Re: Does $^ preserve the order of the prerequisites?

[Peng Yu]

On Wed, Jan 27, 2010 at 3:30 AM, Oleksandr Gavenko <address@hidden> wrote:
> On 2010.01.25 17:41, Peng Yu wrote:
>>
>> target: a b c d
>>   some_command_whose_argument_order_mattters a b c d
>>
>> Suppose I have the above rule, I want to reduce it to the following.
>> But I'm wondering if $^  preserve the order of the prerequisites.
>> Could somebody let me know?
>>
>> target: a b c d
>>   some_command_whose_argument_order_mattters $^
>>
> From info make "10.5.3 Automatic Variables":
>
> $^
>    The names of all the prerequisites, with spaces between them. For
> prerequisites which are archive members, only the member named is used (see
> Archives). A target has only one prerequisite on each other file it depends
> on, no matter how many times each file is listed as a prerequisite. So if
> you list a prerequisite more than once for a target, the value of $^
> contains just one copy of the name. This list does not contain any of the
> order-only prerequisites; for those see the `$|' variable, below.
>
>
> $|
>    The names of all the order-only prerequisites, with spaces between them.

I read the explanations before I posted the original. But they are not
clear to as there is no definition on what "order-only" mean? Does it
mean that $^ does not necessarily preserve the order but $| does?
Also, I suggest to revise the explanation to make it clear.