[1/1] selftests: gpio: use pkg-config to determine libmount CFLAGS/LDLIBS

Message ID 20170629065802.24062-1-fathi.boudra@linaro.org
State New
Headers show
Series
  • [1/1] selftests: gpio: use pkg-config to determine libmount CFLAGS/LDLIBS
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Commit Message

Fathi Boudra June 29, 2017, 6:58 a.m.
Fix hardcoded and misplaced libmount headers. Use pkg-config instead to
figure out CFLAGS/LDLIBS, fixing also their value for cross-compilation.

If pkg-config isn't installed, it gives an error (command not found) and
gpio test will fail to build because it won't be able to find the headers
or link to libmount library.

Signed-off-by: Fathi Boudra <fathi.boudra@linaro.org>

---
 tools/testing/selftests/gpio/Makefile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

-- 
2.13.0

Comments

Michael Ellerman June 29, 2017, 9:01 a.m. | #1
Fathi Boudra <fathi.boudra@linaro.org> writes:

> Fix hardcoded and misplaced libmount headers. Use pkg-config instead to

> figure out CFLAGS/LDLIBS, fixing also their value for cross-compilation.


Can you explain how it fixes the values for cross-compilation?

cheers
Fathi Boudra June 29, 2017, 11:39 a.m. | #2
On 29 June 2017 at 12:01, Michael Ellerman <mpe@ellerman.id.au> wrote:
> Fathi Boudra <fathi.boudra@linaro.org> writes:

>

>> Fix hardcoded and misplaced libmount headers. Use pkg-config instead to

>> figure out CFLAGS/LDLIBS, fixing also their value for cross-compilation.

>

> Can you explain how it fixes the values for cross-compilation?


When pkg-config is invoked in a cross-build environment, it will
return your sysroot headers path instead of the hardcoded
-I/usr/include/libmount

For example in my oe environment, when I invoke "pkg-config --cflags
mount", it returns:
-I/build/tmp-rpb-glibc/sysroots/hikey/usr/include/libmount

> cheers

> --

> To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in

> the body of a message to majordomo@vger.kernel.org

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Bamvor Zhang Jian June 30, 2017, 2:20 a.m. | #3
On 29 June 2017 at 19:39, Fathi Boudra <fathi.boudra@linaro.org> wrote:
> On 29 June 2017 at 12:01, Michael Ellerman <mpe@ellerman.id.au> wrote:

>> Fathi Boudra <fathi.boudra@linaro.org> writes:

>>

>>> Fix hardcoded and misplaced libmount headers. Use pkg-config instead to

>>> figure out CFLAGS/LDLIBS, fixing also their value for cross-compilation.

>>

>> Can you explain how it fixes the values for cross-compilation?

>

> When pkg-config is invoked in a cross-build environment, it will

> return your sysroot headers path instead of the hardcoded

> -I/usr/include/libmount

>

> For example in my oe environment, when I invoke "pkg-config --cflags

> mount", it returns:

> -I/build/tmp-rpb-glibc/sysroots/hikey/usr/include/libmount

I suppose we could also pass the extra CFLAGS and LDFLAGS directly to
make it work. correct?

Regards

Bamvor
>

>> cheers

>> --

>> To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in

>> the body of a message to majordomo@vger.kernel.org

>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
Fathi Boudra June 30, 2017, 5:53 a.m. | #4
On 30 June 2017 at 05:20, Bamvor Zhang Jian <bamvor.zhangjian@linaro.org> wrote:
> On 29 June 2017 at 19:39, Fathi Boudra <fathi.boudra@linaro.org> wrote:

>> On 29 June 2017 at 12:01, Michael Ellerman <mpe@ellerman.id.au> wrote:

>>> Fathi Boudra <fathi.boudra@linaro.org> writes:

>>>

>>>> Fix hardcoded and misplaced libmount headers. Use pkg-config instead to

>>>> figure out CFLAGS/LDLIBS, fixing also their value for cross-compilation.

>>>

>>> Can you explain how it fixes the values for cross-compilation?

>>

>> When pkg-config is invoked in a cross-build environment, it will

>> return your sysroot headers path instead of the hardcoded

>> -I/usr/include/libmount

>>

>> For example in my oe environment, when I invoke "pkg-config --cflags

>> mount", it returns:

>> -I/build/tmp-rpb-glibc/sysroots/hikey/usr/include/libmount

> I suppose we could also pass the extra CFLAGS and LDFLAGS directly to

> make it work. correct?


or use the appropriate tool for getting CFLAGS/LDFLAGS instead of:
1. hardcoding it and potentially get them wrong
2. expecting the user will have to take extra steps, while he can just run make

> Regards

>

> Bamvor

>>

>>> cheers

>>> --

>>> To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in

>>> the body of a message to majordomo@vger.kernel.org

>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
Michael Ellerman June 30, 2017, 11:01 a.m. | #5
Fathi Boudra <fathi.boudra@linaro.org> writes:

> On 29 June 2017 at 12:01, Michael Ellerman <mpe@ellerman.id.au> wrote:

>> Fathi Boudra <fathi.boudra@linaro.org> writes:

>>

>>> Fix hardcoded and misplaced libmount headers. Use pkg-config instead to

>>> figure out CFLAGS/LDLIBS, fixing also their value for cross-compilation.

>>

>> Can you explain how it fixes the values for cross-compilation?

>

> When pkg-config is invoked in a cross-build environment, it will

> return your sysroot headers path instead of the hardcoded

> -I/usr/include/libmount

>

> For example in my oe environment, when I invoke "pkg-config --cflags

> mount", it returns:

> -I/build/tmp-rpb-glibc/sysroots/hikey/usr/include/libmount


Right, presumably because OE is setting PKG_CONFIG_SYSROOT_DIR etc.

So for folks doing it by hand it doesn't really help with cross
compiling, but I guess it doesn't hurt either.

cheers
Michael Ellerman July 1, 2017, 1:48 a.m. | #6
Fathi Boudra <fathi.boudra@linaro.org> writes:

> On 30 June 2017 at 05:20, Bamvor Zhang Jian <bamvor.zhangjian@linaro.org> wrote:

>> On 29 June 2017 at 19:39, Fathi Boudra <fathi.boudra@linaro.org> wrote:

>>> On 29 June 2017 at 12:01, Michael Ellerman <mpe@ellerman.id.au> wrote:

>>>> Fathi Boudra <fathi.boudra@linaro.org> writes:

>>>>

>>>>> Fix hardcoded and misplaced libmount headers. Use pkg-config instead to

>>>>> figure out CFLAGS/LDLIBS, fixing also their value for cross-compilation.

>>>>

>>>> Can you explain how it fixes the values for cross-compilation?

>>>

>>> When pkg-config is invoked in a cross-build environment, it will

>>> return your sysroot headers path instead of the hardcoded

>>> -I/usr/include/libmount

>>>

>>> For example in my oe environment, when I invoke "pkg-config --cflags

>>> mount", it returns:

>>> -I/build/tmp-rpb-glibc/sysroots/hikey/usr/include/libmount

>> I suppose we could also pass the extra CFLAGS and LDFLAGS directly to

>> make it work. correct?

>

> or use the appropriate tool for getting CFLAGS/LDFLAGS instead of:

> 1. hardcoding it and potentially get them wrong

> 2. expecting the user will have to take extra steps, while he can just run make


Sure. But by using the "appropriate tool" you create a new dependency on
that tool.

For folks building natively it's probably not a big deal, they probably
already have pkg-config installed, but for cross building it's another
thing to get working.

Currently most of the selftests build, and cross-build, with nothing but
a C compiler and libc, and we should try to maintain that as much as
possible.

cheers
Fathi Boudra July 3, 2017, 11:23 a.m. | #7
On 1 July 2017 at 04:48, Michael Ellerman <mpe@ellerman.id.au> wrote:
> Fathi Boudra <fathi.boudra@linaro.org> writes:

>

>> On 30 June 2017 at 05:20, Bamvor Zhang Jian <bamvor.zhangjian@linaro.org> wrote:

>>> On 29 June 2017 at 19:39, Fathi Boudra <fathi.boudra@linaro.org> wrote:

>>>> On 29 June 2017 at 12:01, Michael Ellerman <mpe@ellerman.id.au> wrote:

>>>>> Fathi Boudra <fathi.boudra@linaro.org> writes:

>>>>>

>>>>>> Fix hardcoded and misplaced libmount headers. Use pkg-config instead to

>>>>>> figure out CFLAGS/LDLIBS, fixing also their value for cross-compilation.

>>>>>

>>>>> Can you explain how it fixes the values for cross-compilation?

>>>>

>>>> When pkg-config is invoked in a cross-build environment, it will

>>>> return your sysroot headers path instead of the hardcoded

>>>> -I/usr/include/libmount

>>>>

>>>> For example in my oe environment, when I invoke "pkg-config --cflags

>>>> mount", it returns:

>>>> -I/build/tmp-rpb-glibc/sysroots/hikey/usr/include/libmount

>>> I suppose we could also pass the extra CFLAGS and LDFLAGS directly to

>>> make it work. correct?

>>

>> or use the appropriate tool for getting CFLAGS/LDFLAGS instead of:

>> 1. hardcoding it and potentially get them wrong

>> 2. expecting the user will have to take extra steps, while he can just run make

>

> Sure. But by using the "appropriate tool" you create a new dependency on

> that tool.

>

> For folks building natively it's probably not a big deal, they probably

> already have pkg-config installed, but for cross building it's another

> thing to get working.

>

> Currently most of the selftests build, and cross-build, with nothing but

> a C compiler and libc, and we should try to maintain that as much as

> possible.


As you said, most of selftests build. There's a precedent. memfd test
is also using pkg-config. That's why I followed similar approach.

> cheers

> --

> To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in

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Patch

diff --git a/tools/testing/selftests/gpio/Makefile b/tools/testing/selftests/gpio/Makefile
index 298929df97e6..11eed0cdec2a 100644
--- a/tools/testing/selftests/gpio/Makefile
+++ b/tools/testing/selftests/gpio/Makefile
@@ -17,8 +17,8 @@  override define CLEAN
 	$(RM) -r $(EXTRA_DIRS)
 endef
 
-CFLAGS += -O2 -g -std=gnu99 -Wall -I../../../../usr/include/
-LDLIBS += -lmount -I/usr/include/libmount
+CFLAGS += -O2 -g -std=gnu99 -Wall -I../../../../usr/include/ $(shell pkg-config --cflags mount)
+LDLIBS += $(shell pkg-config --libs mount)
 
 $(BINARIES): ../../../gpio/gpio-utils.o ../../../../usr/include/linux/gpio.h