[Info-vax] VMS Software Releases Roadmap Updates

[Arne Vajhøj]

On 9/28/2021 9:56 AM, Craig A. Berry wrote:
> On 9/28/21 7:44 AM, Arne Vajhøj wrote:
>> If you simply use BUILD.COM then replacing "basic" with
>> "basic/whateverswitchthecrosscompilationrequires" will probbaly
>> do.
>>
>> Of course there are work.
>>
>> But in the overall effort to add support for VMS x86-64, then
>> I will expect the effort to get cross compilation working
>> to be relative small.
> 
> You haven't seen the Perl build system, which generates a top-level
> descrip.mms from a template with substitutions to include details for
> configuration options chosen and the results of probes to see what
> features are actually working on the version/architecture of VMS on
> which it's running. Then it compiles and links a minimal version of Perl
> which is used to generate hundreds of additional descrip.mms files,
> which it then runs to generate many additional .c files and build
> additional parts of the whole package and run the test suite.
> 
> To get this to work in a cross-compile environment, you'd need to
> configure and build the minimal Perl with the native Itanium tools,
> manually edit the configuration output to look like it had been run on
> OpenVMS x86_64, switch to the cross-compile tools, and try to complete
> the build. It *might* work, for some definition of work, but would also
> probably take a lot of manual tweaking, which is one reason I haven't
> attempted it yet.  And then you couldn't run the test suite.
> 
> I do not expect any other build environment to look like the Perl build
> environment, but I do expect there are many build systems that employ
> similar bootstrapping principles and would encounter similar challenges
> in a cross-compile environment.

Maybe.

I think that everybody should strive for simple builds
and modular build tools where compiler switches is just
set one place.

But yes sometimes builds end up very complex in the real
world.

Arne