Re: [jamboost] Dependencies & generated headers

From: Vladimir Prus (ghost_at_[hidden])
Date: 2002-09-10 08:12:07

David Abrahams wrote:

>>2. Make sure a.cpp depends on "a_parser.h". This can be quite simply
>>accomplished if the dependency scanner
>>will check is there's intermediate file called "a_parser.h" in the
>>dependency graph for the given main target.
> 
> 
> I don't understand why this is so complicated. It already works in
> Boost.Build v1.
> Why would we need to check for intermediate files?
> It just puts a_parser.h in the dependency graph and sets SEARCH
> appropriately so it can be found.

Suppose a clean build. There's no a_parser.h on disk. In dependency 
scanner, you set a dependency to a_parser.h and set SEARCH to a lot of
directories. When creating real targets from virtual targets, you create
another target called "a_parser.h" and set LOCATE to some dir. However, 
there's no relation between those two targets. Jam can try to compile
a.cpp before it generated a_parser.h.

Maybe V1 used dependency on "first" to work this around?

- Volodya