TweetFollow Us on Twitter

XCMD ANSI Library
Volume Number:6
Issue Number:6
Column Tag:Programmer's Forum

XCMD ANSI Library

By Gerry H. Kenner, David Burggraaf, Salt Lake City, UT

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

XCMD ANSI Library

[Gerry Kenner is a conservative senior citizen who has been working with computers and writing scientific papers since 1962 when the era first began. David Burggraaf is a newcomer to the field who got his first computer (a Sinclair) in 1980 and hasn’t stopped being excited since. Suffice it to say that most of the ideas and all of the work involved in this project were done by David.]

With their fixed methods of entering, retrieving and manipulating data, code resource packages appear to be the ideal system of object oriented programming. In this case, the object is the code resource. The popularity of this concept is shown by the use of code resources under different names by 4th Dimension™(external objects), Excel™ (DDLs) and Hypercard™ (XCMDs and XFCNs). Further, pioneer systems for using code resources in standalone programs are becoming available, the first example being Serius89™ but other programs are not far behind.

A problem with this type of programming is that the libraries must be replicated whenever they are used in different code resources. Further, when doing code resources at least some compilers link in all functions in a library and not just the ones being used. This is in contrast to the smart linking which occurs when standalone applications are generated. Experience has shown us that the size of most code resources can be reduced by 50% while some can be reduced by as much as 70% or more if the library routines are removed.

This paper reports on a method for installing the libraries and a jump table to access them as a separate code resources and then using a simple series of calls to access them from other code resources (Hypercard XCMDs in this case).

The Project

The project consisted of putting all the library functions in two code resources of type “LIB “ called CodeLib and FCodeLib. Two code resources were used because the dispatch routines for functions which return arguments longer than 32 bits are different from the cases where the return value will fit in register D0. Included in each library is the code of the library functions and a dispatch routine (main()) to provide access to them. The “LIB “ type resources are loaded into Hypercard or stacks using ResEdit.

The .h file

The CodeLib.h file includes the necessary definitions and macros for setting up the libraries in XCMD projects. Included are the list of index variables for each function call (i.e., CLatoi, CLatol, etc.), macro definitions for redefining return parameters and library function call names (#define atoi(str) ((**idispatch) (CLatoi,(char*)(str))), and typedef void (**Vfunch) (CodeLib,...);, etc.) and the macro calls which are added to the XCMD project for incorporating the above material in source code.

Perhaps the best method for understanding the contents of this file is to follow the compilation and execution of the main routine of the XCMD following the addition of the special library code. First of all, the contents of CodeLib.h are read in. In addition to declaring the macros and index variables, this file defines the handles VFunch, IFunch, etc and declares extern global variables of these types (dispatch, idispatch, etc). When executed the macro CODELIB legitimitizes the extern declaration of these variables by declaring them within the XCMD.

LOADCODELIB() is a function which appears as follows when unfolded.

/* 1 */

LOADCODELIB()
if (!initCodeLib())
 return;
else
 HLock(dispatch);
if (!initFCodeLib())
 HUnlock(dispatch);
 return;
else
 HLock(ddispatch);

Its function is to determine whether the libraries are present, get handles to them and then lock the handles so the libraries won’t move. Otherwise it returns with nothing being done. The task of getting the handles is done by initCodeLib() and initFCodeLib. The initCodeLib macro is expanded to show how this is done.

/* 2 */

initCodeLib()
fdispatch = (Ffunch)GetResource(‘LIB ‘, 18000);
pdispatch = (Pfunch)fdispatch;
cdispatch = (Cfunch)pdispatch;
ldispatch = (Lfunch)cdispatch;
idispatch = (Ifunch)ldispatch;
dispatch = (Vfunch)idispatch;

Note that all the handles point to the same address.

With the above code in place, execution of a code line such as

/* 3 */

 TempInt = atoi(TempStr);

will result in the following at compilation time.

/* 4 */

 TempInt = ((**idispatch)(CLatoi, (char*)TempStr)));

When executed, this code will pass the address of idispatch, the value of the index CLatoi and the contents of TempStr to the library code resource.

A Special Case

An exception to the above ease of use are function calls such as sprintf which pass variable numbers of arguments. In these cases, the definitions in the CodeLib.h file serve as templates for inserting the code manually. For instance, the definition of sprintf(s,f) is ((**idispatch)(CLsprintf, (s), (f), ...)). When a statement such as sprintf(TempStr, “Good Day”) is encountered the programmer must replace it manually with ((**idispatch) (CLsprintf, TempStr, “Good Day”) using the definition as a guide.

CodeLibDispatch.c

This file shares the CodeLib.h file except it does not include the NOCODELIB definitions for redefining the library function call names. Addressing the library functions is taken care of by declaring the following code before the main routine is called.

/* 5 */

typedef void (*Function)(void);
FunctionfuncTable[ROUTINES + 1]

where the value of ROUTINES was declared in CodeLib.h. Values are assigned to the funcTable variable within the main routine as follows.

/* 6 */

funcTable[CLdispatchErr]=dispatchErr;
funcTable[CLatoi]=(Function)atoi;
funcTable[CLatol]=(Function)atol;
funcTable[CLsprintf]=(Function)sprintf;
funcTable[CLsrand]=(Function)srand;
funcTable[CLstrcpy]=(Function)strcpy;

It would be nice if these could be declared statically, but we have not been able to figure out a method for doing it.

There are two segments of assembly language code. The first segment replaces the calls RememberA4() and SetUpA4() which are not used because they shift things around on the stack. This code stores the current value of A4 and replaces it with the address of the main routine which is stored in A0 when the code is called. The second assembly language segment is a glue routine for configuring the stack before jumping to the desired library function.

/* 7 */

 asm  {
 move.l (a7)+, returnAddr;/*save return address*/
 move.w (a7)+, a1; /*remove index*/
 lea funcTable, a0;/*do jump to indexed subroutine*/
 jsr ([0,a0,a1.w*4],0);
 move.w a1, -(a7); /*restore stack and return*/
 move.l returnAddr, -(a7);
 move.l oldA4, a4; /*restore a4  */
 }

It removes the return address and saves it before doing a jsr to the requested funcTable entry after which it is put back on the stack. The index value is also removed from the stack, placed in a1 for use as an offset and then replaced on the stack at the end of the call. The last line of code restores the old value of a4.

General

Note that there are six dispatch types although only four are used in this code. The remaining two are for functions which return floats and structures. Further functions can be added to by using the formats given. We have included the code of a sample Hypercard XCMD which uses the libraries or of a Hypercard stack to exercise the XCMD. Other examples are left as an exercise for the reader.

This project is written with THINK C. Similar code would be difficult though possible to implement in Pascal. An important point to note if you are using calls which use floating point arithmetic or call the printf type functions is that the standard ANSI-A4 library does not include floating point functions nor math functions. The math functions are gained by adding math.c to the ANSI-A4 library project. Floating point capabilities are added by opening the ansi-config.h file which is found in the source code of the ANSI-A4 project and commenting out the line #define _NOFLOATING_ and then recompiling the project under a different name such as ANSI-A4(f). Another point to remember is that other functions such as qsort and atof are also not part of the ANSI-A4 project and must be added if they are to be used.

If you have any questions David can be reached on internet at BURGGRAAF @ cc.utah.edu.

Installation Instructions:

1. Install the Library code resource wherever it is needed, i.e., as a code resource in your Hypercard stack.

2. Include the “CodeLib.h” header file before any of the functions in the code library are called.

3. Enter the line

CODELIB;

before any function in the library is called. It must be typed outside of any function. It is a preprocessor declaration of the necessary global variables.

4. If they are not already part of your code put in the instructions RememberA0, SetUpA4 and RestoreA4, so that the above global variables can be used.

5. In the main function, at the beginning type the line.

LOADCODELIB();

This should be the first function call other than functions which setup registers for global variable access. (i.e., SetupA4()).

6. In the main function, at the end enter the line.

UNLOADCODELIB();

7. If present, remove any duplicate libraries which are present in your project.

8. Build the project.

Listing:  CodeLib.h

#ifndef _CODE_LIB_
#define _CODE_LIB_
typedef enum
 {
 CLdispatchErr=0,
 CLatoi,
 CLatol,
 CLsprintf,
 CLsrand,
 CLstrcpy,
 CLsqrt=1 /*Double/struct lib */
 } CodeLib;

#define ROUTINES 5
#define FROUTINES  1

#ifndef NOCODELIBDEF
#define atoi(str) ((**idispatch)(CLatoi,(char *)(str)))
#define atol(str) ((**ldispatch)(CLatol,(char *)(str)))
#define sprintf(s,f) ((**idispatch)(CLsprintf,(s),(f),...))
#define srand(s) ((**dispatch)(CLsrand,(unsigned)(s)))
#define strcpy(s1,s2) ((char *)((**pdispatch)(CLstrcpy,(char*)(s1),(char 
*)(s2))))
#define sqrt(d) ((**ddispatch)(CLsqrt, (double)(d)))
#endif NOCODELIBDEF

typedef void (**Vfunch)(CodeLib,...);
typedef int (**Ifunch)(CodeLib,...);
typedef long (**Lfunch)(CodeLib,...);
typedef char (**Cfunch)(CodeLib,...);
typedef float (**Ffunch)(CodeLib,...);
typedef double (**Dfunch)(CodeLib,...);
typedef void *(**Pfunch)(CodeLib,...);

#define CODELIB Vfunch dispatch;Ifunch idispatch;Lfunch ldispatch;Cfunch 
cdispatch;Ffunch fdispatch;Dfunch ddispatch;Pfunch pdispatch;
#ifndef NOTLLIB
#define initCodeLib() (dispatch=(Vfunch)(idispatch=(Ifunch)(ldispatch=(Lfunch)(cdispatch=( 
Cfunch)(pdispatch=(Pfunch)(fdispatch=(Ffunch)GetResource(‘LIB ‘, 18000)))))))
#else
#define initcodeLib() 1
#endif CODELIB

#ifndef NOFLOATLIB
#define initFCodeLib() (ddispatch=(Dfunch)GetResource(‘LIB ‘, 18001))
#else
#define initFCodeLib() 1
#endif NOFLOATLIB

#define LOADCODELIB() {if (!initCodeLib()) return;else HLock(dispatch);if 
(!initFCodeLib()) {HUnlock(dispatch);return;}else HLock(ddispatch);}
#define UNLOADCODELIB() {HUnlock(dispatch);HUnlock(ddispatch);}

extern Vfunch dispatch;
extern Ifunch idispatch;
extern Lfunch ldispatch;
extern Cfunch cdispatch;
extern Ffunch fdispatch;
extern Dfunch ddispatch;
extern Pfunch pdispatch;
#endif
Listing:  CodeLibDispatch.c

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#define NOCODELIBDEF
#include “CodeLib.h”

typedef void (*Function)(void);

long returnAddr, oldA4;
int funcIndex;
void dispatchErr(void);
Function funcTable[ROUTINES+1];
 
void main(void)
 { /* CodeLib routine*/
 asm  {
 move.l a4, a1;  /*setup a4 */
 move.l a0, a4;
 move.l a1, oldA4;
 };
 funcTable[CLdispatchErr]=dispatchErr;
 funcTable[CLatoi]=(Function)atoi;
 funcTable[CLatol]=(Function)atol;
 funcTable[CLsprintf]=(Function)sprintf;
 funcTable[CLsrand]=(Function)srand;
 funcTable[CLstrcpy]=(Function)strcpy;
 asm  {
 move.l (a7)+, returnAddr;/*save return address*/
 move.w (a7)+, a1; /*remove index  */
 lea funcTable, a0;/*do jump to indexed subroutine*/
 jsr ([0,a0,a1.w*4],0);
 move.w a1, -(a7); /*restore stack and return*/
 move.l returnAddr, -(a7);
 move.l oldA4, a4; /*restore a4  */
 }
 UnloadA4Seg(0L);
 } /* Main*/

void dispatchErr(void)
 {
 SysBeep(5);
 }
Listing:  FCodeLibDispatch.c

#include <math.h>

#define NOCODELIBDEF
#include “CodeLib.h”

typedef void (*Function)(void);

long returnAddr, oldA4, returnStruct;
int funcIndex;
void dispatchErr(void);
Function funcTable[FROUTINES+1];
 
void main(void)
 { /*CodeLib routine*/
 asm  {
 move.l a4, a1;  /*setup a4 */
 move.l a0, a4;
 move.l a1, oldA4;
 };
 funcTable[CLdispatchErr]=dispatchErr;
 funcTable[CLsqrt]=(Function)sqrt;
 asm  {
 move.l (a7)+, returnAddr;/*save return address*/
 move.l (a7)+, returnStruct;/*save return StructPtr*/
 move.w (a7)+, a1; /*remove index  */
 move.l returnStruct, -(a7);/*put return StructPtr*/
 lea funcTable, a0;/*do jump to indexed subroutine*/
 jsr ([0,a0,a1.w*4],0);
 move.l (a7)+, returnStruct;/*get return structPtr*/
 move.w a1, -(a7); /*restore stack and return*/
 move.l returnStruct, -(a7);
 move.l returnAddr, -(a7);
 move.l oldA4, a4; /*restore a4  */
 }
 UnloadA4Seg(0L);
 } /* Main*/

void dispatchErr(void)
 {
 SysBeep(5);
 }

Listing: testCodeLib.c

#include “CodeLib.h”
#include “HyperXCmd.h”
#include “SetUpA4.h”

CODELIB;

pascal void main(XCmdBlockPtr paramPtr)
{
 int    TempInt1, TempInt2;
 unsigned int  Seed;
 long   TempLong;
 StringHandle  TempHdl;
 double TempDouble1, TempDouble2;
 Ptr    TempPtr;
 Str255 TempStr;
 
 RememberA0();
 SetUpA4();
 LOADCODELIB();
 TempHdl = (StringHandle)NewHandle(256);
 TempPtr = *(paramPtr->params[0]);
 TempInt1 = atoi((char*)TempPtr);
 TempPtr = *(paramPtr->params[1]);
 TempLong = atol((char*)TempPtr);
 TempInt2 = (int)TempLong;
 TempInt1 = TempInt1 * TempInt2;
 TempDouble2 = (double)TempInt1;
 TempDouble1 = sqrt(TempDouble2);
 Seed = (unsigned int)TempDouble1;
 srand(Seed);
 (**idispatch)(CLsprintf,TempStr, “The square root of %d is %.2g.”,
 TempInt1, TempDouble1);
 strcpy(*TempHdl, TempStr);
 paramPtr->returnValue = (Handle)TempHdl;
 
 UNLOADCODELIB();
 RestoreA4();
}

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Apple iBooks Author 2.5 - Create and pub...
Apple iBooks Author helps you create and publish amazing Multi-Touch books for iPad. Now anyone can create stunning iBooks textbooks, cookbooks, history books, picture books, and more for iPad. All... Read more
TunnelBear 3.0.1 - Subscription-based pr...
TunnelBear is a subscription-based virtual private network (VPN) service and companion app, enabling you to browse the internet privately and securely. Features Browse privately - Secure your data... Read more
ExpanDrive 5.4.0 - 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
Opera 40.0.2308.62 - High-performance We...
Opera is a fast and secure browser trusted by millions of users. With the intuitive interface, Speed Dial and visual bookmarks for organizing favorite sites, news feature with fresh, relevant content... Read more
Apple iOS 10.0.2 - The latest version of...
iOS 10 is the biggest release of iOS ever. A massive update to Messages brings the power of the App Store to your conversations and makes messaging more personal than ever. Find your route with... Read more
Herald 7.0 - Notification plugin for Mai...
Note: Versions 2.1.3 (for OS X 10.7), 3.0.6 (for OS X 10.8), 4.0.8 (for OS X 10.9), 5.0.2 (for OS X 10.10), and 6.0.3 (for OS X 10.11) are no longer supported by the developer. Herald is a... Read more
Postbox 5.0.2 - Powerful and flexible em...
Postbox is a new email application that helps you organize your work life and get stuff done. It has all the elegance and simplicity of Apple Mail, but with more power and flexibility to manage even... Read more
Yummy FTP Pro 1.11.10 - $29.99
Yummy FTP Pro is an advanced Mac file transfer app which provides a full-featured professional toolkit combined with blazing speeds and impeccable reliability, so whether you want to transfer a few... Read more
Tidy Up 4.1.17 - $29.99
Tidy Up is a full-featured duplicate finder and disk-tidiness utility. Features With Tidy Up you can search for duplicate files and packages by the owner application, content, type, creator,... Read more
Logitech Control Center 3.9.5 - Keyboard...
Logitech Control Center (LCC) is designed to support OS X and allows you to take full advantage of your Logitech keyboard, mouse, or trackball. With the LCC you can: Browse the Internet using... Read more

How to build and care for your team in D...
Before you hit the trail and become a dog sledding legend, there’s actually a fair bit of prep work to be done. In Dog Sled Saga, you’re not only racing, you’re also building and caring for a team of furry friends. There’s a lot to consider—... | Read more »
How to win every race in Dog Sled Saga
If I had to guess, I’d say Dog Sled Saga is the most adorable racing game on the App Store right now. It’s a dog sled racing sim full of adorable, loyal puppies. Just look at those fluffy little tails wagging. Behind that cute, pixelated facade is... | Read more »
Let the war games commence in Gunship Ba...
Buzz Lightyear famously said, “This isn’t flying, this is falling – with style!” In the case of Gunship Battle: Second War, though, this really is flying - with style! The flight simulator app from Joycity puts you in control of 20 faithfully... | Read more »
How to get a high score in Fired Up
Fired Up is Noodlecake Games’ high score chasing, firefighting adventure. You take control of a wayward firefighter who propels himself up the side of a highrise with blasts of water. Sound silly? It is. It’s also pretty difficult. You can’t... | Read more »
NBA 2K17 (Games)
NBA 2K17 1.0 Device: iOS iPhone Category: Games Price: $7.99, Version: 1.0 (iTunes) Description: Following the record-breaking launch of NBA 2K16, the NBA 2K franchise continues to stake its claim as the most authentic sports video... | Read more »
Dog Sled Saga (Games)
Dog Sled Saga 1.0.1 Device: iOS Universal Category: Games Price: $3.99, Version: 1.0.1 (iTunes) Description: A game by Dan + Lisa As a rookie musher, foster a dogsledding team whose skills will grow if they're treated right. Week by... | Read more »
60 Seconds! Atomic Adventure (Games)
60 Seconds! Atomic Adventure 1.2 Device: iOS Universal Category: Games Price: $2.99, Version: 1.2 (iTunes) Description: 60 Seconds! is a dark comedy atomic adventure of scavenge and survival. Collect supplies and rescue your family... | Read more »
Tons of Bullets! (Games)
Tons of Bullets! 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Tons of BulletsA retro 2D pixel platformer infused with tons of bullets and tons of features!Fight as Kenji the Ninja and... | Read more »
Sorcery! 4 (Games)
Sorcery! 4 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: *** PLEASE NOTE: Sorcery! 4 requires a minimum of iPad 3 or iPhone 4 *** An epic adventure through a cursed citadel of monsters,... | Read more »
Building the perfect Animation Throwdown...
Animation Throwdown is a casual card game full of plenty of inside jokes from some of your favorite cartoons. It’s accessible as far as card games go, but that’s not to say that it hands your victories to you easily. There’s quite a bit that goes... | Read more »

Price Scanner via MacPrices.net

Duplicate Sweeper Free On Mac App Store For O...
To celebrate the launch of Apple’s latest macOS Sierra, Stafford, United Kingdom based Wide Angle Software has announced that its duplicate file finder software, Duplicate Sweeper, is now available... Read more
13-inch Retina MacBook Pros on sale for up to...
B&H Photo has 13″ Retina Apple MacBook Pros on sale for up to $150 off MSRP. Shipping is free, and B&H charges NY tax only: - 13″ 2.7GHz/128GB Retina MacBook Pro: $1174.99 $125 off MSRP - 13... Read more
Evidence Surfaces Pointing To New A10X Chip F...
Citing a job description for a Project Lead position at Apple’s Austin, Texas engineering labs, Motley Fool’s Ashraf Eassa deduces that development is progressing well on Apple’s next-generation in-... Read more
Check Print’R for macOS Allows Anyone to Easi...
Delaware-based Match Software has announced the release and immediate availability of Check Print’R 3.21, an important update to their easy-to-use check printing application for macOS. Check Print’R... Read more
Apple refurbished 11-inch MacBook Airs availa...
Apple has Certified Refurbished 11″ MacBook Airs (the latest models), available for up to $170 off the cost of new models. An Apple one-year warranty is included with each MacBook, and shipping is... Read more
Apple refurbished 15-inch Retina MacBook Pros...
Apple has Certified Refurbished 2015 15″ Retina MacBook Pros available for up to $380 off the cost of new models. An Apple one-year warranty is included with each model, and shipping is free: - 15″ 2... Read more
Major Version 5 Release Of Free myTuner Radio...
AppGeneration Software has announced the release of myTuner Radio 5.0.1, an important update to their live radio app for iOS and Android platforms. With myTuner Radio, you can listen to more than 30,... Read more
TheAppStore Searches And Filters iOS And macO...
Boston based InchWest has announced the official launch of TheAppStore, a free web based service that lets users search iOS and Mac apps on the web without iTunes or the App store. TheAppStore... Read more
2TB Time Capsule on sale for $199, save $100
Amazon has 2TB Apple Time Capsules on sale for $199 including free shipping. Their price is $100 off MSRP. Choose Amazon as the seller when making your purchase, rather than a third party seller. Read more
12-inch 1.2GHz Rose Gold Retina MacBook on sa...
Amazon.com has the 2016 12″ 1.2GHz Rose Gold Retina MacBook on sale for $1254.02 including free shipping. Their price is $345 off MSRP, and it’s the lowest price available for this model from any... Read more

Jobs Board

US- *Apple* Store Leader Program - Apple (Un...
…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 Read more
Senior *Apple* Administrator - Pratt Instit...
POSITION SUMMARY: Directs the coordination and standardization of campus-wide Apple systems, including planning, analysis and implementation of Apple -related Read more
Restaurant Manager (Neighborhood Captain) - A...
…in every aspect of daily operation. WHY YOU'LL LIKE IT: You'll be the Big Apple . You'll solve problems. You'll get to show your ability to handle the stress and Read more
*Apple* Retail - Multiple Positions- Napervi...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
US- *Apple* Store Leader Program - Apple (Un...
…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 Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.