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From: normt@ihlpa.ATT.COM (N. R Tiedemann)
Newsgroups: comp.lang.fortran
Subject: Re: Can a subroutine find the name of the calling routine?
Message-ID: <3800@ihlpa.ATT.COM>
Date: Fri, 1-May-87 10:42:40 EDT
Article-I.D.: ihlpa.3800
Posted: Fri May  1 10:42:40 1987
Date-Received: Sun, 3-May-87 01:00:27 EDT
References: <13160003@acf4.UUCP>
Organization: AT&T Bell Laboratories - Naperville, Illinois
Lines: 23

In article <13160003@acf4.UUCP>, woo@acf4.UUCP (Alex C. Woo) writes:
> Is there anything comparable to getarg and iargc for subroutines
> or functions?  How can a function determine the name of the function
> which calls it or the number of calling arguments, either in C
> or f77?
> Alex Woo

	I'm not sure if this is standard or a specific implementation, but
f77 on DEC machines uses a general purpose register (r5) as the argument
pointer for both function and subroutine calls. The first thing on this 
list is the number of argument, then the address of each. The only real
different between a function and subroutine in fortran is a function returns
its value in r0. (again the r0 may be DEC specific.) I don't think there is
any way to determine the calling function short of looking at the return
address on the stack and comparing that to the loader map file, to see
in which function that address lies. Not something to do in code.

Hope this helps a little

	Norm Tiedemann		ihnp4!ihlpa!normt
	AT&T Bell Labs
	Naperville, IL
		 60566