tools lib api: Add install target

This allows libapi to be installed as a dependency.
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cmc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: bpf@vger.kernel.org
Cc: nicolas schier <nicolas@fjasle.eu>
Link: http://lore.kernel.org/lkml/20221109184914.1357295-2-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/api/Makefile

@@ -15,6 +15,16 @@ LD ?= $(CROSS_COMPILE)ld
 
 MAKEFLAGS += --no-print-directory
 
+INSTALL = install
+
+
+# Use DESTDIR for installing into a different root directory.
+# This is useful for building a package. The program will be
+# installed in this directory as if it was the root directory.
+# Then the build tool can move it later.
+DESTDIR ?=
+DESTDIR_SQ = '$(subst ','\'',$(DESTDIR))'
+
 LIBFILE = $(OUTPUT)libapi.a
 
 CFLAGS := $(EXTRA_WARNINGS) $(EXTRA_CFLAGS)
@@ -45,10 +55,23 @@ RM = rm -f
 
 API_IN := $(OUTPUT)libapi-in.o
 
+ifeq ($(LP64), 1)
+  libdir_relative = lib64
+else
+  libdir_relative = lib
+endif
+
+prefix ?=
+libdir = $(prefix)/$(libdir_relative)
+
+# Shell quotes
+libdir_SQ = $(subst ','\'',$(libdir))
+
 all:
 
 export srctree OUTPUT CC LD CFLAGS V
 include $(srctree)/tools/build/Makefile.include
+include $(srctree)/tools/scripts/Makefile.include
 
 all: fixdep $(LIBFILE)
 
@@ -58,6 +81,32 @@ $(API_IN): FORCE
 $(LIBFILE): $(API_IN)
 	$(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $(API_IN)
 
+define do_install_mkdir
+	if [ ! -d '$(DESTDIR_SQ)$1' ]; then             \
+		$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$1'; \
+	fi
+endef
+
+define do_install
+	if [ ! -d '$(DESTDIR_SQ)$2' ]; then             \
+		$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$2'; \
+	fi;                                             \
+	$(INSTALL) $1 $(if $3,-m $3,) '$(DESTDIR_SQ)$2'
+endef
+
+install_lib: $(LIBFILE)
+	$(call QUIET_INSTALL, $(LIBFILE)) \
+		$(call do_install_mkdir,$(libdir_SQ)); \
+		cp -fpR $(LIBFILE) $(DESTDIR)$(libdir_SQ)
+
+install_headers:
+	$(call QUIET_INSTALL, headers) \
+		$(call do_install,cpu.h,$(prefix)/include/api,644); \
+		$(call do_install,debug.h,$(prefix)/include/api,644); \
+		$(call do_install,io.h,$(prefix)/include/api,644);
+
+install: install_lib install_headers
+
 clean:
 	$(call QUIET_CLEAN, libapi) $(RM) $(LIBFILE); \
 	find $(or $(OUTPUT),.) -name \*.o -or -name \*.o.cmd -or -name \*.o.d | xargs $(RM)