The libc-compat.h first appeared in kernel version 3.12. Trying to build a
musl toolchain using earlier headers leads to the following failure:
/bin/sed: can't read .../output/host/usr/arm-buildroot-linux-musleabi/sysroot/usr/include/linux/libc-compat.h: No such file or directory
package/pkg-generic.mk:266: recipe for target '.../output/build/toolchain/.stamp_staging_installed' failed
Don't apply the sed patch to older headers.
Reported-by: Florent Jacquet <florent.jacquet@free-electrons.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
# IFF_DORMANT and IFF_ECHO, add another macro to suppress them in the
# kernel header, and avoid macro/enum conflict.
#
+# Kernel version 3.12 introduced the libc-compat.h header.
+#
# [1] http://www.openwall.com/lists/musl/2015/10/08/2
-ifeq ($(BR2_TOOLCHAIN_USES_MUSL),y)
+ifeq ($(BR2_TOOLCHAIN_USES_MUSL)$(BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_12),yy)
define TOOLCHAIN_MUSL_KERNEL_HEADERS_COMPATIBILITY_HACK
$(SED) 's/^#if defined(__GLIBC__)$$/#if 1/' \
$(STAGING_DIR)/usr/include/linux/libc-compat.h