selftests can be built from the toplevel kernel makefile (e.g. make
kselftest-all) or directly (make -C tools/testing/selftests all).
The toplevel kernel makefile explicitly disables implicit rules with
"MAKEFLAGS += -rR", which is passed to tools/testing/selftests. Some
selftest makefiles require implicit make rules, which is why
commit 67d8712dcc70 ("selftests: Fix build failures when invoked from
kselftest target") reenables implicit rules by clearing MAKEFLAGS if
MAKELEVEL=1.
So far so good. However, if the toplevel makefile is called from an
outer makefile then MAKELEVEL will be elevated, which breaks the
MAKELEVEL equality test.
Example wrapped makefile error:
$ cat ~/Makefile
all:
$(MAKE) defconfig
$(MAKE) kselftest-all
$ make -sf ~/Makefile
futex_wait_timeout.c /src/tools/testing/selftests/kselftest_harness.h /src/tools/testing/selftests/kselftest.h ../include/futextest.h ../include/atomic.h ../include/logging.h -lpthread -lrt -o /src/tools/testing/selftests/futex/functional/futex_wait_timeout
make[4]: futex_wait_timeout.c: Command not found
Rather than checking $(MAKELEVEL), check for $(LINK.c), which is a more
direct side effect of "make -R". This enables arbitrary makefile
nesting.
Signed-off-by: Greg Thelen <[email protected]>
---
tools/testing/selftests/Makefile | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 1195bd85af38..289a2e4b3f6f 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -84,10 +84,10 @@ endif
# of the targets gets built.
FORCE_TARGETS ?=
-# Clear LDFLAGS and MAKEFLAGS if called from main
-# Makefile to avoid test build failures when test
-# Makefile doesn't have explicit build rules.
-ifeq (1,$(MAKELEVEL))
+# Clear LDFLAGS and MAKEFLAGS when implicit rules are missing. This provides
+# implicit rules to sub-test Makefiles which avoids build failures in test
+# Makefile that don't have explicit build rules.
+ifeq (,$(LINK.c))
override LDFLAGS =
override MAKEFLAGS =
endif
--
2.28.0.rc0.142.g3c755180ce-goog
On Tue, Jul 28, 2020 at 12:32 AM Greg Thelen <[email protected]> wrote:
>
> selftests can be built from the toplevel kernel makefile (e.g. make
> kselftest-all) or directly (make -C tools/testing/selftests all).
>
> The toplevel kernel makefile explicitly disables implicit rules with
> "MAKEFLAGS += -rR", which is passed to tools/testing/selftests. Some
> selftest makefiles require implicit make rules, which is why
> commit 67d8712dcc70 ("selftests: Fix build failures when invoked from
> kselftest target") reenables implicit rules by clearing MAKEFLAGS if
> MAKELEVEL=1.
>
> So far so good. However, if the toplevel makefile is called from an
> outer makefile then MAKELEVEL will be elevated, which breaks the
> MAKELEVEL equality test.
> Example wrapped makefile error:
> $ cat ~/Makefile
> all:
> $(MAKE) defconfig
> $(MAKE) kselftest-all
> $ make -sf ~/Makefile
> futex_wait_timeout.c /src/tools/testing/selftests/kselftest_harness.h /src/tools/testing/selftests/kselftest.h ../include/futextest.h ../include/atomic.h ../include/logging.h -lpthread -lrt -o /src/tools/testing/selftests/futex/functional/futex_wait_timeout
> make[4]: futex_wait_timeout.c: Command not found
>
> Rather than checking $(MAKELEVEL), check for $(LINK.c), which is a more
> direct side effect of "make -R". This enables arbitrary makefile
> nesting.
>
> Signed-off-by: Greg Thelen <[email protected]>
> ---
> tools/testing/selftests/Makefile | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
> index 1195bd85af38..289a2e4b3f6f 100644
> --- a/tools/testing/selftests/Makefile
> +++ b/tools/testing/selftests/Makefile
> @@ -84,10 +84,10 @@ endif
> # of the targets gets built.
> FORCE_TARGETS ?=
>
> -# Clear LDFLAGS and MAKEFLAGS if called from main
> -# Makefile to avoid test build failures when test
> -# Makefile doesn't have explicit build rules.
> -ifeq (1,$(MAKELEVEL))
> +# Clear LDFLAGS and MAKEFLAGS when implicit rules are missing. This provides
> +# implicit rules to sub-test Makefiles which avoids build failures in test
> +# Makefile that don't have explicit build rules.
> +ifeq (,$(LINK.c))
> override LDFLAGS =
> override MAKEFLAGS =
> endif
> --
> 2.28.0.rc0.142.g3c755180ce-goog
Is there any feedback on this patch? It's not high priority but something that
will help me make more use of selftests.
On 8/5/20 1:36 PM, Greg Thelen wrote:
> On Tue, Jul 28, 2020 at 12:32 AM Greg Thelen <[email protected]> wrote:
>>
>> selftests can be built from the toplevel kernel makefile (e.g. make
>> kselftest-all) or directly (make -C tools/testing/selftests all).
>>
>> The toplevel kernel makefile explicitly disables implicit rules with
>> "MAKEFLAGS += -rR", which is passed to tools/testing/selftests. Some
>> selftest makefiles require implicit make rules, which is why
>> commit 67d8712dcc70 ("selftests: Fix build failures when invoked from
>> kselftest target") reenables implicit rules by clearing MAKEFLAGS if
>> MAKELEVEL=1.
>>
>> So far so good. However, if the toplevel makefile is called from an
>> outer makefile then MAKELEVEL will be elevated, which breaks the
>> MAKELEVEL equality test.
>> Example wrapped makefile error:
>> $ cat ~/Makefile
>> all:
>> $(MAKE) defconfig
>> $(MAKE) kselftest-all
>> $ make -sf ~/Makefile
>> futex_wait_timeout.c /src/tools/testing/selftests/kselftest_harness.h /src/tools/testing/selftests/kselftest.h ../include/futextest.h ../include/atomic.h ../include/logging.h -lpthread -lrt -o /src/tools/testing/selftests/futex/functional/futex_wait_timeout
>> make[4]: futex_wait_timeout.c: Command not found
>>
>> Rather than checking $(MAKELEVEL), check for $(LINK.c), which is a more
>> direct side effect of "make -R". This enables arbitrary makefile
>> nesting.
>>
>> Signed-off-by: Greg Thelen <[email protected]>
>> ---
>> tools/testing/selftests/Makefile | 8 ++++----
>> 1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
>> index 1195bd85af38..289a2e4b3f6f 100644
>> --- a/tools/testing/selftests/Makefile
>> +++ b/tools/testing/selftests/Makefile
>> @@ -84,10 +84,10 @@ endif
>> # of the targets gets built.
>> FORCE_TARGETS ?=
>>
>> -# Clear LDFLAGS and MAKEFLAGS if called from main
>> -# Makefile to avoid test build failures when test
>> -# Makefile doesn't have explicit build rules.
>> -ifeq (1,$(MAKELEVEL))
>> +# Clear LDFLAGS and MAKEFLAGS when implicit rules are missing. This provides
>> +# implicit rules to sub-test Makefiles which avoids build failures in test
>> +# Makefile that don't have explicit build rules.
>> +ifeq (,$(LINK.c))
>> override LDFLAGS =
>> override MAKEFLAGS =
>> endif
>> --
>> 2.28.0.rc0.142.g3c755180ce-goog
>
> Is there any feedback on this patch? It's not high priority but something that
> will help me make more use of selftests.
>
No issues with the patch. I will apply it once the merge window ends.
thanks,
-- Shuah
Shuah Khan <[email protected]> wrote:
> On 8/5/20 1:36 PM, Greg Thelen wrote:
>> On Tue, Jul 28, 2020 at 12:32 AM Greg Thelen <[email protected]> wrote:
>>>
>>> selftests can be built from the toplevel kernel makefile (e.g. make
>>> kselftest-all) or directly (make -C tools/testing/selftests all).
>>>
>>> The toplevel kernel makefile explicitly disables implicit rules with
>>> "MAKEFLAGS += -rR", which is passed to tools/testing/selftests. Some
>>> selftest makefiles require implicit make rules, which is why
>>> commit 67d8712dcc70 ("selftests: Fix build failures when invoked from
>>> kselftest target") reenables implicit rules by clearing MAKEFLAGS if
>>> MAKELEVEL=1.
>>>
>>> So far so good. However, if the toplevel makefile is called from an
>>> outer makefile then MAKELEVEL will be elevated, which breaks the
>>> MAKELEVEL equality test.
>>> Example wrapped makefile error:
>>> $ cat ~/Makefile
>>> all:
>>> $(MAKE) defconfig
>>> $(MAKE) kselftest-all
>>> $ make -sf ~/Makefile
>>> futex_wait_timeout.c /src/tools/testing/selftests/kselftest_harness.h /src/tools/testing/selftests/kselftest.h ../include/futextest.h ../include/atomic.h ../include/logging.h -lpthread -lrt -o /src/tools/testing/selftests/futex/functional/futex_wait_timeout
>>> make[4]: futex_wait_timeout.c: Command not found
>>>
>>> Rather than checking $(MAKELEVEL), check for $(LINK.c), which is a more
>>> direct side effect of "make -R". This enables arbitrary makefile
>>> nesting.
>>>
>>> Signed-off-by: Greg Thelen <[email protected]>
>>> ---
>>> tools/testing/selftests/Makefile | 8 ++++----
>>> 1 file changed, 4 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
>>> index 1195bd85af38..289a2e4b3f6f 100644
>>> --- a/tools/testing/selftests/Makefile
>>> +++ b/tools/testing/selftests/Makefile
>>> @@ -84,10 +84,10 @@ endif
>>> # of the targets gets built.
>>> FORCE_TARGETS ?=
>>>
>>> -# Clear LDFLAGS and MAKEFLAGS if called from main
>>> -# Makefile to avoid test build failures when test
>>> -# Makefile doesn't have explicit build rules.
>>> -ifeq (1,$(MAKELEVEL))
>>> +# Clear LDFLAGS and MAKEFLAGS when implicit rules are missing. This provides
>>> +# implicit rules to sub-test Makefiles which avoids build failures in test
>>> +# Makefile that don't have explicit build rules.
>>> +ifeq (,$(LINK.c))
>>> override LDFLAGS =
>>> override MAKEFLAGS =
>>> endif
>>> --
>>> 2.28.0.rc0.142.g3c755180ce-goog
>>
>> Is there any feedback on this patch? It's not high priority but something that
>> will help me make more use of selftests.
>>
>
> No issues with the patch. I will apply it once the merge window ends.
>
> thanks,
> -- Shuah
Great. Thank you.