commit d70a6be1e2ab98f13688e4a529b326e8e11230d0
author Ilya Leoshkevich <iii@linux.ibm.com> Tue Jun 02 19:56:48 2020 +0200
committer Daniel Borkmann <daniel@iogearbox.net> Tue Jun 02 22:02:38 2020 +0200
tree 639cc6eba6d0d30925f816a0de2084a7c3636920
parent 9bc499befeef07a4d79f4924bfca05634ad8fc97

tools/bpf: Don't use $(COMPILE.c)

When using make kselftest TARGETS=bpf, tools/bpf is built with
MAKEFLAGS=rR, which causes $(COMPILE.c) to be undefined, which in turn
causes the build to fail with

  CC       kselftest/bpf/tools/build/bpftool/map_perf_ring.o
/bin/sh: 1: -MMD: not found

Fix by using $(CC) $(CFLAGS) -c instead of $(COMPILE.c).

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200602175649.2501580-2-iii@linux.ibm.com

tools/bpf/Makefile

diff --git a/tools/bpf/Makefile b/tools/bpf/Makefile
index f897eee..77472e2 100644
--- a/tools/bpf/Makefile
+++ b/tools/bpf/Makefile
@@ -64,12 +64,12 @@
 	$(QUIET_FLEX)$(LEX) -o $@ $<
 
 $(OUTPUT)%.o: $(srctree)/tools/bpf/%.c
-	$(QUIET_CC)$(COMPILE.c) -o $@ $<
+	$(QUIET_CC)$(CC) $(CFLAGS) -c -o $@ $<
 
 $(OUTPUT)%.yacc.o: $(OUTPUT)%.yacc.c
-	$(QUIET_CC)$(COMPILE.c) -o $@ $<
+	$(QUIET_CC)$(CC) $(CFLAGS) -c -o $@ $<
 $(OUTPUT)%.lex.o: $(OUTPUT)%.lex.c
-	$(QUIET_CC)$(COMPILE.c) -o $@ $<
+	$(QUIET_CC)$(CC) $(CFLAGS) -c -o $@ $<
 
 PROGS = $(OUTPUT)bpf_jit_disasm $(OUTPUT)bpf_dbg $(OUTPUT)bpf_asm