Re: Adding "-C <dir>" option to runtest(1)

Ben Elliston wrote:
> On Mon, Nov 12, 2018 at 06:17:13PM -0600, Jacob Bachmeyer wrote:
>   
>> I have a few options:
>>
>> (1)  Use a different long option name, perhaps "--base-directory".
>> (2)  Add a shell script shim for the testsuite to use that changes directory
>> and invokes "runtest".
>> (3)  Allow overriding the configfile name (default "site.exp") via
>> command-line option.
>>     
> I vote for (3), even if it is only ever used by the testsuite.
>   

On further examination, runtest.exp uses $configfile to load up to three 
different files:  $base_dir/$configfile $objdir/$configfile 
$libdir/$configfile.

This suggests to me a useful distinction between "local" config files 
and "global" config files ($libdir/$configfile $DEJAGNU), and so leads 
to both --local-init and --global-init options, with --local-init 
influencing the search under $base_dir and $objdir and --global-init 
influencing the search under $libdir.  These options can stand in for 
(2), since the parameter could include "/" and the loaded file can use 
Tcl's "cd" command, since init files are sourced before logs are 
opened.  The use of the --local-init option is obvious, and 
--global-init is a simple extension from there with relevance for more 
complex testing labs.

There should be some way to inhibit loading local or global init files 
entirely; I suggest that setting --{local,global}-init to the empty 
string should do so.  Per GNU conventions, this suggests that 
--no-local-init and --no-global-init should be aliases for 
--local-init='' and --global-init='' respectively.

The "configfile" variable is defined with a comment that it is local to 
runtext.exp, so removing it should not require a deprecation period.

The distinction is that "local" init files are specific to a testsuite, 
while "global" init files are specific to a site.

The config search order would become:
    (local)     $base_dir/$local_initfile -> $objdir/$local_initfile ->
    (global)    installed($global_initfile) -> $DEJAGNU -> $HOME/.dejagnurc

As a further step, should specifying an absolute path (matches {^/}) for 
--local-init or --global-init drop the default prefix?  In this mode, 
the two local config files would be collapsed to the given 
local_initfile and the given global_initfile would be used as-is without 
prepending $libdir.

The DejaGnu testsuite would write $objdir/testsuite/runtest.all/site.exp 
and select it using "--local-init testsuite/runtest.all/site.exp"; that 
site.exp would in turn execute { cd ${objdir}/testsuite/runtest.all } or 
similar.

This is starting to look more useful than my original proposal.

-- Jacob