#797: Eliminate need to expand Makefile variables in parrot_config and other
external programs
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Reporter: jkeenan | Owner: jkeenan
Type: RFC | Status: assigned
Priority: normal | Milestone:
Component: configure | Version: 1.3.0
Severity: medium | Keywords: configure makefile
Lang: | Patch:
Platform: all |
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Comment(by doughera):
Replying to [comment:3 jkeenan]:
> More specifically, should it be our goal to '''eliminate all conditional
determination''' of configuration values from the ''Makefile''?
That's probably not worth the effort. Things like
> {{{ #IF(darwin):export DYLD_LIBRARY_PATH :=
@blib_dir@:$(DYLD_LIBRARY_PATH) }}}
are relatively simple, straightforward, and easy to understand.
> Why, for instance, do we need code like this in
''config/gen/makefiles/root.in'':
{{{
> LIBPARROT_STATIC := @blib_dir@/@libparrot_static@
> #IF(win32):LIBPARROT_SHARED := @libparrot_shared@
> #ELSE:LIBPARROT_SHARED := @blib_dir@/@libparrot_shared@
}}}
I know of no compelling reason. The variables "libparrot_static" and
"libparrot_shared" aren't really documented that well (i.e. are they
supposed to include the path or not?) so you end up with the confusing
situation here where LIBPARROT_STATIC includes the path, but the almost-
identically-named libparrot_static does not. Either is reasonable.
> By the second-to-last configuration step, don't we already know what OS
we're on?
Yes, we certainly do.
> Moreover, if it is ''make'' that has the last word on, ''e.g.,'' what
the value of `libparrot` is,
{{{
> # This line controls whether a static or shared library is built
> LIBPARROT := @libparrot@
}}}
I don't see a problem with this. Perhaps if the variable were named {{{
libparrot_target_for_makefile_in_the_build_directory_but_useless_otherwise
}}} then it would be obvious that it's not intended to be used outside of
the build directory main makefile. As it is, it has a name that makes it
look like it might be something useful to know, and there's no
documentation to tell you otherwise.
> ... then none of the generated files or compiled programs which depend
on values stored in ''lib/Parrot/Config/Generated.pm'' or
''config_lib.pasm'' would '''ever''' contain or have available to it the
final values -- as ''make'' determines those values after those two files
have been created by ''Configure.pl''?
But I don't see why any of those generated files need to care either.
That variable is only intended for use as a {{{ Makefile }}} target in the
build directory. Outside of that context, it is useless and irrelevant.
I don't see anything wrong with "fixing" it, but I don't see much of a
point either. I suspect effort could be better spent documenting
parrot_config variables so it's clearer which ones are worth worrying
about in an installed parrot and which ones aren't.
--
Ticket URL: <https://trac.parrot.org/parrot/ticket/797#comment:5>
Parrot <https://trac.parrot.org/parrot/>
Parrot Development
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