Declare statement bug?

[Darren James]

Is this a bug or there for a reason?

It seems that if a declare statement has more than 16 arguments
the compiler will not compile it. I came across this problem
using the JacommPB interface, trying to access a word statement.

i used this test program to test my theory

DECLARE FUNCTION Test (a AS STRING, b AS STRING, c AS STRING, d AS STRING,_
e AS STRING, f AS STRING, g AS STRING, h AS STRING, _
i AS STRING, j AS STRING, k AS STRING, l AS STRING, _
m AS STRING, n AS STRING, m AS STRING, p AS STRING) AS DWORD

This Compiles fine but if I put one more argument in it doesnt

DECLARE FUNCTION Test (a AS STRING, b AS STRING, c AS STRING, d AS STRING,_
e AS STRING, f AS STRING, g AS STRING, h AS STRING, _
i AS STRING, j AS STRING, k AS STRING, l AS STRING, _
m AS STRING, n AS STRING, m AS STRING, p AS STRING, q AS STRING) AS DWORD

This gets an error 414 ")" expected.

Any Ideas?

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Darren James
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TARSC Travel Systems



[This message has been edited by Darren James (edited May 09, 2001).]

[Mark Newman]

The maximum number of arguments to a PB sub/function is 16, so
what you're seeing is correct. If you need to pass more than 16
consider using TYPE or array variables.


------------------
Mark Newman

[Darren James]

I am passing to external source, no option.

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Darren James
------------
TARSC Travel Systems

[Eric Pearson]

Darren --

> no option.

Sure there is!

Create a TYPE structure that has the same memory layout as the parameters you need to pass, and pass that instead of individual parameters.

Imagine that the DLL is sitting there expecting two LONG parameters. You could declare the function this way...

DECLARE FUNCTION ExtFunc(Param1 AS LONG, Param2 AS LONG) AS whatever

...or this way...

TYPE TwoLongs
    Param1 AS LONG
    Param2 AS LONG
END TYPE
 
DECLARE FUNCTION ExtFunc(MyStruct AS TwoLongs) AS whatever

...and the external function will never know the difference. As long as the memory structure that is passed to the DLL is correct, everything will work fine.

Depending on the calling convention you might need to build the TYPE "backwards", but it would still be very easy. And you may need to use pointers for some of the TYPE elements, but again it's fairly straightforward.

This is NOT a show stopper!

-- Eric


------------------
Perfect Sync Development Tools
Perfect Sync Web Site
Contact Us: mailto:[email protected][email protected]</A>

[Darren James]

I shall try this

Thanks

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Darren James
------------
TARSC Travel Systems

[Lance Edmonds]

PowerBASIC passes UDT's BYREF, not BYVAL, so unless you can change the library being called, that solution probably won't work for you.

The alternative is to PUSH the parameters onto the stack and call the target DLL function with CALL DWORD. Sorry I don't have any examples of using this method, but I know it has been used successfully.


------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

[Eric Pearson]

Lance --

I stand corrected. You're right of course, but I'd have sworn that I've actually done that before! Obviously not. Getting old I guess... Like Richard Pryor says, I don't have Alzheimer's, I have Some-Timers...

-- Eric


------------------
Perfect Sync Development Tools
Perfect Sync Web Site
Contact Us: mailto:[email protected][email protected]</A>



[This message has been edited by Eric Pearson (edited May 09, 2001).]

[Michael Mattias]

PowerBASIC passes UDT's BYREF, not BYVAL, so unless you can change the library being called, that solution probably won't work for you.

Well,if some parameters are BYVAL and some BYREF, you can pass addresses as DWORD UDT members.

Alternately (and I haven't tried this), if you can pass a QUAD BYVAL, you can effectively get 32 "BYVAL LONG" parameters out of 16 "BYVAL QUADs."

MCM

[Lance Edmonds]

Originally posted by Michael Mattias:
Well,if some parameters are BYVAL and some BYREF, you can pass addresses as DWORD UDT members.

I don't follow you here... passing a UDT (BYREF) means that just one 32-bit parameter (a pointer to the UDT) is passed. The content of the UDT is irrelavent as far as the stack frame is concerned (and the stack frame is where the parameters (or their pointers for BYREF's) are placed immediately before the call to the DLL/sub/function.

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

[Michael Mattias]

What I meant was if there is a structure to be passed by value, followed by additional parameter items to be passed by a mixture of reference and value.

However, I just realized the best solution to this situation is to fire the programmer and start over.

MCM

[Guest]

Darren, how many and what type variable are the parameters you need to send?
Do you have the declaration/prototype for the external function you are trying to call?

Ron

[Darren James]

This is my codethat I am calling, generated by JacomPB

DECLARE FUNCTION COMApplication_PrintOut CDECL(BYVAL pThis AS DWORD, _
BYREF Background AS VARIANT, BYREF dApp AS VARIANT, _
BYREF Range AS VARIANT, BYREF OutputFileName AS VARIANT, _
BYREF dFROM AS VARIANT, BYREF dTO AS VARIANT, _
BYREF Item AS VARIANT, BYREF Copies AS VARIANT, _
BYREF Pages AS VARIANT, BYREF PageType AS VARIANT, _
BYREF PrintToFile AS VARIANT, BYREF dCol AS VARIANT, _
BYREF dFile AS VARIANT, BYREF ActivePrinterMacGX AS VARIANT, _
BYREF ManualDuplexPrint AS VARIANT, BYREF PrintZoomColumn AS VARIANT, _
BYREF PrintZoomRow AS VARIANT, BYREF PrintZoomPaperWidth AS VARIANT, _
BYREF PrintZoomPaperHeight AS VARIANT) AS DWORD

This is the Print Declaration for Word 2000


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Darren James
------------
TARSC Travel Systems

[Lance Edmonds]

As an aside, can I ask if you have informed Philippe that JACOM/PB generates PowerBASIC code with more than 16 parameters?

Are you intending to use WORD 2000 just for printing? That would make it like the largest resource hogging printer driver in the world, by a huge factor!

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Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

[Paul Dwyer]

Jesus,

What an ugly function, At least M$ know how to use structs to keep their params down.

I'd almost go so far as to to call it a bug in the function design, yuk

------------------
Paul Dwyer
Network Engineer
Aussie in Tokyo

[Darren James]

Lance, I am unaware of Philippe email address.

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Darren James
------------
TARSC Travel Systems

[Lance Edmonds]

It should be in the JACOMPB doc's, or the About box, etc... You must have emailed him to get hold of JACOMPB, right?

Failing that, you can get his email from his site at www.jazzagesoft.com


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Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

[Darren James]

Basically we are trying to provide integration into MS Office
products from our software. We provide a Travel System, in which
users run many reports and Print many Templated letters. We want
to provide this so that our customers can tailor the look and
feel of the reports to their own needs.

Is there a reason why PB only
supports 16 arguments for a Function?

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Darren James
------------
TARSC Travel Systems

[This message has been edited by Darren James (edited May 10, 2001).]

[Darren James]

Following on from what I said above, I have only gone a little
into the Word stuff, without touching Excel. So The limit on the
number of arguments could prove to be a right pain in the neck.


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Darren James
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TARSC Travel Systems

[Lance Edmonds]

Have you tried my suggestion of pushing the parameters on the stack and calling the function with !CALL DWORD ?

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Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

[Darren James]

After much tinkering I finally got it to work using the call
DWORD Method.

Cheers Lance

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Darren James
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TARSC Travel Systems