Re: [PATCH dwarves] dwarf_loader: handle DWARF5 DW_OP_addrx properly

[Sedat Dilek <sedat.dilek@xxxxxxxxx>]

I hoped to drop "test_core_extern.skel.h"
tools/testing/selftests/bpf/Makefile as test_cpp.cpp includes it:

$ git grep include tools/testing/selftests/bpf/test_cpp.cpp
tools/testing/selftests/bpf/test_cpp.cpp:#include "test_core_extern.skel.h"

$ git diff
diff --git a/tools/testing/selftests/bpf/Makefile
b/tools/testing/selftests/bpf/Makefile
index 044bfdcf5b74..a93e4d6ff93c 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -450,7 +450,7 @@ $(OUTPUT)/test_verifier: test_verifier.c
verifier/tests.h $(BPFOBJ) | $(OUTPUT)
       $(Q)$(CC) $(CFLAGS) $(filter %.a %.o %.c,$^) $(LDLIBS) -o $@

# Make sure we are able to include and link libbpf against c++.
-$(OUTPUT)/test_cpp: test_cpp.cpp $(OUTPUT)/test_core_extern.skel.h $(BPFOBJ)
+$(OUTPUT)/test_cpp: test_cpp.cpp $(BPFOBJ)
       $(call msg,CXX,,$@)
       $(Q)$(CXX) $(CFLAGS) $^ $(LDLIBS) -o $@

When using g++:

$ llvm-objdump-12 -Dr test_cpp | grep test_core_extern
   77dd: e8 be 01 00 00                callq   0x79a0
<_ZL25test_core_extern__destroyP16test_core_extern>
   7842: e8 59 01 00 00                callq   0x79a0
<_ZL25test_core_extern__destroyP16test_core_extern>
00000000000079a0 <_ZL25test_core_extern__destroyP16test_core_extern>:
   79a3: 74 1a                         je      0x79bf
<_ZL25test_core_extern__destroyP16test_core_extern+0x1f>
   79af: 74 05                         je      0x79b6
<_ZL25test_core_extern__destroyP16test_core_extern+0x16>
   799e: 74 06                         je      0x79a6
<_ZL25test_core_extern__destroyP16test_core_extern+0x6>
   7942: 73 61                         jae     0x79a5
<_ZL25test_core_extern__destroyP16test_core_extern+0x5>
   7945: 70 6c                         jo      0x79b3
<_ZL25test_core_extern__destroyP16test_core_extern+0x13>
   794b: 70 65                         jo      0x79b2
<_ZL25test_core_extern__destroyP16test_core_extern+0x12>
   7954: 73 5f                         jae     0x79b5
<_ZL25test_core_extern__destroyP16test_core_extern+0x15>
   79aa: 79 00                         jns     0x79ac
<_ZL25test_core_extern__destroyP16test_core_extern+0xc>

When using clang++-12:

$ llvm-objdump-12 -Dr test_cpp | grep test_core_extern
[ empty ]

Last I tried:

selftests-bpf-Makefile-EXTRA_CXXFLAGS-x-c-header.diff
diff --git a/tools/testing/selftests/bpf/Makefile
b/tools/testing/selftests/bpf/Makefile
index 044bfdcf5b74..df07fd9325d0 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -27,6 +27,7 @@ CFLAGS += -g -rdynamic -Wall -O2 $(GENFLAGS)
$(SAN_CFLAGS)            \
         -Dbpf_prog_load=bpf_prog_test_load                            \
         -Dbpf_load_program=bpf_test_load_program
LDLIBS += -lcap -lelf -lz -lrt -lpthread
+EXTRA_CXXFLAGS := -x c-header

# Order correspond to 'make run_tests' order
TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map
test_lpm_map test_progs \
@@ -452,7 +453,7 @@ $(OUTPUT)/test_verifier: test_verifier.c
verifier/tests.h $(BPFOBJ) | $(OUTPUT)
# Make sure we are able to include and link libbpf against c++.
$(OUTPUT)/test_cpp: test_cpp.cpp $(OUTPUT)/test_core_extern.skel.h $(BPFOBJ)
       $(call msg,CXX,,$@)
-       $(Q)$(CXX) $(CFLAGS) $^ $(LDLIBS) -o $@
+       $(Q)$(CXX) $(CFLAGS) $(EXTRA_CXXFLAGS) $^ $(LDLIBS) -o $@

# Benchmark runner
$(OUTPUT)/bench_%.o: benchs/bench_%.c bench.h

NOPE.

- Sedat -