TweetFollow Us on Twitter

Sep 96 Top 10
Volume Number:12
Issue Number:9
Column Tag:Symantec Top Ten

Symantec Top 10

By Craig Conner

Note: Source code files accompanying article are located on MacTech CD-ROM or source code disks.

This month we start with a few THINK Pascal questions, then run through questions dealing with exception handling (or lack thereof), and then finish off with some miscellaneous topics.

The first question is from a news post:

Q: I have a large THINK Pascal project that I have always compiled for 68K with a floating-point unit. I now want to compile for a 68030-based PowerBook that has no FPU. Unfortunately, I am having some problems linking. If I turn off 68881/68882 under Code Generation in the Compile Options dialog, I get a link error:

undefined: 3SINH2 (Activation.p)

undefined: 3TANH2 (Activation.p)

I need to use these functions but I do not know how to get rid of this error. I did remove the SANELib881.lib library and replace it with SANELib.lib, but I still get the error. Any suggestions?

A: Unfortunately, those functions are defined in SANE.p only if you are compiling with 68881/68882 on. Fortunately, here are sinh, cosh, and tanh defined:

 function SinH(x:real):extended;
 begin
 sinH:=(exp(x) - exp(-x))/2;
 end;

 function CosH(x:real):extended;
 begin
 cosH := (exp(x)+exp(-x))/2;
 end;

 function TanH(x:real):extended;
 begin
 TanH := SinH(x)/CosH(x);
 end;

 TanH can be optimized like this:

 function TanH(x:real):extended;
 var
 eToX, eToNegX:extended;
 begin
 eToX := exp(x);
 eToNegX := exp(-x);
 TanH := ( eToX - eToNegX ) / (eToX + eToNegX);
 end;

It will be a tad slower than using SANE, but it will work. You can look at how exp(x) works on p. 358 of the THINK Pascal Users Manual, and the hyperbolic functions in any trigonometry textbook.

Q: When using THINK Pascal, I want to create my own pattern for use with the PenPat routine. How do I do this?

A: You should use the StuffHex routine (QuickDraw) to build your patterns. StuffHex will interpret its argument as an 8-by-8 bit-pattern with 1’s denoting “on” bits, and 0’s denoting “off” bits. Like so:

var
 myPat :Pattern;

StuffHex(@myPat, 'FFFFFFFFFFFFFFFF'); {All on}

Q: In THINK Pascal, whenever I try TextFace(bold), I get an “incompatible type” error. Why?

A: The “styles” used in Pascal are values in a set and need to be expressed as [bold], [underline], [italic], etc. Normal text is specified as the empty set, []. Try:

TextFace([bold]);


Q: In a TCL project that I am updating to version 8.1, I get an “undefined” error on catch_. What might cause this?

A: If you are using native exceptions (which is standard for 8.1 projects), catch_ has been redefined as catch_reference. Here is an example:

try_
{
   DoIt();
}
catch_reference(CException, e)
{
   errVal = e.GetErr();
}
catch_all_()
{
   errVal = -1;
}
end_try_

Q: I have just completed my latest project using TCL, and want to use MrC++ for the finishing touch. However, I get link errors when trying to build it. Why?

A: MrC and MrC++ do not have native exceptions built in, so you need to change the libraries some to get your project to link correctly. Remove the current CPlusLib TCL.o and BRLib libraries, and replace them with the ones that use the non-native exception handling. These are CPlusLib TCL_BELeh.o and BRLib(non-native eh).o. That should get it working.

Q: I just saw a note in the fp.h header recently about dtox80 and x80tod being contained in a library called MathLib v.2. Why was it not included on the last CD?

A: That note in the header file is premature. Apple has not released a new version yet. Currently you can use ldtox80 and x80told and they will work correctly.

Q: While compiling the OpenDoc project ODFFramewrk.RB.Π I get “not enough memory” errors when trying to load the precompiled header called ODFHeaders.RB. How can I fix this?

A: The obvious answer is to get more RAM. OpenDoc will require at least 32 megs, and the more the merrier. Turning on Virtual Memory should also work, but will slow compiling down. If Virtual Memory is too slow, you can change the size of the precompiled header using a switch set up for the headers. In the ODF.pch file, there is a:

#define FW_AGGRESSIVE_PRECOMPILE 1

Change this to 0 and then do the same for FWEnvDev.h. After re-precompiling, the ODFHeaders.RB file will be smaller.

Q: I am trying to build a 68K version of one of my SPM projects. I get the following error at link time using Link via ToolServer:

### While reading file "long pathname:MPW68KRuntime.o.o"
### Link: Error: PC-relative edit, offset out of range.
(Error 48) %__MAIN (309)
Reference to: main in file: pathname:main.cp.o

A: There are some nuances that you need to take care of when using ToolServer to link a 68K application in the link order file (the .lo file). The MPW68KRuntime library uses Near code, so it needs to be near the top of the list (in one of the first two segments that get created). Also, since that library calls the main routine, the file that contains that routine needs to be near that library. If you get a similar error after rearranging, then you need to turn on Far Code in the linker options, and use Far libraries where possible. Any library that does not have a Far version (like the runtime lib) needs to go near the top of the list.

Q: When using the alloc_gla memory package with the Vector demo, it reports heap corruption. What is wrong with the example?

A: Looking at the example, we see code like this:

    vector(int size)   { v = new T[size]; sz = size; };
    ~vector()          { delete v; };

This code may have been correct at one time, but nowadays it is not. Since the new call allocates an array, the delete operator is no longer the proper operator to use. Instead, the delete[] operator should be used, and alloc_gla will stop complaining:

    vector(int size)   { v = new T[size]; sz = size; };
    ~vector()          { delete[] v; };

Q: If I realign a structure like so:

#pragma options align=mac68k
struct{
...
}myStruct;
#pragma options align=powerpc 

my program crashes when trying to use myStruct. What might be happening?

A: The default setup for PPC projects is to use four-byte boundaries. align=powerpc will align to two-byte boundaries, and could cause incompatibilities. Use #pragma options align=reset instead, and that should fix the problem.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Latest Forum Discussions

See All

How to evolve Eevee in Pokemon GO
By now, almost everyone should be hip to how to evolve Pokemon in Pokemon GO (and if not, there's a guide for that). Just gather enough candy of the appropriate type, feed them all to the Pokemon, and evolution happens. It's a miracle that would... | Read more »
CSR Racing 2: Guide to all game modes
It might not seem like there are all that many ways to go fast in a straight line, but CSR Racing 2 begs to differ. [Read more] | Read more »
Bulb Boy (Games)
Bulb Boy 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Multi-award winning 2D point & click horror adventure about a boy with a glowing head. | Read more »
5 top free emoji keyboard apps
If we're not at peak emoji yet as a society, it feels like we definitely should be. The emoji concept has gone far beyond what anyone in Japan could have envisioned when the people there unleashed it on an unsuspecting world, but the West has... | Read more »
How to unlock more characters in Disney...
One of the big charms of Disney Emoji Blitz is seeing a wide variety of beloved Disney and Pixar characters transformed into smiling emojis. Even someone like the sneaky Randall from Monsters Inc., who probably never cracked a smile on film, is... | Read more »
Cubway (Games)
Cubway 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Cubway is a journey with an abstract story of lifecycle of rebirth, called Samsara. Guide the cube through the long way full of dangers... | Read more »
Colorcube (Games)
Colorcube 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Turn pieces and blend colours in this minimal yet visually stunning puzzler.Over 200 handcrafted and challenging levels. Features... | Read more »
Doodle God Griddlers (Games)
Doodle God Griddlers 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: | Read more »
Crusader Kings: Chronicles (Games)
Crusader Kings: Chronicles 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: Crusader Kings: Chronicles is an interactive text based game that puts you in the shoes of Guy de Rose as you make... | Read more »
Roads of Rome: New Generation (Games)
Roads of Rome: New Generation 1.0 Device: iOS Universal Category: Games Price: $5.99, Version: 1.0 (iTunes) Description: | Read more »

Price Scanner via MacPrices.net

Free iOS Business App notably* Helps Service...
PayStudio Inc. has introduced their new business app notably* 1.0, developed for iPhone and iPod touch. notably* was specifically developed to help service and trade professionals go digital and... Read more
27-inch iMacs on sale for $200 off MSRP
Amazon has 27″ iMacs on sale for $200 off MSRP including free shipping: - 27″ 3.3GHz iMac 5K: $2099 $200 off MSRP - 27″ 3.2GHz/1TB Fusion iMac 5K: $1799.99 $200 off MSRP - 27″ 3.2GHz/1TB HD iMac 5K... Read more
Mac Pros on sale for $200 off MSRP
B&H Photo has Mac Pros on sale for $200 off MSRP. Shipping is free, and B&H charges sales tax in NY only: - 3.7GHz 4-core Mac Pro: $2799, $200 off MSRP - 3.5GHz 6-core Mac Pro: $3799, $200... Read more
Save up to $600 with Apple refurbished Mac Pr...
Apple has Certified Refurbished Mac Pros available for up to $600 off the cost of new models. An Apple one-year warranty is included with each Mac Pro, and shipping is free. The following... Read more
Apple price trackers, updated continuously
Scan our Apple Price Trackers for the latest information on sales, bundles, and availability on systems from Apple’s authorized internet/catalog resellers. We update the trackers continuously: - 15″... Read more
13-inch 2.5GHz MacBook Pro (Apple refurbished...
Apple has Certified Refurbished 13″ 2.5GHz MacBook Pros available for $829, or $270 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free: - 13″ 2.5GHz MacBook Pros... Read more
21-inch iMacs on sale for up to $120 off MSRP
B&H Photo has 21″ iMacs on sale for up to $120 off MSRP including free shipping plus NY sales tax only: - 21″ 3.1GHz iMac 4K: $1379 $120 off MSRP - 21″ 2.8GHz iMac: $1199.99 $100 off MSRP - 21″ 1... Read more
Charitybuzz Set to Auction Unique Apple-1 Com...
Offering an opportunity to own the computer that sparked a revolution, on Monday, July 25, leading online charity auction platform Charitybuzz will auction what is claimed to be the world’s most... Read more
MacBook Airs on sale for up to $150 off MSRP
Amazon has 11″ and 13″ MacBook Airs on sale for up to $150 off MSRP for a limited time. Shipping is free: - 13″ 1.6GHz/128GB MacBook Air (sku MMGF2LL/A): $899.99 $100 off MSRP - 13″ 1.6GHz/256GB... Read more
Apple refurbished 13-inch Retina MacBook Pros...
Apple has Certified Refurbished 13″ Retina MacBook Pros available for up to $270 off the cost of new models. An Apple one-year warranty is included with each model, and shipping is free: - 13″ 2.7GHz... Read more

Jobs Board

*Apple* Retail - Multiple Positions, Willow...
Job Description:SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Evangelist - JAMF Software (United S...
The Apple Evangelist is responsible for building and cultivating strategic relationships with Apple 's small and mid-market business development field teams. This Read more
*Apple* Solutions Consultant - APPLE (United...
Job Summary As an Apple Solutions Consultant, you'll be the link between our future customers and our products. You'll showcase your entrepreneurial spirit as you Read more
*Apple* Professional Learning Specialist - A...
Job Summary The Apple Professional Learning Specialist is a full-time position for one year with Apple in the Phoenix, AZ area. This position requires a high Read more
*Apple* Picker - Apple Hill Orchard (United...
Apple Hill Orchard, Co. Rte. 21,Whitehall, NY 9/7/16-10/228/16. Pick fresh market or processing apples Productivity of 60 boxes and 80 boxes processing fruit per Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.