| Message ID | 20200524154235.380482-10-masahiroy@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | modpost: various fixes, cleanups, optimizations | expand |
On Mon, May 25, 2020 at 12:43 AM Masahiro Yamada <masahiroy@kernel.org> wrote: > > $(firstword ...) in scripts/Makefile.modpost was added by commit > 3f3fd3c05585 ("[PATCH] kbuild: allow multi-word $M in Makefile.modpost") > to build multiple external module directories. > > It was a solution to resolve symbol dependencies when an external > module depends on another external module. > > Commit 0d96fb20b7ed ("kbuild: Add new Kbuild variable > KBUILD_EXTRA_SYMBOLS") introduced another solution by passing symbol > info via KBUILD_EXTRA_SYMBOLS, then broke the multi-word M= support. > > include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \ > $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile) > > ... does not work if KBUILD_EXTMOD contains multiple words. > > This feature has been broken for more than a decade. Remove the > bitrotten code, and stop parsing if M or KBUILD_EXTMOD contains > multiple words. > > As Documentation/kbuild/modules.rst explains, if your module depends > on another one, there are two solutions: > - add a common top-level Kbuild file > - use KBUILD_EXTRA_SYMBOLS > > Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> This patch, applied to linux-kbuild. > --- > > Changes in v2: > - Add more commit log > > Makefile | 3 +++ > scripts/Makefile.modpost | 2 +- > 2 files changed, 4 insertions(+), 1 deletion(-) > > diff --git a/Makefile b/Makefile > index 72eb55a36545..48a2dfaf3bf3 100644 > --- a/Makefile > +++ b/Makefile > @@ -218,6 +218,9 @@ ifeq ("$(origin M)", "command line") > KBUILD_EXTMOD := $(M) > endif > > +$(if $(word 2, $(KBUILD_EXTMOD)), \ > + $(error building multiple external modules is not supported)) > + > export KBUILD_CHECKSRC KBUILD_EXTMOD > > extmod-prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/) > diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost > index 957eed6a17a5..b79bf0e30d32 100644 > --- a/scripts/Makefile.modpost > +++ b/scripts/Makefile.modpost > @@ -44,7 +44,7 @@ include include/config/auto.conf > include scripts/Kbuild.include > > kernelsymfile := $(objtree)/Module.symvers > -modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers > +modulesymfile := $(KBUILD_EXTMOD)/Module.symvers > > MODPOST = scripts/mod/modpost \ > $(if $(CONFIG_MODVERSIONS),-m) \ > -- > 2.25.1 >
diff --git a/Makefile b/Makefile index 72eb55a36545..48a2dfaf3bf3 100644 --- a/Makefile +++ b/Makefile @@ -218,6 +218,9 @@ ifeq ("$(origin M)", "command line") KBUILD_EXTMOD := $(M) endif +$(if $(word 2, $(KBUILD_EXTMOD)), \ + $(error building multiple external modules is not supported)) + export KBUILD_CHECKSRC KBUILD_EXTMOD extmod-prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/) diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost index 957eed6a17a5..b79bf0e30d32 100644 --- a/scripts/Makefile.modpost +++ b/scripts/Makefile.modpost @@ -44,7 +44,7 @@ include include/config/auto.conf include scripts/Kbuild.include kernelsymfile := $(objtree)/Module.symvers -modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers +modulesymfile := $(KBUILD_EXTMOD)/Module.symvers MODPOST = scripts/mod/modpost \ $(if $(CONFIG_MODVERSIONS),-m) \
$(firstword ...) in scripts/Makefile.modpost was added by commit 3f3fd3c05585 ("[PATCH] kbuild: allow multi-word $M in Makefile.modpost") to build multiple external module directories. It was a solution to resolve symbol dependencies when an external module depends on another external module. Commit 0d96fb20b7ed ("kbuild: Add new Kbuild variable KBUILD_EXTRA_SYMBOLS") introduced another solution by passing symbol info via KBUILD_EXTRA_SYMBOLS, then broke the multi-word M= support. include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \ $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile) ... does not work if KBUILD_EXTMOD contains multiple words. This feature has been broken for more than a decade. Remove the bitrotten code, and stop parsing if M or KBUILD_EXTMOD contains multiple words. As Documentation/kbuild/modules.rst explains, if your module depends on another one, there are two solutions: - add a common top-level Kbuild file - use KBUILD_EXTRA_SYMBOLS Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> --- Changes in v2: - Add more commit log Makefile | 3 +++ scripts/Makefile.modpost | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-)