Add a build intermediary lib for zstd

This add a new build intermediary libzstd. This allows us to keep zstd
cleanly separated from libzpool and to override the frame-size compiler
option without for zstd only. (This is needed due to unused coude in
the unmodified zstd source.)

Signed-off-by: Michael Niewöhner <foss@mniewoehner.de>

configure.ac

@@ -155,6 +155,7 @@ AC_CONFIG_FILES([
 	lib/libzfs/libzfs_core.pc
 	lib/libzfs_core/Makefile
 	lib/libzpool/Makefile
+	lib/libzstd/Makefile
 	lib/libzutil/Makefile
 	man/Makefile
 	man/man1/Makefile

lib/Makefile.am

@@ -2,6 +2,9 @@
 # These six libraries are intermediary build components.
 SUBDIRS = libavl libefi libicp libshare libspl libtpool libzutil libunicode
 
+# zstd intermediary build component
+SUBDIRS += libzstd
+
 # These four libraries, which are installed as the final build product,
 # incorporate the six convenience libraries given above.
 SUBDIRS += libuutil libnvpair libzpool libzfs_core libzfs

lib/libzpool/Makefile.am

@@ -196,7 +196,8 @@ libzpool_la_LIBADD = \
 	$(top_builddir)/lib/libicp/libicp.la \
 	$(top_builddir)/lib/libnvpair/libnvpair.la \
 	$(top_builddir)/lib/libunicode/libunicode.la \
-	$(top_builddir)/lib/libzutil/libzutil.la
+	$(top_builddir)/lib/libzutil/libzutil.la \
+	$(top_builddir)/lib/libzstd/libzstd.la
 
 libzpool_la_LIBADD += $(ZLIB) -ldl
 libzpool_la_LDFLAGS = -pthread -version-info 2:0:0

lib/libzstd/Makefile.am

@@ -0,0 +1,45 @@
+include $(top_srcdir)/config/Rules.am
+
+VPATH = \
+	$(top_srcdir)/contrib/zstd \
+	$(top_srcdir)/contrib/zstd/common \
+	$(top_srcdir)/contrib/zstd/compress \
+	$(top_srcdir)/contrib/zstd/decompress \
+	$(top_srcdir)/module/zstd
+
+DEFAULT_INCLUDES += \
+	-I$(top_srcdir)/contrib/zstd \
+	-I$(top_srcdir)/contrib/zstd/common \
+	-I$(top_srcdir)/contrib/zstd/compress \
+	-I$(top_srcdir)/contrib/zstd/decompress
+
+noinst_LTLIBRARIES = libzstd.la
+
+KERNEL_C = \
+	zstd_common.c \
+	fse_decompress.c \
+	entropy_common.c \
+	xxhash.c \
+	hist.c \
+	error_private.c \
+	zstd_compress.c \
+	zstd_compress_literals.c \
+	zstd_compress_sequences.c \
+	fse_compress.c \
+	huf_compress.c \
+	zstd_double_fast.c \
+	zstd_fast.c \
+	zstd_lazy.c \
+	zstd_ldm.c \
+	zstd_opt.c \
+	zstd_ddict.c \
+	zstd_decompress.c \
+	zstd_decompress_block.c \
+	huf_decompress.c \
+	zstd.c
+
+nodist_libzstd_la_SOURCES = $(KERNEL_C)
+
+# -fno-tree-vectorize gets set for gcc in zstd/common/compiler.h
+# Set it for other compilers, too.
+CFLAGS_zstd_decompress_block.o := -fno-tree-vectorize