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authorJesper Dangaard Brouer <brouer@redhat.com>2016-04-28 14:20:53 +0200
committerDavid S. Miller <davem@davemloft.net>2016-04-29 14:25:32 -0400
commit6ccfba75d3137efc3b665a337b946fd6df1162b9 (patch)
tree15cebd90b5049e5a8fde9c852f2d1630bf93f988
parentc23846c143e81963096e922d91b7b00284c22bed (diff)
downloadlwn-6ccfba75d3137efc3b665a337b946fd6df1162b9.tar.gz
lwn-6ccfba75d3137efc3b665a337b946fd6df1162b9.zip
samples/bpf: add back functionality to redefine LLC command
It is practical to be-able-to redefine the location of the LLVM command 'llc', because not all distros have a LLVM version with bpf target support. Thus, it is sometimes required to compile LLVM from source, and sometimes it is not desired to overwrite the distros default LLVM version. This feature was removed with 128d1514be35 ("samples/bpf: Use llc in PATH, rather than a hardcoded value"). Add this features back. Note that it is possible to redefine the LLC on the make command like: make samples/bpf/ LLC=~/git/llvm/build/bin/llc Fixes: 128d1514be35 ("samples/bpf: Use llc in PATH, rather than a hardcoded value") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--samples/bpf/Makefile6
1 files changed, 5 insertions, 1 deletions
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 744dd7a16144..5bae9536f100 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -81,10 +81,14 @@ HOSTLOADLIBES_spintest += -lelf
HOSTLOADLIBES_map_perf_test += -lelf -lrt
HOSTLOADLIBES_test_overhead += -lelf -lrt
+# Allows pointing LLC to a LLVM backend with bpf support, redefine on cmdline:
+# make samples/bpf/ LLC=~/git/llvm/build/bin/llc
+LLC ?= llc
+
# 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 $@