[PATCH 04/13] trace-cmd: Add versioning to libtracecmd.so

[Steven Rostedt <rostedt@goodmis.org>]

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

In preparation to installing libtracecmd.so as a system library, it is
required that it has a versioning in the name. Add three levels:

 LIBTC_VERSION : The main version level that is updated on breakage of apiS
 LIBTC_PATCHLEVEL: That is updated for new functionality
 LIBTC_EXTRAVERSION: That is updated for minor bug fixes

The main .so binary will have the full version which includes:

 libtracecmd.so.$(LIBTC_VERSION).$(LIBTC_PATCHLEVEL).$(LIBTC_EXTRAVERSION)

Then soft links will be created to this as follows:

 libtracecmd.so -> libtracecmd.so.$(LIBTC_VERSION)
 libtracecmd.so.$(LIBTC_VERSION) ->
      libtracecmd.so.$(LIBTC_VERSION).$(LIBTC_PATCHLEVEL).$(LIBTC_EXTRAVERSION)

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 Makefile               | 14 ++++++++++++--
 lib/trace-cmd/Makefile | 19 +++++++++++++++++--
 2 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/Makefile b/Makefile
index 8edd217b87b5..ea07e9ee7081 100644
--- a/Makefile
+++ b/Makefile
@@ -10,6 +10,16 @@ export TC_PATCHLEVEL
 export TC_EXTRAVERSION
 export TRACECMD_VERSION
 
+LIBTC_VERSION = 0
+LIBTC_PATCHLEVEL = 0
+LIBTC_EXTRAVERSION = 1
+LIBTRACECMD_VERSION = $(LIBTC_VERSION).$(LIBTC_PATCHLEVEL).$(LIBTC_EXTRAVERSION)
+
+export LIBTC_VERSION
+export LIBTC_PATCHLEVEL
+export LIBTC_EXTRAVERSION
+export LIBTRACECMD_VERSION
+
 MAKEFLAGS += --no-print-directory
 
 # Makefiles suck: This macro sets a default value of $(2) for the
@@ -200,7 +210,7 @@ LIBTRACEEVENT_SHARED = $(LIBTRACEEVENT_DIR)/libtraceevent.so
 
 LIBTRACECMD_DIR = $(obj)/lib/trace-cmd
 LIBTRACECMD_STATIC = $(LIBTRACECMD_DIR)/libtracecmd.a
-LIBTRACECMD_SHARED = $(LIBTRACECMD_DIR)/libtracecmd.so
+LIBTRACECMD_SHARED = $(LIBTRACECMD_DIR)/libtracecmd.so.$(LIBTRACECMD_VERSION)
 
 LIBTRACEFS=libtracefs
 LIBTRACEFS_DIR = $(obj)/lib/tracefs
@@ -347,7 +357,7 @@ $(LIBTRACECMD_STATIC): force
 	$(Q)$(MAKE) -C $(src)/lib/trace-cmd $@
 
 $(LIBTRACECMD_SHARED): force $(LIBTRACEEVENT_SHARED_BUILD)
-	$(Q)$(MAKE) -C $(src)/lib/trace-cmd $@
+	$(Q)$(MAKE) -C $(src)/lib/trace-cmd libtracecmd.so
 
 $(LIBTRACEFS_STATIC): force
 	$(Q)$(MAKE) -C $(src)/lib/tracefs $@
diff --git a/lib/trace-cmd/Makefile b/lib/trace-cmd/Makefile
index 42f1f5c447eb..ec68831de610 100644
--- a/lib/trace-cmd/Makefile
+++ b/lib/trace-cmd/Makefile
@@ -40,7 +40,19 @@ $(LIBTRACECMD_STATIC): $(OBJS)
 
 LIBS = -L$(obj)/lib/traceevent -ltraceevent
 
-$(bdir)/libtracecmd.so: $(OBJS)
+LIBTRACECMD_SHARED_VERSION = $(shell echo $(LIBTRACECMD_SHARED) | sed -e 's/\(\.so\.[0-9]*\).*/\1/')
+
+LIBTRACECMD_SHARED_SO = $(shell echo $(LIBTRACECMD_SHARED) | sed -e 's/\(\.so\).*/\1/')
+
+$(LIBTRACECMD_SHARED_VERSION): $(LIBTRACECMD_SHARED)
+	@ln -sf $(<F) $@
+
+$(LIBTRACECMD_SHARED_SO): $(LIBTRACECMD_SHARED_VERSION)
+	@ln -sf $(<F) $@
+
+libtracecmd.so: force $(LIBTRACECMD_SHARED_SO)
+
+$(LIBTRACECMD_SHARED): $(OBJS)
 	$(Q)$(call do_compile_shared_library)
 
 $(bdir)/%.o: %.c
@@ -58,6 +70,9 @@ ifneq ($(dep_includes),)
 endif
 
 clean:
-	$(RM) $(bdir)/*.a $(bdir)/*.so $(bdir)/*.o $(bdir)/.*.d
+	$(RM) $(bdir)/*.a $(bdir)/*.so $(bdir)/*.so.* $(bdir)/*.o $(bdir)/.*.d
 
 .PHONY: clean
+
+PHONY += force
+force:
-- 
2.29.2