| # Makefile for csu code for GNU C library. |
| # Copyright (C) 1995-2018 Free Software Foundation, Inc. |
| # This file is part of the GNU C Library. |
| |
| # The GNU C Library is free software; you can redistribute it and/or |
| # modify it under the terms of the GNU Lesser General Public |
| # License as published by the Free Software Foundation; either |
| # version 2.1 of the License, or (at your option) any later version. |
| |
| # The GNU C Library is distributed in the hope that it will be useful, |
| # but WITHOUT ANY WARRANTY; without even the implied warranty of |
| # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| # Lesser General Public License for more details. |
| |
| # You should have received a copy of the GNU Lesser General Public |
| # License along with the GNU C Library; if not, see |
| # <http://www.gnu.org/licenses/>. |
| |
| # This directory contains the C startup code (that which calls main). This |
| # consists of the startfile, built from start.c and installed as crt0.o |
| # (traditionally) or crt1.o (for ELF). In ELF we also install crti.o and |
| # crtn.o, special "initializer" and "finalizer" files used in the link |
| # to make the .init and .fini sections work right. |
| |
| subdir := csu |
| |
| include ../Makeconfig |
| |
| routines = init-first libc-start $(libc-init) sysdep version check_fds \ |
| libc-tls elf-init dso_handle |
| aux = errno |
| elide-routines.os = libc-tls |
| static-only-routines = elf-init |
| csu-dummies = $(filter-out $(start-installed-name),crt1.o Mcrt1.o) |
| extra-objs = start.o \ |
| $(start-installed-name) g$(start-installed-name) $(csu-dummies) \ |
| S$(start-installed-name) |
| omit-deps = $(patsubst %.o,%,$(start-installed-name) g$(start-installed-name) \ |
| b$(start-installed-name) $(csu-dummies) \ |
| S$(start-installed-name) \ |
| r$(start-installed-name) \ |
| gr$(start-installed-name)) |
| install-lib = $(start-installed-name) g$(start-installed-name) $(csu-dummies) |
| |
| # No tests are allowed in the csu/ subdirectory because the startup |
| # code is compiled with special flags. |
| tests = |
| |
| CFLAGS-.o += $(no-stack-protector) |
| CFLAGS-.op += $(no-stack-protector) |
| CFLAGS-.os += $(no-stack-protector) |
| |
| ifeq (yes,$(build-shared)) |
| extra-objs += S$(start-installed-name) gmon-start.os |
| ifneq ($(start-installed-name),$(static-start-installed-name)) |
| extra-objs += gmon-start.o |
| endif |
| install-lib += S$(start-installed-name) |
| generated += start.os |
| else |
| extra-objs += gmon-start.o |
| endif |
| |
| ifneq ($(start-installed-name),$(static-start-installed-name)) |
| # FIXME: Only Hurd defines static-start-installed-name. Hurd needs to |
| # provide special rules to support static PIE. |
| extra-objs += $(static-start-installed-name) g$(static-start-installed-name) |
| omit-deps += $(patsubst %.o,%,$(static-start-installed-name) \ |
| g$(static-start-installed-name)) |
| install-lib += $(static-start-installed-name) g$(static-start-installed-name) |
| else |
| ifeq (yes,$(enable-static-pie)) |
| extra-objs += r$(start-installed-name) gr$(start-installed-name) |
| install-lib += r$(start-installed-name) gr$(start-installed-name) |
| endif |
| endif |
| |
| before-compile += $(objpfx)abi-tag.h |
| generated += abi-tag.h |
| |
| # These are the special initializer/finalizer files. They are always the |
| # first and last file in the link. crti.o ... crtn.o define the global |
| # "functions" _init and _fini to run the .init and .fini sections. |
| crtstuff = crti crtn |
| |
| install-lib += $(crtstuff:=.o) |
| extra-objs += $(crtstuff:=.o) |
| |
| ifneq ($(multidir),.) |
| multilib-extra-objs = $(addprefix $(multidir)/, $(install-lib)) |
| extra-objs += $(multilib-extra-objs) |
| endif |
| |
| extra-objs += abi-note.o init.o static-reloc.o |
| ifeq (yes,$(build-shared)) |
| extra-objs += static-reloc.os |
| endif |
| asm-CPPFLAGS += -I$(objpfx). |
| |
| # Enable unwinding so backtrace unwinds to __libc_start_main |
| CFLAGS-libc-start.c += -funwind-tables |
| |
| include ../Rules |
| |
| # Make these in the lib pass so they're available in time to link things with. |
| subdir_lib: $(extra-objs:%=$(objpfx)%) |
| |
| ifeq ($(LLVM_OBJCOPY),) |
| OBJCOPY_FOR_ADDRSIG = ${OBJCOPY} |
| else |
| OBJCOPY_FOR_ADDRSIG = ${LLVM_OBJCOPY} |
| endif |
| |
| define link-relocatable |
| $(CC) -nostdlib -nostartfiles -r -o $@.precopy $^ |
| # Remove a section generated by clang for safe ICF; when lld links and |
| # retains relocs, the section is garbled and causes errors in later |
| # links done with --icf=safe. The removal can be unconditional as it |
| # is a no-op for non-clang/lld. |
| $(OBJCOPY_FOR_ADDRSIG) --remove-section=.llvm_addrsig $@.precopy $@ |
| rm $@.precopy |
| endef |
| |
| ifndef start-installed-name-rule |
| # We link the ELF startfile along with a SHT_NOTE section indicating |
| # the kernel ABI the binaries linked with this library will require. |
| $(objpfx)$(start-installed-name): $(objpfx)start.o $(objpfx)abi-note.o \ |
| $(objpfx)init.o $(objpfx)static-reloc.o |
| $(link-relocatable) |
| $(objpfx)r$(start-installed-name): $(objpfx)start.o $(objpfx)abi-note.o \ |
| $(objpfx)init.o |
| $(link-relocatable) |
| $(objpfx)S$(start-installed-name): $(objpfx)start.os $(objpfx)abi-note.o \ |
| $(objpfx)init.o |
| $(link-relocatable) |
| endif |
| |
| # The profiling startfile is made by linking together the normal |
| # startfile with gmon-start.o, which defines a constructor function |
| # to turn on profiling code at startup. |
| ifeq (yes,$(build-shared)) |
| $(objpfx)g$(start-installed-name): \ |
| $(objpfx)g%: $(objpfx)S% $(objpfx)gmon-start.os $(objpfx)static-reloc.os |
| $(link-relocatable) |
| $(objpfx)gr$(start-installed-name): \ |
| $(objpfx)gr%: $(objpfx)r% $(objpfx)gmon-start.o |
| $(link-relocatable) |
| ifneq ($(start-installed-name),$(static-start-installed-name)) |
| $(objpfx)g$(static-start-installed-name): \ |
| $(objpfx)g%: $(objpfx)% $(objpfx)gmon-start.o |
| $(link-relocatable) |
| endif |
| else |
| $(addprefix $(objpfx),$(sort g$(start-installed-name) \ |
| g$(static-start-installed-name))): \ |
| $(objpfx)g%: $(objpfx)% $(objpfx)gmon-start.o |
| $(link-relocatable) |
| endif |
| |
| # These extra files are sometimes expected by system standard linking |
| # procedures, but we have nothing for them to do. So compile empty files. |
| $(addprefix $(objpfx),$(filter-out $(start-installed-name), $(csu-dummies))):\ |
| $(before-compile) |
| $(COMPILE.c) -o $@ -x c /dev/null |
| |
| # These headers are used by the startup code. |
| $(objpfx)abi-tag.h: $(..)abi-tags |
| $(make-target-directory) |
| rm -f $@.new |
| sed -e 's/#.*$$//' -e '/^[ ]*$$/d' $< | \ |
| while read conf tagos tagver; do \ |
| test `expr '$(config-machine)-$(config-vendor)-$(config-os)' \ |
| : "$$conf"` != 0 || continue; \ |
| ( echo "$$tagos" | \ |
| sed -e 's/[^0-9xXa-fA-F ]//' \ |
| -e 's/^/#define __ABI_TAG_OS /'; \ |
| echo "#ifndef __ABI_TAG_VERSION"; \ |
| echo "$$tagver" | \ |
| sed -e 's/[^0-9xXa-fA-F]/ /g' -e 's/ *$$//' \ |
| -e 's/ /,/g' -e 's/^/# define __ABI_TAG_VERSION /'; \ |
| echo "#endif" ) > $@.new; \ |
| done |
| if test -r $@.new; then mv -f $@.new $@; \ |
| else echo >&2 'This configuration not matched in $<'; exit 1; fi |
| |
| ifneq ($(multidir),.) |
| $(addprefix $(objpfx)$(multidir)/, $(install-lib)): $(addprefix $(objpfx), $(install-lib)) |
| $(make-link-multidir) |
| endif |