tools build: Allow duplicate objects in the object list
It's sometimes useful to specify the object affiliation to multiple
config options like:
libperf-$(CONFIG_X86) += tsc.o
libperf-$(CONFIG_AUXTRACE) += tsc.o
while the object itself is linked only once. Adding the support for this
and ignoring duplicate objects in the object list.
Suggested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20150826130103.GF22670@krava.redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/build/Documentation/Build.txt b/tools/build/Documentation/Build.txt
index 00ad2d6..aa5e092 100644
--- a/tools/build/Documentation/Build.txt
+++ b/tools/build/Documentation/Build.txt
@@ -66,6 +66,7 @@
ex/Build:
ex-y += a.o
ex-y += b.o
+ ex-y += b.o # duplicates in the lists are allowed
libex-y += c.o
libex-y += d.o
diff --git a/tools/build/Makefile.build b/tools/build/Makefile.build
index 8120af9..0c5f485 100644
--- a/tools/build/Makefile.build
+++ b/tools/build/Makefile.build
@@ -63,7 +63,7 @@
# If there's nothing to link, create empty $@ object.
quiet_cmd_ld_multi = LD $@
cmd_ld_multi = $(if $(strip $(obj-y)),\
- $(LD) -r -o $@ $(obj-y),rm -f $@; $(AR) rcs $@)
+ $(LD) -r -o $@ $(filter $(obj-y),$^),rm -f $@; $(AR) rcs $@)
# Build rules
$(OUTPUT)%.o: %.c FORCE
diff --git a/tools/build/tests/ex/Build b/tools/build/tests/ex/Build
index 70d8762..429c7d4 100644
--- a/tools/build/tests/ex/Build
+++ b/tools/build/tests/ex/Build
@@ -1,6 +1,7 @@
ex-y += ex.o
ex-y += a.o
ex-y += b.o
+ex-y += b.o
ex-y += empty/
ex-y += empty2/