Re: Antwort: Re: Feature request: meta files & wildcards (once again)

[Ralf Corsepius]

Am Die, 2002-05-07 um 10.26 schrieb Alex Hornby:
> On Mon, 2002-05-06 at 06:30, Tom Tromey wrote:
> > Nowadays we could probably implement pattern rules purely in automake.
> > Back in the old days we didn't have the machinery to allow this.
> > Automake itself was too primitive.  But now it would be more possible,
> > if someone were motivated.  Maybe this would help with the
> > longstanding CORBA problems?
> > 
> > Tom
> 
> Hi Tom,
> 
> Certainly would. The problem I had with suffix rules, was that one
> invocation of the idl compiler on one .idl file expands into many .h and
> .cpp files, therefore I needed a suffix rule for each product. So far so
> good, but when I do a parallel build the rules then race each other and
> overwrite each others products (as the compiler always writes all
> files), which can be bad if the compiler is reading one of those files
> at the time..
> 
> My solution is to wrap a locking script around the suffix rules so that
> any one .idl file only has the idl compiler run on it once.
> 
> I guess if automake was to do the pattern->suffix rule conversion itself
> it would ship with such a script (in a similar way to the packaging of
> depcomp etc), and use it to protect the generated rules against parallel
> builds.
An alternative approach could be (I have no clue about CORBA) to
implement a stamp-file mechanism encapsulated into suffix-rules. 

I.e. to let all generated sources depend on this stamp file instead of
the original source file they are generated from and to let generation
of the stamp-file generate the sources as side-effects of generating the
stamp-file.
(A similar approach is applied to generating *infos from *.texi)

Ralf