Re: Dependency flaw in cons (and scons) ?

[Brad Garcia]

On Mon, 25 Feb 2002, Johan Holmberg wrote:

> On Mon, 25 Feb 2002, Frank Thomas wrote:
> >
> > The question is how much of the filename you'd like to take.
> 
> If the "logical path" (ie. the relative path within the repository)
> was used, wouldn't that be OK ?

Well, there's also the cons cache to consider.  Logical path might still
be ok, but I haven't convinced myself of that yet.  If anybody else has
thoughts, please share them.

I'm not really concerned by Johan's example of two different Command
invocations.  Especially since, in his example, the target filename
is part of the command line, and therefore I believe it doesn't
demonstrate the problem.  And even when the command line does not contain
the target filename, if the command is the same, then the output will
be the same, even if it is placed in a different file.  So I think that
example is a non-issue.

But single commands that have multiple targets do concern me.  We
could add relative pathnames to the signature calculation.  I can't
currently think of any better way to solve the problem.

I don't like the idea that the build signature will change if I simply
change the name of one of the target files.  Maybe its a moot point,
since you'd probably have to change the command line to get a different
output filename.

But, I will continue arguing with myself ;^).

I would rather have a build signature that changes along with the target
filename than to have all of the targets get the same build signature.
Having multiple targets with the same build signature would be Very Bad
for the cache, right?  Or does the cache already take filename into
account?

Brad Garcia