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Conference bulova::decw_jan-89_to_nov-90

Title:	DECWINDOWS 26-JAN-89 to 29-NOV-90
Notice:	See 1639.0 for VMS V5.3 kit; 2043.0 for 5.4 IFT kit
Moderator:	STAR::VATNE

Created:	Mon Oct 30 1989
Last Modified:	Mon Dec 31 1990
Last Successful Update:	Fri Jun 06 1997
Number of topics:	3726
Total number of notes:	19516

529.0. "MACRO Problem(s)" by BOOTIS::BAILEY (The Pursuit Of _Knowledge_) Tue Apr 04 1989 08:36

Any idea what I doing wrong here ???

I'am trying to call  QueryTree from macro, the program (extract below)
complies and links fine, but gives me a 

%SYSTEM-F-ACCVIO, access violation, reason mask=04, virtual address=00000000, 
PC=000918A7, PSL=03C000002

when it calls  QueryTree, The Window & Display Id's returned look
fine to me (the Window ID is the same as shown by one of the Tree display
programs from the Examples Conf)


; Open the display connection to the DECwindows server
	pushl	#0			;display name is NULL
	calls	#1,g^XOpenDisplay	;open the display connnection
	movl	R0,Display		;save screen number



	pushl	Display			; display argument
	calls	#1,g^XDefaultScreen	; get default screen number
	movl	R0,Screen		; save it


	pushl	Screen			; screen number
	pushl	Display			; display
	calls	#2,g^XRootWindow	; get root window
	movl	R0,Window		; save it


	pushal	window			
	pushal	display
	calls	#2,g^XQueryTree


The Complie/Link command  was

$ mac  'p1'+xlibdef/lib+xlibdef/lib
$ link 'p1',sys$input/opt
        sys$share:decw$xlibshr/share





Any idea whats wong



Peter  (I must get on a C course)   Bailey

T.R	Title	User	Personal Name	Date	Lines
529.1	There are no optional arguments	STAR::BRANDENBERG	Intelligence - just a good party trick?	`Tue Apr 04 1989 11:02`	12
	Can't say as I can read this macro stuff but :-) ... you have two problems. First, XQueryTree's display and window arguments are pass-by-value not pass-by-reference so replace pushal with pushl. Second, XQueryTree has six arguments, not two and short changing this call isn't going to make you friends. Add the remaining arguments (root_return, parent_return, children_return, and nchildren_return {all by reference}). m
529.2	It Works, It Works hahahaha	BOOTIS::BAILEY	The Pursuit Of _Knowledge_	`Tue Apr 04 1989 11:53`	18
	>you have two problems. First, XQueryTree's display and window >arguments are pass-by-value not pass-by-reference so replace Well acording to my manual all the arguments are pass-by-reference > . Second, XQueryTree has six arguments, not > two and short changing this call isn't going to make you friends. Again acording to my manual you must give display & window_id but the others are 'vax only optional' Having said that if I do it as suggested it seems to work Thanks for the answers (thought I was cracking up :-)
529.3		STAR::BRANDENBERG	Intelligence - just a good party trick?	`Tue Apr 04 1989 12:10`	12
	Remember, there are two bindings: C and VAX. The example you gave used C bindings called from Macro so I assumed that's what you wanted. Your comments suggest you meant to use the VAX bindings, easily recognizable by that Americentic character: '$'. I suppose I could agree that an argument like XQueryTree( Display *display ... ) is pass-by-reference ( display.mr.r ) but the way it is used in an application is more of an address passed by value ( display.ra.v ) and that's why I say pass-by-value. m
529.4		LESLIE::LESLIE	Andy �� Leslie, CSSE	`Tue Apr 04 1989 12:31`	3
	If the documentation is unclear, I suggest you submit a QAR and/or post a note in BULOVA::VMS_DOCUMENTATION....
529.5		BOOTIS::BAILEY	The Pursuit Of _Knowledge_	`Tue Apr 04 1989 16:23`	14
	> Remember, there are two bindings: C and VAX. The example you gave used > C bindings called from Macro so I assumed that's what you wanted. Your _no_ what I WANTED to do was get my head straight before coding, take 1000 lines.... read the documentation before coding Thanks for the help (I think I'am going to need all the help I can get) Ta Peb