[LTP] 回复：[PATCH v1] include/mk/env_post.mk: enable __ANDROID__ definition for Android build

[Petr Vorel <pvorel@suse.cz>]

Hi Sandeep, Steve,

> Could anyone help me to review this patch? This is useful to cross-compile ltp for Android without specifying '-D__ANDROID__' in configure step.

> Thanks!
> Zhengwang


> ------------------------------------------------------------------
> 发件人：Zhengwang Ruan <ruanzw@xiaopeng.com>
> 发送时间：2019年4月9日(星期二) 12:05
> 收件人：ltp <ltp@lists.linux.it>
> 抄　送：Zhengwang Ruan <ruanzw@xiaopeng.com>
> 主　题：[PATCH v1] include/mk/env_post.mk: enable __ANDROID__ definition for Android build

> Enable the __ANDROID__ definition by default for Android build, otherwise we
> should manually enable it by configure command.

> Signed-off-by: Zhengwang Ruan <ruanzw@xiaopeng.com>
> ---
>  include/mk/env_post.mk | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

> diff --git a/include/mk/env_post.mk b/include/mk/env_post.mk
> index 913bdf5..7953e0a 100644
> --- a/include/mk/env_post.mk
> +++ b/include/mk/env_post.mk
> @@ -44,7 +44,7 @@ endif
>  ifeq ($(ANDROID),1)
>  # There are many undeclared functions, it's best not to accidentally overlook
>  # them.
> -CFLAGS    += -Werror-implicit-function-declaration
> +CFLAGS    += -Werror-implicit-function-declaration -D__ANDROID__
Would adding __ANDROID__ definition help building LTP with distro
cross-compiler? (i.e. no NDK, no inside AOSP tree)?
I guess so and therefore, I'd be for this change.
I see some projects added it as well (busybox [1] [2], dnsmasq [3]).
BTW: where is defined for AOSP and NDK?

BTW (@cyril): I guess -Werror-implicit-function-declaration is the code which
requires adding <string.h> and <strings.h> (see my fix 4053a2551 ("lib: Add
missing <string.h> and <strings.h> includes")), I'd be for either adding it to
for all or removing it.

>  LDFLAGS    += -L$(top_builddir)/lib/android_libpthread
>  LDFLAGS    += -L$(top_builddir)/lib/android_librt

Kind regards,
Petr

[1] https://git.busybox.net/busybox/tree/configs/android_defconfig
[2] https://git.busybox.net/busybox/tree/configs/android_ndk_defconfig
[3] http://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=blob_plain;f=bld/Android.mk;hb=HEAD