Fix libspl/asm-generic/atomic for VPATH build

Currently, asm-generic/atomic.c is compiled into a .S file, with a
comment saying this is to simplify the upper-level Makefile.

However, this doesn't work properly with a VPATH build, which would
require better logic to deal with generated sources correctly.

It also doesn't seem more complex to just specify the .c/.S source file,
depending on the cpu, instead of only the source directory in
lib/libspl/Makefile.am, which eliminates the need to do the intermediate
compilation.

Reviewed-by: Ryan Moeller <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Arvind Sankar <[email protected]>
Closes #10493

4 files changed, 8 insertions, 29 deletions

diff --git a/lib/libspl/Makefile.am b/lib/libspl/Makefile.am
index 77d8aba0e..e11b165d7 100644
--- a/lib/libspl/Makefile.am
+++ b/lib/libspl/Makefile.am
@@ -1,20 +1,16 @@
 include $(top_srcdir)/config/Rules.am
 
 if TARGET_CPU_I386
-TARGET_CPU_DIR = asm-i386
+TARGET_CPU_ATOMIC_SOURCE = asm-i386/atomic.S
 else
 if TARGET_CPU_X86_64
-TARGET_CPU_DIR = asm-x86_64
+TARGET_CPU_ATOMIC_SOURCE = asm-x86_64/atomic.S
 else
-TARGET_CPU_DIR = asm-generic
+TARGET_CPU_ATOMIC_SOURCE = asm-generic/atomic.c
 endif
 endif
 
-VPATH = \
-	$(top_srcdir)/lib/libspl \
-	$(top_srcdir)/lib/libspl/$(TARGET_CPU_DIR)
-
-SUBDIRS = include $(TARGET_CPU_DIR)
+SUBDIRS = include
 DIST_SUBDIRS = include asm-generic asm-i386 asm-x86_64
 
 AM_CFLAGS += $(LIBTIRPC_CFLAGS)
@@ -48,14 +44,11 @@ USER_C += \
 	os/freebsd/gethostid.c \
 	os/freebsd/getmntany.c \
 	os/freebsd/mnttab.c
-
 endif
 
-USER_ASM = atomic.S
-
 nodist_libspl_la_SOURCES = \
 	$(USER_C) \
-	$(USER_ASM)
+	$(TARGET_CPU_ATOMIC_SOURCE)
 
 libspl_la_LIBADD = -lrt $(LIBTIRPC_LIBS)
 
diff --git a/lib/libspl/asm-generic/Makefile.am b/lib/libspl/asm-generic/Makefile.am
index 396823160..1d5e224b1 100644
--- a/lib/libspl/asm-generic/Makefile.am
+++ b/lib/libspl/asm-generic/Makefile.am
@@ -1,15 +1 @@
-include $(top_srcdir)/config/Rules.am
-
-atomic_SOURCE = atomic.c
-atomic_ASM = atomic.S
-
-COMPILE = $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) \
-	  $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS) -fPIC
-EXTRA_DIST = $(atomic_SOURCE)
-
-# Generates assembly to simplify inclusion in ../Makefile.am
-all-am:
-	$(COMPILE) -c -S $(atomic_SOURCE) -o $(atomic_ASM)
-
-clean-generic:
-	$(RM) $(atomic_ASM)
+EXTRA_DIST = atomic.c
diff --git a/lib/libspl/asm-i386/Makefile.am b/lib/libspl/asm-i386/Makefile.am
index e1126102f..e954ec401 100644
--- a/lib/libspl/asm-i386/Makefile.am
+++ b/lib/libspl/asm-i386/Makefile.am
@@ -1 +1 @@
-noinst_HEADERS = atomic.S
+EXTRA_DIST = atomic.S
diff --git a/lib/libspl/asm-x86_64/Makefile.am b/lib/libspl/asm-x86_64/Makefile.am
index e1126102f..e954ec401 100644
--- a/lib/libspl/asm-x86_64/Makefile.am
+++ b/lib/libspl/asm-x86_64/Makefile.am
@@ -1 +1 @@
-noinst_HEADERS = atomic.S
+EXTRA_DIST = atomic.S