Re: [XEN PATCH] libs: Fix unstable libs build on FreeBSD, auto-generate version-script

[Jan Beulich <jbeulich@xxxxxxxx>]

On 15.02.2023 16:21, Anthony PERARD wrote:
> @@ -13,6 +14,10 @@ MAJOR := $(shell $(XEN_ROOT)/version.sh 
> $(XEN_ROOT)/xen/Makefile)
>  endif
>  MINOR ?= 0
>  
> +ifeq ($(origin version-script), undefined)
> +version-script := libxen$(LIBNAME).map.tmp
> +endif

Such a use of $(origin ...) is pretty fragile. Maybe better use ?= ?

> @@ -72,6 +77,10 @@ headers.lst: FORCE
>       @{ set -e; $(foreach h,$(LIBHEADERS),echo $(h);) } > $@.tmp
>       @$(call move-if-changed,$@.tmp,$@)
>  
> +libxen$(LIBNAME).map.tmp: FORCE
> +     echo 'VERS_$(MAJOR).$(MINOR) { global: *; };' >.$@.tmp
> +     $(call move-if-changed,.$@.tmp,$@)

Isn't this going to get in the way of your "build everything from root"
effort, where $@ will include a path? Also do we really need .tmp.tmp
files?

>  lib$(LIB_FILE_NAME).a: $(OBJS-y)

Seeing this right adjacent in context - any reason you use libxen$(LIBNAME)
and not the same lib$(LIB_FILE_NAME) for the base file name?

> @@ -120,7 +129,7 @@ TAGS:
>  clean::
>       rm -rf $(TARGETS) *~ $(DEPS_RM) $(OBJS-y) $(PIC_OBJS)
>       rm -f lib$(LIB_FILE_NAME).so.$(MAJOR).$(MINOR) 
> lib$(LIB_FILE_NAME).so.$(MAJOR)
> -     rm -f headers.chk headers.lst
> +     rm -f headers.chk headers.lst libxen*.map.tmp

If I hadn't checked, I'd have assumed that *.tmp are removed without
being named explicitly. So yes, I see the need for the addition, but then
I wonder why you don't also remove the .*.tmp.tmp file, which may be left
around if the build is interrupted at exactly the "right" time.

Jan