[Omake] error when defining a rule inside of a function

[Aleksey Nogin]

On 13.01.2007 12:06, Erick Tryzelaar wrote:

> Erick Tryzelaar wrote:
>> Hmm, this led me to a stack overflow, with this OMakefile:
> 
> Here's a smaller file that still has the Stack_overflow:
> 
> OMakefile:
> comflags(sources) =
>    return $(sources)
> 
> make-rule(target, sources) =
>    $(target):
>        echo $(comflags $(sources))
>    return $(target)
> 
> .DEFAULT: $(make-rule cmain, foo)

The issues are:
  - The "rule" function is being applied lazily (so that it can be 
overwritten later).
  - A lazy application of a function causes all the arguments to be 
evaluated lazily as well (IMO this is a bug, although I am not sure 
whether Jason would agree - I've filed 
http://bugzilla.metaprl.org/show_bug.cgi?id=628 on this one).
  - Because of is, the comflags function gets called with sources set to 
$`(sources) instead of "foo", which results in an infinite loop when 
trying to evaluate "return $(sources)".

See the above Bugzilla URL for some additional detail. Note that in this 
example, if you alpha-rename the "sources" argument variable in one of 
the functions so that the two do not clash, the problem will go away. 
You can also work around this by explicitly making the call to comflags 
eager by either using the $,(comflags ...) syntax or by using an 
intermediate variable, like you did.

Aleksey