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

Viber 6.5.5 - 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, so... Read more
Opera 42.0.2393.137 - High-performance W...
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
iClock Pro 3.4.7 - Customize your menuba...
iClock Pro is a menu bar replacement clock for Apple's default clock. iClock Pro is an update, total rewrite and improvement to the popular iClock. Have the day, date and time in different fonts and... Read more
PhotoDesk 4.1.5 - Instagram client for p...
PhotoDesk lets you view, like, comment, and download Instagram pictures/videos. (NO Uploads! / Image Posting! Instagram forbids that! AND you need an existing Instagram account). But you can do so... Read more
Capo 3.5.1 - Slow down and learn to play...
Capo lets you slow down your favorite songs so you can hear the notes and learn how they are played. With Capo, you can quickly tab out your songs atop a highly-detailed OpenCL-powered spectrogram... Read more
HandBrake 1.0.2 - Versatile video encode...
HandBrake is a tool for converting video from nearly any format to a selection of modern, widely supported codecs. Features Supported Sources VIDEO_TS folder, DVD image or real DVD (unencrypted... Read more
Sound Studio 4.8.6 - Robust audio record...
Sound Studio lets you easily record and professionally edit audio on your Mac. Easily rip vinyls and digitize cassette tapes, or record lectures and voice memos. Prepare for live shows with live... Read more
HandBrake 1.0.2 - Versatile video encode...
HandBrake is a tool for converting video from nearly any format to a selection of modern, widely supported codecs. Features Supported Sources VIDEO_TS folder, DVD image or real DVD (unencrypted... Read more
PhotoDesk 4.1.5 - Instagram client for p...
PhotoDesk lets you view, like, comment, and download Instagram pictures/videos. (NO Uploads! / Image Posting! Instagram forbids that! AND you need an existing Instagram account). But you can do so... Read more
Sound Studio 4.8.6 - Robust audio record...
Sound Studio lets you easily record and professionally edit audio on your Mac. Easily rip vinyls and digitize cassette tapes, or record lectures and voice memos. Prepare for live shows with live... Read more

Super Mario Run dashes onto Android in M...
Super Mario Run was one of the biggest mobile launches in 2016 before it was met with a lukewarm response by many. While the game itself plays a treat, it's pretty hard to swallow the steep price for the full game. With that said, Android users... | Read more »
WarFriends Beginner's Guide: How to...
Chillingo's new game, WarFriends, is finally available world wide, and so far it's a refreshing change from common mobile game trends. The game's a mix of tower defense, third person shooter, and collectible card game. There's a lot to unpack here... | Read more »
Super Gridland (Entertainment)
Super Gridland 1.0 Device: iOS Universal Category: Entertainment Price: $1.99, Version: 1.0 (iTunes) Description: Match. Build. Survive. "exquisitely tuned" - Rock Paper Shotgun No in-app purches, and no ads! | Read more »
Red's Kingdom (Games)
Red's Kingdom 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: Mad King Mac has kidnapped your father and stolen your golden nut! Solve puzzles and battle goons as you explore and battle your... | Read more »
Turbo League Guide: How to tame the cont...
| Read more »
Fire Emblem: Heroes coming to Google Pla...
Nintendo gave us our first look at Fire Emblem: Heroes, the upcoming mobile Fire Emblem game the company hinted at last year. Revealed at the Fire Emblem Direct event held today, the game will condense the series' tactical RPG combat into bite-... | Read more »
ReSlice (Music)
ReSlice 1.0 Device: iOS Universal Category: Music Price: $9.99, Version: 1.0 (iTunes) Description: Audio Slice Machine Slice your audio samples with ReSlice and create flexible musical atoms which can be triggered by MIDI notes or... | Read more »
Stickman Surfer rides in with the tide t...
Stickson is back and this time he's taken up yet another extreme sport - surfing. Stickman Surfer is out this Thursday on both iOS and Android, so if you've been following the other Stickman adventures, you might be interested in picking this one... | Read more »
Z-Exemplar (Games)
Z-Exemplar 1.4 Device: iOS Universal Category: Games Price: $3.99, Version: 1.4 (iTunes) Description: | Read more »
5 dastardly difficult roguelikes like th...
Edmund McMillen's popular roguelike creation The Binding of Isaac: Rebirth has finally crawled onto mobile devices. It's a grotesque dual-stick shooter that tosses you into an endless, procedurally generated basement as you, the pitiable Isaac,... | Read more »

Price Scanner via MacPrices.net

Roundup of 15-inch Touch Bar MacBook Pro sale...
B&H Photo has the new 2016 15″ Apple Touch Bar MacBook Pros in stock today and on sale for up to $150 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 15″ 2.7GHz Touch Bar... Read more
Apple refurbished iPad Pros available for up...
Apple has Certified Refurbished 9″ and 12″ Apple iPad Pros available for up to $160 off the cost of new iPads. An Apple one-year warranty is included with each model, and shipping is free: - 32GB 9″... Read more
16GB iPad Air 2, Apple refurbished, available...
Apple has Certified Refurbished 16GB iPad Air 2s available for $319 including free shipping. A standard Apple one-year is included. Their price is $60 off original MSRP for this model. Read more
Apple iMacs on sale for up to $120 off MSRP
B&H Photo has 21″ and 27″ Apple iMacs on sale for up to $120 off MSRP, each including free shipping plus NY sales tax only: - 27″ 3.3GHz iMac 5K: $2199 $100 off MSRP - 27″ 3.2GHz/1TB Fusion iMac... Read more
Apple refurbished Apple TVs available for up...
Apple has Certified Refurbished 32GB and 64GB Apple TVs available for up to $30 off the cost of new models. Apple’s standard one-year warranty is included with each model, and shipping is free: -... Read more
Save up to $350 with Apple Certified Refurbis...
Apple has Certified Refurbished 2015 21″ & 27″ iMacs available for up to $350 off MSRP. Apple’s one-year warranty is standard, and shipping is free. The following models are available: - 21″ 3.... Read more
2015 12-inch Retina MacBooks, Apple refurbish...
Apple has Certified Refurbished 2015 12″ Retina MacBooks available for up to $410 off original MSRP. Apple will include a standard one-year warranty with each MacBook, and shipping is free. The... Read more
Apple offering Certified Refurbished Series 1...
Apple is now offering Certified Refurbished Series 1 and Series 2 Apple Watches for 14-16% off MSRP, starting at $229. An Apple one-year warranty is included with each watch. Shipping is free: Series... Read more
12-inch 1.2GHz Space Gray Retina MacBook on s...
Amazon has the 2016 12″ 1.2GHz/512GB Space Gray Retina MacBook (Apple model #MLH82LL/A) on sale for $1299.99 including free shipping. Their price is $300 off MSRP. Read more
Twelve South Releases RelaxedLeather Cases fo...
Inspired by the laid-back luxury of burnished leather boots and crafted in rich tones of taupe, herb and marsala, RelaxedLeather cases deliver smart, easy protection for the iPhone 7. Each genuine... Read more

Jobs Board

*Apple* macOS Systems Integration Administra...
…most exceptional support available in the industry. SCI is seeking an Junior Apple macOS systems integration administrator that will be responsible for providing Read more
*Apple* Retail - Multiple Positions- Deer Pa...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Technician - nfrastructure (United S...
Let’s Work Together Apple Technician This position is based in Portland, ME Life at nfrastructure At nfrastructure, we understand that our success results from our Read more
*Apple* Mobile Master - Best Buy (United Sta...
**467692BR** **Job Title:** Apple Mobile Master **Location Number:** 000602-Columbia MO-Store **Job Description:** **What does a Best Buy Apple Mobile Master Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.