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();
}

 
AAPL
$119.00
Apple Inc.
+1.40
MSFT
$47.75
Microsoft Corpora
+0.28
GOOG
$540.37
Google Inc.
-0.71

MacTech Search:
Community Search:

Software Updates via MacUpdate

HoudahSpot 3.9.6 - Advanced file search...
HoudahSpot is a powerful file search tool built upon MacOS X Spotlight. Spotlight unleashed Create detailed queries to locate the exact file you need Narrow down searches. Zero in on files Save... Read more
RapidWeaver 6.0.3 - Create template-base...
RapidWeaver is a next-generation Web design application to help you easily create professional-looking Web sites in minutes. No knowledge of complex code is required, RapidWeaver will take care of... Read more
iPhoto Library Manager 4.1.10 - Manage m...
iPhoto Library Manager lets you organize your photos into multiple iPhoto libraries. Separate your high school and college photos from your latest summer vacation pictures. Or keep some photo... Read more
iExplorer 3.5.1.9 - View and transfer al...
iExplorer is an iPhone browser for Mac lets you view the files on your iOS device. By using a drag and drop interface, you can quickly copy files and folders between your Mac and your iPhone or... Read more
MacUpdate Desktop 6.0.3 - Discover and i...
MacUpdate Desktop 6 brings seamless 1-click installs and version updates to your Mac. With a free MacUpdate account and MacUpdate Desktop 6, Mac users can now install almost any Mac app on macupdate.... Read more
SteerMouse 4.2.2 - Powerful third-party...
SteerMouse is an advanced driver for USB and Bluetooth mice. It also supports Apple Mighty Mouse very well. SteerMouse can assign various functions to buttons that Apple's software does not allow,... Read more
iMazing 1.1 - Complete iOS device manage...
iMazing (was DiskAid) is the ultimate iOS device manager with capabilities far beyond what iTunes offers. With iMazing and your iOS device (iPhone, iPad, or iPod), you can: Copy music to and from... Read more
PopChar X 7.0 - Floating window shows av...
PopChar X helps you get the most out of your font collection. With its crystal-clear interface, PopChar X provides a frustration-free way to access any font's special characters. Expanded... Read more
Carbon Copy Cloner 4.0.3 - Easy-to-use b...
Carbon Copy Cloner backups are better than ordinary backups. Suppose the unthinkable happens while you're under deadline to finish a project: your Mac is unresponsive and all you hear is an ominous,... Read more
ForeverSave 2.1.3 - Universal auto-save...
ForeverSave auto-saves all documents you're working on while simultaneously doing backup versioning in the background. Lost data can be quickly restored at any time. Losing data, caused by... Read more

Latest Forum Discussions

See All

Raby (Games)
Raby 1.0.3 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0.3 (iTunes) Description: ***WARNING - Raby runs on: iPhone 5, iPhone 5C, iPhone 5S, iPhone 6, iPhone 6 Plus, iPad Mini Retina, iPad Mini 3, iPad 4, iPad Air,... | Read more »
Oddworld: Stranger's Wrath (Games)
Oddworld: Stranger's Wrath 1.0 Device: iOS Universal Category: Games Price: $5.99, Version: 1.0 (iTunes) Description: ** PLEASE NOTE: Oddworld Stranger's Wrath requires at least an iPhone 4S, iPad 2, iPad Mini or iPod Touch 5th gen... | Read more »
Bounce On Back (Games)
Bounce On Back 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: | Read more »
Make Way for Fat Chicken, from the Maker...
Make Way for Fat Chicken, from the Makers of Scrap Squad Posted by Jessica Fisher on November 26th, 2014 [ permalink ] Relevant Games has announced they will be releasing their reverse tower defense game, | Read more »
Tripnary Review
Tripnary Review By Jennifer Allen on November 26th, 2014 Our Rating: :: TRAVEL BUCKET LISTiPhone App - Designed for the iPhone, compatible with the iPad Want to create a travel bucket list? Tripnary is a fun way to do exactly that... | Read more »
Ossian Studios’ RPG, The Shadow Sun, is...
Ossian Studios’ RPG, The Shadow Sun, is Now Available for $4.99 Posted by Jessica Fisher on November 26th, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Mmmm, Tasty – Having the Angry Birds for...
The very first Angry Birds debuted on iOS back in 2009. When you sit back and tally up the number of Angry Birds games out there and the impact they’ve had on pop culture as a whole, you just need to ask yourself: “How would the birds taste... | Read more »
Rescue Quest Review
Rescue Quest Review By Jennifer Allen on November 26th, 2014 Our Rating: :: PATH BASED MATCH-3Universal App - Designed for iPhone and iPad Guide a wizard to safety by matching gems. Rescue Quest might not be an entirely original... | Read more »
You Can Play the Final Chapter of Lone W...
You Can Play the Final Chapter of Lone Wolf: Dawn Over V’taag Right Now Posted by Jessica Fisher on November 26th, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Swords of Anima (Games)
Swords of Anima 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: A new tactical turn-based RPG experience. Command the Savior Rex Squad in an epic journey of courage and deception. Can you... | Read more »

Price Scanner via MacPrices.net

2014 1.4GHz Mac mini on sale for $449, save $...
 B&H Photo has the new 1.4GHz Mac mini on sale for $449.99 including free shipping plus NY tax only. Their price is $50 off MSRP, and it’s the lowest price available for this new model. Adorama... Read more
Early Black Friday pricing on 27-inch 5K iMac...
 B&H Photo continues to offer Black Friday sale prices on the 27″ 3.5GHz 5K iMac, in stock today and on sale for $2299 including free shipping plus NY sales tax only. Their price is $200 off MSRP... Read more
Early Black Friday sale prices on iPad Air 2,...
 MacMall is discounting iPad Air 2s by up to $75 off MSRP as part of their Black Friday sale. Shipping is free: - 16GB iPad Air WiFi: $459 $40 off - 64GB iPad Air WiFi: $559 $40 off - 128GB iPad Air... Read more
Early Black Friday MacBook Air sale prices, $...
 MacMall has posted early Black Friday MacBook Air sale prices. Save $101 on all models for a limited time: - 11″ 1.4GHz/128GB MacBook Air: $798 - 11″ 1.4GHz/256GB MacBook Air: $998 - 13″ 1.4GHz/... Read more
Why iPhone 6 Tablet/Laptop Cannibalization Is...
247wallst.com blogger Douglas A. McIntyre noted last week that according to research posted on the Applovin blog site the iPhone 6 is outselling the iPhone 6 Plus by a wide margin . Hardly a surprise... Read more
Worldwide Tablet Growth Expected to Slow to 7...
The global tablet market is expected to record massive deceleration in 2014 with year-over-year growth slowing to 7.2%, down from 52.5% in 2013, according to a new forecast from International Data... Read more
Touchscreen Glove Company Announces New Produ...
Surrey, United Kingdom based TouchAbility specializes in design and manufacture of a wide variety of products compatible with touchscreen devices including smartphones, tablets and computers. Their... Read more
OtterBox Alpha Glass Screen Protectors for iP...
To complement the bigger, sharper displays on the latest Apple devices, OtterBox has introduced Alpha Glass screen protectors to the iPhone 6 and iPhone 6 Plus. The fortified glass screen protectors... Read more
Early Black Friday Mac Pro sale, 6-Core 3.5GH...
 B&H Photo has the 6-Core 3.5GHz Mac Pro on sale today for $3499 including free shipping plus NY sales tax. Their price is $500 off MSRP, and it’s the lowest price available for this model from... Read more
Early Black Friday sale price: 15-inch 2.2GHz...
 B&H Photo has the 2014 15″ 2.2GHz Retina MacBook Pro on sale today for $1699.99. Shipping is free, and B&H charges NY sales tax only. Their price is $300 off MSRP, equalling Best Buy’s price... Read more

Jobs Board

*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
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* 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* 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
*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.