Re: [jamboost] Header scanning change

From: Vladimir Prus (ghost_at_[hidden])
Date: 2003-10-13 00:13:31

Mark Sheppard wrote:
> I've just been debugging a problem I had with header scanning failing.
> Turned out I'd managed to delete the spaces from the regular expression
> leaving just the tabs (doh!). But while I was debugging it and working out
> what Jam was doing I made the following change so that the rule specified
> by $(HDRRULE) gets the bound name of the source/header file:
>
> --- boost-jam-3.1.4.orig/headers.c 2003-10-10 16:25:09.000000000 +0100
> +++ boost-jam-3.1.4/headers.c 2003-10-10 16:09:07.000000000 +0100
> @@ -86,7 +86,7 @@
> {
> FRAME frame[1];
> frame_init( frame );
> - lol_add( frame->args, list_new( L0, t->name ) );
> + lol_add( frame->args, list_new( L0, t->boundname ) );
> #ifdef OPT_HEADER_CACHE_EXT
> lol_add( frame->args, hcache( t, rec, re, hdrscan ) );
> #else
>
>
> This allows you to have something like this in your Jambase:
>
> rule HdrRule ( source : headers + )
> {
> if $(SEARCH) {
> SEARCH on $(headers) = $(source:D) $(SEARCH[2-]) ;
> }
> else {
> SEARCH on $(headers) = $(source:D) $(INCPATH) ;
> }
>
>
> I never use SEARCH for finding sources - I guess this would need tweaking
> if you do. Anyway my changes mean that Jam can now correctly find d.h in
> the following case:
>
> a.cpp:
> #include "b/c.h"
>
> b/c.h:
> #include "d.h"
>
> b/d.h:
> whatever

Mark,
I have two remarks.

First, I believe that V2 already handles "" includes. In fact, I believe V1 
handles them as well, since I've added that code to it a long time ago.

Second, your change is very interesting. For example, to find out the location 
of the scanned target, V2 has to store binding and later retrive it. I though 
about adding "BINDING" variable, which will be automatically set. Passing 
boundname as 'target' is an interesting idea. 

But there's a problem, though. V2, V2 and Perforce Jambase use grist on header 
targets to distinguish between different scans of the same file. And with 
your change, grist is no longer available in scanner. I'm not sure how to 
handle this.

- Volodya