Em Tue, Mar 19, 2019 at 10:58:13AM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Tue, Mar 19, 2019 at 06:05:30AM +0000, Song Liu escreveu:
> > test-disassembler-four-args.c is an existing test used by bpftool.
> > It was added in fb982666e380c1632a74495b68b3c33a66e76430 .
> > > After applying this test it "works":
> > > make: Entering directory '/home/acme/git/perf/tools/perf'
> > > BUILD: Doing 'make -j8' parallel build
> > > Auto-detecting system features:
> > > ... dwarf: [ on ]
> > > ... dwarf_getlocations: [ on ]
> > > <SNIP>
> > > ... bpf: [ on ]
> > > ... libaio: [ on ]
> > > ... disassembler-four-args: [ on ]
> > >
> > > Because you added it to FEATURE_TESTS_BASIC, and this means that if
> > > tools/build/feature/test-all.c builds, then what is in
> > > FEATURE_TESTS_BASIC is set to 'on', but you didn't add anything to
> > > tools/build/feature/test-all.c, so it works because all the other
> > > features are present.
> > > Take a look at:
> > > 2a07d814747b ("tools build feature: Check if libaio is available")
> > > To see what needs to be done.
> > I used different versions of gcc to verify that current version of the
> > patch works for both test-succeed and test-fail cases. I guess something
> > like the following is needed? But the test does work without it.
> Even with the file below, it fails, as:
> [acme@quaco perf]$ cat /tmp/build/perf/feature/test-all.make.output
> /usr/bin/ld: /tmp/ccTj7iV6.o: in function `main_test_disassembler_four_args':
> /home/acme/git/perf/tools/build/feature/test-disassembler-four-args.c:9: undefined reference to `disassembler'
> collect2: error: ld returned 1 exit status
> [acme@quaco perf]$
> Then we do the test for each of the features and _then_ this works:
> [acme@quaco perf]$ ls -la /tmp/build/perf/feature/test-disassembler-four-args.*
> -rwxrwxr-x. 1 acme acme 2098312 Mar 19 10:51 /tmp/build/perf/feature/test-disassembler-four-args.bin
> -rw-rw-r--. 1 acme acme 1079 Mar 19 10:51 /tmp/build/perf/feature/test-disassembler-four-args.d
> -rw-rw-r--. 1 acme acme 0 Mar 19 10:51 /tmp/build/perf/feature/test-disassembler-four-args.make.output
> [acme@quaco perf]$
>
> So there is still something missing, i.e. which objects to add to the
> test-all case, I'll fix it.
This was missing:
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index c51b59e43dcc..4f491ad4f492 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -227,6 +227,8 @@ FEATURE_CHECK_LDFLAGS-libpython-version := $(PYTHON_EMBED_LDOPTS)
FEATURE_CHECK_LDFLAGS-libaio = -lrt
+FEATURE_CHECK_LDFLAGS-disassembler-four-args = -lopcodes
+
CFLAGS += -fno-omit-frame-pointer
CFLAGS += -ggdb3
CFLAGS += -funwind-tables
----------------------
After that, and with a clean /tmp/build/perf, re-running:
make -C tools/perf O=/tmp/build/perf
we get:
[acme@quaco perf]$ ls -la /tmp/build/perf/feature/
total 2888
drwxrwxr-x. 2 acme acme 400 Mar 19 11:08 .
drwxrwxr-x. 16 acme acme 4280 Mar 19 11:08 ..
-rwxrwxr-x. 1 acme acme 2680352 Mar 19 11:07 test-all.bin
-rw-rw-r--. 1 acme acme 38753 Mar 19 11:07 test-all.d
-rw-rw-r--. 1 acme acme 0 Mar 19 11:07 test-all.make.output
-rw-rw-r--. 1 acme acme 168 Mar 19 11:07 test-bionic.make.output
-rwxrwxr-x. 1 acme acme 140960 Mar 19 11:08 test-cplus-demangle.bin
-rw-rw-r--. 1 acme acme 101 Mar 19 11:08 test-cplus-demangle.d
-rw-rw-r--. 1 acme acme 0 Mar 19 11:08 test-cplus-demangle.make.output
-rwxrwxr-x. 1 acme acme 17976 Mar 19 11:08 test-jvmti.bin
-rwxrwxr-x. 1 acme acme 17984 Mar 19 11:08 test-jvmti-cmlr.bin
-rw-rw-r--. 1 acme acme 1107 Mar 19 11:08 test-jvmti-cmlr.d
-rw-rw-r--. 1 acme acme 0 Mar 19 11:08 test-jvmti-cmlr.make.output
-rw-rw-r--. 1 acme acme 1014 Mar 19 11:08 test-jvmti.d
-rw-rw-r--. 1 acme acme 0 Mar 19 11:08 test-jvmti.make.output
-rwxrwxr-x. 1 acme acme 18368 Mar 19 11:07 test-libbabeltrace.bin
-rw-rw-r--. 1 acme acme 1470 Mar 19 11:07 test-libbabeltrace.d
-rw-rw-r--. 1 acme acme 0 Mar 19 11:07 test-libbabeltrace.make.output
-rw-rw-r--. 1 acme acme 179 Mar 19 11:07 test-libunwind-aarch64.make.output
-rw-rw-r--. 1 acme acme 163 Mar 19 11:07 test-libunwind-x86.make.output
[acme@quaco perf]$
I.e. test-all.bin got built, and if we look at it:
[acme@quaco perf]$ nm /tmp/build/perf/feature/test-all.bin | grep disassembler
0000000000061f90 T disassembler
0000000000062110 T disassembler_options_cmp
0000000000061fb0 T disassembler_usage
0000000000061f40 T main_test_disassembler_four_args
000000000006b7c0 T print_i386_disassembler_options
[acme@quaco perf]$
I.e. the -lopcodes was added to the test-all.bin, and as we include that
itest-disassembler-four-args.c in the test-all.c file, it gets linked
and that test-all.c build doesn't fail, so all that is in
FEATURE_TESTS_BASIC is marked as present, CFLAGS +=
-DDISASM_FOUR_ARGS_SIGNATURE gets set, etc.
Now the test is really being performed, the test-all.bin feature
detection fast path is working, proceeding.
- Arnaldo
