Where did Configure.pl option '--cxx' go to?

[jkeenan]

In Configure.pl, we have command-line option cxx documented as follows:

       "--cxx=(compiler)"
           Specify which C++ compiler to use (for ICU).

In lib/Parrot/Configure/Options/Conf.pm, we have this:

   --cxx=(compiler)     Use the given C++ compiler

And cxx is an element of @Parrot::Configure::Options::Conf::Shared::shared_valid_options.

But I can no longer find any place in the configuration system where the value provided to --cxx gets assigned to anything in the data part of the Parrot::Configure object. Hence, it never appears in lib/Parrot/Config/Generated.pm or config_lib.pir (except in the entries for configure_args).

$> perl  Configure.pl --cxx=abc
$> grep -nE '(abc|cxx)' lib/Parrot/Config/Generated.pm
102:  'configure_args' => '"--cxx=abc"'

Didn't we used to be able to assign our choice of C++ compiler to cxx? If so, does anyone know why we can do so no longer? Or when this option slipped away?

Thank you very much.

kid51

[jkeenan]

$>  make realclean
$>  perl Configure.pl
$>  mv lib/Parrot/Config/Generated.pm ~/learn/parrot/no.cxx.Generated.pm
$>  make realclean
$>  perl Configure.pl --cxx=foobar
$>  mv lib/Parrot/Config/Generated.pm ~/learn/parrot/foobar.cxx.Generated.pm
$>  cd ~/learn/parrot
$>  diff -w no.cxx.Generated.pm foobar.cxx.Generated.pm
100c100
<   'configdate' => 'Fri Feb 11 02:51:48 2011 GMT',
---
>   'configdate' => 'Fri Feb 11 02:52:49 2011 GMT',
102c102
<   'configure_args' => '',
---
>   'configure_args' => '"--cxx=foobar"',

So you might think you're selecting a C++ compiler to use during make, but you aren't.

[coke]

--cxx was originally used when we had to build ICU because it was
internal to parrot.

I am fairly certain that it serves no purpose these days.

(This is different from passing in a c++ compiler to --cc)

[doughera]

On Fri, 11 Feb 2011, Parrot wrote:

> #2004: Where did Configure.pl option '--cxx' go to?

The option was removed in TT #1457.

The C++ option used to serve at least two main purposes:

1.  Parrot used to bundle ICU, which required a C++ compiler to build.

2.  Extensions or embedded programs that work with C++ code or libraries 
might need a C++ compiler compatible with the compiler used to compile 
parrot.  The -cxx option offered a way to specify the appropriate C++ 
compiler.  Perl 5's Configure does not include such an option, and does 
not select a C++ compiler.  It is left to extensions to guess at an 
appropriate one, which has caused all sorts of difficulties.  Seeking to 
avoid that mistake, Parrot offered the option of specifying a working C++ 
compiler.

-- 
    Andy Dougherty		doughera@lafayette.edu

[jkeenan]

Coke, Andy: Thanks. I guess the patch applied in TT #1457 didn't cover all instances of cxx. I'll try to root out the remaining ones.

Thank you very much.

kid51

[jkeenan]

Replying to jkeenan:

Coke, Andy: Thanks. I guess the patch applied in TT #1457 didn't cover all instances of cxx. I'll try to root out the remaining ones.

commit 9dadd29: Per TT #2004: Remove remaining references to former '--cxx' option to Configure.pl.

I didn't touch references under the ports/ directory, but took care of the others -- including translations of the README!

Closing ticket. Thank you very much.

[doughera]

On Fri, 11 Feb 2011, Parrot wrote:

>  Coke, Andy:  Thanks.  I guess the patch applied in TT #1457 didn't cover
>  all instances of `cxx`.  I'll try to root out the remaining ones.

Well, as I tried to say above, I think the option still served a useful 
purpose, and removing it in TT #1457 was a mistake.  But, I shan't pursue 
it any further.

-- 
    Andy Dougherty		doughera@lafayette.edu

[jkeenan]

Replying to doughera:

Well, as I tried to say above, I think the option still served a useful purpose, and removing it in TT #1457 was a mistake. But, I shan't pursue it any further.

Umm, Andy, if you reopened the ticket and deleted the 'fixed' resolution, then, by definition, you are pursuing it further. :-)

Re-inserting it as a command-line option, and then making sure it gets into (first) the Parrot::Configure object and (then) the Makefile, %PConfig, etc. would be relatively easy. But where exactly would it be used in the configuration system?

(It was --cxx's non-use in the configuration system that caught my attention in this ticket. I personally don't have a vested interest one way or the other, as long as we're consistent about its inclusion/exclusion.)

As the other Andy would say, "Patches welcome!"

Thank you very much.

kid51

[doughera]

Replying to jkeenan:

Umm, Andy, if you reopened the ticket and deleted the 'fixed' resolution, then, by definition, you are pursuing it further. :-)

I didn't, or at least I didn't intend to. Apparently the email-to-ticket system "helpfully" did that without my knowledge or consent. This time, I'm going in directly through Trac, and I'll reclose it.

Re-inserting it as a command-line option, and then making sure it gets into (first) the Parrot::Configure object and (then) the Makefile, %PConfig, etc. would be relatively easy. But where exactly would it be used in the configuration system?

It wouldn't. It would simply be a place to record the C++ compiler that might be used by a hypothetical future someone embedding or extending parrot in a project that involved C++ code.

As the other Andy would say, "Patches welcome!"

(I thought that was my line!) Anyway, I already wrote the patch once -- it was commit c528c234cd400c7fcb7019c8e1270e40913e778b.