perf pmu-events: Make pmu-events a library

Make pmu-events into a library so it may be linked against things like
the python module and not built from source.
Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: James Clark <james.clark@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Gary Guo <gary@garyguo.net>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Cc: Ze Gao <zegao2021@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andrei Vagin <avagin@google.com>
Cc: Yicong Yang <yangyicong@hisilicon.com>
Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: Björn Roy Baron <bjorn3_gh@protonmail.com>
Cc: Andreas Hindborg <a.hindborg@samsung.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240625214117.953777-4-irogers@google.com

tools/perf/Makefile.perf

@@ -428,11 +428,14 @@ export PERL_PATH
 LIBPERF_UI_IN := $(OUTPUT)perf-ui-in.o
 LIBPERF_UI := $(OUTPUT)libperf-ui.a
 
+LIBPMU_EVENTS_IN := $(OUTPUT)pmu-events/pmu-events-in.o
+LIBPMU_EVENTS := $(OUTPUT)libpmu-events.a
+
 PERFLIBS = $(LIBAPI) $(LIBPERF) $(LIBSUBCMD) $(LIBSYMBOL)
 ifdef LIBBPF_STATIC
   PERFLIBS += $(LIBBPF)
 endif
-PERFLIBS += $(LIBPERF_UI)
+PERFLIBS += $(LIBPERF_UI) $(LIBPMU_EVENTS)
 
 # We choose to avoid "if .. else if .. else .. endif endif"
 # because maintaining the nesting to match is a pain.  If
@@ -721,8 +724,6 @@ strip: $(PROGRAMS) $(OUTPUT)perf
 	$(STRIP) $(STRIP_OPTS) $(PROGRAMS) $(OUTPUT)perf
 
 PERF_IN := $(OUTPUT)perf-in.o
-
-PMU_EVENTS_IN := $(OUTPUT)pmu-events/pmu-events-in.o
 export NO_JEVENTS
 
 build := -f $(srctree)/tools/build/Makefile.build dir=. obj
@@ -730,18 +731,21 @@ build := -f $(srctree)/tools/build/Makefile.build dir=. obj
 $(PERF_IN): prepare FORCE
 	$(Q)$(MAKE) $(build)=perf
 
-$(PMU_EVENTS_IN): FORCE prepare
+$(LIBPMU_EVENTS_IN): FORCE prepare
 	$(Q)$(MAKE) -f $(srctree)/tools/build/Makefile.build dir=pmu-events obj=pmu-events
 
+$(LIBPMU_EVENTS): $(LIBPMU_EVENTS_IN)
+	$(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $<
+
 $(LIBPERF_UI_IN): FORCE prepare
 	$(Q)$(MAKE) $(build)=perf-ui
 
 $(LIBPERF_UI): $(LIBPERF_UI_IN)
 	$(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $<
 
-$(OUTPUT)perf: $(PERFLIBS) $(PERF_IN) $(PMU_EVENTS_IN)
+$(OUTPUT)perf: $(PERFLIBS) $(PERF_IN)
 	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) \
-		$(PERF_IN) $(PMU_EVENTS_IN) $(LIBS) -o $@
+		$(PERF_IN) $(LIBS) -o $@
 
 $(GTK_IN): FORCE prepare
 	$(Q)$(MAKE) $(build)=gtk