Re: [PATCH 2/4] samples/bpf: Use llc in PATH, rather than a hardcoded value
From: Alexei Starovoitov
Date: Thu Mar 31 2016 - 13:47:29 EST
On 3/31/16 4:25 AM, Naveen N. Rao wrote:
While at it, fix some typos in the comment.
Cc: Alexei Starovoitov <ast@xxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
---
samples/bpf/Makefile | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 502c9fc..88bc5a0 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -76,16 +76,13 @@ HOSTLOADLIBES_offwaketime += -lelf
HOSTLOADLIBES_spintest += -lelf
HOSTLOADLIBES_map_perf_test += -lelf -lrt
-# point this to your LLVM backend with bpf support
-LLC=$(srctree)/tools/bpf/llvm/bld/Debug+Asserts/bin/llc
-
-# asm/sysreg.h inline assmbly used by it is incompatible with llvm.
-# But, ehere is not easy way to fix it, so just exclude it since it is
+# asm/sysreg.h - inline assembly used by it is incompatible with llvm.
+# But, there is no easy way to fix it, so just exclude it since it is
# useless for BPF samples.
$(obj)/%.o: $(src)/%.c
clang $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) \
-D__KERNEL__ -D__ASM_SYSREG_H -Wno-unused-value -Wno-pointer-sign \
- -O2 -emit-llvm -c $< -o -| $(LLC) -march=bpf -filetype=obj -o $@
+ -O2 -emit-llvm -c $< -o -| llc -march=bpf -filetype=obj -o $@
clang $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) \
-D__KERNEL__ -D__ASM_SYSREG_H -Wno-unused-value -Wno-pointer-sign \
- -O2 -emit-llvm -c $< -o -| $(LLC) -march=bpf -filetype=asm -o $@.s
+ -O2 -emit-llvm -c $< -o -| llc -march=bpf -filetype=asm -o $@.s
that was a workaround when clang/llvm didn't have bpf support.
Now clang 3.7 and 3.8 have bpf built-in, so make sense to remove
manual calls to llc completely.
Just use 'clang -target bpf -O2 -D... -c $< -o $@'