Re: VPATH and prerequisites

[Joost Leeuwesteijn]

Paul D. Smith wrote:
> %% Joost Leeuwesteijn <address@hidden> writes:
>
>   jl> You can check if make is run from the root directory by including a 
>   jl> first/default rule in the dir1 makefile that stops the build. Something 
>   jl> like:
>   jl> ----------------------------------------
>   jl> .PHONY : dir1_default_rule
>   jl> dir1_default_rule :
>   jl>       echo "ERROR: only run the toplevel makefile"
>   jl>       <not sure what's the best way to bail out (exit 1?, $$(error ...)>
>
>   jl> and/or check on a variable that must be set by the toplevel makefile and 
>   jl> call $(error ...)
>   jl> ----------------------------------------
>
> You could instead check the MAKELEVEL variable to see whether this is
> the top-level make, or a recursive invocation.

If you also want to rule out the single (sub)makefile "execution" you 
can't use MAKELEVEL, I believe. If you run 'make -f submakefile' the 
MAKELEVEL would still indicate toplevel make (right?), but I was trying 
to force execution of the toplevel makefile only. By bailing out in the 
default rule, or checking a variable that should be set by the toplevel 
makefile before including the submakefiles. If you execute the 
submakefile on it's own, I need to bail out because of variables that 
are supposed to be set from the toplevel makefile.

I was talking about the include situation, not recursion. My build 
environment doesn't use recursion; seems to be harmful ;-)

Regards,
Joost