Re: [UNIKRAFT PATCH 1/3] build: Support multiple symbol export files

["felipehuici ." <felipehuici@xxxxxxxxx>]

Reviewed-by: Felipe Huici <felipe.huici@xxxxxxxxx>

On Wed, Apr 8, 2020 at 2:11 AM Simon Kuenzer <simon.kuenzer@xxxxxxxxx> wrote:
>
> Adds support that `$(LIBNAME_EXPORTS)` can contain a list of symbol
> export files instead of only a single one. In order to simplify
> writing of `Makefile.uk` files, a `$(LIBNAME_EXPORTS-y)` variant is
> provided, too. With this variant, export symbols can be dependent to
> library configuration, for example:
>  LIBNAME_EXPORTS-$(CONFIG_MYLIB_EXTENDEDABI) += extendedsyms.uk
> Having this feature, library symbols can be masked even without the
> existence of a single `exportsyms.uk` file: Because of this, this
> patch removes the "missing exportsyms.uk"-warning. In the case an
> `exportsyms.uk` file exists for a library, it is still automatically
> included and used: The previous behavior is preserved.
>
> Signed-off-by: Simon Kuenzer <simon.kuenzer@xxxxxxxxx>
> ---
>  support/build/Makefile.rules | 13 +++++--------
>  1 file changed, 5 insertions(+), 8 deletions(-)
>
> diff --git a/support/build/Makefile.rules b/support/build/Makefile.rules
> index af08f830..384f24f0 100644
> --- a/support/build/Makefile.rules
> +++ b/support/build/Makefile.rules
> @@ -189,7 +189,7 @@ $(call mk_sub_build_dir,$(1))
>  UK_LIBS += $(1)
>  $(eval $(call uc,$(1))_BASE    := $(_IMPORT_BASE))
>  $(eval $(call uc,$(1))_BUILD   := $(BUILD_DIR)/$(1))
> -$(eval $(call uc,$(1))_EXPORTS := $(_IMPORT_BASE)/exportsyms.uk)
> +$(eval $(call uc,$(1))_EXPORTS += $(wildcard $(_IMPORT_BASE)/exportsyms.uk))
>  endef
>
>  # addlib_s $libname,$switch
> @@ -206,7 +206,7 @@ $(eval $(call uc,$(2))_PLATS   += $(call uc,$(1)))
>  $(eval $(call uc,$(1))_LIBS    += $(2))
>  $(eval $(call uc,$(2))_BASE    := $(_IMPORT_BASE))
>  $(eval $(call uc,$(2))_BUILD   := $(BUILD_DIR)/$(2))
> -$(eval $(call uc,$(2))_EXPORTS := $(_IMPORT_BASE)/exportsyms.uk)
> +$(eval $(call uc,$(2))_EXPORTS += $(wildcard $(_IMPORT_BASE)/exportsyms.uk))
>  endef
>
>  # addplatlib_s $platname,$libname,$switch
> @@ -718,10 +718,6 @@ endef
>
>  # buildrule_olib $libname
>  define buildrule_olib =
> -$(if $(wildcard $($(call vprefix_lib,$(1),EXPORTS))),,\
> -       $(call verbose_info,Warning: Definition of exported symbols for $(1) 
> missing: $($(call vprefix_lib,$(1),EXPORTS))) \
> -)
> -
>  $(call libname2preolib,$(1)): $($(call vprefix_lib,$(1),OBJS)) \
>                               $($(call vprefix_lib,$(1),OBJS-y)) \
>                               $($(call vprefix_lib,$(1),ALIBS)) \
> @@ -742,9 +738,10 @@ $(call libname2preolib,$(1)): $($(call 
> vprefix_lib,$(1),OBJS)) \
>                       -Wl$(comma)--end-group \
>                       -o $(call libname2preolib,$(1)))
>
> -$(call libname2olib,$(1)): $(call libname2preolib,$(1)) $(if $(wildcard 
> $($(call vprefix_lib,$(1),EXPORTS))),$($(call vprefix_lib,$(1),EXPORTS)),)
> +$(call libname2olib,$(1)): $(call libname2preolib,$(1)) \
> +                          $($(call vprefix_lib,$(1),EXPORTS)) $($(call 
> vprefix_lib,$(1),EXPORTS-y)) \
>         $(call build_cmd,OBJCOPY,,$(call libname2olib,$(1)),\
> -               $(OBJCOPY) $(if $(wildcard $($(call 
> vprefix_lib,$(1),EXPORTS))),--keep-global-symbols=$($(call 
> vprefix_lib,$(1),EXPORTS)),) \
> +               $(OBJCOPY) $(addprefix --keep-global-symbols=,$($(call 
> vprefix_lib,$(1),EXPORTS)) $($(call vprefix_lib,$(1),EXPORTS-y))) \
>                            $(OBJCFLAGS) $(OBJCFLAGS-y) \
>                            $($(call vprefix_lib,$(1),OBJCFLAGS)) $($(call 
> vprefix_lib,$(1),OBJCFLAGS-y)) \
>                            $(call libname2preolib,$(1)) $(call 
> libname2olib,$(1)))
> --
> 2.20.1
>
>