Re: Is it possible to break from a GMAKE foreach loop and then exit from make?

[Pierre Rouleau]

On Sun, May 29, 2022 at 12:09 PM Paul Smith <psmith@gnu.org> wrote:

> On Sun, 2022-05-29 at 11:50 -0400, Pierre Rouleau wrote:
> > On Sat, May 28, 2022 at 2:11 AM Kaz Kylheku <kaz@kylheku.com> wrote:
> > > What you probably want is to generate clauses joined by &&
> > >
> > >   $(foreach ....) --> patch < this && patch < that && ... && patch
> > > < last
> > >
> > > You mean unroll the loop manually?
> > Unfortunately the file I'm dealing with is part of a *large* build
> > system with over 2000 make file, with make recursion and multi-layer
> > decision making  that end up building the list of patch files,
> > storing it inside a variable.
> >
> > Are you also saying that adding `|| exit 1' to the statement inside
> > the foreach loop would not work?
> > ie as in:
> >         (cd $(OUTPUT_ROOT_DIR)/$(CFG_GLOBAL_LINUX_VERSION); $(foreach
> > thepatch,$(KERNEL_PATCH_ONE),echo patching $(thepatch); patch
> > --ignore-whitespace -p1 < $(thepatch) || exit 1;))
>
> It will work.  It's simple to test so did you try it and it didn't work
> and that's why you're asking?
>

I did try and it worked, but since I could not find documentation on it I
wanted to double check.
I must say I find debugging large makefile sets difficult.


>
> But I don't understand why the method Kaz suggests wouldn't work.  If
> you can change the loop to add "|| exit 1;" after each patch command
> why can't you change the loop to add "&&" between each patch command?
>

I can, I just misunderstood Kaz reply.


> It would be something like:
>
>   $(foreach p,$(KERNEL_PATCH_ONE),echo patching $p && patch ... < $p &&)
> true
>
> The advantage of the "&&" is that your script is shorter which means
> you'll be less likely to run into a limit for lots of patches (although
> the limits in modern POSIX systems are pretty large).
>
> In what sense is the script shorter?
Is it not the same as with  the ; separator except that it acts as a logic
AND?

> In the end do you mean that all I could do is prepend the rule with
> > `set -e; ' and that would ensure termination on the first error?
> > As in:
> >          set -e; (cd $(OUTPUT_ROOT_DIR)/$(CFG_GLOBAL_LINUX_VERSION);
> > $(foreach thepatch,$(KERNEL_PATCH_ONE),echo patching $(thepatch);
> > patch
> > --ignore-whitespace -p1 < $(thepatch)))
>
> You need a semicolon after the patch command but yes, this will work as
> well.
>
Correct, I should have kept it in there.

Thanks

-- 
/Pierre