mk: add .so name versioning, resolves #32

Makefile

@@ -8,6 +8,7 @@
 VER_MAJOR := 1
 VER_MINOR := 1
 VER_PATCH := 0
+VER_ABI   := 1
 
 PROJECT   := re
 VERSION   := $(VER_MAJOR).$(VER_MINOR).$(VER_PATCH)
@@ -47,9 +48,14 @@ INCDIR  := $(PREFIX)/include/re
 MKDIR   := $(PREFIX)/share/re
 CFLAGS	+= -Iinclude
 
-MODMKS	:= $(patsubst %,src/%/mod.mk,$(MODULES))
-SHARED  := libre$(LIB_SUFFIX)
-STATIC	:= libre.a
+MODMKS         := $(patsubst %,src/%/mod.mk,$(MODULES))
+SHARED         := libre$(LIB_SUFFIX)
+SHARED_SONAME  := libre$(LIB_SUFFIX).$(VER_ABI)
+STATIC         := libre.a
+
+ifeq ($(OS),linux)
+SH_LFLAGS      += -Wl,-soname,$(SHARED_SONAME)
+endif
 
 include $(MODMKS)
 
@@ -109,7 +115,12 @@ install: $(SHARED) $(STATIC) libre.pc
 		$(DESTDIR)$(INCDIR) $(DESTDIR)$(MKDIR)
 	$(INSTALL) -m 0644 $(shell find include -name "*.h") \
 		$(DESTDIR)$(INCDIR)
+ifeq ($(OS),linux)
+	$(INSTALL) -m 0755 $(SHARED) $(DESTDIR)$(LIBDIR)/$(SHARED_SONAME)
+	cd $(DESTDIR)$(LIBDIR) && ln -sf $(SHARED_SONAME) $(SHARED)
+else
 	$(INSTALL) -m 0755 $(SHARED) $(DESTDIR)$(LIBDIR)
+endif
 	$(INSTALL) -m 0755 $(STATIC) $(DESTDIR)$(LIBDIR)
 	$(INSTALL) -m 0644 libre.pc $(DESTDIR)$(LIBDIR)/pkgconfig
 	$(INSTALL) -m 0644 $(MK) $(DESTDIR)$(MKDIR)
@@ -118,6 +129,7 @@ uninstall:
 	@rm -rf $(DESTDIR)$(INCDIR)
 	@rm -rf $(DESTDIR)$(MKDIR)
 	@rm -f $(DESTDIR)$(LIBDIR)/$(SHARED)
+	@rm -f $(DESTDIR)$(LIBDIR)/$(SHARED_SONAME)
 	@rm -f $(DESTDIR)$(LIBDIR)/$(STATIC)
 	@rm -f $(DESTDIR)$(LIBDIR)/pkgconfig/libre.pc