-frecord-marker

[Brooks Moses]

Keith Bennett wrote:
> On Thu, Jul 20, 2006, Adrian Umpleby wrote:
>>I just think that the possibility of specifying per-unit record marker formats is very useful.
>>(Clearly so, since I can't actually do what I want with just -frecord-marker as it stands at the
>>moment.)
> 
> Maybe, but you would also be able to do what you want if -frecord-marker
> worked at compile-time for non-main objects. I think that's the real fix
> for this problem. (I know - easier said than done!)

I don't see that as preferable to Adrian's suggestion, for a couple of 
reasons.  Consider, for the sake of argument, a small program which 
reads in a file with one marker format, and writes it immediately back 
out with a different format.

First, a critical part of the program behavior is in what record-marker 
format it uses when it opens the files.  Adrian's suggestion puts this 
information in the source code, with the OPEN statement, where it's 
relevant; this ensures that it's clear to someone reading the code, and 
will always be done correctly.  Keith's suggestion puts the information 
in the command line when the compiler is called, which is separate from 
the code and is only saved at all if one's using some form of makefile 
or the equivalent.  I think that this makes a very dramatic difference 
in the long-term maintainability of the code.

Second, suppose that a file is opened in a program unit that is compiled 
with one -frecord_marker setting, and then the unit number is passed to 
another program unit (compiled with a different setting) which reads 
from it.  While the obviously-correct functionality here is that the 
record marker format for a file should be set at the time it is opened, 
and that that should persist even if it is accessed in a program unit 
compiled with a different record marker format, I do not think the 
syntax makes it at all clear to the user that this is what will actually 
happen in practice.

I think it's also worth noting that Adrian's suggestion, at least in 
syntax, allows for the posibility of selecting the marker type at runtime.

- Brooks