avoid recompiling dll every time under mingw

diff --git a/lib/Makefile b/lib/Makefile
index cf8e45b0f0523a0a5ea51438ec504083f749ccc0..70fb649f79227dd97988df56b9004ca20c28e4ea 100644 (file)
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -94,8 +94,6 @@ else
        SHARED_EXT_VER = $(SHARED_EXT).$(LIBVER)
 endif
 
-LIBZSTD = libzstd.$(SHARED_EXT_VER)
-
 
 .PHONY: default all clean install uninstall
 
@@ -111,19 +109,28 @@ libzstd.a: $(ZSTD_OBJ)
 libzstd.a-mt: CPPFLAGS += -DZSTD_MULTITHREAD
 libzstd.a-mt: libzstd.a
 
-$(LIBZSTD): LDFLAGS += -shared -fPIC -fvisibility=hidden
+ifneq (,$(filter Windows%,$(OS)))
+
+LIBZSTD = dll\libzstd.dll
 $(LIBZSTD): $(ZSTD_FILES)
        @echo compiling dynamic library $(LIBVER)
-ifneq (,$(filter Windows%,$(OS)))
-       @$(CC) $(FLAGS) -DZSTD_DLL_EXPORT=1 -shared $^ -o dll\libzstd.dll
-       dlltool -D dll\libzstd.dll -d dll\libzstd.def -l dll\libzstd.lib
+       @$(CC) $(FLAGS) -DZSTD_DLL_EXPORT=1 -shared $^ -o $@
+       dlltool -D $@ -d dll\libzstd.def -l dll\libzstd.lib
+
 else
+
+LIBZSTD = libzstd.$(SHARED_EXT_VER)
+$(LIBZSTD): LDFLAGS += -shared -fPIC -fvisibility=hidden
+$(LIBZSTD): $(ZSTD_FILES)
+       @echo compiling dynamic library $(LIBVER)
        @$(CC) $(FLAGS) $^ $(LDFLAGS) $(SONAME_FLAGS) -o $@
        @echo creating versioned links
        @ln -sf $@ libzstd.$(SHARED_EXT_MAJOR)
        @ln -sf $@ libzstd.$(SHARED_EXT)
+
 endif
 
+
 libzstd : $(LIBZSTD)
 
 libzstd-mt : CPPFLAGS += -DZSTD_MULTITHREAD