#
# Make Linux headers of the host platform available to the program
#
include $(call select_from_repositories,lib/import/import-syscall-linux.mk)

#
# Manually supply all library search paths of the host compiler to our tool
# chain.
#
HOST_LIB_SEARCH_DIRS = $(shell $(CUSTOM_HOST_CC) $(CC_MARCH) -print-search-dirs | grep libraries |\
                               sed "s/.*=//"   | sed "s/:/ /g" |\
                               sed "s/\/ / /g" | sed "s/\/\$$//")
#
# Add search path for 'limits.h'
#
# We cannot simply extend 'INC_DIR' because this would give precedence to the
# host include search paths over Genode search path. The variable HOST_INC_DIR
# is appended to the include directory list.
#
HOST_INC_DIR += $(shell echo "int main() {return 0;}" |\
                        LANG=C $(CXX) -x $(CUSTOM_HOST_CXX) -v -E - 2>&1 |\
                        sed '/^\#include <\.\.\.> search starts here:/,/^End of search list/!d' |\
                        grep "include-fixed")

#
# Add search paths for normal libraries
#
CXX_LINK_OPT += $(addprefix -L,$(HOST_LIB_SEARCH_DIRS))

#
# Determine ldconfig executable
#
# On Ubuntu, /sbin/ is in the PATH variable. Hence we try using the program
# found via 'which'. If 'which' does not return anything (i.e., on Debian),
# try using the expected location '/sbin/'.
#
LDCONFIG := $(firstword $(wildcard $(shell which ldconfig) /sbin/ldconfig))
ifeq ($(LDCONFIG),)
$(error ldconfig is not found)
endif

#
# Add search paths for shared-library lookup
#
# We add all locations of shared libraries present in the ld.cache to our
# library search path.
#
HOST_SO_SEARCH_DIRS := $(sort $(dir $(shell $(LDCONFIG) -p | sed "s/^.* \//\//" | grep "^\/")))
LINK_ARG_PREFIX := -Wl,
CXX_LINK_OPT += $(addprefix $(LINK_ARG_PREFIX)-rpath-link $(LINK_ARG_PREFIX),$(HOST_SO_SEARCH_DIRS))

#
# Make exceptions work
#
CXX_LINK_OPT += -Wl,--eh-frame-hdr

#
# Add all libraries and their dependencies specified at the 'LX_LIBS'
# variable to the linker command line
#
ifneq ($(LX_LIBS),)
LX_LIBS_OPT = $(shell pkg-config --static --libs $(LX_LIBS))
endif

#
# Use the host's startup codes, linker script, and dynamic linker
#
LD_TEXT_ADDR     ?=
LD_SCRIPT_STATIC ?=

EXT_OBJECTS += $(shell $(CUSTOM_HOST_CC) $(CC_MARCH) -print-file-name=crt1.o)
EXT_OBJECTS += $(shell $(CUSTOM_HOST_CC) $(CC_MARCH) -print-file-name=crti.o)
EXT_OBJECTS += $(shell $(CUSTOM_CC) $(CC_MARCH) -print-file-name=crtbegin.o)
EXT_OBJECTS += $(shell $(CUSTOM_CC) $(CC_MARCH) -print-file-name=crtend.o)
EXT_OBJECTS += $(shell $(CUSTOM_HOST_CC) $(CC_MARCH) -print-file-name=crtn.o)

LX_LIBS_OPT += -lgcc -lgcc_s -lsupc++ -lc -lpthread

USE_HOST_LD_SCRIPT = yes

#
# We need to manually add the default linker script on the command line in case
# of standard library use. Otherwise, we were not able to extend it by the
# stack area section.
#
ifeq (x86_64,$(findstring x86_64,$(SPECS)))
CXX_LINK_OPT     += -Wl,--dynamic-linker=/lib64/ld-linux-x86-64.so.2
LD_SCRIPT_DEFAULT = ldscripts/elf_x86_64.xc
endif

ifeq (x86_32,$(findstring x86_32,$(SPECS)))
CXX_LINK_OPT     += -Wl,--dynamic-linker=/lib/ld-linux.so.2
LD_SCRIPT_DEFAULT = ldscripts/elf_i386.xc
endif

ifeq (arm,$(findstring arm,$(SPECS)))
CXX_LINK_OPT    += -Wl,--dynamic-linker=/lib/ld-linux.so.3
LD_SCRIPT_STATIC = ldscripts/armelf_linux_eabi.xc
endif

#
# Because we use the host compiler's libgcc, omit the Genode toolchain's
# version and put all libraries here we depend on.
#
LD_LIBGCC = $(LX_LIBS_OPT)

# use the host c++ for linking to find shared libraries in DT_RPATH library paths
LD_CMD = $(CUSTOM_HOST_CXX)

# disable format-string security checks, which prevent non-literal format strings
CC_OPT += -Wno-format-security

#
# Disable position-independent executables (which are enabled by default on
# Ubuntu 16.10 or newer)
#
CXX_LINK_OPT_NO_PIE := $(shell \
	(echo "int main(){}" | $(LD_CMD) -no-pie -x $(CUSTOM_HOST_CXX) - -o /dev/null >& /dev/null \
	&& echo "-no-pie") || true)
CXX_LINK_OPT += $(CXX_LINK_OPT_NO_PIE)