################################################################################
#
# toolchain
#
################################################################################

ifeq ($(BR2_TOOLCHAIN_BUILDROOT),y)
TOOLCHAIN_DEPENDENCIES += toolchain-buildroot
else ifeq ($(BR2_TOOLCHAIN_EXTERNAL),y)
TOOLCHAIN_DEPENDENCIES += toolchain-external
endif

TOOLCHAIN_ADD_TOOLCHAIN_DEPENDENCY = NO
TOOLCHAIN_INSTALL_STAGING = YES

# Apply a hack that Rick Felker suggested[1] to avoid conflicts between libc
# headers and kernel headers. This is needed for kernel headers older than
# 4.15. Kernel headers 4.15 and newer don't require __GLIBC__ to be defined.
#
# Augment the original suggestion with __USE_MISC since recent kernels
# (older than 4.15) require this glibc internal macro. Also, as musl defines
# IFF_LOWER_UP, 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 ($(BR2_TOOLCHAIN_USES_MUSL)$(BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_12):$(BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_15),yy:)
define TOOLCHAIN_MUSL_KERNEL_HEADERS_COMPATIBILITY_HACK
	$(SED) 's/^#if defined(__GLIBC__)$$/#if 1/' \
		$(STAGING_DIR)/usr/include/linux/libc-compat.h
	$(SED) '1s/^/#define __USE_MISC\n/' \
		$(STAGING_DIR)/usr/include/linux/libc-compat.h
	$(SED) '1s/^/#define __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO 0\n/' \
		$(STAGING_DIR)/usr/include/linux/libc-compat.h
endef
TOOLCHAIN_POST_INSTALL_STAGING_HOOKS += TOOLCHAIN_MUSL_KERNEL_HEADERS_COMPATIBILITY_HACK
endif

# Install default nsswitch.conf file if the skeleton doesn't provide it
ifeq ($(BR2_TOOLCHAIN_USES_GLIBC),y)
define TOOLCHAIN_GLIBC_COPY_NSSWITCH_FILE
	@if [ ! -f "$(TARGET_DIR)/etc/nsswitch.conf" ]; then \
		$(INSTALL) -D -m 0644 package/glibc/nsswitch.conf $(TARGET_DIR)/etc/nsswitch.conf ; \
	fi
endef
TOOLCHAIN_POST_INSTALL_TARGET_HOOKS += TOOLCHAIN_GLIBC_COPY_NSSWITCH_FILE
endif

# Not really a virtual package, but we use the virtual package infra here so
# both the build log and build directory look nicer (toolchain-virtual instead
# of toolchain-undefined)
$(eval $(virtual-package))