Add SOVERSION and properly name library filename

We should be a good citizen, and properly name our libraries on-disk and
within the shared library, where appropriate

src/Make.inc

@@ -22,16 +22,32 @@ ifneq (,$(findstring MINGW,$(OS))$(findstring MSYS,$(OS))$(findstring CYGWIN,$(O
   OS := WINNT
 endif
 
+LBT_SOVERSION_MAJOR := 4
+LBT_SOVERSION_MINOR := 1
+LBT_SOVERSION_PATCH := 0
+
 ifeq ($(OS), WINNT)
   SHLIB_EXT := dll
   EXE := .exe
   binlib := bin
+
+  LIB_FULL_VERSION := libblastrampoline-$(LBT_SOVERSION_MAJOR)-$(LBT_SOVERSION_MINOR)-$(LBT_SOVERSION_PATCH).dll
+  LIB_MAJOR_VERSION := libblastrampoline-$(LBT_SOVERSION_MAJOR).dll
+  SONAME_FLAG :=
 else ifeq ($(OS), Darwin)
   SHLIB_EXT := dylib
   binlib := lib
+
+  LIB_FULL_VERSION := libblastrampoline.$(LBT_SOVERSION_MAJOR).$(LBT_SOVERSION_MINOR).$(LBT_SOVERSION_PATCH).dylib
+  LIB_MAJOR_VERSION := libblastrampoline.$(LBT_SOVERSION_MAJOR).dylib
+  SONAME_FLAG := -Wl,-install_name=@rpath/$(LIB_FULL_VERSION)
 else
   SHLIB_EXT := so
   binlib := lib
+
+  LIB_FULL_VERSION := libblastrampoline.so.$(LBT_SOVERSION_MAJOR).$(LBT_SOVERSION_MINOR).$(LBT_SOVERSION_PATCH)
+  LIB_MAJOR_VERSION := libblastrampoline.so.$(LBT_SOVERSION_MAJOR)
+  SONAME_FLAG := -Wl,-soname=$(LIB_FULL_VERSION)
 endif
 
 LBT_CFLAGS := -g -O2 -std=c99 -fPIC -DLIBRARY_EXPORTS -D_GNU_SOURCE $(CFLAGS)

src/Makefile

@@ -31,19 +31,26 @@ $(builddir)/trampolines/%.o: trampolines/%.S exported_funcs.inc | $(builddir)/tr
 dump-trampolines: trampolines/trampolines_$(ARCH).S
 	$(CC) $< -S | sed -E 's/ ((%%)|;) /\n/g' | sed -E 's/.global/\n.global/g'
 
-$(builddir)/libblastrampoline.$(SHLIB_EXT): $(MAIN_OBJS)
-	@$(call PRINT_CC,$(CC) -o $@ $(call IMPLIB_FLAGS,$@) $(LBT_CFLAGS) $^ -shared $(LBT_LDFLAGS))
+
+$(builddir)/$(LIB_FULL_VERSION): $(MAIN_OBJS)
+	@$(call PRINT_CC,$(CC) -o "$@" $(call IMPLIB_FLAGS,$@) $(LBT_CFLAGS) $^ -shared $(LBT_LDFLAGS))
+
+$(builddir)/$(LIB_MAJOR_VERSION): | $(builddir)/$(LIB_FULL_VERSION)
+	ln -sf "$(LIB_FULL_VERSION)" "$@"
+
+$(builddir)/libblastrampoline.$(SHLIB_EXT): | $(builddir)/$(LIB_MAJOR_VERSION)
+	ln -sf "$(LIB_MAJOR_VERSION)" "$@"
 
 # Install both libraries and our headers
 install: $(builddir)/libblastrampoline.$(SHLIB_EXT)
 	@mkdir -p $(prefix)/include/libblastrampoline
 	-@cp -Ra $(LBT_ROOT)/include/* $(prefix)/include/libblastrampoline
 	@cp -a $(LBT_ROOT)/src/libblastrampoline.h $(prefix)/include/
 	@mkdir -p $(prefix)/$(binlib)
-	@cp -a $(builddir)/libblastrampoline.$(SHLIB_EXT) $(prefix)/$(binlib)
+	@cp -a $(builddir)/libblastrampoline*$(SHLIB_EXT)* $(prefix)/$(binlib)/
 ifeq ($(OS),WINNT)
 	@mkdir -p $(prefix)/lib
-	@cp -a $(builddir)/libblastrampoline.$(SHLIB_EXT).a $(prefix)/lib
+	@cp -a $(builddir)/$(LIB_FULL_VERSION).a $(prefix)/lib
 endif
 
 clean: