# 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)

# Dummy object not actually used for anything.  It is linked into

# crt1.o nevertheless, which in turn is statically linked into

# applications, so that build flags matter.

# See <https://sourceware.org/ml/libc-alpha/2018-07/msg00101.html>.

# NB: Using $(stack-protector) in this way causes a wrong definition

# STACK_PROTECTOR_LEVEL due to the preceding $(no-stack-protector),

# but it does not matter for this source file.

CFLAGS-static-reloc.os += $(stack-protector)

# This file is not actually part of the startup code in the nonshared

# case and statically linked into applications.  See

# <https://sourceware.org/bugzilla/show_bug.cgi?id=23323>,

# <https://sourceware.org/ml/libc-alpha/2018-06/msg00717.html>.

# Also see the note above regarding STACK_PROTECTOR_LEVEL.

CFLAGS-elf-init.oS += $(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)%)

define link-relocatable

$(CC) -nostdlib -nostartfiles -r -o $@ $^

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