Generate libraries with correct DT_NEEDED entries

Libraries that depend on other libraries should list them in ELF's
DT_NEEDED field so that programs linking to them do not need to specify
those libraries unless they depend on them as well. This is not the case
in the current code and the consequence is that anything that needs a
library must know its dependencies. This is fragile and caused GRUB2's
configure script to break when a dependency was added on libblkid in
libzfs.

This resolves that problem by using LIBADD/LDADD to specify libraries in
Makefile.am instead of LDFLAGS. This ensures that proper DT_NEEDED
entries are generated and prevents GRUB2's configure script from
breaking in the presence of a libblkid dependency. This also removes
unneeded dependencies from various files.

Signed-off-by: Richard Yao <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Issue #1751

8 files changed, 7 insertions, 11 deletions

diff --git a/cmd/mount_zfs/Makefile.am b/cmd/mount_zfs/Makefile.am
index 7abcc30c1..74524f031 100644
--- a/cmd/mount_zfs/Makefile.am
+++ b/cmd/mount_zfs/Makefile.am
@@ -20,5 +20,4 @@ mount_zfs_LDADD = \
 	$(top_builddir)/lib/libzpool/libzpool.la \
 	$(top_builddir)/lib/libzfs/libzfs.la
 
-mount_zfs_LDFLAGS = \
-	-pthread -lm $(ZLIB) -lrt -ldl $(LIBUUID) $(LIBBLKID) $(LIBSELINUX)
+mount_zfs_LDADD += $(LIBSELINUX)
diff --git a/cmd/zdb/Makefile.am b/cmd/zdb/Makefile.am
index f82f1a3b5..49dbf50bc 100644
--- a/cmd/zdb/Makefile.am
+++ b/cmd/zdb/Makefile.am
@@ -16,4 +16,4 @@ zdb_LDADD = \
 	$(top_builddir)/lib/libzpool/libzpool.la \
 	$(top_builddir)/lib/libzfs/libzfs.la
 
-zdb_LDFLAGS = -pthread -lm $(ZLIB) -lrt -ldl $(LIBUUID) $(LIBBLKID)
+zdb_LDADD += $(ZLIB)
diff --git a/cmd/zfs/Makefile.am b/cmd/zfs/Makefile.am
index c1499a2a8..08580c92d 100644
--- a/cmd/zfs/Makefile.am
+++ b/cmd/zfs/Makefile.am
@@ -19,4 +19,5 @@ zfs_LDADD = \
 	$(top_builddir)/lib/libzfs/libzfs.la \
 	$(top_builddir)/lib/libzfs_core/libzfs_core.la
 
-zfs_LDFLAGS = -pthread -lm $(ZLIB) -lrt -ldl $(LIBUUID) $(LIBBLKID)
+zfs_LDADD += $(ZLIB)
+zfs_LDFLAGS = -pthread
diff --git a/cmd/zhack/Makefile.am b/cmd/zhack/Makefile.am
index 47da2453e..944e64257 100644
--- a/cmd/zhack/Makefile.am
+++ b/cmd/zhack/Makefile.am
@@ -15,4 +15,4 @@ zhack_LDADD = \
 	$(top_builddir)/lib/libzpool/libzpool.la \
 	$(top_builddir)/lib/libzfs/libzfs.la
 
-zhack_LDFLAGS = -pthread -lm $(ZLIB) -lrt -ldl $(LIBUUID) $(LIBBLKID)
+zhack_LDADD += $(ZLIB)
diff --git a/cmd/zinject/Makefile.am b/cmd/zinject/Makefile.am
index d1d32d57f..f53956911 100644
--- a/cmd/zinject/Makefile.am
+++ b/cmd/zinject/Makefile.am
@@ -16,5 +16,3 @@ zinject_LDADD = \
 	$(top_builddir)/lib/libuutil/libuutil.la \
 	$(top_builddir)/lib/libzpool/libzpool.la \
 	$(top_builddir)/lib/libzfs/libzfs.la
-
-zinject_LDFLAGS = -pthread -lm $(ZLIB) -lrt -ldl $(LIBUUID) $(LIBBLKID)
diff --git a/cmd/zpool/Makefile.am b/cmd/zpool/Makefile.am
index 2ce8efc5c..e7d31c60c 100644
--- a/cmd/zpool/Makefile.am
+++ b/cmd/zpool/Makefile.am
@@ -18,5 +18,3 @@ zpool_LDADD = \
 	$(top_builddir)/lib/libuutil/libuutil.la \
 	$(top_builddir)/lib/libzpool/libzpool.la \
 	$(top_builddir)/lib/libzfs/libzfs.la
-
-zpool_LDFLAGS = -pthread -lm $(ZLIB) -lrt -ldl $(LIBUUID) $(LIBBLKID)
diff --git a/cmd/zstreamdump/Makefile.am b/cmd/zstreamdump/Makefile.am
index 3d7ec4124..175874ffa 100644
--- a/cmd/zstreamdump/Makefile.am
+++ b/cmd/zstreamdump/Makefile.am
@@ -15,4 +15,4 @@ zstreamdump_LDADD = \
 	$(top_builddir)/lib/libzpool/libzpool.la \
 	$(top_builddir)/lib/libzfs/libzfs.la
 
-zstreamdump_LDFLAGS = -pthread -lm $(ZLIB) -lrt -ldl $(LIBUUID) $(LIBBLKID)
+zstreamdump_LDADD += $(ZLIB)
diff --git a/cmd/ztest/Makefile.am b/cmd/ztest/Makefile.am
index 39892013a..403b858c4 100644
--- a/cmd/ztest/Makefile.am
+++ b/cmd/ztest/Makefile.am
@@ -17,4 +17,4 @@ ztest_LDADD = \
 	$(top_builddir)/lib/libzpool/libzpool.la \
 	$(top_builddir)/lib/libzfs/libzfs.la
 
-ztest_LDFLAGS = -pthread -lm $(ZLIB) -lrt -ldl $(LIBUUID) $(LIBBLKID)
+ztest_LDADD += -lm -ldl