Re: broken build environment - explanation and fix

[Jose E. Marchesi]

> Arsen Arsenović wrote:
>> IIRC, the JITTER executable is not built in the cross case from
>> dists.  Do you know if this still work with this dependency added?
>> (i.e. run distcheck and build a cross-compiled poke from the new dist)
>
> Good point. When cross-compiling, the JITTER (= jitter/bin/jitter)
> executable does get built, but it cannot be executed:
>
> make[3]: Entering directory '/POKE/poke/build-arm64/libpoke'
> /POKE/poke/build-arm64/jitter/bin/jitter ../../libpoke/pvm.jitter --output . \
> && { test . = ../../libpoke \
>      || { mv pvm-vm.h ../../libpoke/pvm-vm.h \
>           && mv pvm-vm1.c ../../libpoke/pvm-vm1.c \
>           && mv pvm-vm2.c ../../libpoke/pvm-vm2.c; \
>         }; \
>    } \
> || { rm -f pvm-vm.h pvm-vm1.c pvm-vm2.c; false; }
> /bin/bash: line 1: /POKE/poke/build-arm64/jitter/bin/jitter: cannot execute 
> binary file: Exec format error
> make[3]: *** [Makefile:3572: generate-vm-files] Error 1
>
> So, with the patch I proposed yesterday, the ability to cross-compile
> would get lost. Here's a revised patch. It emits a
>   warning: not regenerating pvm-vm.h, pvm-vm[12].c since we are 
> cross-compiling
> instead.
>
> The warning is justified, because if pvm-vm.h, pvm-vm[12].c are outdated
> (like it was for me yesterday) we would not know, and the build might
> continue but produce broken binaries.
>
> New proposed patch is attached.

OK for master and maint/poke-3.
Thanks.

>
>>From 6f7e335ff266f9211afb6f4d63d6b76d60091844 Mon Sep 17 00:00:00 2001
> From: Bruno Haible <bruno@clisp.org>
> Date: Sun, 19 Feb 2023 00:59:28 +0100
> Subject: [PATCH] build: Regenerate pvm-vm.h, pvm-vm1.c, pvm-vm2.c when jitter
>  has changed.
>
> * libpoke/Makefile.am (generate-vm-files): When cross-compiling, don't fail,
> just emit a warning.
> (pvm-vm.h): Depend also on $(JITTER).
> ---
>  libpoke/Makefile.am | 27 +++++++++++++++++----------
>  1 file changed, 17 insertions(+), 10 deletions(-)
>
> diff --git a/libpoke/Makefile.am b/libpoke/Makefile.am
> index 7e256cf7..a16049c2 100644
> --- a/libpoke/Makefile.am
> +++ b/libpoke/Makefile.am
> @@ -225,19 +225,26 @@ MAINTAINERCLEANFILES += $(srcdir)/pvm-vm.h 
> $(srcdir)/pvm-vm1.c $(srcdir)/pvm-vm2
>  # <https://lists.gnu.org/archive/html/bug-make/2020-09/msg00008.html>, so 
> that
>  # it works also in parallel 'make'.
>  generate-vm-files:
> -     $(JITTER) $(srcdir)/pvm.jitter --output $(builddir) \
> -     && { test $(builddir) = $(srcdir) \
> -          || { mv pvm-vm.h $(srcdir)/pvm-vm.h \
> -               && mv pvm-vm1.c $(srcdir)/pvm-vm1.c \
> -               && mv pvm-vm2.c $(srcdir)/pvm-vm2.c; \
> -             }; \
> -        } \
> -     || { rm -f pvm-vm.h pvm-vm1.c pvm-vm2.c; false; }
> +     if $(JITTER) --help >/dev/null 2>/dev/null; then \
> +       $(JITTER) $(srcdir)/pvm.jitter --output $(builddir) \
> +       && { test $(builddir) = $(srcdir) \
> +            || { mv pvm-vm.h $(srcdir)/pvm-vm.h \
> +                 && mv pvm-vm1.c $(srcdir)/pvm-vm1.c \
> +                 && mv pvm-vm2.c $(srcdir)/pvm-vm2.c; \
> +               }; \
> +          } \
> +       || { rm -f pvm-vm.h pvm-vm1.c pvm-vm2.c; false; }; \
> +     else \
> +       echo "warning: not regenerating pvm-vm.h, pvm-vm[12].c since we are 
> cross-compiling" 1>&2; \
> +     fi
>  .PHONY: generate-vm-files
>  # The above rule will generate files with time-stamp order
>  # pvm.jitter <= pvm-vm.h <= pvm-vm1.c <= pvm-vm2.c
> -pvm-vm.h: pvm.jitter
> -     @{ test -f $(srcdir)/pvm-vm.h && test ! $(srcdir)/pvm-vm.h -ot 
> $(srcdir)/pvm.jitter; } || $(MAKE) generate-vm-files
> +pvm-vm.h: pvm.jitter $(JITTER)
> +     @{ test -f $(srcdir)/pvm-vm.h \
> +        && test ! $(srcdir)/pvm-vm.h -ot $(srcdir)/pvm.jitter \
> +        && test ! $(srcdir)/pvm-vm.h -ot $(JITTER); \
> +     } || $(MAKE) generate-vm-files
>  pvm-vm1.c: pvm-vm.h
>       @{ test -f $(srcdir)/pvm-vm1.c && test ! $(srcdir)/pvm-vm1.c -ot 
> $(srcdir)/pvm-vm.h; } || $(MAKE) generate-vm-files
>  pvm-vm2.c: pvm-vm1.c