook Pros on sale for up to $150 off MSRP as part of their Holiday pricing. Shipping is free, and B&H charges NY sales tax only: - 13″ 2.5GHz MacBook Pro: $979 save... Read more
Holiday sale continues: 15-inch Retina MacBoo...
 B&H Photo has the new 2014 15″ Retina MacBook Pros on sale for up to $300 off MSRP for a limited time. Shipping is free, and B&H charges NY sales tax only: - 15″ 2.2GHz Retina MacBook Pro: $... Read more
Holiday sale: 13-inch 128GB MacBook Air for $...
 Best Buy has the 2014 13-inch 1.4GHz 128GB MacBook Air on sale for $849.99, or $150 off MSRP, on their online store. Choose free home shipping or free local store pickup (if available). Price valid... Read more
13-inch 2.6GHz Retina MacBook Pro on sale for...
Best Buy has lowered their price on the 2014 13″ 2.6GHz/128GB Retina MacBook Pro to $1149.99 on their online store for a limited time. That’s $150 off MSRP and the lowest price available for this... Read more
Kodak Returns to CES With New Consumer Produ...
Former photography colossus Kodak is returning to CES for the first time in three years where the Kodak booth (#21818 South Hall 1) will showcase a wide range of innovative, imaging-related products... Read more
Invaluable Launches New Eponymously -Named A...
Invaluable, the world’s largest online live auction marketplace, hhas announced the official launch of the Invaluable app for iPad, now available for download in the iTunes App Store. Invaluable... Read more
IDC Reveals Worldwide Mobile Enterprise Appli...
International Data Corporation (IDC) last week hosted the IDC FutureScape: Worldwide Mobile Enterprise Applications and Solutions 2015 Predictions Web conference. The session provided organizations... Read more

Jobs Board

*Apple* Store Leader Program (US) - Apple, I...
…Summary Learn and grow as you explore the art of leadership at the Apple Store. You'll master our retail business inside and out through training, hands-on experience, Read more
Project Manager, *Apple* Financial Services...
**Job Summary** Apple Financial Services (AFS) offers consumers, businesses and educational institutions ways to finance Apple purchases. We work with national and 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
*Apple* Retail - Multiple Positions (US) - A...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.